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GVWD corrosion control initiative, phase II: inhibitor chemical testing at Seymour Dam MacQuarrie, Doug M. 1993

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GVWD CORROSION CONTROL INITIATIVE - PHASE IIINHIBITOR CHEMICAL TESTING AT SEYMOUR DAMbyDoug M. MacQuarrieB.Eng., Royal Military College, 1969A THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFMASTER OF APPLIED SCIENCEinTHE FACULTY OF GRADUATE STUDIESDepartment of Civil EngineeringWe accept this thesis as conformingto the required standardTHE UNIVERSITY OF BRITISH COLUMBIAMARCH 1993© Doug M. MacQuarrie, 1993In presenting this thesis in partial fulfillment of the requirements for an advanced degreeat the University of British Columbia I agree that the Library shall make it freelyavailable for reference and study. I further agree that permission for extensive copyingof this thesis for scholarly purposes may be granted by the Head of my Department or byhis or her representatives. It is understood that copying or publication of this thesis forfinancial gain shall not be allowed without my written permission.Department of Civil EngineeringUniversity of British Columbia2324 Main MallVancouver< B.C.V6T 1W5Date: March 1993ABSTRACTGreater Vancouver Regional District (GVRD) waters have some of the highestcorrosion potentials in North America. A previous pilot study determined that coppercorrosion could be reduced by 60 to 80 percent and lead corrosion could be reduced by10 to 60 percent by disinfecting with chloramine instead of chlorine and by adjusting pHand alkalinity to 8-8.5 and 20 mg/L as calcium carbonate (CaCO3) respectively. Thestudy also recommended that further corrosion control pilot testing be carried out withchemical inhibitors as an adjunct to pH and alkalinity adjustments. The purposes of theinhibitor testing would be to determine their effectiveness in further reducing lead levelsat the tap, reducing iron pipe deterioration in some of the older municipal systems, and todetermine the impact of inhibitors on re-growth potential.A literature search, and extensive discussion with chemical suppliers determinedthat zinc orthophosphate and Type N sodium silicate offered the best potential ascorrosion inhibitors with GVWD type waters. Thus it was decided to evaluate (withinthe limitations that the seven loop pilot plant would allow) zinc orthophosphate, type Nsodium silicate and a commercial blend of the two. pH and alkalinity were adjusted bythe addition of lime [Ca(OH)2] and sodium bicarbonate (NaHCO3) respectively, and thewater was disinfected with 2.5 mg/L of monochloramine (NH2C1).The copper and cast iron corrosion rates were measured over the course of 12months on pipe inserts removed at 3 month intervals. The removed inserts weremeasured for weight loss, pitting corrosion, and interior biofilm was monitored. In ad-dition, corrosion rates were monitored weekly using an electrical resistance measuringdevice. Standing water samples taken regularly from lead/tin solder jointed soft copperplumbing coils, submerged free standing coils of 50/50 lead/tin solder, and from faucetson each loop were measured for lead, zinc and copper leaching.The results of the weight loss determinations from the pipe inserts and the weeklyresistance measurements indicate that all of the inhibitors, particularly the zincorthophosphate, work very favorably with copper, but they offer negligible additionalbenefit over that obtained from the pH and alkalinity adjustments alone in the case of thecast iron coupons.Some very high metal levels were measured in some of the leaching samples. Itis postulated that these high levels were due to the redissolution and sloughing (duringthe 24-hour standing period) of some of the protective scale that formed during periodswhen the water was flowing. Previous studies have shown that inhibitors such asphosphates and silicates work best in a constant flowing situation. A further suggestionof this sloughing was demonstrated by the appearance of sediment in the samples eventhough the water was clear prior to isolation of the standing samples. The protectivescale which is formed by inhibitors is generally a metal and silicate combination or ametal, phosphate and zinc combination. Thus if the scale sloughs off, more metal will bein the sample when it is digested.Another problem which can occur with zinc orthophosphate at pH above about7.5 is that the zinc orthophosphate can precipitate out before forming a protective scale(EEC 1990). Sometimes, zinc levels were found to be a great deal higher than can beattributed to the feed itself (0.37 mg/L). It seems likely that these high zinc levels weredue to a combination of precipitation and sloughing. The occurrence of sediment furthercorroborates this hypothesis.Generally, in the leaching samples from the solder coils, the lowest lead levelsoccurred in the raw water. It could be that the lead reacted adversely to all of thetreatments tried.Peak metals levels occurred in several loops at the same time. The reason forthese coincidental peaks is not clear. There is no obvious pattern. It may be that thedegree of scale dissolution and sloughing is dependent on pH and/or alkalinity levelsand/or fluctuations, or it may be due to some other factors or combinations of factors.During the standing period the scale appears to weaken but it may not come off untilseveral weeks later. There did not appear to be a correlation between metal levels andtotal chlorine levels. More work is needed in this area to try and ascertain what causesthe extremely high metal levels at certain times and not others. The scale formed seemsto be very much a dynamic and ever evolving component in the corrosion situation.The biofilm examinations showed no significant differences between loops withthe copper coupons, but higher growth levels were found with the cast iron coupons inthe loops with the zinc orthophosphate feed.ivTABLE OF CONTENTSABSTRACT^ iiLIST OF TABLES xiLIST OF FIGURES^ xiiACKNOWLEDGMENTS xv1. INTRODUCTION^ 11.1 Background Information^ 11.2 Costs of Corrosion  11.3 Metal Levels and Regulatory Concerns^ 31.4 Health, Aesthetic, and Other Effects 51.4.1 Lead^ 51.4.2 Copper 61.4.3 Ferrous Metals^ 71.5 Previous Study^ 81.6 Objective and Scope 82. BACKGROUND AND LITERATURE SEARCH^ 102.1 Basic Corrosion Theory^ 102.2 Types Of Corrosion 132.2.1. Uniform corrosion^ 132.2.2. Galvanic corrosion 132.2.3. Crevice corrosion^ 132.2.4. Pitting corrosion 142.2.5. Concentration cell corrosion^ 142.2.6. Cracking corrosion^ 142.2.7. Selective leaching 152.2.8. Erosion corrosion^ 152.2.9. Stress corrosion^ 152.2.10. Microbiologically induced corrosion^ 152.3 Factors Affecting Corrosivity^ 162.3.1. Alkalinity, buffering capacity, and buffer intensity^ 162.3.2. Ammonia^ 162.3.3. Dissolved inorganic carbonate (DIC), totalinorganic carbon (TIC)^ 162.3.4. Dissolved oxygen (DO) 182.3.5. Halides^ 182.3.6. Hardness 182.3.7. Hydrogen sulfide^ 182.3.8. Organic tannins 192.3.9. pH^ 192.3.10. Chlorination^ 222.3.11. Silicates 232.3.12. Sulfates^ 232.3.13. Temperature 232.3.14. Velocity^ 232.3.15. Water Treatment Processes^ 242.3.16. Other parameters^ 252.4. Chemical Approaches To Corrosion Control^ 252.4.1. pH and alkalinity adjustment 282.4.2. Disinfection with chloramine^ 292.4.3. Phosphate and silicate inhibitors 312.5. Phosphate Inhibitors^ 312.6. Silicate Inhibitors 362.7 Factors Affecting Inhibitor Selection^ 39vi3. EXPERIMENTAL METHODS^ 413.1 Selection of Inhibitors and Plant Configuration^ 413.2 Pilot Plant Physical Description^ 463.2.1. Pipe Coupon Inserts 483.2.2. Lead Soldered Copper Plumbing Coils^ 483.2.3. Lead/Tin Solder Coils^ 493.2.4. Brass Faucets^ 503.2.5. Granular Activated Carbon (GAC) Filters^ 503.3 Modifications to the Existing Pilot Plant 503.4 Operation Procedures^ 523.4.1. Daily Routine 523.4.2. Weekly Routine^ 533.4.3. Batching of Chemicals 543.4.4. Metals Sampling Routine^ 563.4.5. Cast Iron and Copper Coupons 583.5. Quality Control^ 594. RESULTS AND DISCUSSION 604.1. Pipe Coupon Inserts^ 604.1.1. Copper Coupon Inserts^ 604.1.1.1. Copper Coupon Weight Loss Rates^ 604.1.1.2. Copper Coupon Insert Pitting Analyses^ 644.1.2. Cast Iron Coupon Inserts^ 694.1.2.1. Cast Iron Coupon Weight Loss Rates^ 694.1.2.2. Cast Iron Coupon Insert Pitting Analyses^ 744.1.2.3. Cast Iron Coupon Scaling Rates^ 804.2. Corrosometer Probes^ 814.2.1. Copper Cormsometer Probes^ 81vii4.2.2. Mild Steel Corrosometer Probes^ 944.3 . Comparison of Coupon and Corrosometer RelativeCorrosion Rates^ 1064.4. Metal Concentrations in Standing Water Samples^ 1074.4.1. Copper Concentrations in Standing Water Samples^ 1084.4.1.1. Copper Concentrations in Plumbing CoilStanding Water Samples^ 1084.4.1.2. Copper Concentrations in Faucet StandingWater Samples^ 1094.4.2. Lead Concentrations in Standing Water Samples^ 1134.4.2.1. Lead Concentrations in Plumbing CoilStanding Water Samples^ 1134.4.2.2. Lead Concentrations in Lead/Tin SolderCoil Standing Water Samples^ 1204.4.2.3. Lead Concentrations in Faucet StandingWater Samples^ 1214.4.3. Zinc Concentrations in Standing Water Samples^ 1224.4.4. Relative Metal Mobility of Water Treatments^ 1274.5. Water Quality Parameters^ 1294.5.1. Temperature 1294.5.2. Conductivity^ 1294.5.3. pH^ 1294 5 4 Alkalinity  1314.5.5. Combined Chlorine^  1314.6. Possible Causes of Inhibitor Instability^ 1364.7. Bacterial Growth^ 1374.7.1. Copper Coupons - Bacteriological Results^ 1374.7.2. Cast Iron Coupons - Bacteriological Results^ 1374.8. Quality Control^ 1464.9. Power Failures, Breakdowns, and Other Problems^ 1475. SUMMARY AND CONCLUSIONS^ 1485.1 Major Findings^ 1485.1.1. Copper Coupons^ 1485.1.2. Cast Iron Coupons 1485.1.3. Copper Corrosometer Probes^ 1485.1.4. Mild Steel Corrosometer Probes 1495.1.5. Metal Mobility^ 1495.1.6. Bacterial Regrowth 1505.1.7. Chloramine^ 1515.2 Recommendations 1516. REFERENCES^ 153APPENDICES 159A. Copper Coupons Summary of Laboratory Data Sheets^ 160B. Cast Iron Coupons Summary of Laboratory Data Sheets^ 162C. Copper Corrosometer Probe Data^ 166D. Mild Steel Corrosometer Probe Data 169E. Faucet Copper Levels^ 172F. Faucet Lead Levels 173G. Faucet Zinc Levels^ 174H. Plumbing Coil Copper Levels^ 175I. Plumbing Coil Lead Levels 176J. Plumbing Coil Zinc Levels^ 177K. Solder Coil Copper Levels 178L. Solder Coil Lead Levels^ 179ixM. Solder Coil Zinc Levels^ 180N. Temperature Measurements 1810. Conductivity Measurements^ 184P. pH Measurements^ 189Q. Alkalinity Measurements 194R. Chloramine Measurements^ 199S. Coupons - Bacteriological Results 204T. Quality Control Samples^ 206U. Phosphorus Content 210V. Silica Content^ 211W. Incidents Which May Have Impacted the Outcome of theExperiment^ 212xLIST OF TABLES2-1 Common Silicate Inhibitors^ 374-1 Copper Coupon Corrosion Rates 614-2 Copper Coupon Pitting Analysis^ 654-3 Copper Coupon Relative Corrosion Rates^ 694-4 Cast Iron Coupon Corrosion Rates 714-5 Cast Iron Coupon Pitting Rates^ 764-6 Cast Iron Coupon Relative Corrosion Rates^ 794-7 Cast Iron Coupon Relative Scale Build-up 814-8 Copper Corrosometer Probe Corrosion Rates^ 824-9 Copper Corrosometer Probe Relative Corrosion Rates^ 854-10 Copper Corrosometer Probe Prevailing Corrosion Rates 874-11 Mild Steel Corrosometer Probe Corrosion Rates^ 944-12 Mild Steel Corrosometer Probe Relative Corrosion Rates^ 974-13 Mild Steel Corrosometer Probe Prevailing Corrosion Rates 984-14 Comparison of Coupon and Corrosometer Corrosion Relative to RawWater^ 1074-15 Relative Metal Mobility^  128xiLIST OF FIGURES2-1 Corrosion Cell Showing Anodic And Cathodic Regions^ 112-2 Effect of pH on Distribution of Free Chlorine Forms at 20° C 212-3 Corrosion Scale Transport^ 273-1 Seymour Pilot Plant Schematic 473-2 Pipe Coupon Inserts and Assembly^ 494-1 Corrosion Rates of Copper Coupon Inserts (Line Graph)^ 624-2 Corrosion Rates of Copper Coupon Inserts (Bar Graph) 634-3 Average Nominal Pitting Rates of Copper Coupon Inserts^ 664-4 Maximum Nominal Pitting Rates of Copper Coupon Inserts 674-5 Corrosion Rates of Cast Iron Coupon Inserts (Line Graph)^ 724-6 Corrosion Rates of Cast Iron Coupon Inserts (Bar Graph) 734-7 Average Nominal Pitting Rates of Cast Iron Coupon Inserts^ 774-8 Maximum Nominal Pitting Rates of Cast Iron Coupon Inserts 784-9 Corrosion Rates of Copper Corrosometer Probes (Line Graph)^ 834-10 Corrosion Rates of Copper Corrosometer Probes (Bar Graph) 844-11 Copper Corrosometer Probes - Resistance Change Over Time^ 884-12 Copper Corrosometer Probes - Resistance Change Over Time Loops 1and 4^ 894-13 Copper Corrosometer Probes - Resistance Change Over Time Loops 2,5 and 6^ 904-14 Copper Corrosometer Probes - Resistance Change Over Time Loops 3and 6^ 914-15 Copper Corrosometer Probes - Prevailing Corrosion Rates(Line Graph)^ 92xii4-16 Copper Corrosometer Probes - Prevailing Corrosion Rates(Bar Graph)^ 934-17 Mild Steel Corrosometer Probe Corrosion Rate (Line Graph)^ 954-18 Mild Steel Corrosometer Probe Corrosion Rate (Bar Graph) 964-19 Mild Steel Corrosometer Probes - Resistance Change Over Time^ 994-20 Mild Steel Corrosometer Probes - Resistance Change Over Time Loops 1and 7^ .1004-21 Mild Steel Corrosometer Probes - Resistance Change Over Time Loops 2,4 and 6^ 1014-22 Mild Steel Corrosometer Probes - Resistance Change Over TimeLoop 3^ 1024-23 Mild Steel Corrosometer Probes - Resistance Change Over TimeLoop 5^ 1034-24 Mild Steel Corrosometer Probes - Prevailing Corrosion Rates(Line Graph)^ 1044-25 Mild Steel Conosometer Probes - Prevailing Corrosion Rates(Bar Graph)^ 1054-26 Copper Levels From Plumbing Coils^ 1104-27 Copper Levels From Plumbing Coils - Best Four Loops^ 1114-28 Copper Levels From Faucets^ 1124-29 Lead Levels From Plumbing Coils 1144-30 Lead Levels From Plumbing Coils - Best Three Loops^ 1154-31 Lead Levels From Solder Coils^ 1164-32 Lead Levels From Solder Coils - Best Two Loops^ 1174-33 Lead Levels From Faucets^ 1184-34 Lead Levels From Faucets - Best Three Loops^ 1194-35 Zinc Levels From Plumbing Coils^ 1234-36 Zinc Levels From Solder Coils^ 1244-37 Zinc Levels From Faucets 1254-38 Copper Levels From Solder Coils^ 1264-39 pH Comparisons - Loop 1 1324-40 pH Comparisons - Loop 2^ 1334-41 pH Comparisons - Loop 7 1344-42 pH Comparisons - Loop 4^ 1354-43 - 4-50 pH and Alkalinity Versus Metals Levels^ 138 - 145xivACKNOWLEDGMENTSThis work was funded by the Greater Vancouver Regional District and by aGraduate Research Engineering And Technology (GREAT) scholarship from the BritishColumbia Science Council. The receipt of the funds is greatly appreciated. My thanks toDr. Don Mavinic, my thesis advisor, for his helpful advice and encouragement and foralways being available throughout the duration of the work. Thanks to Doug Neden ofthe GVRD and Dr. Ken Hall at UBC for reviewing this thesis. Many thanks to DougNeden also for initiating this project and for his valuable advice and assistance. Thanksto Peter Zadorozny, Andrew Gibson and the rest of the staff at the GVRD laboratory forall of their assistance. I thank Dennis Beattie and the GVRD chlorination crew for all thework they did in modifying the plant for this experiment and for their ongoing assistancewhen repairs or changes were required. Also many thanks to Bill Horwood and the restof the Seymour Dam custodial crew for their willing help when it was required and forlending me the tools when I needed them to complete a task. Finally, heartfelt thanks toSusan Harper, Paula Parkinson, and Jufang Zhou for their invaluable assistance andexpert advice in the UBC Environmental Engineering Laboratory. All of the leadleaching measurements were done by Susan, and the phosphate and silicatemeasurements were done by Paula and Jufang. In addition, the digestion of metalssamples was done by Paula and Jufang. My sincere appreciation to all the others notmentioned who provided assistance.XV1. INTRODUCTION1.1 Background InformationMost consumers in greater Vancouver are quite pleased with the pristine nature ofthe water available to them at the tap. Most of the time, the water is colour and odourfree, and it is very soft which makes it a pleasure to bathe in and ideal for laundry pur-poses. Unfortunately, these same qualities give the water one of the highest corrosionpotentials in North America. The corrosivity is due to the following main factors:• Low pH - All of the water consumed by the Greater Vancouver Water District(GVWD) comes from surface sources. The rainfall in the British Columbia lowermainland area is acidic [pH 5 or less (House of Commons Sub-committee onAcid Rain, 1991)] and the granitic rock in the watershed does little to buffer it.The raw water pH range is 6.0 to 6.3, and after chlorination it is 5.4 to 5.9.• Low alkalinity and buffering capacity - Raw water total alkalinity range is 1.5 to3.7 mg/L as CaCO3, and after chlorination it is 0.5 to 2.0.• Low mineral content - Total dissolved solids range is 12 to 16 mg/L.• High dissolved oxygen content - Typically the water is at or close to DO satura-tion.• Disinfection with chlorine - Chlorine is not only an aggressive oxidizer in itself,but it also lowers the pH of the water even further, as mentioned.The impact of corrosion is felt in terms of economics, health, and aesthetics.1.2 Costs of CorrosionThe following are some of the cost considerations resulting from corrosivity indrinking water:• Technical support of utility staff and consultants;• Corrosion control measures;• Replacement, maintenance, and repair of plant, equipment and material;• Plant shutdowns for repairs and replacement;• Special processing;• Corrosion allowance;• Process upsets resulting from corrosion;• Product contamination;• Product loss from corroded vessels;• Overdesign to allow for corrosion and inability to use otherwise desirablematerials;• Cooling requires excessive water use because heat transfer is retarded by de-posits of corrosion products;• Flow Impairment. Tuberculation can result in severe reduction in flow ca-pacity. In water mains this decreases the effective value of the system and in-creases pumping costs due to reduction of the open area in the pipe and in-creased resistance due to tubercle build-up;• Clogging meters due to corrosion products;• Extra cleaning requirements due to staining of fixtures;• Water damage and insurance; and• Health care costs.Ryder (1980) defines direct costs as those which result in a loss to the economyand indirect costs as those resulting from the consumption of energy and materials thatwould not otherwise be required. In 1975 In the United States, annual corrosion costswere estimated at $70 billion of which the direct costs were approximately 25 percent.Ryder estimated that corrosion control measures could have reduced the direct costs by15 percent or $2.6 billion.2In 1976, plumbing contractors estimated that the cost of replacing the accessibleparts of a single family home hot and cold water system at $500 for small one bathhomes and $1000 for larger one and a half and two bath homes. The cost to replacepiping enclosed in walls and ceilings would be much higher due to the requirement forother trades to cut and replace these finishes. Kirmeyer and Logsdon (1983) estimatedthe cost of replacing all of the plumbing in a home to be at least $2000 to $3000 US.According to Ryder (1980), in Seattle, pH and alkalinity adjustments to suppresscorrosion reduced overall corrosion related costs by 25 percent. And for newer build-ings, the relative savings may be as much as 75 percent because the effects of corrosionare much more severe on new piping systems which have not had any protective scalebuild-up.1.3 Metal Levels and Regulatory ConcernsMetals which are leached from distribution and plumbing systems can be con-sumed causing health problems. Health factors led the United States EnvironmentalProtection Agency (EPA) in 1991 to mandate that US utilities take specified correctiveaction when standing water lead levels exceed 0.015 mg/L or copper levels exceed 1.3mg/L in more than 10 percent of samples taken at the tap. In his study which sampledovernight standing tap water in 36 Vancouver homes, Singh (1990) determined that thefirst 1/4 L samples had levels that exceeded the EPA action levels 64 percent of the timefor copper and 24 percent of the time for lead.The Guidelines for Canadian Drinking Water Quality (Health and Welfare Can-ada, 1989) proposed maximum acceptable concentration (MAC) for lead is 0.01 mg/L,but that is for a "thoroughly flushed" sample. Presently, there is no Canadian MAC forcopper but there is an aesthetic objective (AO) of 1.0 mg/L, presumably to reduce blue-green staining of plumbing fixtures and laundry. There is no specification whether thecopper sample should be flushed or not, so presumably, the AO could be applied to a3standing sample. The objective for copper is under review. Singh (1990) found thateven after prolonged flushing of the taps sampled in high-rise buildings, the CanadianMAC for lead and the AO for copper were exceeded in 6 percent and 9 percent of thecases, respectively. However, with single family dwellings, after 5 minutes of flushing,cold water samples were within both EPA and Canadian compliance levels.Plumbing age has a direct effect on metal levels, particularly in waters not treatedfor corrosivity. Electrical grounding also increases metal levels but plumbing age ismore significant Lee et al., (1989). Lead levels from lead soldered copper plumbing arehighest within the first 24 months of construction after which they level off (Boffardi,1988). In a study of lead soldered copper pipe in age groups of 0 to 1 year, 1 to 5 years,and 6 to 20 years, at a pH of 7.5 the average lead levels 10 seconds after first flush were100 gg/L, 40 ps/L and 4 gg/L respectively (Murrell, 1988).Lead levels increase substantially in standing water, exceeding 50 gg/L in 1.5 to 2hours and continue to increase for 6 hours or more (Boffardi, 1988; Bailey et al., 1986).Brass faucets will contribute one third of lead levels in the first 1 litre draw sample (Leeet al., 1989). In a first draw sample from a faucet, 60 to 75 percent of the lead is pickedup in the first 125 ml. After 200 to 250 ml of water has flowed, 95 percent or more ofthe lead has normally been flushed from the faucet. (Gardels and Sorg, 1989). Unfortu-nately, flushing the tap before consumption takes time and wastes water. To save timeand water the consumer may not flush; indeed he may not even be aware that he shouldflush. Regardless of any other measures taken, a serious effort must be made on the partof municipalities to ensure consumer awareness of the health implications of metal in-gestion at the tap.11There are, of course, other sources of lead besides the tap, such as the air we breathe due toleaded gasoline (no longer a problem in Canada, but still a serious one in most other countries includingthe United States). Lead based paints and soils are important sources for small children; and,surprisingly, the lead crystal found in many home china cabinets can leach significant levels of lead.Any effort to foster public awareness of the health hazard posed by lead should also consider these othersources.41.4 Health, Aesthetic, and Other Effects1.4.1 LeadLead has been used to convey water since the days of the Roman Empire and onlyrecently has it been banned for use as a drinking water conduit. As recently as 1979, leadservice lines were still being installed in some areas of the U.S. (Patterson and O'Brien,1979). Its popularity was due to the fact that certain naturally forming salts can form ad-herent passivation scales that make lead highly resistant to corrosion and attack by natu-ral waters. However, soft water is corrosive to lead due to the high solubility of leadoxide (ibid.). Corrosion rarely causes lead pipe failure because the actual amount of themetal that is corroded away is very small. Rather the problem is health related because,being a cumulative poison, even minute ingested quantities of dissolved or particulatelead salts can be toxic over time. There are no known beneficial effects from lead inges-tion. Toxic effects (Patterson and O'Brien, 1979) in children include learning disabilitiesand even mental retardation, hyperactivity, motor and behavioral problems, renal insuf-ficiency, and hypoglycemia. In adults, symptoms include diarrhea, headaches, chestpains, frequent fatigue, and hypertension.In Scotland, lead was used traditionally for domestic plumbing until the late1960's (Richards and Moore, 1984). The lead problem was further exacerbated by the---mmon practice in home construction of including a lead lined storage tank to supplywater for all domestic use. The European Community drinking water directive, whichcame into effect in July 1985, specified that where lead plumbing is installed and leadlevels frequently exceed 100 pg/L, "measures must be taken to reduce the consumers' ex-posure to lead". Prior to any measures being taken to reduce corrosivity, lead levels inAyr (population 49,000) water were very high. In 112 samples from dwellings, the meanlead level was 466 pg/L, 72 percent of the samples exceeded 1001.1g/L and 14 percent5exceeded 1000 .tg/L. After a treatment program was instituted, in which pH was ad-justed to 9, 95 percent of samples had less than 100 p,g/L and the majority had less than50 p,g/L. More importantly, lead blood levels decreased by 40 percent after water treat-ment was instituted.Even though lead pipe is no longer used for new pipe installations, it is still inexistence in many municipal distribution systems. Moreover, as already mentioned, sig-nificant quantities of lead can be leached from the solder and from the brass fixtures inmost premises plumbing. Even though 50/50 lead/tin solder has been banned fromplumbing use in British Columbia (in favour of 95/5 tin/antimony solder) since 1989, itstill exists in most of the homes built prior to that date.1.4.2 CopperCopper has been used to convey drinking water since the early days of civiliza-tion, but only in the past 75 years or so has it been widely used in domestic plumbing(Rambow and Holmgren 1966). Its popularity is due to its relative durability. Naturallyforming copper scale consists mainly of cuprous and cupric oxides and hydroxides. It isthin (<0.1 mm), is uniformly distributed, dense, adherent, forms rapidly and it is resistantto abrasion, unlike the scale that usually forms on iron or galvanized surfaces. Youngcopper scales weighing less than 0.1 mg/cm2 are remarkably protective (Reiber, 1989).Nevertheless, soft waters are very corrosive to copper, which can lead to premature fail-ure of the pipe. Although localized attack (pitting) is rare on copper surfaces, where itdoes occur, the intensity of the attack along with the thinness of the copper pipe can re-duce the copper pipe service life from decades to months (ibid.)In contrast to lead, copper is an essential nutrient to both plants and animals.However, in humans, extremely large doses can lead to severe mucosal irritation andbreakdown, capillary damage, liver and renal damage, central nervous system irritationand depression (World Health Organization, 1984). Due to its tendency to induce vomit-6ing if ingested in large quantities, copper poisoning in humans is rare and there is no evi-dence of chronic toxicity due to long term ingestion at low levels. Copper is a bacteri-cide and is toxic to fish at quite low levels, so it can pose a threat to sewage treatmentplants and/or receiving waters.Copper salts can cause blue green staining of plumbing fixtures, laundry, andbleached hair. Stained bathroom fixtures are very common in Greater Vancouver.1.4.3 Ferrous MetalsCast iron and steel pipe have been used to transport water for centuries. Thesematerials are cheap and durable from a structural point of view. Of all materials used forwater conveyance purposes, ferrous metals are the most subject to corrosion but failureof the pipe due to leakage or breakage is rare due to the thickness of the material used.Generally, the most serious result of ferrous pipe corrosion is loss of flow capacity due totuberculation and scale accumulation. Schneider and Stumm (1956) showed that a castiron pipe can lose 15 percent of its flow capacity within one month. If 2.5 percent of thethickness of a one inch ferrous pipe is corroded away, the pipe may be completely filledwith corrosion products (Smith, undated). Studies by Curry and Wright (1975) in somesouthern Illinois communities found arterial mains having only 20 to 30 percent of theiroriginal capacity because of corrosion product build-up.Ferrous pipe is often protected from corrosion by application of protective coat-ings, cement linings etc., or by cathodic protection; by galvanizing or using zinc or mag-nesium alloy anodes.Since significant quantities of iron are required in the human diet on a daily basis,deleterious health effects from ingestion of dissolved or particulate iron are rare. Inges-tion of very large quantities of iron can cause a condition known as haemochromatosis (acondition wherein normal body regulatory mechanisms fail to function correctly), butsuch occurrences are extremely rare.7Iron salts in drinking water can make the water less palatable, and can cause redstaining of plumbing fixtures and clothing during laundering.1.5 Previous StudyPhase I of the Greater Vancouver Water District (GVWD) Corrosion Control In-itiative was a 1988-1990 pilot scale study by Economic and Engineering Services (EES)of Olympia WA (March 1990), which compared the effects of disinfection with chlo-ramine versus chlorine in raw and pH and alkalinity adjusted water. The study con-cluded that copper corrosion could be reduced by 60 to 80 percent and lead corrosioncould be reduced by 10 to 60 percent over corrosion levels of the normal chlorinatedwater currently produced by the GVWD, by disinfecting with chloramine instead ofchlorine and by adjusting pH and alkalinity to 8-8.5 and 20 mg/L respectively. It wasrecommended that further corrosion control pilot testing be carried out with chemicalinhibitors as an adjunct to pH and alkalinity adjustments. The inhibitor testing shouldattempt to determine their effectiveness in further reducing lead levels at the tap, reduc-ing iron pipe deterioration in some of the older municipal systems, and the impact of in-hibitors on re-growth potential.1.6 Objective and ScopeThe objective of this study was to evaluate the corrosion inhibition capability(within the limitations that the pilot plant allowed) of zinc orthophosphate, type N so-dium silicate and a commercial blend of the two, with concurrent adjustment of pH andalkalinity. Due to the limited number of loops available for testing, this study could notlead to outright acceptance or rejection of a particular inhibitor. At best it was hoped todetermine an idea of the effectiveness of the inhibitors tested relative to raw water, pHand alkalinity adjusted water, and each other. Further, it was expected that enough in-8formation could be gained to give an indication of the direction to be taken for furtherstudy.92. BACKGROUND AND LITERATURE SEARCH 2.1 Basic Corrosion TheoryThe word corrode which comes from the Latin "rodere", meaning to gnaw, is de-fined by Webster's Encyclopedic Dictionary of the English Language2 as "to eat awaygradually as if by gnawing, especially by chemical action".During the smelting and manufacturing process, a great deal of energy is ex-pended to remove bound oxygen and moisture from ore to produce a finished metal. Thefinished metal is highly stressed due to stored energy. If the metal comes into contactwith oxygen and moisture some of the stored energy may be released resulting in corro-sion. Usually the greater the energy input in the manufacture the greater the tendency forthe metal to corrode.According to U.R. Evans (Obrecht and Pourbaix 1967) practically all corrosion ofmetals in aqueous environments is due to electrochemical processes. How readily anelectrochemical reaction can take place at the interface of a metal and an electrolyte de-pends on the relative values of the electrode potential, E, of the metal and the thermody-namic equilibrium potential, E0, of the reaction. Oxidation can only occur if the elec-trode potential of the metal is greater than the equilibrium potential of the reaction. Con-versely, a reduction reaction can only proceed if the electrode potential of the metal isless than the equilibrium potential.In order for corrosion to occur, a corrosion cell consisting of four critical ele-ments must be formed as shown in Figure 2.1.2Port1and House. New York. 1989.1 0M >^ M4. + eAnodic area where metaldissolves andpassivation film formsA + e - >A -Cathodic area wherereduction of oxygen,chlorine, etc., takes place\vConducting Solution (Electrolyte)_Ion Migration-/Conductin . MetalCorrosion Cell Showing Anodic and Cathodic RegionsFigure 2.1The four critical elements are the:a. anode - where the metal is oxidized and electrons are generated that flowthrough the metal and through the electrolyte to the cathode;b. cathode - where the electrons flowing from the anode reduce corrosive sub-stances such as dissolved oxygen, chlorine, and hydrogen ions; typical reduc-tion reactions could be:02+ 2H20 + 4e- —> 40H-;^ 2-1HOC1 + H+ + 2e- —> CP + H20; and^2-22H+ + 2e- —> H21‘^2-3among many other possibilities;c. conductor - between the two electrodes, i.e., the metal itself which willpermit the transfer of electrons from the anode to the cathode; and1 1d. electrolyte - the other medium which will conduct various ions between thecathode and the anode and complete the circuit.The corrosion cell is by no means static. The electrodes usually change locationcontinuously, and the distance between the anode and the cathode is often infinitesimaland will vary continuously as well.Some of the cations generated at the anode along with other cations present in theelectrolyte will tend to migrate to the cathode where the electrode potential is lower,while some of the anions will tend to migrate to the higher potential at the anode. If pre-sent, some of the ferrous ions that migrate to the anode will react as follows:Fe2+ + 20H- Fe(OH)2^ 2-4This reaction could also take place at the anode as a result of the migration ofsome of the hydroxyl ions.Some other reactions that may occur are:Fe3+ + 30H- Fe(OH)31;^2-5Fe3+ + 202 ---> Fe3041; and^ 2-6Fe2+ + CO3= FeCO31 among numerous others.^2-7Some reactions can lead to a build-up of corrosion scale due to precipitation.Since the overall corrosion rate is limited by the rate of the slowest step in the circuit,that form of corrosion scale which tends to impede the migration of ions can assist in re-ducing corrosion.122.2 Types Of CorrosionIn a potable water system the following are the main types of corrosion that canoccur.2.2.1. Uniform corrosionThe corrosion attack is spread more or less equally giving a uniform depth ofpenetration over the entire surface. It normally occurs with acid solutions or in waterwith a high level of total dissolved solids (TDS) and high electrical conductivity. Uni-form corrosion is most common in copper and lead pipe.2.2.2. Galvanic corrosionGalvanic corrosion arises from the uninsulated contact of two dissimilar metals ofdifferent electrode potentials. The less noble metal becomes the sacrificial anode whilethe nobler metal acts as the cathode and the area near the galvanic anode remains corro-sion free as long as the anode and electrical conductivity continue to exist. Galvanic cor-rosion can occur in copper pipe with lead soldered joints, with the solder forming the an-ode. Oliphant (1983) found total lead levels of one to two orders of magnitude higherfrom lead soldered joints than would be expected from equilibrium solubility calcula-tions.2.2.3. Crevice corrosionCrevice corrosion occurs in areas where there is poor circulation and usually oxy-gen depletion (e.g., where metal overlaps as with a rivet). Halides and sulfates tend tomigrate into crevices and combine with the dissolved metal to form strong acids. For ex-ample, if there are chloride ions in the water, iron pipe crevices will accumulate a highconcentration of FeCl2 with resulting hydrolysis:FeC12 + 2H20 --) Fe(OH)21 + 2H+ + 2C1-^ 2-813As the acidic conditions increase metal corrosion locally, even more of these cat-ions tend to migrate into the crevice and the process accelerates with time. Poor con-struction practices can lead to crevice corrosion from such things as mud, sand, or cin-ders that can act as long lasting anodes. Threaded junctions, screwed joints and invertedseams are other potential sites for crevice corrosion.2.2.4. Pitting corrosionPitting corrosion occurs when an anodic site remains static and a tubercle forms.It can occur when a portion of protective corrosion scale comes off leaving a bare metalspot that quickly becomes a localized permanent anodic site. As with crevices, circula-tion is very poor inside the tubercle resulting in a build-up of halides and sulfates. Uhlig(1948) measured pHs in the range of 3 to 4 in some pits. Pitting corrosion is typicallyfound in ferrous materials.2.2.5. Concentration cell corrosionConcentration cell corrosion is believed to be the most common type of corro-sion, but it is difficult to measure (AWWA 1990). It occurs when differences in the totalor the type of mineralization exist. If the concentration of aqueous solution species isdifferent between two parts of the metal a difference in electrode potential will exist andcorrosion can occur.2.2.6. Cracking corrosionCracking corrosion results in the formation of either inter granular or transgranu-lar cracks which can lead to premature failure of the pipe. The amount of actual corro-sion may be small but the results can be catastrophic.142.2.7. Selective leachingSoft, aggressive waters can selectively corrode away the zinc in brass leaving aporous mass of soft, brittle copper. Destanification in bronzes is another example of se-lective leaching.2.2.8. Erosion corrosionErosion corrosion most often occurs at the entrance to pipes, sharp bends, neardeposits, and where pipe volume changes suddenly. If water velocity is high enough tocause significant turbulence, severe localized corrosion can occur as a result of impinge-ment attack and cavitation. Impingement attack occurs when gas bubbles strike the metalsurface releasing enough energy to break-up film or corrosion scale. If the impacts keepoccurring at the same location, pits can form. Cavitation is caused by vibration and theformation and collapse of vapour filled cavities at the metal surface where pressurechanges frequently and abruptly.2.2.9. Stress corrosionCold working of pipe during threading can lead to dissimilar stress of the metalwhich can result in localized corrosion. Stress corrosion occurs frequently at thethreaded connections of galvanized steel pipe.2.2.10. Microbiologically induced corrosionMicrobiologically induced corrosion is an area that deserves considerable morestudy. Nitrifying bacteria, for example, contribute to acidity by producing hydrogen ionsin the conversion of ammonia to nitrites and nitrates:NH4+ + 11/202 -- NO2- + 2H+ + H20^ 2-9NH4+ + 202 NO3- + 2H+ + H20^ 2-1015Microbiologically induced corrosion could be made worse if there is an excess ofammonia in a chloramination process and there are nitrifying bacteria present.Another example of microbiologically induced corrosion may be caused by oneof the iron bacteria, Thiobacillus ferrooxidans, which derives energy from oxidation ofiron.2.3 Factors Affecting CorrosivityThere is a myriad of factors that determine the corrosivity of a water and the effi-cacy of corrosion control strategies. The following is a list of some of the more impor-tant ones:2.3.1. Alkalinity, buffering capacity, and buffer intensityThe higher the buffer capacity, the greater the resistance to change in pH; manywater treatment chemicals such as hydroflurosilicic acid, alum, or chlorine tend to reducepH which can contribute to corrosion (see 2.3.9. below). Alkalinity is also important inmetal salt solubility considerations.2.3.2. AmmoniaAmmonia has been shown to be corrosive to copper and copper alloys due to theformation of copper-ammonia complexes such as Cu(NH3)+±.2.3.3. Dissolved inorganic carbonate (DIC), total inorganic carbon (TIC)DIC is the total concentration of all dissolved inorganic carbonate species includ-ing H2CO3*3, HCO3- , CO3=, as well as salts, complexes and ion pairs including for ex-ample: CaHCO3-, CaCO3, PbCO3, Pb(CO3)2=, Pb3(OH)2(CO3)2, CuCO3, Cu(CO3)2=,3H2CO3* refers to the total concentration of dissolved carbon dioxide (CO2) and carbonic acid(H2CO3).16FeCO3 and many others. If total alkalinity, pH, temperature, and ionic strength areknown, DIC can be calculated. DIC is an important factor in lead solubility. It is impor-tant to determine the DIC level and whether the addition of DIC will be necessary beforepH adjustment is initiated, because of the interrelationship of total alkalinity and pH(Schock 1989).The presence of CO3= can lead to formation of protective scale of lead carbonateor basic lead carbonate [Pb3(OH)2(CO3)2, also known as hydrocerussite]. Patterson andO'Brien (1979) found that for minimum lead carbonate salt solubility there is a corre-sponding pH value at a given DIC concentration and a corresponding DIC value for aspecific pH value. They observed that the highest lead corrosion rates occurred in theabsence of carbonate and a slight addition of carbonate reduced the corrosion rate sub-stantially. They also found that carbonate addition alone provides substantially betterprotection than pH adjustment alone. They concluded that the optimum level for mini-mum lead corrosion is in the pH 8 to 8.5 range and a minimum carbonate alkalinity of 20mg/L as CaCO3. Boffardi (1988) suggests that in high alkalinity waters 100 mg/L asCaCO3), lead solubility is insensitive to pH over a range of 6.5 to 8.Schock and Gardels (1983) showed that copper and lead solubility actually in-creases with high levels of carbonate due to complex formation. They concluded thatplumbosolvency can be substantially reduced by increasing the pH to 9 or more with TICin the range of 10 to 80 mg/L as CaCO3. Schock (1980, 1981) showed that in the 8 to8.5 pH range, low concentrations (about 30 mg/L as CaCO3) of TIC are more effective inreducing lead corrosion than higher TIC levels (100 to 200 mg/L).In his investigation of the relationship between pH and TIC and the precipitationof a lead carbonate, hydroxycarbonate or hydroxide film, Schock (1985) showed theminimum lead solubility to occur at a pH of 9.8 with a DIC of 30 to 40 mg/L as CaCO3.172.3.4. Dissolved oxygen (DO)Corrosivity of a water to ferrous piping is directly proportional to DO concentra-tion, but above a certain minimum, its impact on copper and aluminum corrosivity is lesssignificant. Stone et al. (1987) determined oxygen to be the rate-determining reactant inthe corrosion of copper and zinc with the limitation being either diffusion through thecorrosion film or the reduction reaction itself.2.3.5. HalidesHalides aggravate crevice and pitting corrosion as discussed. They can also tendto promote pitting by increasing the porosity of passivation4 film (Kirmeyer andLogsdon, 1983).2.3.6. HardnessGenerally soft, low mineralized waters (hardness < 25 mg/L as CaCO3, TDS <50mg/L) are the most corrosive to piping materials. Moderately hard, mineralized waters(hardness = 25 to 125 mg/L as CaCO3, TDS = 50 to 300 mg/L) are considered non ag-gressive. Hard, mineralized waters (hardness > 125 mg/L as CaCO3, TDS > 300 mg/L)usually form CaCO3 scale on the pipe wall which inhibits corrosion, but pitting corrosioncan be a problem under certain conditions. However, Lee et al., (1989) found no rela-tionship between hardness or calcium levels and lead levels from plumbing materials.2.3.7. Hydrogen sulfideHydrogen sulfide increases corrosivity especially in waters with high organic andsulfate content (AWWARF, 1989).4Passivation is attained as a result of the build-up of insoluble film composed of a metal-oxideor metal-inhibitor compound which reduces the reactivity of the metal.182.3.8. Organic tanninsOrganic tannins which occur frequently in surface waters appear to lay down aprotective film on pipe walls which can inhibit corrosion to some extent (ibid.).However, they can also form complexes with some metals such as copper and aggravatecorrosion.2.3.9. DHpH is a significant factor in corrosivity. In soft, low mineralized waters, decreas-ing pH below about 8 usually increases copper and galvanized steel corrosion but mayactually lower black steel corrosion. Lead solubility decreases in a pH range of 8 to 9.Below a pH of 8 to 8.5, a difference of even a few tenths can yield a lead solubility dif-ference of 3 to 5 times (Schock, 1989). Generally, optimum pH levels for minimizationof corrosion are 8 for copper, 9 for lead, and 7.5 for steel and zinc. Stone et al. (1987)found copper corrosion rates to be highly pH dependent but zinc showed very littledifference. In the soft, low mineralized waters of Boston, Karalekas et al. (1983) foundthat pH adjustment alone will reduce lead corrosion but not sufficiently to reduce lead toacceptable levels.Considering a copper-hydrogen cell, hydrogen ions must be reduced for the cop-per to be oxidized. Based on standard oxidation potential, such a reaction cannot proceedspontaneously since.Half cell^Cu°^=^Cu+ + e-^E0 = -0.521 V^2-11Half cell^H+ + e- ^=^1/2H2^E0  = 0.000 V^2-12Cu° + H+^=^Cu+ + 1/2H2^E = -0.521 V^2-13However, when oxygen is present, it will act as an oxidizing agent.19Half cell^2Cu0^= 2Cu+ + 2e- Eo = - 0.521 V^2-14Half cell^2H+- + 1/202  + 2e - ^=^H20^E0  = +1.229 V^2-152Cuo + 2H+ + 1/202^= 2Cu+ + H20 E = +0.708 V^2-16Thus it can be seen that in a pure water system, without oxygen presence, coppercorrosion will not occur spontaneously.Even though the hydrogen does not play a direct reduction role with copper, pHcan influence copper corrosion in three ways (Reiber, 1989):a. by altering the equilibrium potential of the oxygen reduction half cell; a de-crease in pH shifts the reaction in the anodic direction and the potential of thecopper-oxygen cell is raised increasing the corrosion driving force.b. by changing the speciation of copper in solution; a change in pH alters thedistribution of the dissolved copper species; a decreasing pH shifts the specia-tion from the hydroxocomplex form toward the hydrated (free) form; andc. by affecting the stability and protective qualities of passivating films.According to Reiber et al., (1987) and Reiber (1989) corrosion rates on coppersurfaces with limited scale formation are extremely sensitive to pH, but aged surfaceswith well formed scale are much less so. Reiber suggests that the solubilities of copperoxides [including suspected scale constituent cuprite (Cu02)] increase with decreasingpH, making loss of scale at low pH values probable. At pHs less than 6, the corrosionrate increases rapidly such that, at pH 4, it is an order of magnitude higher than at pH 7.At higher pHs a greater buildup of oxide film layer occurs over time which increases thediffusional barrier and reduces the overall corrosion rate.206^7^8^9^10PHHilburn (1983) proposed that copper corrosion rates may be limited by the trans-port of hydroxyl ions away from the cathodic site. The hydroxyl ions are generated bythe oxygen half cell reduction:02+ 2H20 + 4e- = 40H^E0 -- 0.401 V^2-17The increase in hydroxyl ions at the cathode diminish the half cell reaction ratethus inhibiting the overall rate of corrosion. If the pH of the water is raised, the drivingforce for diffusional transport of the hydroxyl ions from the cathode is reduced.Higher pH levels tend to re-duce the effectiveness of free chlorineand increase rates of formation andfinal concentrations of trihalometh-anes (THM) (Stevens, et al., 1976;Symons et al., 1981). In the pHranges associated with drinkingwater, the only significant free chlo-rine species present are hypochlorousacid (HOC1) and hypochlorite ion(0C1-). Figure 2.2 is an approxima-tion of the relative distribution ofHOC1 and 0C1- at pHs from 5 to 10.Effect of pH on Distrubution of Free Chlorine Forms at 20 deg C(After AWWA, 1990)Figure 2-2Since the disinfection effectiveness of HOC1 isabout 40 to 80 times that of 0C1- (Metcalf & Eddy, 1991) plans to change pH levels toreduce corrosion must take into account the effect it will have on disinfection and theamount of additional chlorine and contact time that may be required. The situation isfurther complicated by data (Berg, 1964) showing that viral destruction is enhanced sub-21stantially by the higher pH associated with lime softening, in spite of the reduced micro-biocidal effectiveness at the higher pH levels.2.3.10. ChlorinationChlorination usually increases corrosivity due to the formation of HOC1 and pHreduction. Consider the strong HOC1 corrosion cell with copper:Half cell^2Cuo^=^2Cu+ + 2e- E0 = - 0.521 V^2-18Half cell^HOC1 + H± + 2e- ^=^Cl  - + H20 E0  = +1.49 V^2-192Cu0 + HOC1 + H-E = 2Cu+ + a- + H20 E = +0.969 V^2-20The 0C1- corrosion cell is also strong:Half cell^2Cu0^= 2Cu+ + 2e-^E0 = - 0.521 V^2-21Half cell^00-  + H20 + 2e- ^= Cl -  + 20H-^Eo  = +0.90 V^2-222Cuo + OC1- + H20 = 2Cu+ + a- + 20H- E = +0.379 V^2-23For each 1 mg/L of chlorine added, 0.7 to 1.4 mg/L of alkalinity as CaCO3 willbe neutralized depending on how the HOC1 is ionized and how the chlorine is consumedby water constituents (Curry, 1978). Stone et al. (1987) found chlorine to be highly cor-rosive to copper with 1 mg/L of free residual chlorine giving roughly the same corrosionrate as 10 mg/L of dissolved oxygen, but the effect of chlorine on zinc corrosion wasnegligible. Note also that both corrosion cells result in the production of chlorides,which contribute to localized corrosion, as discussed earlier.222.3.11. SilicatesSilicates often occur naturally in soft surface waters and in some ground watersdue to leaching of siliceous material from soil and rock. They often act to inhibit corro-sion by combining with corrosion by-products to form a protective scale (AWWARF,1989).2.3.12. SulfatesSulfates are comparable to halides in their effect on pitting corrosion, but they arenot as serious as halides in their effect on crevice corrosion (ibid.).2.3.13. TemperatureGenerally, higher temperatures aggravate corrosion. Reaction rates for oxidationand reduction reactions tend to increase with increasing temperature, and the solubility ofcorrosion scale is also affected. The rate of product transport across the water/filmboundary is temperature dependent as well. The solubility of CaCO3 actually decreaseswith increasing temperature, so with hard waters, hot water lines often experience a sig-nificant drop in flow capacity due to scale buildup.2.3.14. VelocityCorrosivity can be exacerbated by both high and low flow velocity. High veloc-ity can lead to erosion corrosion as discussed. Higher velocities also allow oxygen andother oxidizers to interact more easily with the pipe surface. If velocity is too low ade-quate corrosion scale may not form, or in the case of dead ends, the scale may partiallydissolve or slough. Also, extremely low velocities make for poor circulation whichencourages concentration cell corrosion.232.3.15. Water Treatment Processesa. Turbidity removal - The addition of alum [Al2(SO4)3•14H20] to raw waterfor turbidity removal typically results in the following chemical reactionwhere floc [Al(OH)3] forms as a result of reaction with bicarbonate (HCO3-):Al2(SO4)3•14H20 + 6(HCO3)- —> 2A1(OH)31 + 3SO4= + 6CO2 + 14H202-24If there is not enough naturally occurring alkalinity to react with the alumdose, more will have to be added. Theoretically, each mg/L of alum willneutralize about 0.5 mg/L of alkalinity as CaCO3 and produce 0.44 mg/L ofCO2 leaving a water that has a lower pH and less buffering capacity. For op-timum coagulation, it is often necessary to keep the pH in the low 6 rangeduring flocculation. Therefore, it may be necessary to add alkalinity after theturbidity removal process to maintain the original corrosivity characteristicsof the raw water. But even if that is done, the dissolved sulfate will still bethere to exacerbate pitting corrosion problems.b. Water softening - Water softened by either ion exchange or lime-soda ashprocesses can leave a water more corrosive than before, due to alkalinity andcalcium removal and consequently, lower buffering capacity.242.3.16. Other parametersThe following may also influence corrosivity:Total dissolved solids (TDS)^IronIonic strength^ ZincConductivity CopperPolyphosphates^ SodiumOrthophosphates ManganeseNitrates^ MagnesiumNatural color Other trace metalsTotal organic carbon (TOC)2.4. Chemical Approaches To Corrosion ControlNo approach to corrosion control will be successful at eliminating it completely.At best, one can strive for a reduction in the rate to more manageable levels. That levelof manageability will have to be weighed against the cost of implementing and operatingcorrosion control programs and any effects such programs have on the environment.In terms of plant and equipment, it makes sense to use the most corrosion resis-tant materials available and to make use of corrosion resistant linings, coatings and paintwhere practical provided they are cost effective and they are harmless to human health.It also makes sense to discourage bad work habits in an effort to limit the corrosion thatcan be attributable to such. Even in the event that all reasonable efforts are being madeto ensure that these more controllable factors are dealt with, corrosion can still besignificant. The next step is to consider the use of chemical approaches.Essentially chemical corrosion control programs can choose from two alternativeapproaches. Broadly speaking, they can be referred to as the neutralization approachand the passivation approach. The neutralization approach makes use of reactive chemi-25cals to overcome the effects of corrosive species in the water. For example, consideragain the case of the copper corrosion reaction with HOC1:2Cu + HOC1 + H+ --> 2Cu+ + C1 + H20^ 2-25If the concentration of hydrogen ions is depressed via the addition of some formof alkaline chemical(s), the process will be less inclined to proceed and corrosion fromthis reaction will be less, provided nothing else of significance changes in the overallequilibrium.Consider, once again, the oxidation of copper:2Cu + 2H+ + 1/202 ---> 2Cu+ + H20^ 2-26Oxygen removal would serve to reduce corrosion but that would be too costly tojustify and it might result in a water that is less palatable. If the pH were suppressed, thereaction would also be slower.The neutralization approach is based on stoichiometry and requires a great deal oftheoretical knowledge of electrochemistry. If all the ingredients of a water are knownand all of the significant contributors to corrosion are dealt with, all corrosion should,theoretically, be reduced by the use of neutralization measures. The problem is mostwaters are very dynamic, changing their chemical content continuously. While thesechanges may be minute in terms of percentage content in the water, they may be quitesignificant with respect to corrosion. Another problem is treatments for one corrosionproblem may aggravate another e.g., raising pH to reduce copper corrosion may increaseferrous corrosion, as discussed.The corrosion rate is governed by the slower of either the reaction kinetics at themetal surface or the transport of reactants or products through the solution and the cor-26Corrosion Scale TransportSolutionFigure 2.3rosion scale. Initially the rate is governed only by reaction kinetics and solution trans-port, but later, as corrosion scale develops (Figure 2.3) it becomes another possible ratelimiting barrier. In most waters, the mainreason that copper is so resistant to cor-rosion is due to the formation of a tough,adherent scale formed from naturally oc-curring copper corrosion products. Gen-erally, the scale grows until it reaches asteady state thickness where the rate ofgrowth is equal to the rate of destruction. The scale can be destroyed by dissolution orby spalling. In some cases, e.g., when a calcium carbonate scale is forming, the scale cancontinue to thicken indefinitely until flow becomes significantly impaired.The passivation approach to chemical corrosion control involves physical inter-ference with the operation of corrosion cells by deliberately causing a protective scale tobe formed which tends to block the contact between the electrolyte and the anodes andcathodes. Such is the process that may occur naturally via the formation of CaCO3 scalein some hard waters. While perfect insulation of the electrodes is not realistic, it is oftenpossible to dramatically reduce the corrosion rate through the use of certain inhibitorchemicals whose sole function is to combine with the corrosion by-products and otherwater constituents to form a tough, adherent, protective scale. The scale is still slightlysoluble, however, so inhibitor chemical feeds must continue indefinitely (normally at alower rate after an initial passivation period) if the reduced corrosion rate is to be main-tained. The initial passivation period is quite important. During this time, which may beseveral weeks, the inhibitor is fed at 2-3 times the normal rate in order to build a protec-tive film quickly and minimize the opportunity for pitting corrosion to start before theentire metal surface is covered.27The passivation approach to chemical corrosion control may be easier than theneutralization approach because it is broader in scope, dealing with more corrosionproblems at once. For example, if some form of copper-phosphate scale is formed as aresult of a phosphate inhibitor feed it should afford some protection from both HOC1 andoxygen attack. The better the knowledge of the solubility of the water's various ingredi-ents and corrosion products in combination with each other and the inhibitors, the greaterthe chance of successful application of inhibitors.Available corrosion control technology covers a broad spectrum. For industrialuse, high concentrations of chromates, molybdates, tungstates, nitrates, phosphates,natural organics such as tannins, and synthetics such as mercaptans have been usedsuccessfully. However, treatment for potable water is essentially limited to pH andalkalinity adjustment, switching to chloramine from chlorine for disinfection, and theaddition of phosphate and/or silicate inhibitors.2.4.1. pH and alkalinity adjustmentpH and alkalinity adjustment may be the only method used to reduce corrosivityin some water systems. Systems that have high enough levels of hardness may only re-quire a slight increase in calcium or alkalinity to bring the water to the point of CaCO3saturation to enable the formation of a passivation scale. pH, calcium, and to a limitedextent alkalinity, levels can all be raised by the addition of slaked lime [Ca(OH)2] forexample.In soft, low mineralized waters, it is not practical to attempt to reach CaCO3 satu-ration. However, in some of these waters, merely raising the pH may be enough to re-duce corrosivity to desired levels. In order to maintain stable pH conditions, usually itwill also be necessary to raise the alkalinity as well, so that an adequate buffering inten-sity is available. Sometimes the only chemical required will be soda ash (Na2CO3).Other times it may be necessary to use a strong base like caustic soda (sodium hydroxide,28NaOH) or lime in combination with a buffering chemical like soda ash, sodium bicar-bonate (NaHCO3), or CO2.In some waters it may also be necessary to adjust the carbonate species relative tothe concentration of halides and/or sulfates if the latter two are at significant levels. Analkalinity to (Cl- + SO4') ratio as CaCO3 of at least 5:1 should be maintained tominimize the potential for pitting corrosion (Millette et al., 1980).If pH adjustment is used it should be borne in mind that buffer capacity is mini-mal in the 8 to 8.5 range when the bicarbonate-carbonate system is the main buffer.Therefore, it will be much easier to maintain pH stability if the targeted pH is eitherbelow or above that range. Schock (1989) suggests that the upper limit should be 10.2,primarily based on a lack of field and laboratory data above that level. Pisigan andSingley (1987) found the corrosion rate for steel to be highest at pH 8 where the buffercapacity is near minimum. Stumm (1960) found corrosion rates higher at pH 8 to 8.5and attributed this to the low buffer capacity in this pH range. Larson and Skold (1957,1958) also found higher corrosion rates for cast iron and steel at pH 8.For groundwaters with high CO2 content ( > 10 mg/L) air stripping to reduce theCO2 may be a practical way to raise the pH without reducing the alkalinity.2.4.2. Disinfection with chloramineThe usual way of chlorinating water for disinfection is with chlorine gas (C12).Elemental chlorine combines with water to form hypochlorus acid, chloride ion, and hy-drogen ion as follows:C12 + H20 HOC1 + Cl- + 1-1+^ 2-27The effects on corrosivity of the three products of the reaction have already been dis-cussed.29On the other hand, if HOC1 and ammonia (NH3) are combined to formmonochloramine as follows:HOC + NH3 --> NH2C1 + H2O^ 2-28and then chloramine is used for disinfection in the presence of copper for example:Half cell 2Cu0^= 2Cu+ + 2e^E0 = - 0.521 V 2-29Half cell NH2C1 + H20 + 2e- = Cl-  + NH3  + 0H^E0  = + 0.75 V 2-302Cu0 + NH2C1 + H2O = 2Cu+ + Cl- + NH3 + OH-^E =-F 0.229 V 2-31This corrosion cell is not nearly as strong as the HOC1 and Cu cell or the 00- and Cucell.Being less reactive than either HOC1 or 0C1-, chloramine is less effective as adisinfectant. However, free chlorine (i.e., the combination of C12, HOC1 and OC1-) tendsto dissipate much more quickly than chloramine.In Portland, Ore. Treweek et al. (1985) confirmed experimentally with plaincopper pipe that disinfection with free chlorine increased copper corrosion rates consid-erably over those for the same dose level of chloramine. But, surprisingly, in the case oflead soldered joints, both copper and lead levels were higher in chloraminated water thanin chlorinated water. Treweek suggests that the chloraminated system may increaseequilibrium solubility through complexation or by altering the precipitation kinetics ofthe passivating film on lead materials. Boffardi (1988) proposed that, if lead chloraminesform, they may increase lead solubility by dissociating into lead amine complexes. Onthe other hand, in their study of 94 companies and districts of the American Water WorksService Company, which compared lead levels at the tap, Lee et al., (1989) found that30neither free chlorine levels nor total chlorine levels had any effect on the lead levels con-tributed from plumbing materials.2.4.3. Phosphate and silicate inhibitorsPhosphate and silicate inhibitors are passivation approaches to corrosion control.They form a metal-inhibitor compound on the metal surface which builds to the pointwhere some degree of protection is afforded. The scale is self limiting and does not buildup beyond a certain level, so there is no significant reduction in flow capacity in thewater line.2.5. Phosphate InhibitorsPhosphate inhibitors are available in several different types including phosphatesand metaphosphates, linear and cyclic polyphosphates, glassy polyphosphates, or-thophosphates, blends of ortho and polyphosphates, bimetallic polyphosphates, zincpolyphosphates, and zinc orthophosphates.a. Sodium phosphates - are made by combining soda ash or caustic soda withphosphoric acid (H3PO4) in various combinations to form such products asmonobasic sodium phosphate (NaH2PO4), dibasic sodium phosphate(Na2HPO4), tribasic sodium phosphate (Na3PO4), sodium metaphosphate(NaP03) and sodium tripolyphosphate Na5P3010.b. Glassy polyphosphates - are sodium hexametaphosphates (Nan+2PnO3n+iwhere typically n = 10 to 16). In low dosages (2-4 mg/L) they have beenused to combat red water problems. They complex with the iron in the waterand mask the red color, but do not reduce corrosion. For corrosion control,dosages of up to 10 times higher were required. (AWWA 1990). They werefirst used as corrosion inhibitors around 1940 (11lig 1957).31c. Bimetallic polyphosphates - are usually a combination of 8-15 percent zincwith sodium polyphosphates. Their use as corrosion inhibitors began about1950 (Kleber 1965). They often perform better than plain sodium polyphos-phates in harder waters and can be effective at pH 8 or slightly higher(AWWARF 1989).d. Blended ortho-polyphosphates - which have been available since about 1980are composed of sodium and potassium phosphates in proportions from 10 to30 percent ortho to polyphosphate. They have been successfully applied inmoderately mineralized waters in a pH range of 7.2 to 7.8 for the protectionof steel and copper (AWWARF 1989).e. Zinc orthophosphates - are a blend of zinc sulfate (ZnSO4), sodium dihydro-gen phosphate (NaH2PO4), and sulfonic acid (H3NO3S) in proportions of56:24:20. They initially came into use in the late 1960s (Murray 1970). Theyare most effective in the 6.5 - 7.5 pH range. They are available in liquid formthus eliminating the handling problems of dry, hygroscopic, low solubilityproperties normally associated with polyphosphate or bimetallic inhibitors.Phosphates work best in water flowing at high velocities but are not effective instagnant or near stagnant areas such as household service lines (Katsanis et al., 1985). Inaddition to forming a metal-inhibitor compound on the metal surface, phosphates mayalso combine with oxygen at the metal surface to form a crystalline lattice structure thatanchors the precipitated salts (Nancollas, 1983).Swayze (1983) reported that phosphates tend to soften previously formed scalewhich may cause temporary red water problems as the old scale washes out. However,by solubilizing old scale, phosphates can ultimately minimize red water problems and re-duce head loss (Shull, 1980). Bimetallic polyphosphates were used successfully inPhiladelphia for a number of years (Shull 1980). Reiber (1989) found that on copper,phosphate inhibitor protection develops quickly (at least on relatively fresh surfaces) but32requires at least periodic inhibitor application. Reiber suggests that a three to five folddecrease in corrosion rate is possible using concentrations in the range of 1 to 5 mg/L asP. Quantity of scale is minimal and inhibition is not degraded by the presence of chlo-rine.The solubility of most metallic phosphates is pH dependent, so logically, onewould expect pH to influence the performance of phosphate inhibitors. Hatch (1973)found that, with or without zinc, polyphosphate inhibitor performance decreased with in-creasing pH above about 7. Zinc polyphosphate either as a physical mix or bimetallicglass will reduce steel corrosion in a pH range 6 to 7.5 but pH should be maintainedabove 7 (Boffardi, 1988). When using zinc orthophosphate to control steel and lead cor-rosion Boffardi states, it is extremely important that a pH of 7.2 to 7.4 be maintained.According to Reiber (1989) the phosphate scales on copper appear more labile than theoxide scales formed in noninhibited waters. A low pH (< 6) can dissolve the phosphatescale within hours leading to corrosion rates comparable to those of a freshly polishedcopper surface.Due to lead-carbonate complexation, lower DIC waters will have lower plum-bosolvency, than those waters with higher DIC levels, as discussed. Orthophosphateaddition, however, reduces lead solubility in high DIC situations more than water qualityalterations short of major decarbonation or pH adjustment (Schock 1989). A number ofsparingly soluble lead phosphate compounds can form, many of which are much less sol-uble than lead carbonates. The predominant compounds are hydroxypyromorphite[Pb5(PO4)3011] and possibly tertiary lead orthophosphate [Pb3(PO4)2] (Boffardi, 1988;Schock, 1989). At very low DIC levels (<1 mg C/L), the optimum pH for orthophos-phate film formation is about 8. The optimum pH gradually decreases as the orthophos-phate level increases but it remains >7 for all but the highest DIC concentrations and or-thophosphate dosages. Theoretically, a level of 0.01 mg/L of lead could be obtained forequilibrium lead solubility at a pH of about 7.6 and a DIC of about 5 to 10 mg C/L with33an orthophosphate dosage >4.5 mg/L PO4. Practically speaking, adequate lead controlcan probably be obtained over a fairly wide range of orthophosphate, DIC, and pH con-ditions. The ability to use orthophosphate to control lead solubility at lower pH values,as opposed to pH and DIC adjustment, may prove to be advantageous in systems withTHM formation problems.Sodium dihydrogen orthophosphate at 2 mg/L was fed into the waters of theKing's Park area of Scotland. Samples taken from dwellings showed lead levels of lessthan 25 percent of the levels prior to treatment (Richards and Moore, 1984). Ryder andWagner (1985) found a combination of orthophosphates and polyphosphates to be effec-tive in reducing copper corrosion, even though individually neither compound providedany protection. Studies with metaphosphates and pyrophosphates showed success in leadcorrosion inhibition but they were not as effective as orthophosphate (Sheiham and Jack-son, 1981). These studies also concluded that zinc orthophosphate works best if appliedafter pH adjustment.Hatch (1973) found that the addition of zinc led to a reduction in the amount ofphosphate that was required for the same level of protection. Zinc also reduced the timerequired before some degree of protection was afforded. Ryder and Wagner (1985) cor-roborate this finding. In the soft waters of New Jersey, Mullen and Ritter (1980, 1974)found zinc phosphate to be effective but bimetallic zinc phosphate at the same dose wasnot. They also found that zinc orthophosphate dosages of 0.2 to 0.5 mg/L as zinc pro-vided 60 to 75 percent reduction in steel pipe corrosion. Bailey (1983) and Kelly (1978)reported similar results in Durham, N.C. and Portsmouth, Va, respectively. Kleber(1965) found sodium-zinc glassy phosphate containing 8-9 percent zinc to be three tofive times as effective an inhibitor as straight sodium phosphate glass. According toKleber, the zinc not only speeds up the formation of protective scale, but the scale ismore complete and protective. Schock (1989) suggested that a combination of pH ad-justment and zinc orthophosphate could provide better protection than pH adjustment34with orthophosphate added as a generic chemical (sodium or potassium orthophosphate,or orthophosphoric acid) but more controlled experimentation is needed to confirm this.The study by Lee et al., (1989) (mentioned in paragraph 2.3.6) compared the ef-fect of various pH levels and the addition of various phosphate treatments on lead levelsat the tap, and found zinc orthophosphate to be the most beneficial. They found that so-dium hexametaphosphate and zinc hexametaphosphate gave results similar to pH adjust-ment to 8.There are other studies that show zinc and/or zinc phosphates to be ineffectual.Boffardi (1988) found that zinc orthophosphate provided no better protection of leadover orthophosphate alone, but it was more effective on carbon steel, and it had some ef-ficacy on cast iron and copper and aided in the suppression of asbestos fibres from asbes-tos cement. Patterson and O'Brien (1979) found lead corrosion rates 25 and 60 percenthigher in zinc orthophosphate treated water after one week and two weeks of treatmentrespectively. And in the soft, low mineralized waters of Boston, Karalekas et al. (1983)found no beneficial protection from zinc phosphate on copper, iron, or lead and theyfound no reduction in lead corrosion from zinc orthophosphate addition.Studies by Schock and Wagner (1985) determined that polyphosphates may notonly be ineffective in reducing lead corrosion, but they may actually increase lead levelsby complexation and solubilization of protective films on the pipe. The complexationcapacities of several polyphosphates show a potential for substantially increasing solublelead levels in the absence of orthophosphates (AWWARF 1990). Holm and Schock(1991) showed theoretically that for solutions in equilibrium with hydrocerussite andhaving the same pH and alkalinity levels, a solution containing polyphosphates will havea greater dissolved lead concentration than a solution without polyphosphates. Schock(1989) states categorically that "to date experimental and field evidence does not supportthe use of polyphosphates in preference to almost any other treatment technique for thecontrol of lead solubility".35A major concern about phosphates is that they may stimulate biological growthboth within the distribution system and in the receiving waters. A chlorine or a chlo-ramine residual may reduce the problem throughout the distribution system but will nothelp the receiving waters. However, studies by Rozenzweig (1987) on the effects of twophosphate corrosion control chemicals (one of them orthophosphate) on the growth ofheterotrophic bacteria showed no significant influence.Zinc may also be a concern because it is extremely toxic to fish so its effect onreceiving waters may have to be considered. Also it may result in excessive zinc loadingof wastewater treatment plants.2.6. Silicate InhibitorsSodium silicates are manufactured as a dry chemical called water glass and as aliquid chemical solution. They are most commonly prepared by the fusion of silica sandand sodium or potassium carbonate at high temperatures in a furnace to produce a watersoluble glass as follows:Me2CO3 + nSi02 —> Me2O•nSi02 + CO2i^ 2-32Table 2-1 shows the more common sodium silicate corrosion inhibitors(AWWARF 1989).The type N and 0 silicates are normally used for corrosion control in waters in apH range of 7 to 9 while the more alkaline type D and C silicates are recommended formore acidic waters.Corrosion is inhibited by the formation of a thin metal silicate barrier on top ofand interlatticed with a metal-hydroxide structure. Silicates are considered to be anodicinhibitors initially forming film on anodic areas. The deposition of film depends on the36Type % Na20 % S102 % Ratio % Silicate Solids BaumeN 8.9 28.7 1:3.22 37.6 41.00 9.2 29.8 1:3.22 39.0 42.2D 14.5 29.0 1:2 43.5 50.0C 18.0 36.0 1:2 54.0 59.1Metso-granular 20.5 28.7 1:1 58.2 SolidTable 2.1 - Common Silicate Inhibitorspresence of small amounts of corrosion products on the metal surface. The negativelycharged silicate ions are attracted to the positive metallic ions formed at the anodes toform a protective film (Katsanis et al., 1985). With continuous feeding, the films extendto the cathodic areas, a very important phenomenon, because any reduction in anodic freesurface without a corresponding reduction in the cathodic free surface would lead to anincrease in current density at any unprotected anodic sites and accelerated localized cor-rosion. Microscopic and x-ray diffraction show that two distinct layers are formed withmost of the silica in the surface layer adjacent to the water (ibid.). When the hydrousmetal oxide or metal silicate has been covered with a silica layer, further growth ishalted, so continued silicate feed does not cause a build-up of the films.Silicates are often blended in engine antifreeze for their corrosion inhibitor ca-pabilities and they are included in most cleaning and detergent formulations includinghome laundry and dishwashing products. Silicates contribute to the cleaning process plusinhibit corrosion to metal washing machine parts and other metals that are exposed to thecleaning solutions. Silicate bonded mineral insulation applied to stainless steel pipinginhibits stress corrosion cracking that may occur in corrosive environments.Silicates do not contribute to algal growth or eutrophication.37According to Katsanis et al., (1985) silicate treatment is most effective with softwaters of low pH and high oxygen content. They recommend an initial dose of 24 to 25mg/L as Si02 for the first month or two followed by a maintenance dosage of 8 to 10mg/L. In some cases, maintenance dosages may be as low as 4 to 5 mg/L. They alsorecommend that silicate treatment be started immediately following mechanical cleaningand flushing of distribution pipes.The first documented successful use of silicates in drinking water was for the softmoorland waters in England for the control of lead corrosion from lead piping sometimebefore 1917 (Sussman, 1966). Stericker (1938) reported on successful use of silicates forcorrosion control in domestic water supplies in Pennsylvania and New York. Courcheneand Kirmeyer (1978) and Eastman (1983) report good results with silicates in the soft,low mineralized waters of Seattle and Baltimore, respectively. Schock and Buelow(1981) verified theoretically how silicates are effective in controlling corrosion of asbes-tos cement pipe.Silicates have their detractors as well. Wagner (1985) claims that the beneficialeffects often ascribed to silicates are really due to the fact that the silicates raise the pH ofthe water. Ryder and Wagner (1985), Wagner (1985), and Sontheimer (1985) found lit-tle or no benefit to copper, iron, lead, or zinc under the conditions in which silicates arenormally applied. According to Boffardi (1988), silicates are known as cementing agentsover corrosion products and consequently become effective only after a long period ofexposure (8 to 9 months). This long term requirement is due to the slow formation of akinetically inhibited metal-silicate film. Boffardi suggests that silicates can not matchphosphates for protection of iron and steel. Schock (1985) found that a silicate level ofat least 20 mg/L must be applied for several months to show any appreciable drop in leadlevels. High levels of silica can have an adverse effect in hot water forming precipitatesand tenacious non conducting deposits on heat transfer surfaces (Schock 1989). Due tothe significantly higher dosage that are normally required, both for initial passivation and38long term maintenance, the application of silicates for corrosion control is usually morecostly than phosphates.Silicates can be combined with zinc to make bimetallic inhibitors, and sometimesthey are combined with phosphates or zinc and phosphates in a attempt to combine in-hibitor benefits. To date, the potential synergistic effect of combining two or more in-hibitors has not been investigated to any significant extent.2.7 Factors Affecting Inhibitor SelectionThe following are some factors that should be considered in the corrosion inhibi-tor selection process:a. predominant type of corrosion that is occurring and the relevancy of inhibitoruse;b. potential effects of temperature, velocity, and the concentration of corrosiveagents in the water;c. expected chemical reaction with the corroding medium;d. potential effect on corrosion rate;e. expected effectiveness over time;f. minimum required concentration both for initial passivation and long termmaintenance;g. expected reaction with existing surface films, scales and other corrosion prod-ucts;h. efficacy on already corroded metal;i. potential effect on tanks at the water line;j. potential adverse effects on water quality particularly for industrial, healthcare and other special uses;k. potential effects on other water treatment processes;391. capital and operating and environmental costs and cost/health/aesthetic bene-fits;m. handling factors, toxicity etc.; andn. environmental considerations; effect on wastewater treatment and receivingwaters.403. EXPERIMENTAL METHODS3.1 Selection of Inhibitors and Plant ConfigurationIn addition to the literature search, extensive consultation was carried out withnumerous chemical suppliers to assess the availability, physical form, method of deliv-ery, applicability for use in GVWD type waters, recommended dosages, feed methods,and costs of various inhibitors. In addition, cost estimates were made for the continuoususe of the inhibitors by GVWD based on the recommended maximum and minimumdosages and an average daily water consumption of 1,027,000 m3 (1989 data). Capitalcosts and operation and maintenance considerations were only appraised on a qualitativebasis. The following is the short list of chemical inhibitors from which the final se-lections were made:a. Virchem 932 - a zinc orthophosphate from Technical Products Corp.(TPC), Portsmouth VA. It has a zinc content of 8.3 percent, and azinc to phosphate ratio of 1:1. It is available in liquid form. Themanufacturer's recommended dosage in GVWD water was 5 mg/L asproduct, with maximum/minimum dosages of 2.5 and 7.5 mg/L re-spectively. Thus, at maximum dosage, the phosphate and zinc levelswould be 0.62 mg/L each. If actually used by the GVWD, the esti-mated annual chemical cost varies from a minimum of $608,000 to amaximum of $1,826,000.b. Virchem 939 - another zinc orthophosphate from TPC. It also comesin liquid form with a zinc content of 8.3 percent, but the zinc to phos-phate ratio is 1:3. Recommended dosage was 3 mg/L as product, withmaximum/minimum dosages of 1.5 and 4.5 mg/L respectively. Atmaximum dosage, the phosphate level would be 1.12 mg/L and zinc41would be 0.37 mg/L. Actual use estimated annual chemical cost var-ies from a minimum of $438,000 to a maximum of $1,313,000.c. TPC 223 - a silicate/orthophosphate blend from TPC. Recommendeddosage was 5 mg/L as product, with maximum/minimum dosages of2.5 and 7.5 mg/L respectively. Actual use estimated annual chemicalcost varies from a minimum of $975,000 to a maximum of$2,925,000.d. TG 10 - a zinc-sodium polyphosphate from Calgon Corp., Pittsburgh.Recommended dosages were a minimum 1 mg/L and a maximum 2.5mg/L. It comes in dry form, and batching must be done every day asthe solution becomes unstable after 24+ hours; therefore, much higherhandling costs could be anticipated. Actual use estimated annualchemical cost varies from a minimum of $1,940,000 to a maximum of$4,850,000.e. Type N Sodium Silicate  - a blend of sodium oxide and silicate in a ra-tio of 1:3.22 sodium to silicate. It is available in liquid form at 28.7percent silicate from National Silicates Limited. Recommendedmaximum/minimum dosages were 8 mg/L and 15 mg/L respectivelyas Si02. Estimated actual use annual chemical costs vary from aminimum of $2,405,000 to a maximum of $4,510,000.In addition to annual chemical costs there were a few other things that were con-sidered in making the final selection of the inhibitors that would be used in this study:• Capital Costs - for Virchem 932, 939 and TPC 223 were expected tobe approximately the same. To use Calgon's TG 10, the capital costscould be double or more because it comes in dry form. Due to thesignificantly higher feed rates, the capital costs associated with sodiumsilicate feeding could also be higher.42• Past Success - Past studies have demonstrated mixed results with all ofthese inhibitors. Essentially, each water tends to react in a unique waywith different inhibitors. The only way to ascertain their effectivenessis through exhaustive testing with the water being studied. Of the fivechemicals on the short list, zinc orthophosphate appeared to offer themost consistent results with waters similar to those of the GVWD. Al-though the manufacturer was interested in seeing TPC 223 tested, theyhad little confidence of success with that product in GVWD water.• Microbial Regrowth Potential - With the exception of sodium silicate,all of the inhibitors could cause regrowth problems due to their phos-phate content. The GVRD lab was asked to monitor bacterial growthduring inhibitor testing so that an evaluation of the regrowth risk couldbe made. Since zinc is a bactericide, it could serve as an offset to acertain extent, but the potential effect of additional zinc to sewagetreatment facilities and receiving waters must be assessed, as dis-cussed.• Feed System Operation And Maintenance - Costs should be about thesame for Virchem 932, 939 and TPC 223. Due to Calgon's TG 10being in dry form and the requirement for daily batching, operationand maintenance costs and problems would likely be significantlyhigher with its use. Because of the higher feed requirements, andcaking and blockage problems frequently associated with their feedlines, it is possible that operation and maintenance costs would behigher for silicates as well.Due to the limited number of loops available at the Seymour test facility, therewas no way that all the inhibitor chemicals could be evaluated at one time. In fact, evena single chemical could not be fully evaluated in one study.43Initially, the following two configurations were considered:a. Three Inhibitors• Loop 1 - Control; raw water• Loop 2 - Treated control; pH 8, alkalinity 20 mg/L• Loop 3 - pH 8, alkalinity 20, Inhibitor #1 @ minimum dose• Loop 4 - pH 8, alkalinity 20, Inhibitor #1 @ maximum dose• Loop 5 - pH 8, alkalinity 20, Inhibitor #2 @ minimum dose• Loop 6 - pH 8, alkalinity 20, Inhibitor #2 @ maximum dose• Loop 7 - pH 8, alkalinity 20, Inhibitor #3 @ expected inhibiting doseThis setup could be used to test the three most favored inhibitors, but the resultswould not be conclusive and more testing would still be required.b. Single Inhibitor• Loop 1 - Control; raw water• Loop 2 - Treated control; pH 8, alkalinity 20 mg/L• Loop 3 - Raw water, inhibitor @ minimum dose• Loop 4 - Raw water, inhibitor @ maximum dose• Loop 5 - pH 8, alkalinity 20, inhibitor @ minimum dose• Loop 6 - pH 8, alkalinity 20, Inhibitor @ maximum dose• Loop 7 - pH 7, alkalinity 20, Inhibitor @ expected inhibiting doseThis setup could be used to test the single most favored inhibitor. Again moretesting would likely be required, even with that one inhibitor.If the objective of this study was to obtain as much information as possible aboutthe effect of various inhibitors on GVWD waters, then the three inhibitor setup could beused in the following specific form:• Loop 1 - Control; raw water• Loop 2 - Treated control; pH 8, alkalinity 20 mg/L• Loop 3 - pH 8, alkalinity 20, Virchem 939 @ 1.5 mg/L44• Loop 4 - pH 8, alkalinity 20, Virchem 939 @ 4.5 mg/L• Loop 5 - pH 8, alkalinity 20, Sodium silicate @ 8 mg/L• Loop 6 - pH 8, alkalinity 20, Sodium silicate @ 15 mg/L• Loop 7 - pH 8, alkalinity 20, TPC 223 @ 5 mg/LOn the other hand, if the goal was to begin using an inhibitor as soon as possible,then probably the Virchem 939 should be tested using the single inhibitor setup.Virchem 939 appeared to be the logical choice for the following reasons:• based on the literature search, zinc orthophosphates appeared to offer the bestpotential as inhibitors in GVWD type water;• zinc orthophosphates appeared to be the most economical and Virchem 939appeared to be the least expensive in all respects;• with Virchem 939's higher phosphate content, it would represent a "worstcase" in terms of zinc orthophosphate impact on bacterial regrowth;• if the tests proved successful, it may be possible to initiate the use of this in-hibitor in the distribution system, and carry on with testing of other inhibitors;then if another inhibitor is found to be more effective, it is likely that a switchcould be made with very little disruption;• other studies have shown zinc orthophosphates to be more effective at con-trolling corrosion than pH adjustment; there may be a better way to controlcorrosion than adjusting pH to 8 and alkalinity to 20 mg/L and then addinginhibitors.In the end, a compromise was arrived at and the decision was made to set up theexperiment to test Virchem 939, sodium silicate, and TPC 223 as follows:• Loop 1 - Control; raw water;• Loop 2 - Treated control; pH 8, alkalinity 20 mg/L;• Loop 3 - pH 8, alkalinity 20, TPC 223 @ 5 mg/L;• Loop 4 - pH 8, alkalinity 20, Sodium silicate @ 12 mg/L;45• Loop 5 - pH 8, alkalinity 20, Virchem 939 @ 1.5 mg/L;• Loop 6 - pH 8, alkalinity 20, Virchem 939 @ 4.5 mg/L; and• Loop 7 - pH 7.5, alkalinity 10-12, Virchem 939 @ 4.5 mg/L.The plant configuration was set up as per Figure 3.1. Heavier emphasis was be-ing placed on the Virchem 939 for the reasons discussed above. At the same time, therecould be no way of determining whether or not sodium silicates or a silicate/phosphateblend are effective in GVWD waters without some form of actual testing. Thus, to pre-clude putting all faith in only one inhibitor which may not work, this compromise ap-peared to be the most acceptable.In addition to the above treatments, the water to Loops 2 through 7 was to bedisinfected with chloramines at 2.5 mg/L since, at the time, the plan was for GVWD toswitch to chloramine for secondary disinfection within a few years and it was desired toget as close to a real simulation as possible. Slaked lime [Ca(OH)2] and sodium bicar-bonate (NaHCO3) were to be used for pH and alkalinity adjustment respectively. TheSi02 raised the pH of Loop 4 well above 9 so HC1 was injected to bring it down to 8.3.2 Pilot Plant Physical DescriptionThe pilot plant (see schematic, Figure 3.1) is located at Seymour Dam at the baseof Seymour Lake. The raw water source is Seymour Lake. Water pressure was reducedand regulated permitting constant pressure in the pilot plant. An electronic timer permit-ted automatic operation on a 24 hour basis, but manual operation was also possible.Chemical feed solutions were stored in plastic vats and were delivered by Masterflex L/S46FFigure 3.1 - Seymour Pilot Plant Schematic47peristaltic pump heads using Norprene tubing and driven by model L-07520-25 variablespeed drives5 to injection ports at appropriate doses for the desired treatments. Static, in-line mixers were located downstream of the injection ports to ensure rapid mixing.3.2.1. Pipe Coupon InsertsEach loop contained four pipe insert assemblies, as shown in Figure 3.2; thesewere modified versions of the Illinois State Water Survey Test Assembly (ASTMD2688-83, Method C). The first two assemblies of each loop held two - 4 inch lengthsof 1 inch (inner) diameter cast iron pipe and the second two assemblies held two - 4 inchlengths of 1 inch diameter CDAl22L copper pipe. The inserts were machined to fit theassemblies and to minimize flow distortions so as to reduce the chance of increased cor-rosion due to induced turbulence. The inserts were coated with epoxy on the outer sur-faces and edges to limit corrosion to interior surfaces. They were wrapped in desiccanttreated paper and sealed in a plastic container until ready for use. All coupons were infresh machined condition with no visible evidence of corrosion at the time of insertion inthe assemblies.63.2.2. Lead Soldered Copper Plumbing CoilsAs a simulation of household plumbing systems, each loop had 84 feet (25.6 metres) ofhalf inch (12.5 mm) soft copper tubing coils downstream of the coupon inserts. Thecoils were joined every 4 feet (1.22 metres) with 50/50 lead-tin solder which was typi-cally used in premises plumbing until recently when the building code was changeddisallowing its use. Flow through the coils was set such that the velocity was about 2.6ft/sec (0.79 m/s) which is typical for household plumbing. Water could be isolated in thecoils for any amount of time desired to simulate water standing in a household overnight5Purchased from Cole Panner Instrument Company, Chicago.6The inserts and assemblies were purchased from Metal Samples Co., Inc., Munford, AL.48Pipe Coupon Inserts and Assemblyor longer. Metals content in samples taken from the standing water were used to give anindication of the relative corrosiveness of the treatments in each loop.3.2.3. Lead/Tin Solder CoilsPlastic canisters holding coils of approximately 500 g of 50/50 lead/tin solderwere installed immediately downstream of the plumbing coils. When water was flowingit circulated through the solder coils and the coils were submerged at all times. The can-isters could be isolated to produce standing water samples in contact with the solder.Lead concentrations in the standing water samples were used to indicate the relative leadmobilization in each treatment water.493.2.4. Brass FaucetsA two handled cast brass mixing faucet (manufactured by EMCO Canada Ltd.)was installed at the outlet of each loop. Again, water could be isolated in the faucets togive a standing sample for metals analysis.3.2.5. Granular Activated Carbon (GAC) FiltersDue to the location of a fish hatchery a few hundred yards downstream of thedam, it was imperative that the chloramine be removed from the water prior to dischargefrom the pilot plant. All loops except the raw water loop discharged to vats containingGAC and periodically the water draining from the GAC filters was checked for totalchlorine content. The design of the GAC filters permitted flow reversal for backwashingwhen required.3.3 Modifications to the Existing Pilot PlantThe same pilot plant that EES used for their study (1990) was used for this study.A few modifications were made as follows:The existing 75 feet (22.9 metres) of three quarter inch (19 mm) copperplumbing coils which were soldered every 12 feet (3.66 metres) were replacedwith new half inch (12.5 mm) pipe soldered every 4 feet (1.22 metres) sincethe intention was to simulate household plumbing (which normally consists ofhalf inch pipe). Soldering every 4 feet (1.22 metres), may seem a bit extreme,but the lead levels from the plumbing coils in the EES study were so low thatvalid comparisons between the various treatments were difficult to make. Itwas hoped that the increased lead exposure would increase the absolute leadlevels in the water and make the differences between the various treatmentmethods more obvious.• So that the flow velocity through the plumbing coils would still be similar towhat could be expected in household plumbing [2.6 ft/sec (0.79 m/s) as in the50EES study], bypass lines were installed upstream of the plumbing coils andthe flow through the bypass lines was adjusted accordingly.• In order to ensure that chloramine feed would be equal in Loops 2 to 6, themain water line to the pilot plant was modified so that Na0C1 and NH4OHwere injected upstream of these loops. A check valve was installed upstreamand a static mixer was installed downstream of the injection points. A branchline for Loop 1 (raw water control) was installed upstream of the check valveon the main.• Similarly, the main was also modified downstream of the chloramine staticmixer so that NaHCO3 was injected upstream of Loops 2 through 6. Again acheck valve and a static mixer were installed upstream and downstream of theinjection point and a branch line for Loop 7 was installed upstream of thecheck valve.• The faucets on all loops were replaced with new ones.• Copper and mild steel resistance (Corrosometer) probes7 were installed oneach loop. These probes were used to measure corrosion on a weekly basis.The principle behind their use is that as the probe corrodes, the resistance in-creases and the increased resistance correlates to corrosion rate. Althoughlinear polarization methods are generally accepted as being superior for ongo-ing electrical measurment of corrosion rates, the low conductivity of the water(11 to 15 [tS/cm) precluded their use in this experiment. It would have beenpreferable to use cast iron probes as opposed to mild steel, but cast ironprobes could not be obtained. In fact, due to attempts to obtain cast ironprobes and finally abandoning the search, the probes that were used were notinstalled until May, six weeks after the experiment started.7Purchased from Rohrback Cosasco Systems, Santa Fe Springs, CA.513.4 Operation ProceduresWater flow through the pilot plant was normally controlled by an electrically op-erated ball valve although it could also be controlled manually as stated. The valve wascontrolled by an electronic timer which allowed four on and off cycles daily. The follow-ing schedule was used:0800 - 1000 Valve open, water flowing for 2 hours.1000 - 1300 Valve closed, no flow for 3 hours.1300 - 1400 Valve open, water flowing for 1 hour.1400 - 1700 Valve closed, no flow for 3 hours.1700 - 1900 Valve open, water flowing for 2 hours.1900 - 2300 Valve closed, no flow for 4 hours.2300 - 2400 Valve open, water flowing for 1 hour.2400 - 0800 Valve closed, no flow for 8 hours.Thus water flowed for a total of 6 hours each day. The intention was to simulate house-hold use but the simulation was limited by the capability of the timer. Water flowing at2.6 ft/sec (0.79 m/s) through the half inch (12.5 mm) plumbing coils represents a flowrate of 1.59 US gpm or 573 US gal in six hours (6 L/min or 2,166 L in six hours). For afamily of 4 that would amount to 143 US gal (541 L) per person per day which is not un-reasonable.The total flow rate starting out through each loop was 15 L/min, which resulted ina velocity of about 1.5 ft/sec (0.46 m/s) through the pipe coupons. This was the same asthat used in the EES study and midway between the velocities used in corrosion controlstudies done in Seattle and Portland (EES, 1990).3.4.1. Daily RoutineThe daily routine in the pilot plant consisted of the following:• Flow in each loop was checked and globe valves adjusted as required.52• 1 L flowing water samples were taken from each loop.• Temperature of each sample was measured immediately as it was drawn.• Total chlorine of each sample was measured using a Wallace and TiernanAmperometric Titrator following Standard Methods, 17th Edition (APHA etal., 1989), 4500-C1 D, "Amperometric Titration Method".• 150 ml portions of each sample were brought to 25°C by immersion in awater bath.• A Hanna Model 8733 conductivity meter was calibrated at 25°C and thenconductivity was measured at 25°C. Calibration and measurement procedureswere in accordance with the owner's manual.• A Horiba Model D-13 pH meter was calibrated using 3 standards at 25°C andthen the pH of each sample was measured at 25°C. Calibration and measure-ment procedures were in accordance with the owner's manual.• Alkalinity of each sample was determined at 25°C in accordance with Stan-dard Methods, 17th Edition (APHA et al., 1989), 2320 B "Titration Method",5.b. "Potentiometric titration of low alkalinity".3.4.2. Weekly RoutineIn addition to the daily routine, the following procedures were carried out on aweekly basis:• 500 ml samples were taken from each loop and brought to the UBC environ-mental lab for silica determination in accordance with Standard Methods,17th Edition (APHA et al., 1989), 4500-Si F "Automated Method forMolybdate-Reactive Silica". This was used to monitor the silica levels inLoops 3 and 4 to ensure inhibitor dosages were in line. There was no meansof measuring 5i02 in the pilot plant.53• 300 ml samples were taken from each loop in glass BOD bottles that hadpreviously been rinsed with hot 10 percent HC1. The samples were immedi-ately acidified with 0.3 ml of concentrated HC1 to give a 0.1 percent HC1 ma-trix. They were taken to the UBC environmental lab where phosphorus wasmeasured in accordance with Standard Methods, 17th Edition (APHA et al.,1989), 4500-P F "Automated Ascorbic Acid Reduction Method". This wasused to monitor the phosphorus levels in Loops 3, 5, 6 and 7 since there wasno means of measurement available in the pilot plant.• Beginning on 8 May 92, a week after they were installed, Corrosometerreadings were taken on each probe using a model CK-3 Corrosometer Instru-ments.3.4.3. Batching of ChemicalsThe following procedures were carried out for the batching of chemicals on amore-or-less weekly basis as required:• Sodium Silicate - The concentrate contained 28.7 percent Si02 and was di-luted 100:1 to give a vat concentration of 2870 mg/L. Normally 1 L of con-centrate was added to the vat and then 99 L of water was added via a hose atfairly high pressure which allowed good mixing• TPC 223 - The specific gravity of the concentrate was 1.35 and the vat con-centration was 2000 mg/L as product, so the required dilution was 675:1.Normally enough new chemical was batched to bring the total in the 120L vatto 100 - 110 L. The required amount of concentrate was added to the vat andthen the required water was added with good mixing.• Virchem 939 - The specific gravity of the concentrate was 1.40 and the vatconcentration was 2500 mg/L as product, so the required dilution was 560:1.8Purchased from Rohrback Cosasco, Santa Fe Springs, CA.54Normally enough new chemical was batched to bring the total in the 220 Lvat to 180 - 190 L. The required amount of concentrate was added to the vatand then the required water was added with good mixing.• Slaked Lime - Normally 400 L was mixed at a time in the 600 L mixing vat.Water was added to bring the level in the mixing vat up to 500 L. The vatconcentration was 1000 mg/L and the powdered lime was about 95 percentpure, so the required weight of lime for 400 L of water was 400/0.95 = 421 g.The lime was weighed out and ground up in a blender so that it was a veryfine powder to make it easier to dissolve. An electric mixer was used fordissolving the lime but, due to its low solubility the mixer was run for abouttwo days for each batch. Following mixing, the remaining particulate matterin the mixing vat was allowed to settle for another day before the solution wastransferred to the feed vat. Lime only had to be batched about once everythree weeks.• Sodium Bicarbonate - Normally 300 L was mixed at a time in the 400 Lmixing vat. The vat concentration was 30,000 mg/L and the NaHCO3 wasreasonably pure so the required weight of bicarbonate was 9000 g for 300 Lof water. After the bicarbonate and water were added to the vat, an electricmixer was run for several hours to dissolve the bicarbonate.• Ammonia - The vat solution strength was 1,334 mg/L. Normally enough newchemical was batched to bring the total in the 220 L vat to 180 - 190 L. Thestrength of the ammonium hydroxide concentrate 9 was determined inaccordance with Standard Methods, 17th Edition (APHA et al., 1989), 4500-NH3 "Titrimetric Method". The required amount of concentrate and waterwere then added to the vat with good mixing. The strength of the newsolution was then determined again using the titrimetric method. The strength9Reagent grade, percentage impurity was negligible for the purposes of this study.55of the vat solution was adjusted if required and remeasured; and this processwas repeated until the required strength was reached.• Sodium Hypochlorite - The vat solution strength was 4,000 mg/L. Normallyenough new chemical was batched to bring the total in the 220 L vat to 180 -190 L. The strength of the hypochlorite concentrate9 was determined inaccordance with Standard Methods, 17th Edition (APHA et al., 1989), 4500-Cl "Iodometric Method". The required amount of concentrate and water werethen added to the vat with good mixing. The strength of the new solution wasthen determined again using the iodometric method. The strength of the vatsolution was adjusted if required and remeasured; and this process wasrepeated until the required strength was reached.• Hydrochloric Acid9 - a 1 percent solution was batched as required.3.4.4. Metals Sampling RoutineThe routine outlined herein was undertaken weekly for the first 3 months, bi-weekly for the next 6 months and monthly for the last three months.• Copper Plumbing Coils - The outlet valves on the plumbing coils were closedwhile the water was still flowing and then the valves on the bypass lines wereclosed to isolate water in the coils. At this time the plant was shut down for a24 hour period by opening the main circuit switch which controlled the mainelectrically actuated ball valve and the chemical feed pumps. After the 24hours the main circuit switch was closed and plant operations restarted. Priorto opening the outlet valves, 1 L and two - 500 ml samples were taken fromthe stopcock on each plumbing coil. Then the outlet valves and the valves onthe bypass lines were opened. The 1 L samples were used for temperature,total chlorine, conductivity, pH, and alkalinity measurement as per the dailyroutine. The 500 ml samples were used for measurement of metals content.56• Lead/Tin Solder Coils - At the same time as water was isolated in the plumb-ing coils, it was also isolated in the canisters containing the lead/tin soldercoils by closing the inlet and outlet valves to the canisters. After the 24 hourstanding period, the canisters were removed and the water was divided be-tween two containers. One container which held about 750 ml was used fortemperature, total chlorine, conductivity, pH, and alkalinity measurement asper the daily routine. The other container which held about 250 ml was usedfor metals measurement. The canisters were then reattached and the inlet andoutlet valves reopened.• Brass Faucets - After the standing water samples had been taken from theplumbing and solder coils, the faucets were turned off and the valves leadingto them were closed, isolating about 500 ml of water between the valves andthe faucet outlets. Then the faucet bypass lines were opened so that plant op-eration could continue. 24 hours later 250 ml and 1 L samples were takenfrom each faucet. The 250 ml samples were for metals analysis and the 1Lsample was for temperature, total chlorine, conductivity, pH, and alkalinitymeasurement as per the daily routine.Samples for metals analysis were all subjected to the following procedures:• All samples were acidified with concentrated nitric acid to a 2.5 percent ma-trix in the pilot plant.• The samples were transported to the UBC environmental lab where they wereanalyzed for copper, zinc, and higher lead levels on a Thermo Jarrel AshVideo 22 Atomic Absorption Spectrophotometer in accordance with StandardMethods, 17th Edition(APHA et al., 1989), 3111 B "Direct Air-AcetyleneFlame Method". The low level lead samples were measured on a Perkin-Elmer HGA-500 graphite furnace Atomic Absorption Spectrophotometer in57accordance with Standard Methods, 17th Edition (APHA et al., 1989), 3113 B"Electrothermal Atomic Absorption Spectrometric Method".At the beginning of the experiment, the pilot plant was run for some time withraw water through all loops. Then, on a number of days, 24 hour standing raw watersamples were taken from the plumbing coils, solder coils, and the faucets. These sampleswere acidified and the metals levels measured in order to provide a datum from which tocompare metals content once the inhibitor treatment started. The detailed results of thesemeasurements are presented in Appendices A through I.In order to ensure that the chance of contamination was minimized, a strict sam-ple bottle preparation routine was followed. The bottles were machine washed with soapand then given a deionized rinse. They were then filled with 10 percent nitric acid andallowed to stand for a minimum of 24 hours. Finally, they were thoroughly rinsed withdeionized water, capped and labeled.3.4.5. Cast Iron and Copper CouponsThe cast iron and copper coupon corrosion rates were measured over the courseof 12 months. At 3 month intervals, one copper and one cast iron pipe insert was re-moved from each set of four copper and four cast iron inserts in each treatment loop andreplaced with a new insert of the same type (except at 12 months when all coupons wereremoved and the experiment was terminated). Thus, the final set included of couponsexposed for 3, 6, 9, and 12 months, providing replicates of the 3, 6, and 9 exposures al-though for different times of the year. The initial installation date was 15 March 1991,with changes occurring on 17 June, 16 September, 18 Dec, and 16 March 1992.As each coupon was removed, swabs of the interior biofilm were taken by GVRDlaboratory staff for coliform measurement and heterotrophic plate count in the lab. Theremoved inserts were sent to Kennedy Jenks in San Francisco, where they were measuredfor weight loss and pitting corrosion in accordance with the procedures in ASTM D2688-5883, Method C. Kennedy Jenks were also employed for the same purpose in the EES(1990) study.3.5. Quality ControlAs a means of verifying the phosphorus, silica, and metals measurements done inthe UBC lab, one sample from each weekly seven sample set taken for silica analysis andphosphorus analysis was sent to the GVRD lab for analysis for the same compounds.Also one sample from each of the plumbing coils, lead/tin solder coils, and faucet setswere submitted to the GVRD lab for metals analysis.594. RESULTS AND DISCUSSION4.1. Pipe Coupon InsertsThere are two main data sets associated with the coupon analyses: corrosion interms of weight loss and pitting corrosion.4.1.1. Copper Coupon InsertsA summary of the results from the laboratory data sheets from Kennedy Jenks areincluded at Appendix A.4.1.1.1. Copper Coupon Weight Loss RatesThe copper coupon weight loss rates are expressed in terms of equivalent rates ofpenetration in mm/yr as summarized in Table 4.1.For the 3, 6, and 9 month exposure periods there were two sets of coupons. Es-sentially the only water quality difference between one set and another was one of tem-perature. This difference is apparently significant in all but the raw water loop and pos-sibly Loop 5. With some exceptions, the data show, a fairly consistent pattern of lowercorrosion rates under the colder water conditions which is in keeping with expectations.Figures 4.1 and 4.2 represent the data graphically. The 3, 6 and 9 month plots in Figure4.1 are averages for two measurements. Some significant trends that are apparent fromthe data and graphs are:• All treatments (Loops 2 through 6) resulted in a reduction in corrosion rate.The 12 month rate for Loop 2, the pH and alkalinity adjusted loop, showed a35 percent improvement over that of the raw water. The 12 month rate forLoops 6 and 7, that received the zinc orthophosphate treatment at the higherdose, showed 77 percent improvement over that of the raw water, and 66 per-cent improvement over the rate for Loop 2.60Copper Coupon Corrosion Rates (mm/yr)*ExposureTimeLoop Number1 2 3 4 5 6 73 Months (a) 0.0134 0.0167 0.0161 0.0095 0.0075 0.0046 0.00753 Months (2) (b) 0.0161 0.0075 0.0108 0.0049 0.0106 0.0042 0.00846 Months (c) 0.0130 0.0105 0.0117 0.0073 0.0054 0.0036 0.00696 Months (2) (d) 0.0149 0.0087 0.0107 0.0060 0.0064 0.0022 0.00519 Months (e) 0.0127 0.0083 0.0091 0.0060 0.0059 0.0035 0.00379 Months (2) (f) 0.0134 0.0075 0.0073 0.0047 0.0052 0.0030 0.002812 months (g) 0.0111 0.0072 0.0075 0.0046 0.0045 0.0024 0.0025Copper Coupon Average Corrosion RatesExposureTimeLoop Number1 2 3 4 5 6 73 Months 0.0148 0.0121 0.0135 0.0072 0.0091 0.0044 0.00806 Months 0.0140 0.0096 0.0112 0.0066 0.0059 0.0029 0.00609 Months 0.0131 0.0079 0.0082 0.0054 0.0056 0.0033 0.003312 months 0.0111 0.0072 0.0075 0.0047 0.0045 0.0024 0.0025(a) Exposed 15/03/91 to 17/06/91(warm)^(e) Exposed 15/03/91 to 18/12/91(warm)(b) Exposed 18/12/91 to 16/03/92 (cold)^(1) Exposed 17/06/91 to 16/03/92 (cold)(c) Exposed 15/03/91 to 16/09/91(warm)^(g) Exposed 15/03/91 to 16/03/92(d) Exposed 16/09/91 to 16/03/92 (cold)*Analysis in accordance with ASTM D 2688-83, Method C.Table 4.1 - Copper Coupon Corrosion Rates613 6^ 9^12Figure 4.1 - Corrosion Rates of Copper Coupon InsertsBased on Weight Loss Measurements0.0140.0120.010ai0.008Cl)2^0.006800.0040.0020.000Duration of Exposure, months- Loop 1 - Control^=Loop 2 - pH & Alk Only^- Loop 3 - TPC 223, 5 mg/L^—Loop 4 - Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L - -Loop 6- V939, 4.5 mg/L, pH 8 —Loop 7- V939, 4.5 mg/L, pH 7.5Figure 4.2 - Corrosion Rates of Copper Coupon InsertsBased on Weight Loss Measurements• In all loops, the corrosion rate decreased with time. These lower corrosionrates can be attributed, in part, to protective scale formation which will occureven in raw water. The difference between the raw water and the treatedloops is a combination of less aggressive environment (higher pH andalkalinity) and an even better protective scale formed in Loops 4 through 7.• The results for Loops 6 and 7 show that, when zinc orthophosphate is used asan inhibitor, good results may be obtained at a pH and alkalinity lower than 8and 20 mg/L, respectively. This, in fact, corroborates numerous other studiesthat have been done with zinc orthophosphate. The supplier, TPC, recom-mends a pH range of 6.5 to 8.5 with the optimum at 7.5.4.1.1.2. Copper Coupon Insert Pitting Analyses The most important results from the pitting analyses (see the summary of the datasheets at Appendix A) are summarized in Table 4.2. The average and maximum pitdepths are the actual observed data, while the nominal pitting rates were calculated bydividing the observed pit depths by the exposure time in years. These data are plotted inFigures 4.3 and 4.4.Some significant trends which can be observed from the data and graphs are:• All treatments (Loops 2 through 6) resulted in a reduction in pitting rate.The 12 month rate for Loop 2, the pH and alkalinity adjusted loop, showed a40 percent improvement over that of the raw water. The 12 month rate forLoops 5, 6 and 7, which received the zinc orthophosphate treatment, showed75 percent improvement over that of the raw water, and 58 percent improve-ment over the rate for Loop 2. It is interesting how close these figures are tothose for the weight loss data.64Copper Coupon Pitting Analysis*Pit Depths (mm)Loop#3 Months 6 Months 9 Months 12 MonthsAvg Max Avg Max Avg Max Avg Max1 0.0088 0.0140 0.0047 0.0051 0.0038 0.0051 0.0152 0.02032 0.0053 0.0104 0.0032 0.0046 0.0036 0.0051 0.0089 0.01223 0.0050 0.0071 0.0034 0.0051 0.0036 0.0051 0.0079 0.01044 0.0037 0.0053 0.0038 0.0041 0.0038 0.0071 0.0064 0.00865 0.0039 0.0053 0.0029 0.0043 0.0034 0.0051 0.0043 0.00516 0.0038 0.0053 0.0025 0.0036 0.0034 0.0053 0.0041 0.00517 0.0036 0.0053 0.0030 0.0046 0.0032 0.0051 0.0038 0.0051Nominal Pitting Rate (mm/yr)Loop 3 Months 6 Months 9 Months 12 MonthsAvg Max Avg Max Avg Max Avg Max1 0.0351 0.0559 0.0094 0.0102 0.0051 0.0068 0.0152 0.02032 0.0213 0.0417 0.0064 0.0091 0.0047 0.0068 0.0089 0.01223 0.0198 0.0284 0.0069 0.0102 0.0047 0.0068 0.0079 0.01044 0.0147 0.0213 0.0076 0.0081 0.0051 0.0095 0.0064 0.00865 0.0157 0.0213 0.0058 0.0086 0.0046 0.0068 0.0043 0.00516 0.0152 0.0213 0.0051 0.0071 0.0046 0.0071 0.0041 0.00517 0.0142 0.0213 0.0061 0.0091 0.0042 0.0068 0.0038 0.0051*Analysis in accordance with ASTM D 2688-83, Method C.Table 4.2 - Copper Coupon Pitting Analysis65Figure 4.3 - Average Nominal Pittting Rates of Copper Coupon InsertsAnalysis in accordance with ASTM D 2688-83, Method C.Figure 4.4 - Maximum Nominal Pittting Rates of Copper Coupon InsertsAnalysis in accordance with ASTM D 2688-83, Method C.• Pitting rates appear to decrease with exposure time for all loops for the first 9months. However, from 9 to 12 months the pitting rates in a few of the loopsbegin to increase again, particularly in the raw water loop. This may be anindication of some localized pitting taking place which is supported by the de-scriptions in the laboratory analysis sheets which most often described thepitting as "irregular".• The results for Loops 5, 6 and 7 show that it may be possible to obtain goodcorrosion protection at a zinc orthophosphate dosage lower than 0.37 mg/L asP and Zn., and/or a pH and alkalinity lower than 8 and 20 mg/L, respectively.Table 4.3 is presented as a summary comparing the relative copper corrosivity ofthe various treatments to that of raw water.The relative corrosion rates in Table 4.3 could be used to estimate the expectedservice life of copper pipe under different water quality conditions. For example, therelative corrosivity of GVWD water at pH 8, alkalinity 20 mg/L, 2.5 mg/L of chlo-ramine, and zinc orthophosphate at 0.37 mg/L as zinc and 0.37 mg/L as phosphorus, is0.25 times that of raw water. Thus, the expected service life for copper exposed to thiswater could be approximately 1.00/0.25 = 4 times greater than that expected with rawwaterlo.1°In Greater Vancouver currently, the life of domestic copper piping is typically 20-35 yearswith some failures as early as 3-10 years. Many commercial hot water recirculating systems systemsrequire replacement after 12-15 years (AWWARF, 1989).68Copper Coupon Relative Corrosion Rates*Loop#12 MonthThinningRate(mm/yr)ThinningRateRelative toRaw Water12 MonthPitting Ratemm/yrPitting RateRelative toRaw WaterAveragePenetrationRate(mm/yr)**AveragePenetrationRelative toRaw WaterAvg Max Avg Max1 0.0111 1.00 0.0152 0.0203 1.00 1.00 0.0132 1.002 0.0072 0.65 0.0089 0.0122 0.58 0.60 0.0080 0.613 0.0075 0.68 0.0079 0.0104 0.52 0.51 0.0077 0.584 0.0047 0.42 0.0064 0.0086 0.42 0.43 0.0055 0.425 0.0045 0.41 0.0043 0.0051 0.28 0.25 0.0044 0.336 0.0024 0.22 0.0041 0.0051 0.27 0.25 0.0032 0.257 0.0025 0.23 0.0038 0.0051 0.25 0.25 0.0032 0.24*Analysis in accordance with ASTM D 2688-83, Method C.**Average of the average pitting rate and the thinning rate.Table 4.3 - Copper Coupon Relative Corrosion Rates4.1.2. Cast Iron Coupon InsertsThe results from the laboratory data sheets from Kennedy Jenks are summarizedat Appendix B.4.1.2.1. Cast Iron Coupon Weight Loss RatesThe cast iron coupon weight loss rates are expressed in terms of equivalent ratesof penetration in mm/yr as summarized in Table 4.4.As was the case with the copper coupons, for the 3, 6, and 9 month exposure pe-riods, there were two sets of cast iron coupons with the only water quality difference69between sets being the temperature. The difference, this time, appears to be negligible,however, as there is no apparent trend differentiating the corrosion rates for the warmerand colder temperatures. Except for Loops 1 (raw water) and 6 (zinc orthophosphate,higher dosage), any differences are inconsistent.Figures 4.5 and 4.6 represent the weight loss data graphically. The 3, 6, and 9month plots in Figure 4.5 are averages for two measurements. These results are lessconclusive than those for the copper coupons.• Not all treatments show a reduction in 12 month corrosion rate. Loops 2 and5 are slightly higher at 7 and 4 percent, respectively, than the raw water(negligible difference). The best 12 month rate was in Loop 4, the sodiumsilicate treated loop, which showed a 26 percent improvement over the rawwater and a 30 percent improvement over that of Loop 2. The overall poorperformance may very well be a consequence of attempting to maintain a pHin the low buffer capacity 8 to 8.5 range, offsetting any beneficial effect of thephosphate and silicate inhibitors. This could be an indication that, in terms ofcast iron corrosion, pH is a more important factor than the addition of inhibi-tors.• With a few exceptions, the corrosion rates decreased with time. Loops 3 and7 showed slight increases from the 3 to the 6 month measurement levels,Loop 5 showed an increase from the 6 month to the 9 month levels, and Loop2 increased from the 9 to the 12 month measurements, but these increaseswere negligible. Over all, corrosion rates decreased from the 3 to the 12month measurements. The most dramatic improvement was in Loop 1, rawwater, a decrease of 41 percent; this could be due to a combination of natu-rally occurring protective scale and possibly lower water temperature duringthe latter part of the experiment.70Cast Iron Coupon Corrosion Rates (mm/yr)ExposureTimeLoop Number1 2 3 4 6 73 Months (a) 0.314 0.185 0.196 0.206 0.211 0.242 0.1943 Months (2) (b) 0.252 0.249 0.187 0.227 0.187 0.233 0.1616 Months (c) 0.255 0.182 0.224 0.213 0.131 0.225 0.2396 Months (2) (d) 0.183 0.219 0.197 0.205 0.214 0.190 0.1719 Months (e) 0.224 0.180 0.165 0.156 0.208 0.170 0.1689 Months (2) (f) 0.181 0.191 0.168 0.159 0.192 0.165 0.17112 months (g) 0.181 0.193 0.167 0.135 0.189 0.150 0.159Cast Iron Coupon Average Corrosion RatesExposureTimeLoop Number1 2 3 4 5 6 73 Months 0.283 0.217 0.192 0.216 0.199 0.238 0.1786 Months 0.219 0.201 0.210 0.209 0.173 0.208 0.2059 Months 0.202 0.186 0.167 0.158 0.200 0.167 0.16912 months 0.182 0.194 0.167 0.135 0.190 0.151 0.160(a) Exposed 15/03/91 to 17/06/91(warm)(b) Exposed 18/12/91 to 16/03/92 (cold)(c) Exposed 15/03/91 to 16/09/91(warm)(e) Exposed 15/03/91 to 18/12/91(warm)(f) Exposed 17/06/91 to 16/03/92 (cold)(g) Exposed 15/03/91 to 16/03/92(d) Exposed 16/09/91 to 16/03/92 (cold)*Analysis in accordance with ASTM D 2688-83, Method C.Table 4.4 - Cast Iron Coupon Corrosion Rates713 96 120.300.270.150.12- Loop 1 - ControlNs Loop 2- pH & Alk Only- Loop 3- TPC 223, 5 mg/L— Loop 4- Sodium Silicate, 12 mg/LLoop 5- V939, 1.5 mg/L- - Loop 6- V939, 4.5 mg/L, pH 8— Loop 7 - V939, 4.5 mg/L, pH 7.5Figure 4.5 - Corrosion Rates of Cast Iron Coupon InsertsBased on Weight Loss MeasurementsDuration of Exposure, months-,1w• As an overall observation, it seems obvious, particularly when viewing Figure4.6 and given the margin of error expected in this type of experiment, thatnone of the treatments provided any significant degree of additional protec-tion over that afforded by natural scale formation in the raw water.• Given the results from the copper coupons, the cast iron coupon results appearto mandate further testing of these inhibitors at lower pHs.4.1.2.2. Cast Iron Coupon Insert Pitting AnalysesThe critical results (see Appendix B) pitting analyses are summarized in Table4.5. Again, the average and maximum pit depths are the actual observed data, while thenominal pitting rates were calculated by dividing the observed pit depths by the exposuretime in years. These data are plotted in Figures 4.7 and 4.8.These results show the treatments to be even more questionable in terms of castiron protection.• With the exception of Loop 3, (the sodium silicate/zinc orthophosphate com-bination treated loop) the 12 month average nominal pitting rates in all loopsare higher than that for the raw water. The rate for Loop 4 is 74 percenthigher, and that for Loops 5, 6, and 7 (the loops which showed the lowestcopper pitting rates) the rates are 55, 42, and 53 percent higher, respectively.Without exception, the 12 month maximum nominal pitting rates are higherthan that for the raw water. Loop 6 is 76 percent higher. There are inconsis-tencies, however. For example, the 9 month average and maximum nominalpitting rates for all treatments are lower than the 9 month rates for the rawwater. There is no apparent reason for these inconsistencies. Perhaps, this isan indication of the degree of difficulty that must be involved in providingdata which has a low error level. The preparation of coupons after they are74removed from the water line is, by its very nature, corrosive. How much er-ror does the preparation process introduce? Error level is also increased byvirtue of the fact that, after they are prepared, the examination and measure-ment of the coupons, is a somewhat subjective process. When two parts ofthe same experiment conducted under overlapping conditions yield such dif-ferent results, it means all the results must be viewed with a healthy degree ofskepticism.• Overall, the average and maximum nominal pitting rates decrease with time,but again there are exceptions as can be seen in the graphs.• These results provide further evidence of the need for serious questioning andfurther testing before any of these treatments should be applied in the GVWDdistribution network to control tron corrosion.75Cast Iron Coupon Pitting Analysis*Pit Depths (mm)Loop#3 Months 6 Months 9 Months 12 MonthsAvg Max Avg Max Avg Max Avg Max1 0.071 0.117 0.082 0.093 0.127 0.168 0.097 0.1142 0.037 0.071 0.088 0.109 0.085 0.097 0.124 0.1833 0.037 0.074 0.082 0.094 0.097 0.114 0.091 0.1194 0.076 0.130 0.084 0.099 0.079 0.097 0.168 0.1965 0.076 0.097 0.082 0.084 0.088 0.122 0.150 0.1936 0.048 0.089 0.088 0.099 0.085 0.109 0.137 0.2017 0.046 0.066 0.075 0.079 0.104 0.124 0.147 0.165Nominal Pitting Rate (mm/yr)Loop 3 Months 6 Months 9 Months 12 MonthsAvg Max Avg Max Avg Max Avg Max1 0.284 0.467 0.164 0.186 0.169 0.224 0.097 0.1142 0.147 0.284 0.177 0.218 0.113 0.129 0.124 0.1833 0.149 0.295 0.165 0.187 0.129 0.152 0.091 0.1194 0.305 0.518 0.167 0.198 0.105 0.129 0.168 0.1965 0.305 0.386 0.164 0.168 0.117 0.163 0.150 0.1936 0.193 0.356 0.175 0.198 0.113 0.146 0.137 0.2017 0.183 0.264 0.150 0.157 0.139 0.166 0.147 0.165*Analysis in accordance with ASTM D 2688-83, Method C.Table 4.5 - Cast Iron Coupon Pitting Rates760.320.080.240.16- Loop 1 - Control^=Loop 2 - pH & Alk Only^- Loop 3 - TPC 223, 5 mg/L^— Loop 4 - Sodium Silicate, 12 mg/LLoop 5- V939, 1.5 mg/L - -Loop 6 - V939, 4.5 mg/L, pH 8 —Loop 7- V939, 4.5 mg/L, pH 7.5Figure 4.7 - Average Nominal Pittting Rates of Cast Iron Coupon InsertsAnalysis in accordance with ASTM D 2688-83, Method C.3^6^9^12Time of Exposure, months3 6 9 12Figure 4.8 - Maximum Nominal Piffling Rates of Cast Iron Coupon InsertsAnalysis in accordance with ASTM D 2688-83, Method C.Time of Exposure, months0.600.500.400.300.200.10........-------- ----- Loop 1 - Controlow Loop 2 - pH & Alk Only- Loop 3- TPC 223, 5 mg/L—Loop 4 - Sodium Silicate, 12 mg/L- Loop 5- V939, 15 mg/L- - Loop 6- V939, 4.5 mg/L, pH 8—Loop 7- V939, 4.5 mg/L, pH 7.5Table 4.6 is presented as a summary comparing the relative cast iron corrosivitywith that of raw water.Cast Iron Coupon Relative Corrosion Rates*Loop#12 MonthThinningRate(mm/yr)ThinningRateRelative toRaw Water12 MonthPitting Ratemm/yrPitting RateRelative toRaw WaterAveragePenetrationRate(mm/yr)**AveragePenetrationRelative toRaw WaterAvg Max Avg Max1 0.182 1.00 0.097 0.114 1.00 1.00 0.139 1.002 0.194 1.07 0.124 0.183 1.29 1.60 0.159 1.143 0.167 0.92 0.091 0.119 0.95 1.04 0.129 0.934 0.135 0.74 0.168 0.196 1.74 1.71 0.151 1.095 0.190 1.04 0.150 0.193 1.55 1.69 0.170 1.226 0.151 0.83 0.137 0.201 1.42 1.76 0.144 1.037 0.160 0.88 0.147 0.165 1.53 1.44 0.154 1.10*Analysis in accordance with ASTM D 2688-83, Method C.**Average of the average pitting rate and the thinning rate.Table 4.6 - Cast Iron Coupon Relative Corrosion RatesIf the relative corrosion rates in Table 4.6 were used to estimate the expectedservice life of cast iron under different water quality conditions, a less favorable com-parison would result than that obtained for copper pipe. For example, the relative corro-sivity of GVWD water at pH 8, alkalinity 20 mg/L, 2.5 mg/L chloramine, and zinc or-thophosphate at 0.13 mg/L as zinc and 0.13 mg/L as phosphorus, is 1.22 times that of79raw water. Thus, the expected service life for cast iron exposed to this water could beonly 1.00/1.22 = 82 percent of that expected from exposure to raw water. However,given the margin of error in this experiment, the difference shown in this case is probablystatistically negligible.4.1.2.3. Cast Iron Coupon Scaling RatesThere was extensive build-up of corrosion scale on all the cast iron coupons. Theamount of scaled surface area increased steadily with exposure time until, after 12months, all coupons were 100 percent covered with brown tubercules over black scale.The scale thickness also increased with time. Scaling information from the laboratorydata sheets (Appendix B) is summarized in Table 4.7.As can be seen, the treated loops all have thicker scales and higher scaling ratesthan the raw water. It is also interesting to note that the loops with the thickest scalewere those with the highest relative corrosion rates shown in Table 4.6. These higherscaling rates also have implications in terms of reduction of flow capacity, as mentionedpreviously.80Cast Iron Coupon Relative Scale Build-up*Loop#Scale Thickness (mm)ScalingRate(mm/yr)ScalingRateRelativetoRawWater3 Months 6 Months 9 Months12Months1 0.51 1.02 1.14 1.52 1.52 1.002 0.51 1.27 2.03 3.81 3.81 2.503 0.64 1.27 1.52 2.03 2.03 1.334 0.76 1.71 1.78 2.03 2.03 1.335 0.89 1.02 1.91 3.05 3.05 2.006 0.51 1.27 1.65 2.54 2.54 1.677 1.02 2.92 2.29 3.56 3.56 2.33*Analysis in accordance with ASTM D 2688-83, Method C.Table 4.7 - Cast Iron Coupon Relative Scale Build-up4.2. Corrosometer Probes4.2.1. Copper Corrosometer ProbesThe copper Corrosometer probe data can be found in Appendix C. The formula,provided by the manufacturer, for converting the data to a corrosion rate is:'Corrosion Rate (mm/yr) = A Dial Reading x 0.00927 x Probe SpanA Time (Days)81The Probe Span is a dimensionless constant provided by the manufacturer whichtakes into account the differences in probe types. For the copper Corrosometer probes,the probe span was 1. In order to try and provide some basis for comparison to the cou-pon results, 3, 6, 9, and 10 month corrosion rates were calculated. It was not possible tocalculate 12 month corrosion rates due to the late installation of the probes. These cor-rosion rates are shown in Table 4.8, and they are plotted in Figures 4.9 and 4.10._Copper Corrosometer Probe Corrosion Rates, mm/yrLoop#3Months6Months9Months10Months1 0.0117 0.0090 0.0072 0.00670.0193 0.0147 0.0099 0.00913 0.0118 0.0080 0.0066 0.00624 0.0062 0.0052 0.0037 0.00355 0.0096 0.0097 0.0074 0.00706 0.0014 0.0021 0.0014 0.00147 0.0003 0.0025 0.0025 0.0023Table 4.8 - Copper Corrosometer Probe Corrosion RatesThe following are some observations arising from the data and charts:• The treatments in Loops 3, 4, 6, and 7 had corrosion rates lower than the rawwater rate. Loops 2 and 5 had higher corrosion rates than the raw water. Thelowest 10 month corrosion rate was in Loop 6, 66 percent lower than the rawwater rate and 75 percent lower than the rate in Loop 2. The rate for Loop 1was 26 percent lower than that for Loop 2.820.0200.0150.0100.0050.000Loop 1 Loop 5Virchem 9391.5 mg/LControlLoop 3TPC 2235 mg/LLoop 2pH & AlkOnlyEl3 Months•6 Months09 MonthsEl 1 0 MonthsLoop 6^Loop 7Virchem 939^Virchem 9394.5 mg/L 4.5 mg/LpH 8^pH 7.5Loop 4SodiumSilicate12 mg/LFigure 4.10 - Corrosion Rates of Copper Corrosometer Probes• Generally, corrosion rates in all loops decreased with time. The 3 month ratein Loop 7 appears out of line compared with all the others and should prob-ably be ignored.• As was the case with the copper coupon inserts, the lowest corrosion rates oc-curred in Loops 6 and 7, giving a further indication of the possible potentialfor zinc orthophosphate as a copper corrosion inhibitor.Table 4-9 presents the corrosion rates of the copper Corrosometer probes relativeto raw water.Copper Corrosometer ProbesRelative Corrosion RatesLoop#10 MonthCorrosion Ratemm/yrCorrosion RateRelative toRaw Water1 0.0067 1.002 0.0091 1.353 0.0062 0.924 0.0035 0.525 0.0070 1.046 0.0014 0.207 0.0023 0.34Table 4-9 - Copper Corrosometer Probe Relative Corrosion Rates85Plots of the Corrosometer resistance readings versus time are shown in Figure4.11. The same plots are repeated in Figures 4.12 through 4.14, except that straight lineslope approximations are superimposed. It is worthwhile studying the curves for aqualitative feel. The coincidental drop in dial readings, which occurred on 12/06/91 and19/06/91 is best ignored. It is suspected that those readings were taken just after waterflow had started. The water temperature would have dropped suddenly, causing an errorin the resistance readings. The Corrosometer system does not require adjustment fortemperature, provided the change is gradual or some time passes for the temperature toequalize throughout the probe. The check reading (Appendix C) measures the resistanceof a sealed reference electrode. Due to the fact that the reference electrode is isolatedsuch as it is, some time is required before the temperature of the two electrodes is closeenough so as to minimize resistance differences due to temperature. In Loops 1 through5, the corrosion rates started very high and stayed that way for 1 to 2 months and thenslowed gradually until after about 6 to 7 months, the rates in all loops approached quitelow levels. The corrosion rate in Loop 6 started very low and remained that way, declin-ing slightly. The corrosion rate in Loop 7 started low until, after about 5 months, it in-creased for about 3 months and then leveled off. What is particularly interesting, is thatduring the last few months, the rates in all loops were several orders of magnitude lowerthan they were during the first few. Table 4.10 shows the, more or less, prevailing cor-rosion rates during the early, middle, and latter stages.For the middle and later periods, instead of calculating the corrosion rate by di-viding total change in dial reading by the total time since the start of the experiment, onlythe changes for the period in question were used; that should provide an approximationof the prevailing corrosion rate during that time. For example, the dial reading for Loop5 in the later period went from 361 units to 383.5 over a period of 301 - 212 = 89 days(27/11/91 to 24/02/92). Therefore, the corrosion rate is calculated as per the formula:86Corrosion Rate (mm/yr) = 22.5 x 0.00927 x 189= 0.0023Copper Corrosometer ProbePrevailing Corrosion Rates, mm/yrLoop#EarlyMonthsMiddleMonthsLaterMonths1 0.0146 0.0019 0.00332 0.0177 0.0131 0.00083 0.0307 0.0035 0.00084 0.0113 0.0038 0.00085 0.0126 0.0089 0.00236 0.0004 0.0004 0.00017 0.0007 0.0072 0.0006Table 4.10 - Copper Corrosometer Probe Prevailing Corrosion RatesThese corrosion rates are plotted in Figures 4.15 and 4.16. From this perspective,the convergence to a low corrosion rate in all loops is more obvious. Again it appearsthat the treatment in Loop 6 offers the best protection, but the latter corrosion rates inLoops, 2, 3, 4, and 7 are so close to that in Loop 6, that over the long term, the differ-ences may prove negligible.In order to ensure correct operation of the Corrosometer system, the CheckReading mentioned above should remain constant (± 5 units). If the check readingchanges significantly, it means that the seal on the check electrode has failed and anyfurther readings are not valid. As can be seen in Appendix C all check readings stayed87Figure 4.11 - Copper Corrosometer ProbesResistance Change Over Time275225375325175oo■c)^125ri Loop 1 - Control—Loop 4 - Sodium Silicate, 12 mg/LFigure 4.12- Copper Corrosometer ProbesResistance Change Over Time (Loops 1 and 4)0^25^50^75^100^125^150^175^200^225^250^275^300^325Days After Installation (29 Apr 91)0^25^50^75^100^125^150^175^200^225 250 275 300 325500•■ Loop 2 - pH & Alk OnlyLoop 5 - V 939, 1.5 mg/L- -Loop 6- V939, 4.5 mg/L, pH 8300400200100Figure 4.13- Copper Corrosometer ProbesResistance Change Over Time (Loops 2, 5, and 6)Days After Installation (29 Apr 91)300 325250 2750^25^50^75^100^125^150^175^200^225350- Loop 3 - TPC 223, 5 mg/L,71Loop 7- V939, 4.5 mg/L, pH 7.5300150100250200Figure 4.14 - Copper Corrosometer ProbesResistance Change Over Time (Loops 3 and 7)Days After Installation (29 Apr 91)Figure 4.15- Copper Corrosometer ProbesPrevailing Corrosion RatesLoop 2 Loop 3 Loop 4 Loops Loop 6 Loop 7pH & Alk 1PC 223 Sodium Virchem 939 Virchem 939 Virchem 939Only 5 mg/L Silicate12 mg/L1.5 mg/L 4.5 mg/LpH 84.5 mg/LpH 7.50.0350.0300.0250.0200.0150.0100.0050.000Loop 1ControlEI Early• MiddleEl Later—11N,m:NFigure 4.16- Copper Corrosometer ProbesPrevailing Corrosion Rateswithin the limits.4.2.2. Mild Steel Corrosometer ProbesThe mild steel Corrosometer probe data can be found in Appendix D. The sameformula given above was used to convert the data to a corrosion rate. For the mild steelprobes, the Probe Span was 10. Unfortunately, all of the probes corroded so quickly thatthey did not last through the duration of the experiment. The probe in Loop 3 only lasted155 days. It is unlikely that any of the data is of much use. Even though the electrodesin Loops 4 and 7 lasted a little longer, the check readings on both of them changedenough to render their data suspect after about 18/09/91. Nevertheless, an attempt wasmade to calculate 3 and 6 month corrosion rates on all loops, and 9 month rates on Loops4 and 7. These corrosion rates are shown in Table 4.11, and they are plotted in Figures4.17 and 4.18.Mild Steel Corrosometer Probe Corrosion Rates, mm/yrLoop#3Months6Months9Months1 0.371 0.4002 0.400 0.4143 0.421 0.4384 0.316 0.308 0.3125 0.409 0.4206 0.160 0.2177 0.216 0.265 0.287Table 4.11 - Mild Steel Corrosometer Probe Corrosion Rates94 - Loop 1 - Control=Loop 2 - pH & Alk Only- Loop 3- TPC 223, 5 mg/LLoop 4 - Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L- -Loop 6- V939, 4.5 mg/L, pH 8--Loop 7 - V939, 4.5 mg/L, pH 7.5IMMIIMMI•1111110111■11.110.611111.1....16.Figure 4.17 - Mild Steel Corrosometer Probe Corrosion Rate0.450.400.35CC^0.300Cl)2Le o^0.250.200.153^6Time of Exposure, months0.5000.4000.1000.0000.3000.200ES9 3 MonthsMI6 MonthsC9 MonthsFigure 4.18- Mild Steel Corrosometer Probe Corrosion RateLoop 1^Loop 2^Loop 3^Loop 4^Loop 5^Loop 6^Loop 7Control pH & Alk TPC 223 Sodium^Virchem 939^Virchem 939^Virchem 939^Only^5 mg/L^Silicate 1.5 mg/L 4.5 mg/L 4.5 mg/L12 mg/L pH 8^pH 7.5Despite the foregoing comments, the following observations are offered:• The corrosion rates in Loops 1, 2, 3, and 5 are very similar, any differencesbeing negligible. The lowest corrosion rates occurred in Loops 4, 6 and 7.• It would appear that there may some beneficial protection afforded to mildsteel from zinc orthophosphate and silicates.Table 4-12 shows the mild steel Corrosometer probe relative corrosion ratesMild Steel Corrosometer ProbesRelative Corrosion RatesLoop#10 MonthCorrosion Ratemm/yrCorrosion RateRelative toRaw Water1 0.40 1.002 0.41 1.043 0.44 1.094 0.31 0.775 0.42 1.056 0.22 0.547 0.26 0.66Table 4-12 - Mild Steel Corrosometer Probe Relative Corrosion RatesPlots of the Corrosometer resistance readings versus time are shown in Figure4.19 and are repeated in Figures 4.20 through 4.23, so that straight line slopeapproximations could be superimposed upon the curves. In all except Loop 4, thecorrosion rates started high and stayed that way for 1 to 4 months and then increased97gradually until the curves became non-linear. The non-linearity is an indication ofpitting in the electrodes, which renders them useless from that point on. The useful lifeof the electrode in Loop 3 was less than 4 months. The corrosion rate in Loop 4 wasessentially the same throughout the life of the electrode. Table 4.13 shows theapproximate prevailing corrosion rates during the early and later stages.Mild Steel Corrosometer ProbePrevailing Corrosion Rates, mm/yrLoop#EarlyMonthsLaterMonths1 0.3582 0.49272 0.3179 0.45753 0.3510 0.50994 0.3158 0.31875 0.3413 0.45036 0.1585 0.29997 0.2210 0.4112Table 4.13 - Mild Steel Corrosometer ProbePrevailing Corrosion RatesThe same method used to calculate the prevailing corrosion rates for the copperprobes was used for the mild steel probes. These corrosion rates are plotted in Figures4.24 and 4.25. The uptrend in all loops, except 4, is obvious. It appears that thetreatment in Loop 6 resulted in the lowest corrosion rate; however, it was still increasing9810008002000600400Loop 1 - ControlLoop 2 - pH & Alk Only- Loop 3 - TPC 223, 5 mg/L—Loop 4 - Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L- -Loop 6- V939, 4.5 mg/L, pH 8—Loop 7 - V939, 4.5 mg/L, pH 7.5Figure 4.19 - Mild Steel Corrosometer ProbesResistance Change Over Time0^25^50^75^100^125^150^175^200^225^250Days Since Installation (29 Apr 91)225 250175 20025^50^75^100^125^15010001- Loop 1 - Control—Loop 7 - V939, 4.5 mg/L, pH 7.5800200600400Figure 4.20 - Mild Steel Corrosometer ProbesResistance Change Over Time (Loops 1 and 7)Days After Installation (29 Apr 91)10008002000600400■ Loop 2 - pH & Alk Only— Loop 4- Sodium Silicate, 12 mg/L- -Loop 6- V939, 4.5 mg/L, pH 8Figure 421 - Mild Steel Corrosometer ProbesResistance Change Over Time (Loops 2, 4, and 6)0^25^50^75^100^125^150^175^200^225^250^275Days After Installation (29 Apr 91)10008002000600400Figure 4.22 - Mild Steel Corrosometer ProbesResistance Change Over Time (Loop 3, TPC 223, 5 mg/L)0^25^50^75^100^125^150Days After Installation (29 Apr 91)10008002000600400Figure 4.23 - Mild Steel Corrosometer ProbesResistance Change Over Time (Loop 5, V939, 1.5 mg/L)0^25^50^75^loo^125^150Days After Installation (29 Apr 91)0.60.50.100.40.2- Loop 1 - ControlLoop 2 - pH & Alk Only- - Loop 3 - TPC 223, 5 mg/L— Loop 4 - Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L- - Loop 6- V939, 4.5 mg/L, pH 8—Loop 7- V939, 4.5 mg/L, pH 7.5Figure 4.24 - Mild Steel Corrosometer ProbesPrevailing Corrosion Rates0^50^100^ 150^200Days After Installation (29 Apr 91)ouli-1111C1,,1(at the end of the electrode life. The stability of the corrosion rate in Loop 4 is alsoobviated in Figure 4.24. The clear flaw with these data are the short duration of thecorrosion period. That reason alone should be sufficient to attach little credence to it.4.3. Comparison of Coupon and Corrosometer Relative CorrosionRatesThe coupon and the Corrosometer corrosion measurements are compared in Table4-14. The relative corrosion rates measured for the copper Corrosometer probes inLoops 2, 3, and 5 were a lot higher than those determined for the copper coupons. Theresults for Corrosometer Loop 2 are definitely suspect since numerous previous studieshave confirmed that raising the pH generally reduces copper corrosion rates. TheCorrosometer relative corrosion rates for the mild steel probes were only for six monthssince most of the probes failed shortly after this period. Generally they showed lowerrelative corrosion rates in Loops 4, 6, and 7, compared to the copper probes. Theseresults were not consistent with the cast iron coupon results, but there may no basis forexpecting mild steel corrosion rates to be comparable to those of cast iron. Only a studycomparing the two would tell. As previously stated, it was planned to use cast ironCorrosometer probes, but they could not be obtained in time for this project. TheCorrosometer results generally confirm that both sodium silicate and zinc orthophosphatemay offer some beneficial protection, and merit further study.As a tool for measuring corrosion rates, the Corrosometer Instrument and probes,once installed, are convenient and simple to use. They also provide further insight intothe corrosion process and instantaneous corrosion rates. Judging, particularly by the datagenerated by the mild steel Corrosometer probes, their use as stand-alone corrosionmeasurement devices should not be contemplated. Perhaps if thicker mild steel probeshad been used, the results would have been more meaningful. Nevertheless, the106Corrosometer may prove useful if employed in addition to other means of corrosionmonitoring.Comparison of Coupon and CorrosometerCorrosion Rates Relative to WaterLoop#Copper Cast Iron Mild SteelCouponRelativeCorrosionRateCorrosometerRelativeCorrosionRateCouponRelativeCorrosionRateCorrosometerRelativeCorrosionRate1 1.00 1.00 1.00 1.002 0.61 1.35 1.14 1.043 0.58 0.92 0.93 1.094 0.42 0.52 1.09 0.775 0.33 1.04 1.22 1.056 0.25 0.20 1.03 0.547 0.24 0.34 1.10 0.66Table 4-14 - Comparison of Coupon and CorrosometerCorrosion Rates Relative to Water4.4. Metal Concentrations in Standing Water SamplesAt the beginning of the experiment, it was decided that the standing water sam-ples would not be digested prior to metal measurement. This reasoning was based on theexperience in the EES (1990) study. That study found no significant difference betweenmetal levels in samples that were digested and those that were not. However, due to thehigh level of particulate matter in the samples taken in this experiment, the decision was107made in September to try filtering part of each sample for a few weeks and digest theunfiltered portions before metals measurement. The first filtration took place with thesamples taken on 1 October (day 200 of the experiment). The metal levels measurementsare presented in Appendices E through M. The differences between the unfiltered metallevels and the filtered are quite significant, indicating that most of the metal content inthe water was undissolved. As a standard operating procedure, samples for metals meas-urement are acidified with concentrated nitric acid to a 2.5 percent matrix. Apparently, asignificant portion of the metals contained in the particulate matter was dissolved by theacidification process so there was little difference between unfiltered samples that weredigested and those that were not. In order to ensure that none of the metals would bemissed, all samples were digested from 1 Oct onward. It did not appear to make anoticable difference. There were large swings in metal levels both before and after thatdate. It is certainly possible that some of the metal levels measured prior to October 1stwere actually higher than reported.4.4.1. Copper Concentrations in Standing Water SamplesThe actual measured copper levels in the plumbing coils and the faucets, 24 hourstanding water samples are presented in Appendices H and E. These data are representedgraphically in Figures 4.26, and 4.28 and the data from those plumbing coil loops, whichhad the lowest levels, are shown in Figure 4.27. Some observations that can be madefrom the data and graphs are:4.4.1.1. Copper Concentrations in Plumbing Coil Standing Water Samples• Some extremely high copper levels were encountered, particularly fromLoops 5, 6, and 7, the zinc orthophosphate loops.• The highest copper concentrations occurred in the form of spikes, which werecoincident in most and sometimes all of the loops.108• Generally speaking, the lowest copper levels were from Loop 2, the pH andalkalinity adjusted loop, followed by Loop 4, the sodium silicate loop.Overall, the levels in Loop 3, the zinc orthophosphate/sodium silicate loop,were higher than those in Loop 1, the raw water control loop.• The copper levels in the raw water loop exceeded the EPA action level' 1 of1.3 mg/L often enough so that, if this represented actual consumer tap water,corrective action would be required if the GVWD were under EPA jurisdic-tion. Alternatively, it is possible that pH and alkalinity adjustment to 8 and20 mg/L respectively, along with chloramine injection at 2.5 mg/L, wouldbring the water below the EPA action limits. The further addition of sodiumsilicate would do nothing to reduce copper mobility in pH and alkalinity ad-justed water, but rather might make it slightly worse (practically, thedifference between the average copper levels in Loops 2 and 4 is negligible).4.4.1.2. Copper Concentrations in Faucet Standing Water Samples• None of the loops had copper levels above the EPA action level; however, ina typical household, the metals from the faucets would be combined with themetals from the soldered copper plumbing, as well as the metals from the dis-tribution system, so there is no room for complacency.• The highest copper concentrations again occurred in the form of spikes, whichwere often coincident in a number of the loops; also some of the copper11The metal mobility portion of the experiment measured metal levels from the first draw ofstanding samples, therefore, since EPA action levels apply to first flush samples those standards wereused as the basis for comparison. The Canadian Guidelines on Drinking Water Quality MAC for leadapplies to well flushed samples.10920- Loop 1 - Control■• Loop 2 - pH & Alk Only- Loop 3 - TPC 223, 5 mg/L— Loop 4 - Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L- - Loop 6 - V939, 4.5 mg/L, pH 8— Loop 7 - V939, 4.5 mg/L, pH 7.51510Figure 4.26 - Copper Levels From Plumbing Coils24 Hour Standing Samples (Average Values for Two Samples)50^100^150^ 250^300^350Days From Start^Began Digesting Samples at 200 DaysLoop 1 - Control■•■ Loop 2 - pH & Alk Only- Loop 3 - TPC 223, 5 mg/L— Loop 4 - Sodium Silicate, 12Figure 4.27 - Copper Levels From Plumbing Coils24 Hour Standing Samples (Best Four Loops)50^100^150^ 250^300^350Days From Start^Began Digesting Samples at 200 Days- Loop 1 - ControlLoop 2 - pH & Alk Only- Loop 3 - TPC 223, 5 mg/L— Loop 4 - Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L- - Loop 6- V939, 4.5 mg/L, pH 8—Loop 7- V939, 4.5 mg/L, pH 7.550^100^150^200Days From Start250^300Began Digesting Samples at 200 Days350Figure 4.28 - Copper Levels From Faucets24 Hour Standing Samplesspikes from the faucets also occurred coincidentally with the spikes from theplumbing and solder coils. It is interesting also that a number of the troughsin the faucet copper levels were coincident.• The lowest copper levels were from Loop 6, but all of the treatments ap-peared to provide a significant degree of beneficial protection to the faucetsover that from the raw water.• There was a decreasing trend in copper levels with time in the raw water loop.4.4.2. Lead Concentrations in Standing Water SamplesThe actual measured lead levels in the 24 hour standing water samples are pre-sented in Appendices F, I, and L. These data are represented graphically in Figures 4.29,4.31, and 4.33. The data from those loops which had the lowest lead levels are shown inFigures 4.30, 4.32, and 4.34. Some observations that can be made from the data andgraphs are:4.4.2.1. Lead Concentrations in Plumbing Coil Standing Water Samples• Some high lead levels were encountered, particularly from Loops 6 and 7, thehigher dosage zinc orthophosphate loops. The high lead levels in loop 7,which had the lower pH and alkalinity (7.5 and 10 mg/L) may be indicative ofthe importance those two factors. It is possible that, if pH and alkalinity lev-els are too low, it will negate any potential benefit from zinc orthophosphatetreatment.• Again, the highest lead concentrations occurred in the form of spikes, whichwere coincident in several of the loops, but the trend of coincident spikesamong loops was not as dramatic as occurred for the copper levels. The leadconcentration spikes occurred at the same times as the copper concentrationspikes.113Days From Start50^100^150^200-^250^300Began Digesting Samples at 200 DaysFigure 4.29 - Lead Levels From Plumbing Coils24 Hour Standing Samples (Average Values for Two Samples)3500.60.50.10.30.40.2- Loop 1 - ControlLoop 2 - pH & Alk Only- Loop 3- TPC 223, 5 mg/L— Loop 4 - Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L- -Loop 6- V939, 4.5 mg/L, pH 8Loop 7- V939, 4.5 mg/L, pH 7.5250 300 3500.0250.0200.0150.0100.0050.00050^100^150Days From Startc: Loop 1 - Control■■• Loop 2 - pH & Alk Only— Loop 4 - Sodium Silicate, 12 mg/L0.0350.030Began Digesting Samples at 200 DaysFigure 4.30 - Lead Levels From Plumbing Coils24 Hour Standing Samples (Best Three Loops)Days From Start50^100^150^ 250^300Began Digesting Samples at 200 DaysFigure 4.31 - Lead Levels From Solder Coils24 Hour Standing Samples0 350401002030Loop 1 - ControlLoop 2 - pH & Alk Only- Loop 3 - TPC 223, 5 mg/L— Loop 4- Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L- - Loop 6- V939, 4.5 mg/L, pH 8— Loop 7 - V939, 4.5 mg/L, pH 7.50.250.200.050.000.150.10Days From Start100^150^ 250^300Began Digesting Samples at 200 Days1- Loop 1 - Control■P Loop 2 - pH & Alk Only- Loop 3 - TPC 223, 5 mg/L— Loop 4- Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L- - Loop 6 - V939, 4.5 mg/L, pH 8— Loop 7- V939, 4.5 mg/L, pH 7.5350Figure 4.33 - Lead Levels From Faucets24 Hour Standing Samples0.25c- Loop 1 - Control- Loop 3 - TPC 223, 5 mg/L- - Loop 6 - V939, 4.5 mg/L, pH 8— Loop 7 - V939, 4.5 mg/L, pH 7.50.200.150.100.050.00Figure 4.34 - Lead Levels From Faucets24 Hour Standing Samples (Best Three Loops)50^100^150^ 250^300^350Days From Start^Began Digesting Samples at 200 Days• Again the lowest lead levels were from Loop 2, the pH and alkalinity adjustedloop, followed by Loop 1, the raw water loop. Overall, the levels in Loop 4,the sodium silicate loop, were higher than those in Loop 1.• The lead levels in the raw water loop rarely exceeded the EPA action level of0.015 mg/L; therefore, if this represented actual consumer tap sampling, it isunlikely that any corrective action would be required if the GVWD were un-der EPA jurisdiction.12 pH and alkalinity adjustment to 8 and 20 mg/L alongwith chloramine injection at 2.5 mg/L could cut lead levels by up to 44 per-cent. The further addition of sodium silicate would do nothing to reduce thelead mobility in pH and alkalinity adjusted water but rather might make itworse than the raw water alone.4.4.2.2. Lead Concentrations in Lead/Tin Solder Coil Standing Water Samples• High lead levels were encountered in all loops, with frequent extremely highlevels occurring in all loops expect Loop 1 and possibly Loop 6, depending onwhat level one defines as "extreme" .• Once more, the highest lead concentrations occurred in the form of spikes,which were often coincident in several of the loops. The trend of coincidentspikes among loops was less pronounced than it was in the case with the metalmeasurements from the plumbing coils. However, many of the lead spikesfrom the solder coils occurred coincidentally with both the copper and leadspikes from the plumbing coils.Tqwever, as discussed, Singh (1990) found lead levels often exceeded 0.015 mg/L in standing-1m Vancouver homes, once again confirming that lab results do not necessarily reflect.s points out the need for in home sampling in conjunction with the implementation ofAtrol program.120• Almost without exception, the lowest lead levels were from Loop 1, the rawwater loop. Average lead levels in Loop 1 were 50 percent lower than thosefor Loop 6, the next lowest loop which was, in turn, 38 percent lower thanthose of Loop 3, the third lowest loop.• In sum, none of the treatments provided any lead mobility reduction in leadsolder exposed in isolation. Indeed, all of the treatments that were tried, onlyaggravated the mobility rate. Since the exposure of lead/tin solder in such amanner in no way equates to a real plumbing situation, there is no point inrelating this part of the experiment to EPA action limits. Hopefully, the ex-perience in this study is not indicative of what would happen if these treat-ments were exposed to lead service pipe.4.4.2.3. Lead Concentrations in Faucet Standing Water Samples• Some fairly high lead levels were encountered in Loops 1, 2 and 4.• The highest lead concentrations occurred in the form of spikes which wereoften coincident in a number of the loops; however, the spikes were not nearlyas high as the other cases already discussed. Some of the lead spikes from thefaucets also occurred coincidentally with the spikes from the plumbing andsolder coils.• The lowest lead levels were from Loops 3, 6, and 7. It is quite possible thattreatment corresponding to that in Loop 6 would keep lead levels below theEPA action level but, whether the treatments in Loops 3 and 7 would, isquestionable.• Generally, all of the treatments appeared to provide some degree of leadmobility reduction in the faucets over that from the raw water.• As with the faucet copper concentrations, there was a decreasing trend in leadlevels with time in the raw water loop.1214.4.3. Zinc Concentrations in Standing Water SamplesThe actual measured zinc levels in the 24 hour standing water samples from theplumbing coils and the solder coils is presented in Appendices J and M. These data arerepresented graphically in Figures 4.35 and 4.36. This information should have yieldedan approximation of the zinc feed rates in Loops 3, 5, 6, and 7, but the very high zinclevels in Loops 5, 6 and 7 do not equate to the actual inhibitor feed rates of 0.13 mg/L inLoop 5, and 0.37 mg/L in Loops 6 and 7 (as zinc). As the graphs show, frequently, zincwas present in the standing water samples in large slugs. It is likely that the zinc waseither inhibitor precipitating out before forming a protective scale, or the scale itself wassloughing. According to Schock (1989) "when orthophosphate is added via a formu-lation containing zinc rather than potassium or sodium salts or orthophosphoric acid, it ispossible that basic zinc carbonate [hydrozincite, Zn5(CO3)2(OH)6] could precipitate re-sulting in turbid water, clogging of industrial or commercial filters, formation of corro-sion concentration cells under deposits, or other problems". Such a situation would ob-viously reduce the inhibition potential for materials that would benefit from the presenceof zinc in the water. There were many occasions when the samples taken from theseloops were very turbid, while the raw water was clear. This may have been an indica-tion of either inhibitor precipitation or sloughing of the scale, followed by disintegration.The pattern with the zinc levels in the faucet samples, Figure 4.37, is far less er-ratic. Zinc levels in Loops 5, 6, and 7 are roughly in line with the actual feed rates. Themost important observation from this chart is that the treatments of Loop 2, 3, and 4 willlikely reduce zinc leaching from brass faucets to levels below that which would be thecase with raw water. It also appears that the inhibitor problems which occurred in theplumbing coils and solder coils, were not repeated in the faucets.Figure 4.38 is a chart of the data contained in Appendix K, the copper levels fromthe solder coils. Some very high copper levels were found in Loops 5, 6, and 7. Some1223.5- Loop 1 - Control1m Loop 2 - pH & Alk Only- Loop 3 - TPC 223, 5 mg/L—Loop 4 - Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L- -Loop 6 - V939, 4.5 mg/L, pH 8— Loop 7- V939, 4.5 mg/1_, pH 7.52.53.02.01.5A■1.00.5.................0.00^50^100^150^200Days From Start250^300Began Digesting Samples at 200 Days350Figure 4.35 - Zinc Levels From Plumbing Coils24 Hour Standing Samples (Average Values for Two Samples)Days From Start50^100^150^ 250^300Began Digesting Samples at 200 DaysFigure 4.36 - Zinc Levels From Solder Coils24 Hour Standing Samples0 35076521043- Loop 1 - ControlLoop 2 - pH & Alk Only- Loop 3 - TPC 223, 5 mg/L— Loop 4 - Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L--Loop 6 -V939, 4.5 mg/L, pH 8^ —Loop 7 - V939, 4.5 mg/L, pH 7.5- Loop 1 - ControlLoop 2 - pH & Alk Only- Loop 3 - TPC 223, 5 mg/L— Loop 4- Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L- - Loop 6 - V939, 4.5 mg/L, pH 8— Loop 7- V939, 4.5 mg/L, pH 7.50.60.80.20.4Figure 4.37 - Zinc Levels From Faucets24 Hour Standing Samples50^100^150^ 250^300^350Days From Start^Began Digesting Samples at 200 Days3.02.50.50.01 .52.01.0Loop 1 - ControlLoop 2 - pH & Alk OnlyLoop 3 - TPC 223,5 mg/L— Loop 4- Sodium Silicate, 12 mg/LLoop 5 - V 939, 1.5 mg/L- - Loop 6 - V939, 4.5 mg/L, pH 8— Loop 7- V939, 4.5 mg/L, pH 7.550^100^150^200Days From Start250^300Began Digesting Samples at 200 Days350Figure 4.38 - Copper Levels From Solder Coils24 Hour Standing Samplesof the spikes happened at the same time as the zinc spikes from the solder coils (Figure4.23). This appears to be evidence of scale sloughing. Consider again the copper levelsfrom the plumbing coils (Figure 4.13). Almost all of the copper spikes from that chartcoincide with the zinc spikes in Figure 4.35. Most of the lead peaks from the plumbingcoils (Figure 4.29) also coincide with those same zinc peaks. Also, there appears to be acorrelation between the zinc spikes from the solder coils and the lead spikes from thesame source (Figures 4.36 and 4.31). This pattern is not as apparent in the faucet sam-ples. The spikes in lead levels in Loop 4 samples generally do not coincide with the zincspikes, which would be expected since no zinc was fed to Loop 4. It would appear thatthe spikes in Loop 4 were caused by scale sloughing. It seems there is evidence that theinhibitors broke down for some reason; it remains to be determined what could havecaused it.In the EES study (1990), both treated and untreated standing water samples weretaken on several occasions. Some of the plots of metal concentrations in those samplesshow high upward spikes that are coincident in several or all loops. This may be furtherevidence of scale sloughing, but in the EES case, the scale was not composed of a metal-inhibitor combination. The whole matter of scale viability needs to be investigated thor-oughly.4.4.4. Relative Metal Mobility of Water TreatmentsTable 4.12 rates the relative performance of the various treatments with regard tometal mobilization. Each treatment was given a numerical score based upon the metallevels from each sample. The highest score in each set was 6, corresponding to the high-est overall metal level. The lowest score was 0.127Relative Metal MobilityLoop#Plumbing Coils Solder Coils Faucets TotalScoreScoreRelative toRaw WaterCu Pb Zn Cu Pb Zn Cu Pb Zn1 2 1 0 3 0 0 6 6 3 21 1.002 0 0 0 1 4 0 5 4 0 14 0.673 3 4 0 2 2 0 3 2 1 17 0.814 1 2 0 0 6 0 1 5 2 17 0.815 6 3 4 4 3 4 2 3 4 33 1.576 4 5 6 5 1 6 0 0 5 32 1.527 5 6 5 6 5 5 4 1 6 43 2.05Table 4.15 - Relative Metal MobilityThe lower the score relative to raw water, the better the treatment performed. As can beseen, in terms of metal mobility, the best treatment was in Loop 2, followed by Loops 3and 4. However, even the treatment used in Loop 2 would probably result in lead con-centrations that exceed EPA action levels due to the high lead release from the faucets.On the other hand, copper concentrations would likely be below EPA action levels. Thiswas also the case in the EES study (1990) in the loop with a similar treatment. If treat-ment were in accordance with that in Loop 3, both copper and lead concentrations wouldprobably exceed EPA action levels. Treatment in accordance with that done in Loop 4would yield a water with copper concentrations below the action level but again leadwould exceed the action level. In other words, none of the treatments would be producea water that was below the EPA action levels for trace metals.1284.5. Water Quality Parameters4.5.1. TemperatureWater temperatures measured over the course of the experiment can be found inAppendix N. The raw water temperature went from a low of 4°C at the beginning of theexperiment to a high of about 16°C in August and then back down to 4°C by January.Some of the temperatures of the standing water samples were measured as well, asshown. Those temperatures reached as high as 21.5°C in the summer. It is quite possi-ble that such high temperatures had some influence over the corrosivity of those waters.According to Smith (1989), "in almost all metallic corrosion, higher temperatures in-crease corrosion activity and colder temperatures reduce corrosion".4.5.2. ConductivityThe conductivities measured over the duration of the experiment are tabulated inAppendix 0. The main purpose of recording conductivities was to use them as a moni-toring mechanism, the principle being that if some of them changed significantly fromone day to the next, it would likely be an indication of some chemical feed problem.This proved to be quite useful on a couple of occasions. For example, on 06/04/91, thecircuit breaker for the pumps feeding NaHCO3, Virchem 939, and TPC 223 opened andthe feed stopped. Although it was standard procedure to check all pumps everyday, onthis day the problem was not discovered until the conductivities were measured. Sincethe conductivities were significantly different from where they should have been, an im-mediate investigation determined the cause of the problem and it was rectified.4.5.3. pllThe measured pHs are tabulated in Appendix P. There are a few important pointsregarding the pH measurements which deserve mention.129• On first glance, the effort to maintain the targeted pHs appears quite success-ful, with the averages in all loops being within 0.05 of a unit. However, thestandard deviations were fairly high. For example, in Loop 4, The pH lowwas 7.22 while the high was 9.37. This is an indication of the difficulty in-volved in maintaining a pH level in the 8 range.• pH appears to change after a period of standing. This is indicative of chemi-cal reactions involving hydrogen ions or hydroxyl ions taking place. Figure4.39 is a plot of pH levels in Loop 1. There is a definite trend of higher pHsin the standing water samples from the plumbing coils, while in the soldercoils and faucets standing samples the pHs are very close to that of the flow-ing water. A possible partial explanation for the higher pHs in the plumbingcoil is as follows:Consider again the corrosion reaction of copper in the raw water:2Cuo + 2H+ + 1/202 --> 2Cu+ + H20^4-1As the copper corrodes, both molecular oxygen and hydrogen ions areused up. The system is closed, so it eventually reaches a state of equilib-rium and the reaction stops. Since over time, there are fewer free hydro-gen ions in the system, the pH will be higher.It appears that any reactions which occurred in the solder coil and the fau-cet standing water of Loop 1 were not of sufficient magnitude to cause asignificant shift in pHs.Figures 4.40 and 4.41 are plots of pHs in Loops 2 and 7. The trend in both plotsis to lower pHs after standing. There is a myriad of reactions which could take placewhich would lead to a lower pH such as:Cu° + OH- ---> 1/2Cu20 + 1/2H20 or^ 4-2130Pb0 + Pb+4 + 2011- --> Pb02 + H20 + Pb+2^4-3The opposite trend is apparent in Loop 4 as shown in Figure 4.42. Perhaps someof the negatively charged silicate ions tend to neutralize some of the positive hydrogenions resulting in a higher pH.4.5.4. AlkalinityThe measured alkalinities can be found in Appendix Q. As can be seen, the aver-age alkalinities in Loops 2 to 7 were quite close to the targeted values, but the standarddeviations were fairly high. As was the case with the pHs, the alkalinities of the Loop 1standing water samples from the plumbing coils were consistently higher than the alka-linities of the flowing water. In fact, the standing water samples from the plumbing coilsin all loops were slightly higher than the levels for the flowing waters. Except for Loop4, the alkalinities of the standing water samples from both the solder coils and the faucetsin all loops were lower than the flowing water levels. The alkalinities of the standingwater samples in Loop 4 were consistently higher than the levels for the flowing water.It seems likely that some of the pH and alkalinity instability was due to the water's lowbuffer intensity in the pH 8 range, as discussed in Section 2.4.1 Thus, in spite of almostconstant efforts to maintain stable pH and alkalinity levels, there were other factors thatinfluence them and make control difficult.. These factors must be investigated and takeninto account if pH and alkalinity adjustment are to be used successfully for corrosioncontrol in water supply systems.4.5.5. Combined ChlorineThe combined chlorine levels are tabulated in Appendix R. The average levelswere right on target, and the standard deviations were quite low. The most obvious trendshows up in the plumbing coil standing samples. Over the course of 24 hours, practicallyall of the chloramine vanished. Since the system is sealed, it can only be assumed that1311 3002507.0■• Non Standing— PC Standing- SC StandingF Standing6.86.66.46.2I^I^I^I50 100 150 200Days From Start6.00 350Figure 4.39 - pH Comparisons - Loop 1, ControlFigure 4.40 - pH Comparisons - Loop 2, pH & Alk Adjusted OnlyI■ Non Standing— PC Standing- SC Standing—F Standing8.58.38.17.77.5I^I^I^I^I 50 100 150 200 250Days From Start7.30 300^35050 1501001 3503002501200Figure 4.41 - pH Comparisons - Loop 7Virchem 939, 4.5 mg/L, pH 7.58.37.87.36.844,0Days From StartNon Standing— PC Standing- SC Standing—F Standing7.501350300250Figure 4.42 - pH Comparisons - Loop 4Sodium Silicate 12 mg/L9.5■ Non Standing—PC Standing- SC Standing— F Standing9.08.0I^I^I^I50 100 150 200Days From Startit reacted to form other compounds. As was discussed in para 2.4.2., the reaction ofchloramine with copper is spontaneous, although not as strong as the reaction of freechlorine with copper. It is probably safe to assume that either disinfectant is morecorrosive to copper than raw water alone. The chloramine levels were also lower in thesolder coil standing samples, again leading to the impression that some of it combinedchemically, probably forming some lead-amine complexes. The tendency for thesereactions to occur does not appear to be as great as was the case in the plumbing coils.There was also a slight drop in chloramine levels in the faucet standing samples, but thedifference is almost negligible. The reason the difference is so small may be partiallyattributable to the fact that the samples taken from the faucets for pH, alkalinity,conductivity, and combined chlorine measurements were larger than the volume of wateractually isolated, so some fresh flowing water was also included. There was not enoughwater contained within the faucets to allow sufficient volume for all of the desiredmeasurements to be made.4.6. Possible Causes of Inhibitor InstabilityA number of parameters were examined to see if there was some sort of patternwherein one or a combination of water quality changes may have caused the instability ofthe inhibitor and/or the protective scale. There appears to be no relationship between thehigh metal spikes and changes to other parameters. Figures 4.43 through 4.50 showvarious combinations of plots of pH or alkalinity versus metal levels from some of thesamples. It could be that inhibitor or scale instability occurs as a result of a significantdrop in pH and/or alkalinity, but the instability does not appear until several weeks lateron. Some of the plots tend to show such a pattern, but it is not consistent, as can be seen.If the stability of the inhibitors/scales is pH and/or alkalinity dependent, then theresults provide another reason for avoiding the pH 8.0 to 8.5 range. Not only are136attempts to maintain a pH in this range in water treatment extremely difficult, but theymay also increase the risk of extremely high metal spikes in the water.4.7. Bacterial GrowthThe results of the bacteriological analyses done by the GVRD laboratory are pre-sented in Appendix S. The following are some observations from these data:4.7.1. Copper Coupons - Bacteriological Results• All treatments had lower heterotrophic plate counts than the raw water.• Loop 4 had the lowest heterotrophic plate count, being almost 2 orders ofmagnitude lower than the next lowest loop, Loop 5.• There were no differences between loops in total coliform counts, all of thembeing below meaningful levels (counted as < 2 on the data sheets).4.7.2. Cast Iron Coupons - Bacteriological Results• All treatments had higher heterotrophic plate counts than the raw water.• Loop 3 had the highest heterotrophic plate count, but all loops with phosphatefeeds had higher counts by almost an order of magnitude.• The only loop with a consistent total coliform count was the raw water loop.The others were all below meaningful levels (again counted as < 2 on the datasheets).It appears, from this limited data, that there may be some cause for concern re-garding the bacterial regrowth potential when phosphate inhibitors are used in the pres-ence of ferrous pipe materials. It may be that the phosphates are particularly beneficialto iron bacteria, which could possibly lead to increased corrosion. To go any further wasbeyond the scope of this study, but these data point that these relationships need to bestudied further, to determine the effects of phosphate inhibitors in1374.08.6-- PH Price to 150141441—Copper Lew*32.^,8.28.07.87.6 I^I^..•^I^I 50 100 150 200Days From Start250 3000.03504,0pH—comer7.9 327.8 2.4 a77.6 0.87.5 L0^50 100..0.0150^200^250^300^350Days From StartpH Versus Copper Levels from Plumbing Coils - Loop 2(pH Measured Prior to Water Being Isolated in Coils)pH Versus Copper Levels from Plumbing Coils - Loop 2(pH Measured from Standing Water Sample from Coils)Figure 4.438.58.0559.07.5 ^a 50 100 160Days From Start200^250 300 3602.4^ 8.600.6^ 8.151.8^ 8.4512 3,3,3c'?8.000>50I^I^I 100 150 200^250Days From Start035050 100 150^200Days From Start24t 2°16100 350250^900150^200Days From Start2.4-Manny Prior to Isolman—C.rog Lewis1^ 0.0^ 12250^300^3502715 —1224211812.4pH Versus Copper Levels from Plumbing Coils - Loop 4(pH Measured Prior to Water Being Isolated in Coils)pH Versus Copper Levels from Plumbing Coils - Loop 4(pH Measured from Standing Water Sample from Coils)Alkalinity Versus Copper Levels from Plumbing Coils - Loop 4(Alkalinity Measured Prior to Water Being Isolated in Coils)Alkalinity Versus Copper Levels from Plumbing Coils - Loop 4(Alkalinity Measured from Standing Water Sample from Coils)Figure 4.44pH Versus Lead Levels from Solder Coils - Loop 4(pH Measured Prior to Water Being Isolated in Coils)I^I^I50^100 160 200Days From Start250Alkalinity Versus Lead Levels from Solder Coils - Loop 4(Alkalinity Measured Prior to Water Being Isolated in Coils)pH Versus Lead Levels from Solder Coils - Loop 4(pH Measured from Standing Water Sample from Coils)8.03 ^0 50 1008.608.45X 8.300.150^200Days From StartAlkalinity Versus Lead Levels from Solder Coils - Loop 4(Alkalinity Measured from Standing Water Sample from Coils)27.022.511I^I^I^I^I50 100 150 200 250Days From Start150^200Days From Star!250^300^35012300 350 50 100Figure 4.45Alkalinity Versus Copper Levels from Plumbing Coils - Loop 6(Alkalinity Measured Prior to Water Being Isolated in Coils)Alkalinity Versus Copper Levels from Plumbing Coils - Loop 6(Alkalinity Measured from Standing Water Sample from Coils)Figure 4.46a6486It10342250 300'^ o350I^I^I 50^100 150 200Days From Start102^ 1719- Alkalinity—COppa LeVetsI^300^35026•- Alkalinity Prior to Wagon-Copper Lewis---10 0- 25tT3211814 - ,^ 0.0350250 30075°0 50 1009.0 8.07.5 7.9an 7.84.57.67.57.41.5pH Versus Copper Levels from Plumbing Coils - Loop 6(pH Measured Prior to Water Being Isolated in Coils)9.008.758.500. 8.258.007.75- pH Prior to Polelion[7.Copper LevelspH Versus Copper Levels from Plumbing Coils - Loop 6(pH Measured from Standing Water Sample from Coils)A150^200Days From Start10050^ 0.0350250 300150^200Days From Start9.0^ 0.00350250 3000.240.180.30 8.07.97.87.750 100 150 200 260Days From Start30.120.06-- pH Nor to Isolaion1.0/8158.I^I^I 50^100 160 200Days From Start50 100 150 200 250 300 350- • Alkalinity Riot to Isolation7•Laacl Loyale0.300.240 180.120.06'^  0.00- 22.7C 181410 ^ 0.003600.30• • Aikalinity—Una Lank0.240.1830.12 'IA0.06I^I^tI^I^I so 100 150^200 250 300Days From StartpH Versus Lead Levels from Plumbing Coils - Loop 6(pH Measured Prior to Water Being Isolated in Coils)pH Versus Lead Levels from Plumbing Coils - Loop 6(pH Measured from Standing Water Sample from Coils)Alkalinity Versus Lead Levels from Plumbing Coils - Loop 6(Alkalinity Measured Prior to Water Being Isolated in Coils)Days From StartAlkalinity Versus Lead Levels from Plumbing Coils - Loop 6(Alkalinity Measured from Standing Water Sample from Coils)Figure 4.47pH Versus Copper Levels from Plumbing Coils - Loop 7(pH Measured from Standing Water Sample from Coils)Days From Start8.50 12108.258.00 8pH Versus Copper Levels from Plumbing Coils - Loop 7(pH Measured Prior to Water Being Isolated in Coils)- - pH Prior to IsolationCopps( Lava&a_ 7/57.50725150^200Days From Start7.00 ^0 507.77.57.37.18.9950 150100 20012250 300- Nkanity NO( lo isolation—Copper UM&12.010.59.07.56.04.5- 3.050^100^150^200Days From Start141 3121110Alkalinity Versus Copper Levels from Plumbing Coils - Loop 7(Alkalinity Measured from Standing Water Sample from Coils)- - Alkalinity^)—Copper Law*610.07.55.0100^150^200Days From Start250 30020.017.51210Alkalinity Versus Copper Levels from Plumbing Coils - Loop 7(Alkalinity Measured Prior to Water Being Isolated in Coils)Figure 4.480.450300.150.6 7.70.57.50.4ci60.3 iP-1o. 7.33(P.r027.10.10 6.9-• pH Par lo IsoIron-Lead LarsI^I^I^I 50^100 150 200 250Days From Start300^350-Lrd LaverI^I^I^I^I^I so 100 150 203 250 300Days From Start0.80^ 0.00360pH Versus Lead Levels from Plumbing Coils - Loop 7(pH Measured Prior to Water Being Isolated in Coils)pH Versus Lead Levels from Plumbing Coils - Loop 7(pH Measured from Standing Water Sample from Coils)Alkalinity Versus Lead Levels from Plumbing Coils - Loop 7(Alkalinity Measured Prior to Water Being Isolated in Coils)Alkalinity Versus Lead Levels from Plumbing Coils - Loop 7(Alkalinity Measured from Standing Water Sample from Coils) 0.60 20.0 0.6-- Array Pr, to Isolation-Lead Lars 1-1.ar LiarsAlcalryj17.5 0.50.4515.012.50.40.301+20.310.00.157.5 0 .1^ 0.00 5.0^ I^I^ I I ^050^100^150^200^250^300 350^ o 50^100 150 200^250^360^350Days From Start Days From StartFigure 4.49Figure 4.50pH Versus Lead Levels from Solder Coils - Loop 7(pH Measured Prior to Water Being Isolated in Coils)pH Versus Lead Levels from Solder Coils - Loop 7(pH Measured from Standing Water Sample from Coils)18 7.7157.512739JX 7.758.508.258.00--pHP6toton.7lead Lewis7.507.17.251 160 20()Days From Start0^ 8.93507.000 50 103 250^300Alkalinity Versus Lead Levels from Solder Coils - Loop 7(Alkalinity Measured Prior to Water Being Isolated in Coils)Alkalinity Versus Lead Levels from Solder Coils - Loop 7(Alkalinity Measured from Standing Water Sample from Coils)6181450 1031150 200 250Days ROM Start235018- Alkalinity Prior to leolelton,71.01101410..61^I^I '^2100 150 200^250^300^350Days From Start20.017.515.012.510.07.55.0018—Lead Levels1512I 350the actual distribution system, and their long term bacterial regrowth and possibly in-duced bacterial corrosion effects. Bacterial growth in the presence of other pipe materi-als also needs to be examined.4.8. Quality ControlOn a regular basis, selected samples were sent to the GVRD laboratory for analy-sis for silica, phosphorus, copper, zinc and lead. The results of those analyses, alongwith the UBC analyses for the same parameters, are presented in Appendix T. Withsome exceptions, most of the results are quite comparable between the two labs. In somecases, it is possible that, due to human error, some samples became mixed up and themeasurements recorded for one were, in fact, applicable to another.The comparisons that are somewhat troubling are those for phosphorus in Loop 3.Most of the GVRD laboratory measurements (measured as total phosphorus) were atleast an order of magnitude higher than those of the UBC laboratory. There is no appar-ent reason for this fairly consistent difference. Since Loop 3 was one of the loops thatwas fed zinc orthophosphate, this problem brings into question the actual levels of phos-phate going into Loop 3. By comparison, almost all of the silica measurements for Loop3 by the two labs are all within a 10 to 15 percent range of each other.In spite of these few exceptions, overall, the quality assurance results are quitesatisfactory, with the two labs recording measurements that were consistently within areasonable margin of error (10 to 15 percent) of each other. It must be remembered that,in this study, the absolute metal levels are not of as much concern as the relative levelsbetween loops since the goal was to determine the relative corrosiveness of the varioustreatments. Furthermore, it makes little difference if, for example, lead is present at 10mg/L or 15 mg/L The levels are unacceptably high in either case. Even if there were afairly high level of error in the UBC measurements (unlikely but possible), it can still be146safely concluded that the metal levels mandate a requirement for caution beforeinhibitors are used in the GVWD distribution system.4.9. Power Failures, Breakdowns, and Other ProblemsIn spite of the best of efforts, with any experiment, things do go wrong. Therewas a number of incidents which may have had some influence on the outcome of thisstudy. Fortunately, due to the long term nature of the study, it is unlikely that they hadany serious effect on the overall results. Nevertheless, the incidents were recorded.Appendix W is a complete listing of them.1475. SUMMARY AND CONCLUSIONS5.1 Major FindingsThe purpose of this project was to study the inhibitor effects of zinc orthophos-phate and sodium silicate treatments in GVWD water, as an adjunct to pH and alkalinityadjustment. Several vehicles were used in order to provide as many different measuresof the effects of the inhibitors as possible, within the physical constraints of the existingpilot plant. There was no intention to examine the precise processes involved with theseinhibitors or to attempt to learn exactly why the results turned out the way they did.5.1.1. Copper CouponsThe results of the copper coupon experiments suggest that, with or without treat-ment, copper corrosion rates decrease with time, but all treatments reduce corrosion ratesbelow those of the raw water. Zinc orthophosphate appears to offer the best copper cor-rosion reduction potential, but sodium silicate appears to be beneficial as well, and thebenefits from pH and alkalinity adjustment alone are not insignificant.5.1.2. Cast Iron CouponsThe cast iron coupon experiments again show a generally decreasing corrosionrate over time regardless of the treatment used. However, none of the treatments appearto provide any significant degree of protection over that obtained from the raw water. Itcould be argued that some of the treatments may cause corrosion to increase over levelsobtained with raw water.5.1.3. Copper Corrosometer ProbesThe copper corrosometer probe experiment also showed a trend toward decreas-ing corrosion rates with time, but some of the treatments had corrosion rates that ap-peared to be higher than that of the raw water. Zinc orthophosphate at the higher dose148appeared to offer the best protection, but sodium silicate was effective as well. By exam-ining corrosion rates over shorter periods of time, one can better observe how those rateschange over time. Generally, the copper corrosometer probe data corroborate the coppercoupon data.5.1.4. Mild Steel Corrosometer ProbesThe mild steel corrosometer probe experiment showed similar corrosion rateswith all treatments, but treatment with zinc orthophosphate or sodium silicate may reducecorrosion rates somewhat. Unfortunately, the short life of the probes, evidence of pittingin the probes, and the fact that the check probes showed changing readings all renderthese data inadequate to assess the corrosion of mild steel.5.1.5. Metal MobilityThe metal mobility experiments demonstrated that a high degree of caution is re-quired before inhibitors are used in the actual distribution system. Generally, the inhibi-tor treatments resulted in the highest water-metal levels. The results do not necessarilycontradict the results of the coupon experiments. Overall, corrosion rates do not neces-sarily relate to metal mobility during long standing periods. For the majority of time, thesystem ran on its regular schedule with water flowing 6 hours a day and the longest sta-nding period being 8 hours each day; it is quite likely that corrosion rates were low dur-ing those times. It seems that during the 24 hour standing periods, the formerlyprotective scale (essentially a metal-inhibitor compound) became weakened and began toslough, either during that standing period, or sometime later. It is also likely that someof the zinc orthophosphate precipitated out before forming a scale, as demonstrated bythe presence of zinc levels well in excess of the feed rates. These two phenomena couldaccount for the high metal levels in particulate form.149The reason for the apparent scale weakening is not obvious. It could have some-thing to do with changes in pH and/or alkalinity and the difficulty encountered with try-ing to maintain pH in the 8-8.5 range. It may also be dependent on the length of standingtime. A representative from the zinc orthophosphate supplier, Technical Products Corp.,also suggested that, due to the nature of the raw water, it is possible that the scale insta-bility was because of low dosages of the chemical. He suggested that further experimen-tation be done at significantly higher dosages (up to 3-4 times the levels tried). A repre-sentative of National Silicates, the sodium silicate supplier, suggested that the 24 hour st-anding period is too long for the scale to remain stable. Overall, the lowest copper mo-bility appears to result from simple pH and alkalinity adjustment, but lead mobility mayactually increase with treatment. As the literature corroborates, further experimentationis required to determine the optimum pH and allcalinity/DIC levels for minimization oflead mobility under standing conditions.5.1.6. Bacterial RegrowthThe bacterial regrowth measurements showed no significant differences betweentreatments in the presence of copper, but the apparent effect of the phosphate inhibitorson regrowth in the presence of cast iron gives cause for concern. It may be that ironbacteria are able to benefit from the phosphate, which could lead to increased corrosionrates. The effects of phosphate inhibitors in the actual distribution system, where healthybacterial colonies already exist, could not be demonstrated in this project. However, thelimited work done here should give rise to significant concern. Bacterial regrowthshould be examined fully in field trials before any consideration is given regarding phos-phate inhibitor use in the total distribution system.1505.1.7. ChloramineDue to the fact that a chloramine only loop was not tested, there is no way ofcorroborating the expectation that chloramine should reduce a water's corrosiveness overthat of raw water.5.2 RecommendationsDue to the high metal levels measured from the standing water samples in thisstudy, the use of either zinc orthophosphate or sodium silicate by the GVWD in the dis-tribution system is not recommended at this time. On the other hand, due to the promisethey showed in terms of lowering overall corrosion rates, it is recommended that bothzinc orthophosphate and sodium silicate be further studied as to the effect of the length ofstanding time and the effect of pH and alkalinity fluctuations and other factors on metalmobility. They should also be more closely examined in an effort to determine the opti-mum dosage that should be used for corrosion inhibition.The use of the corrosometer system and other electrical/electronic methods, as ameans to monitor corrosion in GVWD type waters, needs to be further studied. It isquite possible that one or more such methods, properly calibrated, could offer economi-cal and less labour intensive alternatives to coupon studies.The effect of phosphates on bacterial regrowth needs to be more closely exam-ined, hopefully with actual field trials. The problem of bacterial induced corrosion alsorequires extensive investigation.Perhaps the most profound lesson to be learned from this project lies in the con-tradictory conclusions that could be formed (perhaps mistakenly) when considering theresults of either the coupons or the metal mobility experiments in isolation. Taken alone,the coupon experiments could lead to the conclusion that zinc orthophosphate, and per-haps even sodium silicate, administered in the proper manner and dosage, offers goodpotential as a corrosion inhibitor. Yet the metal mobility experiments clearly demon-151strate a cause for caution before inhibitor use is implemented. It seems ironic that con-sideration of the use of an inhibitor may have been, in part, prompted by health concerns.The potential impact of zinc orthophosphate, or any other inhibitor containingzinc, on sewage treatment facilities and the receiving waters also needs to be studied be-fore their use is contemplated in the GVWD. Zinc is a bactericide, and is toxic to fish.Presently, the zinc concentrations at the sewage treatment plants are at or near maximumacceptable levels (Greater Vancouver Regional District, 1989). If more zinc is added, itcould impair sewage treatment operations. The Federal Department of Fisheries andOceans would likely raise serious objections to any increase in zinc concentrations insewage effluents. The current zinc concentration in GVWD sewage sludge is about 600mg/kg. Sludge containing any more than 500 mg/kg is considered contaminated and re-quires remediation before it can be applied to anything but strict industrial use land (B.C.Ministry of Environment, 1989). Obviously, unless that maximum acceptable level is in-creased, additional zinc in the water cannot be tolerated.It is, indeed, possible that some water systems are currently using inhibitors,based on limited coupon experiments which demonstrated potential economic benefit andmistakenly assuming beneficial health effects. The literature clearly demonstrates suc-cessful use of inhibitors in other studies and in actual distribution system use. 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Guidelines for Drinking Water Quality, Vol 2. Geneva(1984).158Inhibitor Chemical Testing at Seymour DamAPPENDICES159Inhibitor Chemical Testing at Seymour Dam^ Appendix ACopper CouponsSummary of Laboratory Data SheetsAs Prepared byKennedy/Jenks Consultants, San FranciscoAnalysis in Accordance with ASTM D 2688-83, Method C.Three MonthsLoopNo.InsertNo.DateotalDaysInitialWt, gRemovedWt, gGain/Loss, gCleanedWt, gScale &Corr ProWt, gCouponWeightLoss, gWeightLoss Ratemm/yrPittingDepth, mmIn-sertedRe-moved Avg Max1 CDAl22L-01 15/03/91 17/06/91 94 92.8135 92.6542 -0.1593 92.5575 0.0967 0.2560 0.0134 0.0094 0.01402 CDAl22L-02 15/03/91 17/06/91 94 92.8568 92.6680 -0.1888 92.5378 0.1302 0.3190 0.0167 0.0071 0.01043 CDAl22L-03 15/03/91 17/06/91 94 92.7828 92.6442 .0.1386 92.4744 0.1698 0.3084 0.0161 0.0058 0.00714 CDAl22L-04 15/03/91 17/06/91 94 92.8572 92.7613 -0.0959 92.6747 0.0866 0.1825 0.0095 0.0038 0.00535 CDAl22L-05 15/03/91 17/06/91 94 92.8905 92.8036 -0.0869 92.7470 0.0566 0.1435 0.0075 0.0041 0.00536 CDAl22L-06 15/03/91 17/06/91 94 92.9433, 92.8891 ,-0.0542 92.8556 0.0335 0.0877 0.0046 0.0038 0.00537 CDAl22L-21 15/03/91 17/06/91 94 92.7194 92.6115 -0.1079 92.5760 0.0355 0.1434 0.0075 0.0036 0.00531 CDAl22L-43 18/12/91 16/03/92 89 92.9908 92.7872 -0.2036 92.6984 0.0888 0.2924 0.0161 0.0036 0.00412 CDAl22L-44 19/12/91 17/03/92 89 92.9039 92.8349 -0.0690 92.7675 0.0674 0.1364 0.0075 0.0036 0.00413 CDAl22L-45 20/12/91 18/03/92 89 92.7088 92.5992 -0.1096 92.5130 0.0862 0.1958 0.0108 0.0041 0.00464 CDAl22L-46 21/12/91 19/03/92 89 92.8072 92.7676 -0.0396 92.7190 0.0486 0.0882 0.0049 0.0036 0.00415 CDAl22L-47 22/12/91 20/03/92 89 92.8551 92.6990 -0.1561 92.6630 0.0360 0.1921 0.0106 0.0038 0.00416 CDAl22L-49 23/12/91 21/03/92 89 92.9063 92.8851 -0.0212 92.8306 0.0545 0.0757 0.0042 0.0038 0.00417 CDAl22L-48 24/12/91 22/03/92 89 92.8324 92.7099 -0.1225 92.6805 0.0294 0.1519 0.0084 0.0036 0.0041Six MonthsI CDAl22L-08 15/03/91 16/09/91 185 92.8831 92.6435 -0.2396 92.3927 0.2508 0.4904 0.0130 0.0053 N/A*2 CDAl22L-09 15/03/91 16/09/91 185 92.9016 92.7252 -0.1764 92.5045 0.2207 0.3971 0.0105 0.0025 N/A*3 CDAl22L-10 15/03/91 16/09/91 185 92.8537 92.6803 -0.1734 92.4111 0.2692 0.4426 0.0117 0.0025 N/A*4 CDAl22L-12 15/03/91 16/09/91 185 92.8370 92.7094 -0.1276 92.5625 0.1469 0.2745 0.0073 0.0041 N/A*5 CDAl22L-11 15/03/91 16/09/91 185 92.8295 92.7385 -0.0910 92.6258 0.1127 0.2037 0.0054 0.0020 N/A*6 CDAl22L-13 15/03/91 16/09/91 185 92.8755 92.8030 -0.0725 92.7407 0.0623 0.1348 0.0036 0.0020 N/A*7 CDAl22L-23 15/03/91 16/09/91 185 92.9583 92.7632 -0.1951 92.6994 0.0638 0.2589 0.0069 0.0023 N/A*1 CDAl22L-39 16/09/91 16/03/92 182 92.6836 92.3981 -0.2855 92.1297 0.2684 0.5539 0.0149 0.0041 0.00512 CDAl22L-40 16/09/91 16/03/92 182 92.8765 92.7462 -0.1303 92.5539 0.1923 0.3226 0.0087 0.0038 0.00463 CDAl22L-41 16/09/91 16/03/92 182 92.8048 92.6362 -0.1686 92.4064 0.2298 0.3984 0.0107 0.0043 0.00514 CDAl22L-36 16/09/91 16/03/92 182 92.7359 92.6195 -0.1164 92.5128 0.1067 0.2231 0.0060 0.0036 0.00385 DAl22L-3 16/09/91 16/03/92 182 92.9664 92.8551 -0.1113 92.7310 0.1241 0.2354 0.0064 0.0038 0.00436 CDAl22L-37 16/09/91 16/03/92 182 92.9955_ 92.4510 -0.5445 92.9124 -0.4614 0.0831 0.0022 0.0030 0.00367 CDAl22L-42 16/09/91 16/03/92 182 92.8149^92.6850 -0.1299 92.6268 0.0582 0.1881 0.0051 0.0038 0.0046* No values for maximum pitting depths provided by Kennedy/Jenks.160Inhibitor Chemical Testing at Seymour Dam^ Appendix ACopper CouponsSummary of Laboratory Data SheetsAs Prepared byKennedy/Jenks Consultants, San FranciscoAnalysis in Accordance with ASTM D 2688-83, Method C.Nine MonthsLoopNo.InsertNo.DateotalDaysInitialWt, gRemovedWt, gGain/Loss, gCleanedWt, gScale &Corr ProWt, gCoupoWeightLoss, gWeightLoss Ratemm/yrPittingDepth, mmIn-sertedRe-moved Avg Max1 CDAl22L-15 15/03/91 18/12/91 278 92.9164 92.5628 -0.3536 92.1996 0.3632 0.7168 0.0127 0.0038 N/A*2 DAl22L-16 15/03/91 18/12/91 278 92.8928 92.7276 -0.1652 92.4201 0.3075 0.4727 0.0083 0.0033 N/A*CDAl22L-18 15/03/91 18/12/91 278 92.8527 92.6563 -0.1964 92.3376 0.3187 0.5151 0.0091 0.0033 N/A*4 CDAl22L-17 15/03/91 18/12/91 278 92.8987 92.8236 -0.0751 92.5577 0.2659 0.3410 0.0060 0.0023 N/A*5 CDAl22L-19 15/03/91 18/12/91 278 92.8053 92.6367 -0.1686 92.4739 0.1628 0.3314 0.0059 0.0028 N/A*6 CDAl22L-07 15/03/91 18/12/91 278 93.0408 92.9290 -0.1118 92.8407 0.0883 0.2001 0.0035 0.0023 N/A*7 CDAl22L-14 15/03/91 18/12/91 278 92.9803 92.8701 -0.1102 92.7710 0.0991 0.2093 0.0037 0.0023 N/A*1 CDAl22L-31 17/06/91 16/03/92 273 92.9076 92.5351 -0.3725 92.1618 0.3733 0.7458 0.0134 0.0038 0.00512 CDAl22L-30 17/06/91 16/03/92 273 92.9082 92.7158 -0.1924 92.4903 0.2255 0.4179 0.0075 0.0038 0.00513 CDAl22L-33 17/06/91 16/03/92 273 92.8300 92.6713 -0.1587 92.4229 0.2484 0.4071 0.0073 0.0038 0.00514 CDAl22L-32 17/06/91 16/03/92 273 92.8903 92.8307 -0.0596 92.6276 0.2031 0.2627 0.0047 0.0053 0.00715 CDAl22L-34 17/06/91 16/03/92 273 92.8521 92.7353 -0.1168 92.5649 0.1704 0.2872 0.0052 0.0041 0.00516 CDAl22L-29,17/06/91 16/03/92 273 92.8949 92.8030 -0.0919 92.7276 0.0754 0.1673 0.0030 0.0046 0.00537 CDAl22L-35 17/06/91 16/03/92 273 92.7999 92.7380 -0.0619 92.6460 0.0920 0.1539 0.0028 0.0041 0.0051Twelve Months1 CDAl22L-22 15/03/91 16/03/92 367 92.8276 92.4328 -0.3948 92.0004 0.4324 0.8272 0.0111 0.0152 0.02032 CDAl22L-24 15/03/91 16/03/92 367 92.9164 92.7461, -0.1703 92.3788 0.3673 0.5376 0.0072 0.0089 0.01223 CDAl22L-25 15/03/91 16/03/92 367 92.8755 92.7175 -0.1580 92.3174 0.4001 0.5581 0.0075 0.0079 0.01044 CDAl22L-27 15/03/91 16/03/92 367 92.8480 92.7600 -0.0880 92.5010 0.2590 0.3470 0.0046 0.0064 0.00865 CDAl22L-28 15/03/91 16/03/92 367, 92.7092 92.5843 -0.1249 92.3760 0.2083 0.3332 0.0045 0.0043 0.00516 CDAl22L-26 15/03/91 16/03/92 367 92.8444 92.7542 -0.0902 92.6687 0.0855 0.1757 0.0024 0.0041 0.00517 CDAl22L-20 15/03/91 16/03/92 367 92.9216 92.8507 -0.0709 92.7378 0.1129 0.1838 0.0025 0.0038 0.0051* No values for maximum pitting depths provided by Kennedy/Jenks.161Inhibitor Chemical Testing at Seymour Dam^ Appendix BCast Iron CouponsSummary of Laboratory Data SheetsAs Prepared byKennedy/Jenks Consultants, San FranciscoAnalysis in Accordance with ASTM D 2688-83, Method C.Three MonthsLoopNo.InsertNo.DateotalDaysInitialWt, gRemovedWt, gGain/Loss, gCleanedWt, gScale &Corr ProWt, gCouponWeightLoss, gWeightLoss Ratemm/yrPittingDepth, mmIn-sertedRe-moved Avg MaxI CI-01 15/03/91 17/06/91 94 237.50 238.70 1.20 232.53 6.17 4.97 0.314 0.079 0.1172 CL-02 15/03/91 17/06/91 94 232.30 230.23 -2.07 229.37 0.86 2.93 0.185 0.020 0.0303 CI-05 15/03/91 17/06/91 94 233.40 231.34 -2.06 230.29 1.05 3.11 0.196 0.019 0.0304 CI-03 15/03/91 17/06/91 94 231.80 232.45 0.65 228.54 3.91 3.26 0.206 0.046 0.0695 CI-04 15/03/91 17/06/91 94 232.00 230.74 -1.26 228.66 2.08 3.34 0.211 0.074 0.0916 CI-06 15/03/91 17/06/91 94 234.60 234.15 -0.45 230.76 3.39 3.84 0.242 0.033 0.0487 CI-07 15/03/91 17/06/91 94 232.30 230.57 -1.73 229.23 1.34 3.07 0.194 0.033 0.0481 CI-43 18/12/91 16/03/92 89 233.80 234.42 0.62 230.02 4.40 3.78 0.252 0.064 0.0942 CI-44 19/12/91 17/03/92 89 235.30 234.57 -0.73 231.57 3.00 3.73 0.249 0.053 0.0713 CI-45 20/12/91 18/03/92 89 234.80 232.80 -2.00 232.00 0.80 2.80 0.187 0.056 0.0744 CI-46 21/12/91 19/03/92 89 232.70 233.17 0.47 229.30 3.87 3.40 0.227 0.107 0.1305 CI-47 22/12/91 20/03/92 89 , 231.00 231.42 0.42 228.19 3.23 2.81 0.187 0.079 0.0976 CI-48 23/12/91 21/03/92 89 232.40 232.03 -0.37 228.91 3.12 3.49 0.233 0.064 0.0897 CI-49 24/12/91 22/03/92 89 234.40 233.37 -1.03 231.99 1.38 2.41 0.161 0.058 0.066Six Months1 CI-08 15/03/91 16/09/91 185 234.00 236.12 2.12 226.06 10.06 7.94 0.255 0.093 *N/A2 CI-09 15/03/91 16/09/91 185 230.60 229.40 -1.20 224.92 4.48 5.68 0.182 0.093 *N/A3 CI-10 15/03/91 16/09/91 185 231.90 229.40 -2.50 224.92 4.48 6.98 0.224 0.094 *N/A4 CI-11 15/03/91 16/09/91 185 231.80 234.61 2.81 225.17 9.44 6.63 0.213 0.088 *N/A5 CI-12 15/03/91 16/09/91 185 231.50 232.82 1.32 227.40 5.42 4.10 0.131 0.080 *N/A6 CI-25 15/03/91 16/09/91 185 233.70 235.58 1.88 226.67 8.91 7.03 0.225 0.096 *N/A7 CI-13 15/03/91 16/09/91 185 232.00 229.34 -2.66 224.56 4.78 7.44 0.239 0.091 *N/ACI-36 16/09/91 16/03/92 182 235.20 237.10 1.90 229.59 7.51 5.61 0.183 0.071 0.0792 CI-37 16/09/91 16/03/92 182 234.60 236.28 1.68 227.87 8.41 6.73 0.219 0.084, 0.1093 CI-39 16/09/91 16/03/92 182 232.50 233.34 0.84 226.46 6.88 6.04 0.197 0.071 0.0864 CI-40 16/09/91,16/03/92 182 232.70 235.94 3.24 226.41 9.53 6.29 0.205 0.079 0.099s CI-38 16/09/91 16/03/92 182 232.80 234.48 1.68 226.24 8.24 6.56 0.214 0.071 0.0846 CI-41 16/09/91 16/03/92 182 234.40 235.97 1.57 228.56 7.41 5.84 0.190 0.079 0.0997 CI-42 16/09/91 16/03/92 182 234.10 236.24 2.14 228.84 7.40 5.26 0.171 0.058 0.079* No values for maximum pitting depths provided by Kennedy/Jenks.162Inhibitor Chemical Testing at Seymour Dam^ Appendix BCast Iron CouponsSummary of Laboratory Data SheetsAs Prepared byKennedy/Jenks Consultants, San FranciscoAnalysis in Accordance with ASTM D 2688-83, Method C.Nine MonthsLoopNo.InsertNo.DateotalDaysInitialWt, gRemovedWt, gGain/Loss, gCleanedWt, gScale &Corr ProWt, gCoupoWeightLoss, gWeightLoss Ratemm/yrPittingDepth, mmIn-sertedRe-moved Avg Max1 CI-15 15/03/91 18/12/91 278 233.30 237.83 4.53 222.82 15.01 10.48 0.224 0.150 *N/A2 CI-16 15/03/91 18/12/91 278 231.90 235.01 3.11 223.45 11.56 8.45 0.180 0.089 *N/A3 CI-17 15/03/91 18/12/91 278 234.10 238.40 4.30 226.37 12.03 7.73 0.165 0.114 *N/A4 CI-18 15/03/91 18/12/91 278 234.00 238.23 4.23 226.67 11.56 7.33 0.156 0.097 *N/A5 CI-19 15/03/91 18/12/91 278 235.10 240.14 5.04 225.34 14.80 9.76 0.208 0.122 *N/ACI-20 15/03/91 18/12/91 278 232.80 237.41 4.61 224.85 12.56 7.95 0.170 0.094 *N/A7 C1-14 15/03/91 18/12/91 278 234.10 239.30 5.20 226.22 13.08 7.88 0.168 0.124 *N/A1 CI-29 17/06/91 16/03/92 273 234.60 237.58 2.98 226.27 11.31 8.33 0.181 0.104 0.1682 CI-30 17/06/91 16/03/92 273 232.70 236.34 3.64 223.90 12.44 8.80 0.191 0.081 0.0973 CI-32 17/06/91 16/03/92 273 232.70 236.59 3.89 224.96 11.63 7.74 0.168 0.079 0.1044 CI-31 17/06/91 16/03/92 273 235.50 239.54 4.04 228.16 11.38 7.34 0.159 0.061 0.0795 CI-33 17/06/91 16/03/92 273 232.90 236.56 3.66 224.04 12.52 8.86 0.192 0.053 0.0746 CI-34 17/06/91 16/03/92 273 232.10 235.73 3.63 224.51 11.22 7.59 0.165 0.076 0.1097 CI-35 17/06/91 16/03/92 273 232.50 236.57 4.07 224.65 11.92 7.85 0.171 0.084 0.104Twelve Months1 CI-22 15/03/91 16/03/92 367 234.00 240.84 6.84 222.80 18.04 11.20 0.181 0.097 0.1142 CI-23 15/03/91 16/03/92 367 232.60 239.09 6.49 220.67 18.42 11.93 0.193 0.124 0.1833 CI-24 15/03/91 16/03/92 367 233.10 239.56 6.46 222.77 16.79 10.33 0.167 0.091 0.1194 CI-27 15/03/91 16/03/92 367 234.80 240.65 5.85 226.45 14.20 8.35 0.135 0.168 0.1965 CI-26 15/03/91 16/03/92 367 232.60 240.67 8.07 220.89 19.78 11.71 0.189 0.150 0.1936 CI-28 15/03/91 16/03/92 367 232.60 239.48 6.88 223.30 16.18 9.30 0.150 0.137 0.2017 CI-21 15/03/91 16/03/92 367 235.60 243.25 7.65 225.75 17.50 9.85 0.159 0.147 0.165* No values for maximum pitting depths provided by Kennedy/Jenks.163Inhibitor Chemical Testing at Seymour Dam^ Appendix BCast Iron CouponsSummary of Laboratory Data SheetsAs Prepared byKennedy/Jenks Consultants, San FranciscoAnalysis in Accordance with ASTM D 2688-83, Method C.Three MonthsLoopNo.InsertNo.DateTotalDaysScaleThickness,mmIn-sertedRe-moved1 CI-01 15/03/91 17/06/91 94 0.512 CL-02 15/03/91 17/06/91 94 0.763 CI-05 15/03/91 17/06/91 94 1.024 CI-03 15/03/91 17/06/91 94 0.765 CI-04 15/03/91 17/06/91 94 1.276 CI-06 15/03/91 17/06/91 94 0.517 CI-07 15/03/91 17/06/91 94 1.021 CI-43 18/12/91 16/03/92 89 0.512 CI-44 19/12/91 17/03/92 89 0.253 CI-45 20/12/91 18/03/92 89 0.254 CI-46 21/12/91 19/03/92 89 0.765 CI-47 22/12/91 20/03/92 89 0.516 CI-48 23/12/91 21/03/92 89 0.517 CI-49 24/12/91 22/03/92 89 1.02Six Months1 CI-08 15/03/91 16/09/91 185 0.762 CI-09 15/03/91 16/09/91 185 1.273 CI-10 15/03/91 16/09/91 185 1.274 CI-11 15/03/91 16/09/91 185 1.525 CI-12 15/03/91 16/09/91 185 1.026 CI-25 15/03/91 16/09/91 185 1.027 CI-13 15/03/91 16/09/91 185 0.761 CI-36 16/09/91 16/03/92 182 1.272 CI-37 16/09/91 16/03/92 182 1.273 CI-39 16/09/91 16/03/92 182 1.274 CI-40 16/09/91 16/03/92 182 1.915 CI-38 16/09/91 16/03/92 182 1.026 CI-41 16/09/91 16/03/92 182 1.527 CI-42 16/09/91 16/03/92 182 5.08164Inhibitor Chemical Testing at Seymour Dam^ Appendix BCast Iron CouponsSummary of Laboratory Data SheetsAs Prepared byKennedy/Jenks Consultants, San FranciscoAnalysis in Accordance with ASTM D 2688-83, Method C.Nine MonthsLoopNo.InsertNo.DateTotalDaysScaleThickness,mmIn-sertedRe-moved1 CI-15 15/03/91 18/12/91 278 1.272 CI-16 15/03/91 18/12/91 278 2.033 CI-17 15/03/91 18/12/91 278 1.524 CI-18 15/03/91 18/12/91 278 2.035 CI-19 15/03/91 18/12/91 278 1.526 CI-20 15/03/91 18/12/91 278 1.277 CI-14 15/03/91 18/12/91 278 2.031 CI-29 17/06/91 16/03/92 273 1.022 CI-30 17/06/91 16/03/92 273 2.033 CI-32 17/06/91 16/03/92 273 1.524 CI-31 17/06/91 16/03/92 273 1.52s CI-33 17/06/91 16/03/92 273 2.296 CI-34 17/06/91 16/03/92 273 2.037 CI-35 17/06/91 16/03/92 273 2.54Twelve Months1 CI-22 15/03/91 16/03/92 367 1.522 CI-23 15/03/91 16/03/92 367 3.813 CI-24 15/03/91 16/03/92 367 2.034 CI-27 15/03/91 16/03/92 367 2.035 CI-26 15/03/91 16/03/92 367 3.056 CI-28 15/03/91 16/03/92 367 2.547 CI-21 15/03/91 16/03/92 367 3.56165Inhibitor Chemical Testing at Seymour Dam^ Appendix DCopper Corrosometer Probe Data (Installed 29 Apr 91)DateDaysSinceInstalledLoop 1 Loop 2 Loop 3 Loop 4CheckReadingDialReadingCheckReadingDialReadingCheckReadingDialReadingCheckReadingDialReading08/05/91 9 798.5 156.0 808.0 179.5 800.0 126.0 798.0 150.021/05/91 22 799.5 187.5 809.0 226.0 801.5 174.0 799.0 167.528/05/91 29 798.0 197.5 808.5 242.5 800.5 195.0 798.5 174.504/06/91 36 799.5 212.5 808.0 261.0 800.5 215.5 798.0 183.012/06/91 44 7963 219.0 805.5 272.0 797.5 2175 794.5 172.019/06/91 51 797.0 208.0 807.0 257.5 799.0 191.5 796.0 149.526/06/91 58 798.0 253.0 808.5 301.5 799.0 221.5 797.0 188.503/07/91 65 798.5 267.5 806.5 316.5 799.5 229.5 796.5 199.010/07/91 72 796.0 266.0 805.0 327.0 798.5 231.5 795.5 200.517/07/91 79 798.0 273.5 808.0 346.0 799.5 240.0 7973 214.024/07/91 86 797.5 268.0 806.5 348.0 799.0 236.5 796.0 207.531/07/91 93 798.0 272.0 808.0 359.0 799.0 240.0 797.0 209.007/08/91 100 797.0 270.5 807.0 368.5 799.5 241.5 796.0 211.014/08/91 107 797.5 269.0 806.5 372.5 798.5 239.5 796.0 210.021/08/91 114 797.0 273.5 806.0 3823 797.5 244.5 796.0 214.028/08/91 121 798.0 280.5 808.0 395.5 800.0 250.5 798.0 220.004/09/91 128 799.0 284.0 809.5 406.0 801.5 255.0 799.0 223.511/09/91 135 798.5 280.5 808.0 411.0 801.0 252.0 797.5 225.518/09/91 142 799.0 286.5 808.0 417.5 799.5 257.0 797.5 229.001/10/91 155 798.0 275.0 807.0 424.0 799.0 2485 797.0 222.009/10/91 163 798.5 291.0 808.5 429.5 799.5 263.0 797.5 238.016/10/91 170 798.5-1292.0 808.0 434.5 800.0 264.0 799.0 234.523/10/91 177 800.0 310.0 802.0 274.0 799.0 245.530/10/91 184 801.0 322.0 810.5 455.0 802.0 275.0 800.0 246.506/11/91 191 801.0 332.5 812.0 469.0 803.0 284.0 8015 253.012/11/91 197 803.0 332.5 811.5 462.5 804.0 282.0 801.5 251.520/11/91 205 802.5 338.5 813.0 459.0 804.0 289.0 802.5 256.527/11/91 212 803.5 338.5 812.5 462.0 804.0 288.5 801.5 258.004/12/91 219 802.5 341.5 813.0 460.0 804.0 288.0 801.5 255.011/12/91 226 803.5 343.0 813.0 461.0 804.0 291.0 8015 257.018/12/91 233 804.0 348.0 812.5 465.0 805.0 292.0 802.0 261.030/12/91 245 803.5 354.0 813.0 463.5 805.0 302.0 802.0 261.006/01/92 252 804.0 362.0 813.0 469.5 805.5 314.0 803.0 266.013/01/92 259 804.0 363.0 813.0 470.0 805.0 319.0 803.5 266.020/01/92 266 803.5 363.0 813.0 469.0 804.0 319.0 803.0 263.027/01/92 273 804.0 369.0 813.0 475.0 805.5 327.0 803.5 270.004/02/92 281 803.5 366.5 812.0 470.0 804.5 319.5 802.0 259.514/02/92 291 804.0 371.0 813.0 472.0 805.5 323.0 802.5 266.019/02/92 296 804.0 369.5 812.5 470.0 805.5 320.0 802.5 265.524/02/92 301 8035 369.0 813.0 472.0 805.0 3225 802.0 265.503/03/92 309 804.0 374.0 812.0 474.0 804.0 326.0 801.0 263.010/03/92 316 802.0 359.0 809.5 463.0 802.0 312.5 800.0 244.0166Inhibitor Chemical Testing at Seymour Dam^ Appendix DCopper Corrosometer Probe Data (Installed 29 Apr 91)DateDaysSinceInstalledLoop 5 Loop 6 Loop 7CheckReadingDialReadingCheckReadingDialReadingCheckReadingDialReading08/05/91 9 802.0 156.5 795.5 163.0 802.0 147.021/05/91 22 803.0 179.0 796.0 172.0 803.5 152.028/05/91 29 802.0 190.5 796.0 169.0 802.0 150.004/06/91 36 802.5 198.0 795.5 170.0 803.0 151.512/06/91 44 799.0 195.5 792.5 151.0 800.0 103.019/06/91 51 800.5 168.5 793.5 123.5 800.5 103.026/06/91 58 800.5 212.5 794.0 162.0 801.5 145.003/07/91 65 800.0 219.0 794.0 168.0 801.5 150.010/07/91 72 798.5 2233 7923 167.0 800.0 142.017/07/91 79 800.0 240.0 795.0 177.0 802.0 153.024/07/91 86 799.0 240.0 793.0 172.0 800.5 143331/07/91 93 798.0 246.5 793.5 173.5 801.0 149.507/08/91 100 798.5 251.0 793.0 177.0 801.5 146.514/08/91 107 798.5 252.0 793.0 176.0 801.5 144.021/08/91 114 797.0 258.0 793.0 179.0 801.5 146.028/08/91 121 800.0 266.5 794.5 185.0 803.0 151.504/09/91 128 799.0 274.5 795.5 188.5 803.0 159.011/09/91 135 800.0 280.0 794.5 187.0 802.5 158.518/09/91 142 798.5 274.5 795.0 187.5 802.0 158.501/10/91 155 797.0 288.0 794.0 1713 8013 144309/10/91 163 797.0 310.5 795.0 188.5 802.5 168.016/10/91 170 797.5 315.0 795.0 183.0 8023 172.023/10/91 177 799.0 330.0 795.5 196.0 804.0 178.530/10/91 184 799.5 337.0 797.5 196.0 805.0 190.006/11/91 191 800.5 347.5 798.5 203.5 806.5 197.012/11/91 197 801.5 347.0 798.5 199.5 806.0 199.520/11/91 205 802.0 360.0 799.0 204.0 807 207.027/11/91 212 802.0 361.0 799.5 203.5 807.0 207.004/12/91 219 802.5 360.5 799.0 199.5 805.5 208.511/12/91 226 801.5 366.0 800.0 201.5 807.0 217.018/12/91 233 802.0 361.0 799.5 209.0 807.5 213.530/12/91 245 803.0 364.0 800.0 205.0 808.0 218.506/01/92 252 8033 372.0 800.0 211.5 807.5 223.013/01/92 259 804.0 374.0 801.0 214.0 808.0 220.520/01/92 266 803.5 3743 800.0 209.0 808.0 226.527/01/92 273 804.5 380.5 801.0 214.0 808.0 229.5,04/02/92 281 802.0 375.0 800.0 204.0 806.0 221.014/02/92 291 804.5 383.0 800.0 212.0 807.5 226.019/02/92 296 803.5 382.5 799.5 204.5 807.5 226.024/02/92 301 803.0 383.5 800.0 210.0 808.0 226.003/03/92 309 802.0 383.5 799.0 207.0 806.5 221.010/03/92 316 800.0 366.0 797.0 188.0 804.0 211.5167Inhibitor Chemical Testing at Seymour Dam^ Appendix DCopper Corrosometer Probe Data (Installed 29 Apr 91)Corrosion Rates, mm/yrInitial Middle Latter3Months6Months9Months10MonthsLoop 1 0.0146 0.0019 0.0033 0.0117 0.0090 0.0072 0.0067Loop 2 0.0177 0.0131 0.0008 0.0193 0.0147 0.0099 0.0091Loop 3 0.0307 0.0035 0.0008 0.0118 0.0080 0.0066 0.0062Loop 4 0.0113 0.0038 0.0008 0.0062 0.0052 0.0037 0.0035Loop 5 0.0126 0.0089 0.0023 0.0096 0.0097 0.0074 0.0070Loop 6 0.0004 0.0004 0.0001 0.0014 0.0021 0.0014 00014Loop 7 0.0007 0.0072 0.0006 0.0003 0.0025 0.0025 0.0023168Inhibitor Chemical Testing at Seymour Dam^ Appendix DMild Steel Corrosometer Probe Data (Installed 29 Apr 91)DateDaysSinceInstalledLoop 1 Loop 2 Loop 3 Loop 4CheckReadingDialReadingCheckReadingDialReadingCheckReadingDialReadingCheckReadingDialReading08/05/91 9 814.0 50.0 815.0 65.0 797.0 44.0 800.0 41.521/05/91 22 814.0 99.5 815.0 113.0 797.0 91.0 801.0 86.528/05/91 29 814.0 125.5 815.0 137.0 797.0 118.0 8003 109.004/06/91 36 814.0 150.0 815.0 161.5 797.0 144.0 800.5 131.512/06/91 44 812.0 175.5 813.0 191.0 795.0 174.0 795.0 174.519/06/91 51 812.0 192.0 813.0 209.0 795.0 187.0 799.0 169.026/06/91 58 814.0 230.0 814.0 247.5 796.5 229.5 800.0 205.503/07/91 65 813.5 260.0 814.5 279.5 796.5 261.5 800.5 238.510/07/91 72 813.0 288.5 813.5 313.5 796.0 294.5 799.5 254.517/07/91 79 813.5 318.0 814.5 347.0 796.5 330.0 800.0 279.524/07/91 86 813.5 347.5 814.0 3815 7965 369.0 800.5 304.031/07/91 93 813.5 380.5 814.0 419.5 796.5 412.0 800.5 329.007/08/91 100 813.5 414.5 814.5 458.0 796.5 457.0 800.0 351.514/08/91 107 8135 438.0 814.5 485.0 796.0 495.0 799.5 366521/08/91 114 812.5 475.5 814.0 518.0 796.5 540.0 798.0 387.028/08/91 121 814.0 511.0 815.0 554.0 796.5 592.5 798.5 409.004/09/91 128 8143 542.5 815.0 584.5 797.0 6393 798.5 428311/09/91 135 814.0 580.0 815.0 620.5 796.5 697.0 797.5 449.018/09/91 142 813.5 624.0 814.5 659.5 796.5 762.0 795.0 472.001/10/91 155 814.5 715.0 8155 743.0 795.5 9505 792.5 519.509/10/91 163 814.5 782.5 815.5 784.5 791.0 544.016/10/91 170 814.0 839.0 815.5 828.0 788.0 568.023/10/91 177 8153 9155 8153 8795 7865 598.530/10/91 184 815.5 930.5 783.5 619.506/11/91 191 816.5 990.0 780.0 645.512/11/91 197 779.0 665.520/11/91 205 776.5 694.027/11/91 212 771.0 717.504/12/91 219 767.5 745.511/12/91 226 764.5 772.018/12/91 233 756.5 803.530/12/91 245 741.0 857.006/01/92 252 730.5 897.013/01/92 259 715.5 938.020/01/92 266 701.0 986.5169Inhibitor Chemical Testing at Seymour Dam^ Appendix DMild Steel Corrosometer Probe Data (Installed 29 Apr 91)DateDaysSinceInstalledLoop 5 Loop 6 Loop 7CheckReadingDialReadingCheckReadingDialReadingCheckReadingDialReading08/05/91 9 797.5 59.5 806.0 52.5 792.5 38.021/05/91 22 797.5 111.0 807.0 74.5 792.5 71.528/05/91 29 797.5 136.0 806.5 84.5 792.5 85.004/06/91 36 797.5 162.5 807.0 93.5 792.5 102.012/06/91 44 796.0 192.0 804.0 102.0 791.0 95.019/06/91 51 795.0 210.0 804.0 102.0 790.0 119.026/06191 58 797.0 256.0 806.5 126.5 792.0 153.503/07/91 65 797.0 291.0 806.5 138.5 792.0 172.010/07/91 72 796.0 325.0 805.5 152.5 791.5 189.517/07/91 79 797.5 357.5 806.5 166.0 792.5 205.024/07/91 86 797.0 390.5 806.5 1803 792.5 218331/07/91 93 797.0 424.0 806.0 195.5 792.5 234.007/08/91 100 796.0 460.5 806.0 210.0 792.0 250.014/08/91 107 796.5 489.0 8063 220.0 792.0 262.521/08/91 114 797.0 523.0 805.5 240.5 791.0 280.528/08191 121 797.0 559.0 806.5 259.0 792.0 297.504/09/91 128 797.0 591.0 806.5 2773 792.0 314311/09/91 135 797.0 630.0 807.0 300.0 791.5 334.518/09/91 142 797.5 674.0 806.5 322.0 790.5 355.001/10/91 155 7963 789.0 807.0 371.0 786.5 389.009/10/91 163 796.5 882.5 806.5 399.0 786.0 430.516/10/91 170 806.5 428.5 782.0 459.523/10/91 177 807.5 471.0 7793 496.030/10/91 184 807.5 504.5 775.0 524.506/11/91 191 807.5 543.0 773.5 557.512/11/91 197 808.0 574.5 770.0 584.520/11/91 205 808.0 627.0 767.5 625.527/11/91 212 808.5 681.5 764.5 665.504/12/91 219 808.0 771.0 763.5 710.011/12/91 226 808.5 918.0 763.0 765.018/12/91 233 762.0 835.030/12/91 245 761.5 889.506/01/92 25213/01/92 25920/01/92 266170Inhibitor Chemical Testing at Seymour Dam^ Appendix DMild Steel Corrosometer Probe Data (Installed 29 Apr 91)Corrosion Rates, mmpyLoop#Initial Later 3Months6Months9Months1 0.3582 0.4927 0.3713 0.40012 0.3179 0.4575 0.4004 0.41443 0.3510 0.5099 0.4208 0.43794 0.3158 0.3187 0.3158 0.3077 0.31215 0.3413 0.4503 0.4085 0.41986 0.1585 0.2999 0.1605 0.21657 0.2210 0.4112 0.2160 0.2646 0.2866171Inhibitor Chemical Testing at Seymour Dam^ Appendix EFaucet Copper Levels, mg/LCopper levels for raw running water samples were measured on 14/02/91,18/02/91,20/02/91, and 28/02/91. Levels in all cases were 0.04 mg/L or less.Copper levels below were measured after a 24 hour standing period.Faucets - Pre-treatmentDateLoop Number1 2 3 4 5 6 718/02/91 0.49 0.43 0.13 0.33 0.23 0.25 0.2820/02/91 0.40 0.27 0.27 0.27 0.31 0.25 0.2127/02/91 0.40 0.37 0.06 0.28 0.22 0.23 0.18Averages 0.43 0.36 0.15 0.29 0.25 0.24 0.22Faucets - TreatedDateDays FromStartLoop Number1 2 3 4 5 6 727/03/91 11 0.40 0.07 0.10 0.06 0.04 0.03 0.0505/04/91 20 0.37 0.35 0.07 0.12 0.08 0.05 0.0710/04/91 25 0.41 0.10 0.23 0.03 0.05 0.05 0.0610/05/91 55 0.37 0.18 0.16 0.06 0.10 0.06 0.1115/05/91 60 0.58 0.07 0.05 0.03 0.04 0.01 0.0623/05/91 68 0.59 0.00 0.00 0.00 0.00 0.00 0.0029/05/91 74 0.64 0.08 0.08 0.04 0.06 0.03 0.0705/06/91 81 0.39 0.09 0.09 0.06 0.07 0.04 0.1112/06/91 88 0.26 0.04 0.02 0.00 0.00 0.00 0.0025/06/91 101 0.26 0.09 0.08 0.06 0.08 0.05 0.0810/07/91 116 0.29 0.09 0.05 0.05 0.04 0.03 0.0624/07/91 130 0.36 0.13 0.09 0.06 0.11 0.07 0.0910/08/91 147 0.37 0.04 0.04 0.02 0.02 0.00 0.0220/08/91 157 0.11 0.09 0.08 0.08 0.04 0.0610/09/91 178 0.35 0.10 0.10 0.08 0.11 0.06 0.0701/10/91* 200 0.37 0.16 0.14 0.10 0.17 0.11 0.2322/10/91 220 0.34 0.13 0.12 0.11 0.14 0.07 0.1105/11/91 234 0.22 0.08 0.08 0.12 0.10 0.02 0.0620/11/91 249 0.26 0.10 0.10 0.05 0.09 0.07 0.0304/12/91 263 0.25 0.09 0.07 0.04 0.12 0.03 0.3118/12/91 277 0.19 0.04 0.06 0.00 0.04 0.08 0.0415/01/92 305 0.15 0.03 0.06 0.02 0.05 0.09 0.0519/02/92 340 0.16 0.04 0.04 0.02 0.02 0.01 0.0512/03/92 362 0.14 0.05 0.05 0.02 0.04 0.02 0.04Averages 0.34 0.09 0.08 0.05 0.07 0.04 0.08*Bjpjjfl 01/10/91 sam les were digested prior to metals analysis.Faucets - Filtered Samples (not digested)DateLoop Number1 2 3 4 5 6 701/10/91 199 0.12 0.06 0.07 0.05 0.06 0.04 0.0422/10/91 220 0.05 0.04 0.03 0.01 0.06 0.03 0.0305/11/91 234 0.03 0.02 0.03 0.02 0.03 0.01 0.0120/11/91 249 0.08 0.06 0.04 0.05 0.05 0.06 0.07172VI:1-1te)1-1aoc;4:2101IreCZ'01cu4-)cucJCL)0.81-46In6or66 6 6VIa)6c.)ZoC)VD6C)V)6C)VI6C)In61■166 66666aotriTr6 6Cs16 6ceen 84--I Ci 81-4 ot-6 6 6 6Cri0 0 0 0N6 6 6 61-1 of!)C) 0.*0•rt•1-46 6 6 6t'31\ 41tCA fq CV 4.)" C) C) C) C))■I 0 C)C9Oef9ItCD2111112111111331 13111112123311111 SEIMMEMEMIE:^111211132111E1111  u imam_^wawaInhibitor Chemical Testing at Seymour Dam^ Appendix GFaucet Zinc Levels, mg/LZinc levels for raw running water samples were measured on 14/02/91,18/02/91,20/02/91, and 28/02/91. Levels in all cases were 0.03 mg/L or less.Zinc levels below were measured after a 24 hour standini period.Faucets - Pre-treatmentDateLoop Number1 2 3 4 5 6 718/02/91 0.46 0.40 0.35 0.40 0.20 0.34 0.3520/02/91 0.45 0.31 1.10 0.44 0.41 0.39 0.5127/02/91 0.72 0.45 0.34 0.44 0.40 0.44 0.37Averages 0.54 0.39 0.60 0.43 0.34 0.39 0.41Faucets - Pre-treatmentDateDays FromStartLoop Number1 2 3 4 5 6 727/03/91 11 0.29 0.08 0.08 0.11 0.20 0.47 0.4705/04/91 20 0.36 0.24 0.06 0.18 0.24 0.50 0.5410/04/91 25 0.32 0.12 0.12 0.15 0.25 0.50 0.7110/05/91 55 0.21 0.08 0.01 0.02 0.23 0.48 0.4715/05/91 60 0.43 0.11 0.09 0.10 0.30 0.45 0.6023/05/91 68 0.34 0.08 0.04 0.06 0.18 0.38 0.3229/05/91 74 0.26 0.06 0.03 0.05 0.16 0.32 0.3605/06/91 81 0.24 0.06 0.03 0.04 0.16 0.38 0.4912/06/91 88 0.27 0.08 0.02 0.00 0.22 0.49 0.4725/06/91 101 0.22 0.06 0.05 0.07 0.21 0.46 0.4310/07/91 116 0.32 0.06 0.04 0.08 0.18 0.36 0.3824/07/91 130 0.33 0.07 0.05 0.07 0.19 0.40 0.4010/08/91 147 0.33 0.03 0.03 0.06 0.16 0.39 0.3520/08/91 157 0.03 0.03 0.09 0.16 0.35 0.3710/09/91 178 0.25 0.01 0.03 0.15 0.08 0.47 0.4501/10/91* 200 0.24 0.07 0.06 0.14 0.12 0.51 0.4922/10/91 220 0.23 0.07 0.06 0.16 0.15 0.70 0.6705/11/91 234 0.13 0.04 0.04 0.10 0.10 0.40 0.4520/11/91 249 0.18 0.07 0.08 0.10 0.30 0.52 0.4904/12/91 263 0.20 0.02 0.03 0.06 0.19 0.44 0.7018/12/91 277 0.13 0.04 0.03 0.04 0.19 0.52 0.4615/01/92 305 0.12 0.00 0.03 0.12 0.20 0.47 0.4619/02/92 340 0.12 0.02 0.02 0.10 0.16 0.42 0.4312/03/92 362 0.12 0.02 0.02 0.07 0.14 0.40 0.41Averages 0.25 0.06 0.05 0.09 0.19 0.45 0.47*Begipjrnig 01/10/91, samples were digested prior to metals analysis.Faucets - Pre-treatmentDateLoop Number1 2 3 4 5 6 701/10/91 199 0.14 0.01 0.01 0.01 0.04 0.29 0.2522/10/91 220 0.10 0.03 0.03 0.02 0.04 0.28 0.2405/11/91 234 0.05 0.00 0.01 0.00 0.02 0.15 0.1320/11/91 249 0.11 0.04 0.03 0.05 0.11 0.23 0.29174Inhibitor Chemical Testing at Seymour Dam^Appendix HPlumbing Coil Copper Levels, mg/LCopper levels for raw running water samples were measured on 14/02/91, 18/02/91.20/02/91, and 28/02/91. Levels in all cases were 0.04 mg/L or less.Conner levels below were measured after a 24 hour standing eriod.Plumbing Coils - Pre-treatment - Average Levels for Two SamplesDateLoop Number1 2 3 4 5 6 718/02/91 1.32 1.57 1.02 1.65 1.36 1.39 1.3427/02/91 1,82 1.88 1.81 1.78 1.32 1.54 1.52Averages 1.57 1.73 1.42 1.72 1.34 1.47 1.43Plumbing Coils - Average Levels for Two SamplesDays FromStartLoop NumberDate 1 2 3 4 5 6 727/03/91 11 1.25 0.35 5.29 1.13 1.33 1.73 1.4105/04/91 20 0.92 0.86 3.55 2.37 3.04 0.51 0.8010/04/91 25 1.20 0.44 0.92 0.59 1.17 0.85 2.3610/05/91 55 1.26 0.69 1.78 1.53 5.63 4.09 11.4315/05/91 60 1.39 0.45 0.73 0.52 2.43 1.98 2.4023/05/91 68 1.48 0.41 0.87 0.73 1.01 0.38 0.8229/05/91 74 1.47 0.45 1.00 0.76 2.39 2.01 2.9905/06/91 81 1.64 0.47 0.90 0.46 1.82 1.87 2.0812/06/91 88 1.35 0.52 0.91 0.76 2.04 2.64 4.9825/06/91 101 1.31 0.95 1.38 0.82 3.39 6.38 10.0110/07/91 116 1.27 0.55 0.74 0.34 3.33 0.77 5.8024/07/91 130 1.50 0.68 0.52 0.65 1.64 0.56 1.8210/08/91 147 1.76 0.57 1.89 0.59 4.63 4.01 8.8620/08/91 157 1.44 1.35 0.40 0.33 3.33 1.64 2.8410/09/91 178 1.34 0.87 1.12 1.40 3.98 3.24 2.8701/10/91* 200 1.24 1.03 1.73 1.07 8.67 5.41 5.8122/10/91 220 1.35 3.56 2.96 2.12 16.19 8.22 9.1805/11/91 234 1.15 0.63 0.45 1.08 3.76 1.98 2.6219/11/91 248 1.29 0.63 4.36 0.41 18.27 3.09 8.1003/12/91 262 1.06 0.46 0.40 0.31 1.06 0.90 0.3117/12/91 276 0.90 0.36 0.27 0.24 0.88 0.45 0.2414/01/92 304 0.97 0.47 0.41 0.33 0.88 0.48 0.5318/02/92 339 1.07 0.42 0.68 0.62 7.00 0.87 3.1311/03/92 361 0.89 0.30 0.98 0.26 1.77 1.17 1.07Averages 1.27 0.73 1.42 0.81 4.15 2.30 3.85*Be nnin 01/10/91 samples were di ested prior to metals analysis.Plumbing Coils - Average Levels for Two SamplesFiltered Samples (Not Digested)DateLoop Number1 2 3 4 5 6 701/10/91 199 0.56 0.29 0.25 0.24 0.31 0.36 0.3122/10/91 220 0.17 0.30 0.22 0.23 0.25 0.17 0.1905/11/91 234 0.17 0.10 0.11 0.11 0.10 0.05 0.0619/11/91 248 0.30 0.16 0.18 0.15 0.19 0.14 0.15175Inhibitor Chemical Testing at Seymour Dam^ Appendix IPlumbing Coil Lead Levels, mg/LLead levels for raw water, running samples were measured on 18/02/91, 20/02/91,and 28/02/91. Levels in all loops were 0.001 mg/L or less in all cases.Lead levels were measured after a 24 hour standing period.Plumbing Coils - Pre-treatment - Average Levels for Two SamplesDateLoop Number1 2 3 4 5 6 720/02/91 0 025 0.011 0.015 0.010 0.015 0.015 0 01628/02/91 0 025 0.015 0.017 0.011 0.013 0.018 0 01504/03/91 0 021 0.013 0 016 0 0 1 1 0 011 0 015 0 013Averages 0.023 0.013 0.016 0.010 0.013 0.016 0.014Plumbing Coils - Average Levels for Two SamplesDays From ^Loop Number Date^Start^1^2^3^4^5WILMS II MEM.. MOM MEM MIME MUM!ME112LEMIMMII EMBEEMOMI 1.1 6 MIMIMMIII=mum^IMMMMILlinf MIMIMIHUMMIMIIMMAMIONMIMEMOLMaarnIMMMII ILW1 MILIMIMME 1.1 6 MIME=Mall IMM2M11 1.116 IMEEMM1M11IlnE MIMI Mr^1.1 6 MIMIUr:MIME MEM. MEM MIMI 1.116 IMMI Mg MI MOMI^I 16 .11M2IML0111 MiLl^1.116 MI 10M11 IMMEMILIMIVLiTJIMUMMIAM1 MIMI 1.116 MIMIIMIME1■1 1MMaMIMMIMIKIMajMISMIIMIMIIMMAIIMMMMIMIMU^IMEIMIIIIMMOIIMI1^1.1 6 MOMMMLUMIMMEMIIIMIIMMIMEMIUJIAI MIMI 1.1 6 11.1.11MMIII.M.I.MallIIIMIIMM.2LOIlf =Air MEM I. I 6 MEENIMOZMIMMItannin.^Mil. MM. Map. MUM MM. MUMSMIELMIIMIMIMIILIMMOMM 1. 6 MIMIMaM111 IMEMMEIMILMMOMMIlIMIIMEMMIMIMIIIMEMIMMIwinum.tammuni^miongKamm^imr Em a Er nommuu hms IE am!imam= 76 ingumor maimagrr•mulmaimmummingiumingulagi nammaguair Eguagnommagiu=11 MEMIIMEUMMUMIMIEMIIMIIMEMIMI1 '^1 rs^III^1^1n:^iix^11:.16Averages^0.009 0.005 0.027 0.017 0.026 0.054 0.128*Beginning 01/10/91, samples were digested prior to metals analysis.Plumbing Coils - Average Levels for Two SamplesFiltered Samples (Not Digested)Days From^Loop NumberDate Start 1 2 3 4 5 6 701/10/91 199 0 .010 0.015 0.007 0.016 0.004 0.012 0 02423/10/91 221 0.001 0.007 0.009 0.016 0.006 0.004 0 00805/11/91 234 0.004 0.007 0.023 0.008 0.004 0.003 0 00519/11/91 248 0 006 0 002 0 005 0 003 0 005 0 003 0 005176Inhibitor Chemical Testing at Seymour Dam^ Appendix JPlumbing Coil Zinc Levels, mg/LZinc levels for raw running water samples were measured on 14/02/91, 18/02/81,20/02/91, and 28/02/91. Levels in all cases were 0.03 mg/L or less.Zinc levels below were measured after a 24 hour standini Period.Plumbing Coils - Pre-treatment - Average Levels for Two SamplesDateLoop Number1 2 3 4 5 6 718/02/91 0.06 0.02 0.05 0.02 0.02 0.02 0.0327/02/91 0.10 0.09 0.09 0.08 0.08 0.09 0.09Averages 0.08 0.06 0.07 0.05 0.05 0.06 0.06Plumbing Coils - Average Levels for Two SamplesDateDays FromStartLoop Number1 2 3 4 5 6 727/03/91 11 0.02 0.00 0.00 0.02 0.28 1.22 0.6705/04/91 20 0.03 0.02 0.01 0.00 0.38 0.35 0.5510/04/91 25 0.00 0.01 0.01 0.01 0.16 0.47 0.6010/05/91 55 0.00 0.00 0.00 0.00 0.30 0.87 1.0715/05/91 60 0.01 0.01 0.01 0.01 0.27 0.62 0.4923/05/91 68 0.01 0.01 0.01 0.01 0.09 0.18 0.1729/05/91 74 0.00 0.00 0.00 0.00 0.21 0.64 0.5205/06/91 81 0.01 0.00 0.00 0.00 0.17 0.78 0.5912/06/91 88 0.00 0.00 0.00 0.00 0.22 0.77 0.7125/06/91 101 0.00 0.00 0.00 0.00 0.25 1.18 1.0410/07/91 116 0.00 0.00 0.00 0.00 0.34 0.45 1.0124/07/91 130 0.00 0.00 0.00 0.00 0.22 0.48 0.5410/08/91 147 0.00 0.00 0.00 0.00 0.77 3.11 1.5220/08/91 157 0.00 0.00 0.00 0.00 0.57 1.54 1.8710/09/91 178 0.00 0.00 0.00 0.00 0.36 1.51 1.4101/10/91* 200 0.04 0.04 0.04 0.10 0.38 2.25 2.1122/10/91 220 0.49 0.01 0.01 0.01 0.46 2.84 1.8505/11/91 234 0.00 0.00 0.00 0.00 0.13 1.48 1.3319/11/91 248 0.00 0.00 0.01 0.00 0.91 2.22 2.6003/12/91 262 0.00 0.00 0.00 0.00 0.15 0.69 0.4317/12/91 276 0.03 0.03 0.03 0.03 0.19 0.57 0.4114/01/92 304 0.02 0.02 0.02 0.02 0.20 0.51 0.4618/02/92 339 0.01 0.01 0.01 0.00 0.90 0.98 1.7711/03/92 361 0.00 0.00 0.00 0.00 0.25 1.00 0.67Averages 0.03 0.01 0.01 0.00 0.57 0.99 1.22*Begipjijng 01/10/91, samples were digested prior to metals analysis.Plumbing Coils - Average Levels for Two SamplesFiltered Samples (Not Digested)DateDays FromStartLoop Number1 2 3 4 5 6 701/10/91 199 0.00 0.00 0.00 0.00 0.03 0.27 0.4122/10/91 220 0.05 0.04 0.05 0.05 0.08 0.33 0.3505/11/91 234 0.00 0.00 0.00 0.00 0.02 0.20 0.2319/11/91 248 0.03 0.03 0.03 0.02 0.10 0.24 0.35177Inhibitor Chemical Testing at Seymour Dam^ Appendix KSolder Coil Copper Levels, mg/LCopper levels for raw running water samples were measured on 14/02/91,18/02/91, 20/20/91, and 28/02/91. Levels in all cases were 0.04 mg/L or less.Copper levels below were measured after a 24 hour standin2 period.Solder Coils - Pre-treatmentDateLoop Number1 2 3 4 5 6 718/02/91 0.07 0.06 0.13 0.12 0.07 0.06 0.0720/02/91 0.03 0.01 0.00 0.03 0.00 0.00 0.0028/02/91 0.06 0.10 0.03 0.06 0.05 0.08 0.05Averages 0.05 0.06 0.05 0.07 0.04 0.05 0.04Solder Coils - Pre-treatmentDateDays FromStartLoop Number1 2 3 4 5 6 727/03/91 11 0.13 0.01 0.09 0.20 0.07 0.19 0.2705/04/91 20 0.09 0.03 0.08 0.11 0.07 0.17 0.1110/04/91 25 0.05 0.04 0.05 0.03 0.06 0.08 0.0710/05/91 55 0.20 0.19 0.37 0.29 0.45 0.30 1.0715/05/91 60 0.14 0.08 0.02 0.07 0.04 0.03 0.1723/05/91 68 0.00 0.00 0.00 0.00 0.00 0.00 1.3529/05/91 74 0.24 0.07 0.10 0.09 0.28 0.12 0.4305/06/91 81 0.23 0.04 0.09 0.07 0.30 0.23 0.6412/06/91 88 0.13 0.03 0.04 0.05 0.08 0.06 0.2125/06/91 101 0.11 0.18 0.19 0.12 0.21 0.17 0.2610/07/91 116 0.09 0.10 0.12 0.07 0.17 0.14 0.2824/07/91 130 0.11 0.13 0.12 0.09 0.31 0.26 0.6210/08/91 147 0.14 0.11 0.11 0.08 0.23 0.15 0.3820/08/91 157 0.25 0.13 0.16 0.12 0.18 0.19 0.3110/09/91 178 0.24 0.18 0.33 0.18 2.28 2.75 0.5901/10/91* 200 0.26 0.21 0.21 0.17 0.42 0.42 0.2422/10/91 220 0.22 0.28 0.11 0.08 0.31 0.41 0.2305/11/91 234 0.12 0.13 0.08 0.17 0.43 0.24 0.1819/11/91 248 0.13 0.16 0.15 0.11 0.35 0.26 0.3003/12/91 262 0.09 0.00 0.03 0.01 0.06 0.05 0.0017/12/91 276 0.06 0.03 0.00 0.00 0.02 0.05 0.2714/01/92 304 0.08 0.02 0.03 0.01 0.10 0.08 0.0618/02/92 339 0.08 0.10 0.05 0.05 0.11 0.05 0.3211/03/92 361 0.09 0.04 0.02 0.03 0.07 0.02 1.59Averages 0.14 0.10 0.11 0.09 0.28 0.27 0.41*Be rmin 01/10/91 samples were digested prior to metals analysisSolder Coils - Pre-treatmentDateDays FromStartLoop Number1 2 3 4 5 6 701/10/91 199 0.04 0.02 0.02 0.04 0.05 0.04 0.0122/10/91 220 0.01 0.03 0.02 0.00 0.00 0.01 0.0105/11/91 234 0.03 0.02 0.02 0.02 0.01 0.01 0.0219/11/91 248 0.06 0.07 0.05 0.07 0.08 0.04 0.04178Inhibitor Chemical Testing at Seymour Dam^ Appendix LSolder Coil Lead Levels, mg/LLead levels for raw water, running samples were measured on 18/02/91,20/02/91,and 28/02/91. Levels in all loops were 0.001 mg/L or less in all cases.Lead levels were measured after a 24 hour standing period.Solder Coils - Pre-treatmentDateLoop Number1 2 3 4 5 6 718/02/91 2.070 2.070 2.950 2.490 2.620 2.530 2.54020/02/91 2.630 2.270 2.590 2.290 2.200 2.460 2.50028/02/91 2.080 2.080 2.350 1.880 1.620 2.260 2.79004/03/91 1.850 2.250 2.470 1.640 1.620 2.000 2.800Averages 2.158 2.168 2.590 2.075 2.015 2.313 2.658Solder Coils - TreatedDateDays FromStartLoop Number1 2 3 4 5gammasmumswammatmEitmENI! imuilimunammiammisimmonvaus 6imugammaimmuumweimmemilNALUMWAIMII .66.^• I MIMI IMIDAM 6.ILIMEIRIMIIIM211 .66RaMMIllinialli . .6^I WillMill IMMINIIIIIIMMIENIMEIimamsommilimmummommumNal, imammummemr [ROMA%IIIIMMONI67MM.iguimommummummiWM.memI. • 61mum•.^61MIMIIIMMIIMUIERINEMBIEMIIMEMIELIMEOMRnummiMIMI' .611MUMmem6.^1MILEUIIILSZIMMEIIKLMMEMmum.INIMAIIMUMIMEMmminramovi,go:missiimrimmougKIMMAIMILMEIMMEI 6.6.1 IIMMW4111:191 .1111111DMIEMUMMAKIIIIIMEM/MUNI MIMI .66* MEMg0711Y/PilIMILEZEIMMIN •. 661 ManMEMREMIllWrj MRMatj.11/11IIIVIIIIMMIlMani=ratINAIIIIIIMIIIIIIMMI11Y/LII:figlIUMIUMEMEME1p4tMD7DIIIMIMMIEMAIII:.161 , .611 litnal 6.^1 MAMAMIMI' .6116.1^1KOMIEWMAIIMMIIIMM■ .6^1 MOM 6. fIIgar onagaimumimommainimmuminwrialiman=Km:ailIMMUMMEMEXIMIECIMIIIMMIImummumwilmiMEMmom6.^ro mugromomKumiIIIIIVIIIMIMMEIMEMRUKIMINEALmrinjoi 6.^ro wa rumnimenmisniimiummum 6.^11 MEMMIMIMEM 6.6 CI MIMIIIMPIPil 6 NUMMI MEMIMMILMIa I1 ig mitiumriffiLair mi loo inFOLIIVAIM11.1111M1FFSIMMIIIIMMII.LiummrIIIIMEIIMMEIIEMAIMMIRMUMMINNIMIMMIIMalrwimair II1VaillMULAyM111 MEM 6.:11 ENIEUE2MWM.simmor mimmEmcmI^• 6 ,^• • • x I ro I , (I 1Averages 1.715 7.516 5.569 15.899 6.426 3.442 9.319* Beginning 01/10/91, samples were digested prior to metals analysis.Solder Coils - Filtered Samples (Not Digested)DateDays FromStartLoop Number1 2 3 4 5inummisiab • milignmagammium 1.6 ro =maim rumgigujo iLammiiiimmigiFacuanaliwiummummonimixomummg lammumNUMMImumigammumg.gummommom=gm• • ' : I^I I^:# I^I I^:1 I^1 1^III I.^11179Inhibitor Chemical Testing at Seymour Dam^ Appendix MSolder Coil Zinc Levels, mg/LZinc levels for raw running water samples were measured on 14/02/91, 18/02/91,20/02/91, and 28/02/91. Levels in all cases were 0.03 me, or less.Zinc levels below were measured after a 24 hour standing eriod.Solder Coils - Pre-treatmentDateLoop Number1 2 3 4 5 6 718/02/91 0.00 0.01 0.01 0.02 0.01 0.01 0.0120/02/91 0.01 0.02 0.02 0.02 0.02 0.03 0.0328/02/91 0.03 0.04 0.06 0.07 0.08 0.08 0.08Averages 0.01 0.02 0.03 0.04 0.04 0.04 0.04Solder Coils - TreatedDateDays FromStartLoop Number1 2 3 4 5 6 727/03/91 11 0.03 0.01 0.00 0.06 0.33 1.44 1.7305/04/91 20 0.00 0.02 0.05 0.06 0.27 0.94 0.8010/04/91 25 0.00 0.00 0.00 0.01 0.19 0.87 0.7310/05/91 55 0.00 0.00 0.00 0.00 0.32 1.08 0.8815/05/91 60 0.00 0.02 0.01 0.02 0.22 0.64 0.6223/05/91 68 0.01 0.03 0.00 0.01 0.09 0.28 0.6729/05/91 74 0.03 0.04 0.04 0.04 0.34 0.80 0.7205/06/91 81 0.00 0.00 0.00 0.00 0.24 0.99 0.6012/06/91 88 0.00 0.00 0.00 0.00 0.33 0.93 0.8825/06/91 101 0.00 0.01 0.02 0.02 0.56 0.93 0.9310/07/91 116 0.00 0.00 0.00 0.00 0.49 1.10 1.1624/07/91 130 0.00 0.00 0.00 0.00 0.19 0.94 0.9010/08/91 147 0.00 0.00 0.00 0.00 0.85 2.55 1.0820/08/91 157 0.00 0.00 0.00 0.00 0.51 3.20 2.4810/09/91 178 0.00 0.00 0.02 0.01 1.11 6.42 3.3601/10/91* 200 0.06 0.04 0.08 0.05 0.35 1.96 0.9322/10/91 220 0.00 0.03 0.07 0.04 0.18 1.91 0.9805/11/91 234 0.01 0.04 0.05 0.08 0.28 2.12 1.1119/11/91 248 0.57 0.17 0.10 0.10 0.64 3.39 2.2303/12/91 262 0.17 0.13 0.11 0.13 0.36 1.57 0.5817/12/91 276 0.03 0.02 0.03 0.04 0.23 0.64 0.7014/01/92 304 0.01 0.00 0.00 0.01 0.35 1.02 0.8318/02/92 339 0.00 0.01 0.00 0.01 0.27 0.59 1.0511/03/92 361 0.01 0.01 0.02 0.01 0.21 0.63 2.16Averages 0.04 0.02 0.03 0.03 0.37 1.54 1.17*B min 01/10/91 sam les were diirested prior to metals analysis.Solder Coils - Filtered Samples (Not Digested)DateDays FromStartLoop Number1 2 3 4 5 6 701/10/91 199 0.01 0.00 0.00 0.00 0.03 0.39 0.1922/10/91 220 0.01 0.01 0.02 0.02 0.02 0.22 0.1605/11/91 234 0.00 0.00 0.00 0.00 0.02 0.22 0.2219/11/91 248 0.38 0.06 0.05 0.04 0.11 0.23 0.27180Inhibitor Chemical Testing at Seymour Dam^ Appendix NTemperature Measurements, Degrees CTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 716/03/91 0 4.0 4.0 4.0 4.0 4.0 4.0 4.017/03/91 1 4.0 4.0 4.0 4.0 4.0 4.0 4.019/03/91 3 4.0 4.0 4.0 4.0 4.0 4.0 4.020/03/91 4 4.0 4.0 4.0 4.0 4.0 4.0 4.021/03/91 5 5.0 5.0 6.0 6.0 6.0 6.0 6.022/03/91 6 6.0 6.0 6.0 6.0 6.0 6.0 6.023/03/91 7 4.0 4.0 4.0 4.0 4.0 4.0 4.528/03/91 12 5.0 5.0 5.0 5.0 5.0 5.0 5.002/04/91 17 6.0 6.0 6.0 6.0 6.0 6.0 6.004/04/91 19 6.0 6.0 6.0 6.0 6.0 6.0 6.008/04/91 23 6.0 6.0 6.0 6.0 6.0 6.0 6.013/04/91 28 6.0 6.0 6.0 6.0 6.0 6.0 6.018/04/91 33 7.0 7.0 7.0 7.0 7.0 7.0 7.023/04/91 38 7.0 7.0 8.0 8.0 8.0 8.0 8.027/04/91 42 7.0 7.0 7.0 7.0 7.0 7.0 7.029/04/91 44 7.0 7.0 7.0 7.0 7.0 7.0 7.006/05/91 51 8.0 8.0 8.0 8.0 9.0 9.0 8.008/05/91 53 8.0 8.0 8.0 8.0 8.0 8.0 8.013/05/91 58 7.0 7.0 7.0 7.0 7.0 7.0 7.017/05/91 62 8.0 8.0 8.0 8.0 8.0 8.0 8.021/05/91 66 7.0 7.0 7.0 7.0 7.0 7.0 7.025/05/91 70 8.0 8.0 8.0 8.0 8.0 8.0 8.027/05/91 72 8.0 8.0 8.0 8.0 8.0 8.0 8.031/05/91 76 8.0 8.0 8.0 8.0 8.0 8.0 8.003/06/91 79 8.0 8.0 8.0 8.0 8.0 8.0 8.006/06/91 82 8.5 8.5 8.5 8.5 8.5 8.5 8.508/06/91 84 8.5 8.5 8.5 8.5 8.5 8.5 8.510/06/91 86 9.0 9.0 9.0 9.0 9.0 9.0 9.014/06/91 90 9.0 9.0 9.0 9.0 9.0 9.0 9.018/06/91 94 9.0 9.0 9.0 9.0 9.0 9.0 9.019/06/91 95 9.0 9.0 9.0 9.0 9.5 9.5 9.021/06/91 97 9.5 9.5 9.5 9.5 9.5 9.5 9.524/06/91 100 9.5 9.5 9.0 9.0 9.0 9.5 9.027/06/91 103 9.0 9.0 9.0 9.5 9.0 9.0 9.002/07/91 108 10.0 10.0 10.0 10.0 10.0 10.0 10.003/07/91 109 10.0 10.0 10.0 10.0 10.0 9.5 9.505/07/91 111 10.0 10.0 10.0 10.0 10.0 10.0 10.008/07/91 114 10.0 10.0 10.0 10.0 10.0 10.0 10.012/07/91 118 11.0 11.0 11.0 11.0 11.0 11.0 11.015/07/91 121 11.0 11.0 11.0 11.0 11.5 11.0 11.017/07/91 123 12.0 11.5 11.5 12.0 11.5 11.5 12.019/07/91 125 11.5 12.0 12.0 12.0 12.0 12.0 12.0181Inhibitor Chemical Testing at Seymour Dam^ Appendix NTemperature Measurements, Degrees CTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 722/07/91 128 12.0 12.0 12.0 12.0 12.0 12.0 12.026/07/91 132 13.0 13.0 13.0 13.0 13.0 13.0 13.029/07/91 135 14.0 14.0 14.0 14.0 14.0 14.0 14.031/07/91 137 15.0 15.0 15.0 15.0 15.0 15.0 15.002/08/91 139 15.5 15.5 15.5 15.5 15.5 15.5 15.506/08/91 143 15.5 16.0 15.5 16.0 16.0 15.5 15.012/08/91 149 14.5 15.0 15.0 15.0 15.0 15.0 15.014/08/91 151 14.5 14.5 14.5 14.5 14.5 14.5 14.515/08/91 152 15.0 15.0 15.0 15.0 15.0 15.0 15.019/08/91 156 14.5 15.0 15.0 15.0 15.0 15.0 15.023/08/91 160 15.0 15.0 15.0 15.0 15.0 15.0 15.026/08/91 163 15.0 15.0 15.0 15.0 15.0 15.0 15.028/08/91 165 15.0 15.0 15.0 15.0 15.0 15.0 15.003/09/91 171 12.0 12.0 12.0 12.5 12.5 12.0 12.004/09/91 172 13.0 13.0 13.0 13.0 13.0 13.0 13.006/09/91 174 13.0 13.0 13.0 13.0 13.0 13.0 13.009/09/91 177 13.5 14.0 14.0 14.0 14.0 14.0 14.013/09/91 181 13.0 13.0 13.0 13.0 13.0 13.0 13.018/09/91 186 15.0 15.0 15.0 15.0 15.0 15.0 15.020/09/91 188 14.0 14.0 14.0 14.0 14.0 14.5 14.527/09/91 195 14.0 15.0 15.0 15.0 14.5 15.0 14.530/09/91 198 15.0 15.0 15.0 15.0 15.0 15.0 15.001/10/91 199 21.5 21.5 21.5 21.5 21.5 21.5 21.5 Solder Coils - 24 hr standing02/10/91 200 21.0 21.0 21.0 21.0 21.0 21.0 21.0 Plumbing Coils - 24 hr standing04/10/91 202 14.5 14.5 14.5 14.5 14.5 14.5 14.507/10/91 205 14.0 14.0 14.0 14.0 14.0 14.0 14.009/10/91 207 14.0 14.0 14.0 14.0 13.5 13.5 13.511/10/91 209 14.0 14.0 14.0 14.0 14.0 14.0 14.015/10/91 213 13.0 13.0 13.0 13.0 13.0 13.0 13.016/10/91 214 12.5 12.5 12.5 12.5 12.0 12.5 12.521/10/91 219 11.0 11.5 11.5 11.5 11.5 11.5 11.022/10/91 220 21.0 21.0 21.0 21.0 21.0 21.0 21.0 Solder Coils - 24 hr standing22/10/91 220 21.5 21.5 21.5 21.5 21.5 21.5 21.5 Plumbing Coils - 24 hr standing23/10/91 221 15.5 15.5 15.5 15.5 15.5 15.5 15.5 Faucets - 24 hr standing25/10/91 223 10.0 10.0 10.0 11.5 10.0 10.0 10.028/10/91 226 8.5 8.5 8.5 8.5 8.5 8.5 8.530/10/91 228 7.5 7.5 7.5 7.5 7.5 7.5 7.501/11/91 230 7.0 7.0 7.0 7.0 7.0 7.0 7.004/11/91 233 6.5 6.5 6.5 6.5 6.5 6.5 6.505/11/91 234 16.5 16.5 16.5 16.5 16.5 16.5 16.5 Solder Coils - 24 hr standing08/11/91 237 7.0 7.0 7.0 7.0 7.0 7.0 7.012/11/91 241 7.0 7.0 7.0 7.0 7.0 7.0 7.0182Inhibitor Chemical Testing at Seymour Dam^ Appendix NTemperature Measurements, Degrees CTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 715/11/91 244 7.0 7.0 7.0 7.0 7.0 7.0 7.018/11/91 247 7.0 7.0 7.0 7.0 7.0 7.0 7.022/11/91 251 6.0 6.0 6.0 6.0 6.0 6.0 6.025/11/91 254 6.0 6.0 6.0 6.0 6.0 6.0 6.027/11/91 256 6.0 6.0 6.0 6.0 6.0 6.0 6.029/11/91 258 6.0 6.0 6.0 6.0 6.0 6.0 6.002/12/91 261 6.0 6.0 6.0 6.0 6.0 6.0 6.006/12/91 265 5.5 6.0 6.0 6.0 6.0 5.5 6.009/12/91 268 5.5 5.5 5.5 5.5 5.5 5.5 5.511/12/91 270 5.0 5.0 5.0 5.0 5.5 5.0 5.013/12/91 272 5.0 5.0 5.0 5.0 5.0 5.0 5.016/12/91 275 4.5 4.5 4.5 4.5 4.5 4.5 4.517/12/91 276 15.5 15.5 15.5 15.0 14.0 13.5 12.5 Solder Coils - 24 hr standing22/12/91 281 4.0 4.0 4.0 4.0 4.0 4.0 4.030/12/91 289 4.5 4.5 4.5 4.5 4.5 4.5 4.506/01/92 296 4.0 4.0 4.0 4.0 4.0 4.0 4.013/01/92 303 4.0 4.0 4.0 4.0 4.0 4.0 4.014/01/92 304 12.0 12.0 12.0 12.0 12.0 12.0 12.0 Solder Coils - 24 hr standing14/01/92 304 11.0 11.0 11.0 11.0 11.0 11.0 11.0 Plumbing Coils - 24 hr standing15/01/92 305 8.0 8.0 8.0 8.0 8.0 8.0 8.0 Faucets - 24 hr standing20/01/92 310 4.0 4.0 3.5 4.0 4.0 4.0 4.027/01/92 317 4.0 4.0 4.0 4.0 4.0 4.0 4.004/02/92 325 5.0 5.0 5.0 5.0 5.0 5.0 5.017/02/92 338 5.0 5.0 5.0 5.0 5.0 5.0 5.018/02/92 339 16.0 16.0 16.0 16.0 16.0 16.0 16.0 Solder Coils - 24 hr standing18/02/92 339 16.0 16.0 16.0 16.0 16.0 16.0 16.0 Plumbing Coils - 24 hr standing24/02/92 345 5.0 5.0 5.0 5.0 5.0 5.0 5.003/03/92 353 6.0 6.0 6.0 6.0 6.0 6.0 6.010/03/92 360 6.0 6.0 6.0 6.0 6.0 6.0 6.011/03/92 361 17.0 17.0 17.0 17.0 17.0 17.0 17.0 Solder Coils - 24 hr standing11/03/92 361 18.0 18.0 18.0 18.0 18.0 18.0 18.0 Plumbing Coils -24 hr standing12/03/92 362 15.0 15.0 15.0 15.0 15.0 15.0 15.0 Faucets - 24 hr standing183Inhibitor Chemical Testing at Seymour Dam^ Appendix 0Conductivity Measurements, u S/cmPre-TreatmentDateLoop NumberComment1 2 3 4 5 6 712/02/91 13.7 14.7 13.6 13.4 13.2 13.3 12.6 Plumbing Coils - 8 hr standing13/02/91 10.4 10.8 10.7 10.8 10.5 10.8 11.113/02/91 15.5 13.7 13.7 14.7 13.2 14.5 14.5 Plumbing Coils - 8 hr standing18/02/91 11.9 12.4 11.8 11.8 12.1 11.9 11.8 Faucets - 8 hr standing18/02/91 11.8 11.9 11.5 11.8 11.6 12.1 11.6 Solder Coils - 8 hr standing27/02/91 14.3 14.1 14.0 13.9 13.6 13.4 13.1 Plumbing Coils - 24 hr standing27/02/91 11.6 11.2 11.1 11.8 11.1 11.4 11.1 Faucets - 24 hr standing02/03/91 14.0 14.1 13.6 13.8 13.9 13.7 13.9 Plumbing Coils - 24 hr standing02/03/91 12.4 12.2 12.3 11.7 11.7 11.9 11.9 Solder Coils - 24 hr standingTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 716/03/91 0 12.1 56.3 57.0 74.0 59.3 65.5 55.217/03/91 1 12.2 54.0 55.8 74.7 61.2 69.0 53.419/03/91 3 12.4 54.5 56.6 72.7 57.2 61.2 44.120/03/91 4 12.0 52.5 52.0 70.6 57.1 59.6 42.022/03/91 6 12.8 57.0 55.9 75.5 59.7 62.4 42.523/03/91 7 12.5 57.8 56.7 71.5 60.8 63.0 43.625/03/91 9 15.6 57.6 60.6 79.2 64.7 65.0 42.6 Plumbing Coils - 24 hr standing26/03/91 10 13.2 57.0 58.4 74.2 58.6 60.8 40.5 Solder Coils - 24 hr standing27/03/91 11 13.1 56.8 57.3 77.0 59.7 61.5 40.8 Faucets - 24 hr standing28/03/91 12 13.3 50.4 50.4 72.7 55.1 55.3 37.902/04/91 17 13.7 50.5 51.8 72.8 53.6 55.2 36.703/04/91 18 16.4 56.2 58.0 74.4 56.5 64.4 38.1 Plumbing Coils - 24 hr standing04/04/91 19 13.1 49.6 49.8 66.2 53.7 55.0 36.205/04/91 20 14.4 49.7 50.7 64.8 50.4 52.5 32.3 Plumbing Coils - 24 hr standing06/04/91 21 13.8 27.5 22.9 46.8 34.3 34.2 25.9 Faucets - 24 hr standing08/04/91 23 13.4 46.0 45.7 62.9 49.3 52.3 34.409/04/91 24 16.0 52.0 49.8 66.6 51.3 48.6 31.5 Plumbing Coils - 24 hr standing10/04/91 25 13.8 51.6 50.8 67.3 49.5 51.5 30.8 Faucets - 24 hr standing11/04/91 26 13.8 46.8 47.2 62.5 47.8 49.7 30.4 Solder Coils - 24 hr standing13/04/91 28 13.7 45.5 47.3 64.4 48.5 50.6 33.718/04/91 33 13.5 43.3 43.4 57.1 47.1 49.1 31.523/04/91 38 13.3 45.2 45.5 60.3 45.9 48.5 32.224/04/91 39 16.7 50.6 50.8 61.4 51.8 51.9 32.7 Plumbing Coils - 24 hr standing25/04/91 40 13.9 46.2 46.9 58.5 47.1 48.2 30.0 Solder Coils - 24 hr standing26/04/91 41 15.5 48.8 49.4 63.4 49.0 51.5 31.4 Faucets - 24 hr standing27/04/91 42 13.3 44.5 48.0 62.6 49.2 51.8 32.229/04/91 44 13.1 45.4 45.4 56.5 45.7 47.8 30.406/05/91 51 13.2 45.4 52.5 54.7 45.2 49.6 30.4184Inhibitor Chemical Testing at Seymour Dam^ Appendix 0Conductivity Measurements, u S/cmPre-TreatmentDateLoop NumberComment1 2 3 4 5 6 708/05/91 53 12.8 44.8 43.9 57.2 47.6 49.9 31.109/05/91 54 15.7 50.5 49.6 59.8 55.0 50.0 28.6 Plumbing Coils - 24 hr standing10/05/91 55 13.1 45.8 46.3 57.0 47.6 45.7 27.5 Solder Coils - 24 hr standing10/05/91 55 12.3 44.7 44.0 56.8 45.3 47.2 26.4 Faucets - 24 hr standing13/05/91 58 12.1 42.7 42.7 55.9 43.5 45.4 26.814/05/91 59 13.6 48.3 47.4 60.6 47.7 48.8 28.7 Solder Coils - 24 hr standing15/05/91 60 16.0 51.6 53.3 65.1 51.2 53.4 33.0 Plumbing Coils - 24 hr standing15/05/91 60 13.4 47.1 47.7 61.2 47.9 50.2 28.2 Faucets - 24 hr standing17/05/91 62 13.3 51.1 53.8 65.7 53.2 56.1 35.621/05/91 66 12.9 46.0 45.0 61.0 48.6 53.0 31.822/05/91 67 13.8 52.0 51.1 65.0 52.1 55.1 32.2 Solder Coils - 24 hr standing23/05/91 68 16.5 55.2 54.2 67.8 55.7 58.1 35.6 Plumbing Coils - 24 hr standing23/05/91 68 13.9 47.6 47.8 61.6 49.0 51.6 29.3 Faucets - 24 hr standing25/05/91 70 12.9 48.4 47.1 65.6 52.3 55.8 34.627/05/91 72 12.9 48.8 46.8 61.5 50.1 51.1 32.428/05/91 73 16.6 54.1 54.4 66.5 55.5 50.6 32.3 Plumbing Coils - 24 hr standing29/05/91 74 13.3 49.8 57.7 63.3 49.1 50.6 30.3 Solder Coils - 24 hr standing29/05/91 74 13.1 48.6 49.1 64.1 51.5 53.2 29.9 Faucets - 24 hr standing31/05/91 76 12.9 46.7 46.6 61.2 50.3 53.0 32.803/06/91 79 13.6 48.6 47.3 62.9 50.4 52.9 33.904/06/91 80 15.9 51.9 51.4 64.1 51.8 53.2 29.5 Solder Coils - 24 hr standing05/06/91 81 17.3 53.7 55.5 66.8 52.1 54.5 32.3 Plumbing Coils - 24 hr standing05/06/91 81 13.5 47.5 46.2 60.0 46.5 49.7 28.1 Faucets - 24 hr standing06/06/91 82 13.5 48.5 47.7 65.3 53.9 55.8 32.608/06/91 84 13.6 50.2 49.7 65.9 52.4 55.3 33.410/06/91 86 13.1 46.6 46.8 62.8 50.7 50.2 32.011/06/91 87 13.8 49.3 49.2 60.8 49.5 51.4 30.4 Solder Coils - 24 hr standing12/06/91 88 16.5 52.5 54.0 64.7 53.4 53.7 33.5 Plumbing Coils - 24 hr standing12/06/91 88 13.2 46.1 46.0 58.7 47.2 47.9 27.7 Faucets - 24 hr standing14/06/91 90 13.1 48.7 47.3 62.7 50.8 52.8 30.918/06/91 94 13.2 51.0 48.0 62.7 55.3 55.4 34.319/06/91 95 13.2 51.7 49.5 63.6 54.0 55.4 35.821/06/91 97 13.2 49.8 49.2 64.7 53.4 55.0 42.424/06/91 100 13.0 48.7 48.8 62.3 50.8 51.7 33.025/06/91 101 14.6 50.2 50.8 61.7 50.4 50.9 31.3 Solder Coils - 24 hr standing26/06/91 102 17.3 54.7 55.6 64.3 54.3 55.1 35.2 Plumbing Coils - 24 hr standing26/06/91 102 13.1 49.9 48.9 61.8 49.3 50.8 30.1 Faucets - 24 hr standing27/06/91 103 13.2 50.7 50.1 65.7 52.5 54.8 33.702/07/91 108 13.0 49.8 46.8 60.6 48.6 52.5 32.903/07/91 109 13.0 47.4 48.1 60.1 50.6 51.8 33.605/07/91 111 13.0 48.8 51.8 62.4 50.0 51.4 36.008/07/91 114 12.9 50.1 50.9 63.7 50.3 51.1 29.809/07/91 115 13.8 50.2 51.2 90.9 50.4 50.8 31.2 Solder Coils - 24 hr standing185Inhibitor Chemical Testing at Seymour Dam^ Appendix 0Conductivity Measurements, u S/cmPre-TreatmentDateLoop NumberComment1 2 3 4 5 6 710/07/91 116 17.0 55.1 56.4 64.8 50.1 55.2 35.6 Plumbing Coils - 24 hr standing10/07/91 116 13.0 49.0 47.8 58.2 48.5 50.4 30.6 Faucets - 24 hr standing12/07/91 118 13.3 48.8 48.7 62.2 50.5 54.3 34.415/07/91 121 12.9 49.4 49.4 62.0 50.7 52.2 35.517/07/91 123 13.0 49.6 49.5 61.7 51.5 53.4 34.619/07/91 125 12.8 51.6 52.8 63.7 53.3 55.7 36.022/07/91 128 12.9 48.6 48.5 59.1 46.9 51.7 34.023/07/91 129 13.7 50.1 49.9 59.7 54.0 60.8 32.1 Solder Coils - 24 hr standing24/07/91 130 17.1 54.0 58.2 61.0 62.3 80.8 39.5 Plumbing Coils - 24 hr standing24/07/91 130 13.5 49.5 49.2 59.7 51.8 52.4 31.9 Faucets - 24 hr standing26/07/91 132 13.1 50.2 51.8 62.5 53.2 53.8 33.529/07/91 135 13.2 48.2 49.3 60.2 51.4 51.3 35.531/07/91 137 13.3 48.1 48.8 59.6 51.3 52.2 31.902/08/91 139 13.2 48.1 47.4 57.7 50.8 52.5 32.706/08/91 143 13.4 50.2 49.9 61.1 52.9 53.9 35.907/08/91 144 13.8 51.3 50.8 58.9 51.9 54.5 32.8 Solder Coils - 24 hr standing08/08/91 145 17.5 55.0 56.8 63.7 57.0 58.7 37.7 Plumbing Coils - 24 hr standing08/08/91 145 14.0 50.1 49.0 58.4 51.7 54.9 33.6 Faucets - 24 hr standing12/08/91 149 14.9 49.4 50.0 58.2 53.2 55.5 35.114/08/91 151 17.7 50.3 50.3 60.9 55.5 55.2 34.815/08/91 152 14.4 50.5 50.8 60.5 54.3 56.5 35.419/08/91 156 14.7 30.5 30.7 40.3 31.8 33.6 32.720/08/91 157 14.9 32.5 32.1 39.7 32.5 34.5 33.1 Solder Coils - 24 hr standing21/08/91 158 17.7 35.5 35.6 43.4 37.1 40.0 38.2 Plumbing Coils - 24 hr standing21/08/91 158 48.5 47.4 54.2 47.7 50.9 34.8 Faucets - 24 hr standing23/08/91 160 13.9 50.4 47.8 62.4 51.3 53.0 32.726/08/91 163 14.0 48.1 47.8 61.1 50.8 52.6 33.328/08/91 165 13.5 45.2 47.3 56.4 49.5 51.2 32.703/09/91 171 9.4 40.7 40.8 52.6 41.6 39.1 26.004/09/91 172 9.6 40.6 42.4 51.5 41.6 40.6 28.606/09/91 174 9.4 41.2 41.9 50.2 43.5 47.3 29.009/09/91 177 10.1 41.9 42.4 52.2 42.2 47.8 30.610/09/91 178 12.7 53.2 53.3 62.6 53.1 54.4 35.2 Solder Coils - 24 hr standing11/09/91 179 15.1 57.4 59.7 66.6 57.3 58.6 39.9 Plumbing Coils - 24 hr standing11/09/91 179 13.4 52.1 52.3 64.6 52.6 54.6 34.1 Faucets -24 hr standing13/09/91 181 13.3 51.7 52.1 66.1 53.3 56.7 40.816/09/91 184 13.3 56.5 56.2 69.4 56.8 59.4 35.718/09/91 186 13.4 55.2 56.4 67.5 57.5 64.6 45.320/09/91 188 14.0 53.2 54.2 66.9 55.0 58.5 41.127/09/91 195 14.4 54.9 56.6 70.1 70.0 60.0 35.430/09/91 198 15.3 54.5 53.7 68.4 55.5 59.8 46.501/10/91 199 15.4 56.0 56.9 67.2 56.1 57.0 36.8 Solder Coils - 24 hr standing02/10/91 200 26.2 64.0 65.3 74.0 65.2 65.4 40.7 Plumbing Coils - 24 hr standing186Inhibitor Chemical Testing at Seymour Dam^Appendix 0Conductivity Measurements, u S/cmPre-TreatmentDateLoop NumberComment1 2 3 4 5 6 702/10/91 200 14.9 55.0 56.7 67.4 57.2 59.7 36.9 Faucets - 24 hr standing04/10/91 202 15.4 56.9 59.7 71.3 59.9 64.3 44.207/10/91 205 15.7 57.5 56.9 70.5 58.2 63.5 40.009/10/91 207 15.7 55.7 56.3 68.8 55.7 61.2 48.111/10/91 209 15.7 55.2 55.8 68.2 58.5 62.3 42.815/10/91 213 15.5 57.2 57.0 70.1 59.2 62.6 45.616/10/91 214 16.3 58.0 59.2 70.8 61.7 63.1 43.521/10/91 219 17.3 59.8 60.6 75.0 65.6 72.3 44.222/10/91 220 15.9 66.1 62.5 71.4 62.7 63.5 40.1 Solder Coils - 24 hr standing22/10/91 220 19.6 68.8 68.5 77.4 67.3 67.6 44.3 Plumbing Coils - 24 hr standing23/10/91 221 15.4 54.6 55.8 66.7 59.4 60.7 35.3 Faucets -24 hr standing25/10/91 223 15.0 51.1 51.3 62.6 50.3 52.7 40.328/10/91 226 14.8 52.5 53.4 63.6 55.7 55.6 46.330/10/91 228 14.8 50.5 51.7 62.9 52.8 55.8 40.501/11/91 230 14.8 49.8 50.5 61.5 51.7 54.2 38.304/11/91 233 14.8 48.7 50.5 61.9 52.7 53.6 42.005/11/91 234 15.0 49.7 50.9 58.7 51.2 52.2 36.0 Solder Coils - 24 hr standing05/11/91 234 16.8 54.4 55.5 62.0 55.1 56.5 39.7 Plumbing Coils - 24 hr standing06/11/91 235 15.7 47.7 49.5 58.7 48.6 51.4 35.0 Faucets - 24 hr standing08/11/91 237 15.3 50.8 50.9 62.9 53.0 55.4 42.112/11/91 241 14.5 47.7 49.1 59.2 50.0 52.7 36.815/11/91 244 14.4 50.1 50.0 62.3 50.6 52.8 36.618/11/91 247 13.7 48.6 49.2 60.6 50.7 52.3 35.319/11/91 248 14.1 50.3 50.4 58.6 50.5 52.9 33.3 Solder Coils - 24 hr standing19/11/91 248 15.4 53.4 55.5 62.7 54.6 56.6 36.1 Plumbing Coils - 24 hr standing20/11/91 249 13.1 47.3 48.0 56.8 48.0 50.1 30.0 Faucets - 24 hr standing22/11/91 251 12.4 46.9 47.9 59.0 49.6 51.5 34.525/11/91 254 12.2 46.9 47.6 58.6 49.3 51.6 33.427/11/91 256 11.8 46.9 46.7 58.1 50.4 53.3 33.729/11/91 258 16.0 59.2 58.8 69.8 59.7 61.4 45.102/12/91 261 13.6 53.9 55.0 67.2 55.7 57.1 38.603/12/91 262 14.1 54.9 56.2 65.2 55.6 59.2 35.7 Solder Coils - 24 hr standing03/12/91 262 16.4 60.4 62.4 70.1 60.8 62.4 40.4 Plumbing Coils - 24 hr standing04/12/91 263 13.8 51.6 52.2 61.8 52.4 54.4 35.0 Faucets -24 hr standing06/12/91 265 14.3 56.1 57.6 69.5 57.8 60.4 38.709/12/91 268 13.6 53.9 54.8 67.9 56.8 58.1 39.911/12/91 270 14.0 53.6 53.8 66.3 56.4 58.1 40.013/12/91 272 13.1 52.8 53.0 65.6 55.3 56.7 38.116/12/91 275 14.0 53.2 52.0 65.2 55.2 57.7 34.317/12/91 276 13.9 54.9 54.6 64.0 55.1 61.6 34.5 Solder Coils - 24 hr standing17/12/91 276 16.1 59.6 60.3 69.2 60.2 67.4 38.3 Plumbing Coils - 24 hr standing18/12/91 277 13.3 49.0 54.0 61.3 49.9 51.9 32.4 Faucets - 24 hr standing22/12/91 281 13.3 51.2 53.2 63.3 53.7 57.1 41.7187Inhibitor Chemical Testing at Seymour Dam^ Appendix 0Conductivity Measurements, u S/cmPre. TreatmentDateLoop NumberComment1 2 3 4 5 6 730/12/91 289 13.7 50.3 52.4 62.9 50.2 56.8 37.706/01/92 296 14.1 52.9 53.1 65.5 54.1 55.4 37.813/01/92 303 14.9 54.0 53.4 66.7 56.3 58.4 39.014/01/92 304 13.7 54.1 54.7 63.8 54.9 58.9 39.8 Solder Coils - 24 hr standing14/01/92 304 15.7 59.0 61.0 68.6 59.5 61.4 39.4 Plumbing Coils - 24 hr standing15/01/92 305 13.3 54.1 54.8 65.4 54.9 57.5 35.6 Faucets - 24 hr standing20/01/92 310 14.3 57.4 58.3 70.6 59.9 62.2 43.127/01/92 317 13.6 55.6 56.5 69.4 59.7 59.4 42.404/02/92 325 11.7 49.9 52.5 63.7 51.9 52.5 34.917/02/92 338 11.4 52.8 53.3 65.8 53.5 57.1 39.518/02/92 339 11.1 54.4 53.8 63.9 53.8 55.1 32.7 Solder Coils - 24 hr standing18/02/92 339 13.1 58.0 60.0 69.0 59.0 60.2 37.7 Plumbing Coils - 24 hr standing19/02/92 340 11.3 51.2 51.6 65.1 51.7 53.9 33.0 Faucets -24 hr standing24/02/92 345 11.7 51.9 52.8 66.2 52.0 57.0 40.103/03/92 353 13.0 52.7 53.8 65.7 55.0 56.1 35.710/03/92 360 17.3 55.4 55.5 68.0 59.1 60.9 45.411/03/92 361 12.9 55.4 57.9 69.6 57.3 59.7 39.3 Solder Coils - 24 hr standing11/03/92 361 15.7 61.1 64.6 73.7 62.8 63.5 43.1 Plumbing Coils - 24 hr standing12/03/92 362 13.0 57.1 48.2 70.7 61.0 44.0 38.6 Faucets - 24 hr standingAverage Conductivities, uS/cmLoop Number1 2 3 4 5 6 7Non Standing 13.5 50.5 50.9 63.9 53.0 55.3 37.0Std Deviation 1.4 4.2 4.3 5.3 4.9 5.2 5.4P Coil - 24 Hr 16.7 55.9 57.2 67.4 56.9 58.9 36.8Std Deviation 2.3 4.5 4.9 5.1 4.9 7.2 4.1S Coil - 24 Hr 13.9 52.1 52.6 64.4 52.5 54.6 33.5Std Deviation 1.0 4.4 4.2 7.2 3.9 4.9 3.8Faucet - 24 Hr 13.0 50.2 50.2 62.5 51.3 52.6 32.5Std Deviation 2.9 3.3 3.5 5.0 4.3 4.1 3.6* On 06/04/91, and 19-21/08/91 the circuit breaker feeding NaHCO3, V939, and TPC 223 wasthrown which accounts for the low conductivities in some loops on those dates.188Inhibitor Chemical Testing at Seymour Dam^ Appendix PpH MeasurementsPre-treatmentDateLoop NumberComment1 2 3 4 5 6 712/02/91 6.47 6.57 6.50 6.46 6.50 6.48 6.45 Plumbing Coils - 8 hr standing13/02/91 6.22 6.32 6.23 6.27 6.25 6.25 6.3513/02/91 6.33 6.34 6.28 6.33 6.40 6.50 6.50 Plumbing Coils - 8 hr standing18/02/91 6.06 6.20 6.19 6.12 6.08 6.07 6.07 Faucets - 8 hr standing18/02/91 6.16 6.19 6.07 6.10 6.07 6.08 6.05 Solder Coils - 8 hr standing27/02/91 6.38 6.50 6.44 6.40 6.37 6.27 6.23 Plumbing Coils - 24 hr standing27/02/91 6.02 6.03 6.03 5.95 6.02 5.99 6.00 Faucets - 24 hr standing02/03/91 6.68 6.69 6.77 6.81 6.71 6.82 6.74 Plumbing Coils - 24 hr standing02/03/91 6.49 6.53 6.50 6.46 6.48 6.45 6.41 Solder Coils - 24 hr standingpH Measurements - Treated SamplesTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 716/03/91 0 6.43 7.89 7.96 7.72 7.96 8.22 7.7417/03/91 1 6.45 7.93 7.80 8.13 7.74 7.89 7.5819/03/91 3 6.53 8.04 8.07 7.96 8.08 8.51 8.1620/03/91 4 6.39 8.06 7.92 7.98 8.06 8.24 7.5821/03/91 5 6.46 8.00 7.97 7.93 8.08 8.09 7.5822/03/91 6 6.54 7.95 7.89 8.03 7.96 8.00 7.5123/03/91 7 6.52 8.40 8.02 9.37 8.45 8.52 8.0025/03/91 9 6.78 8.04 8.11 8.58 8.10 8.01 7.49 Plumbing Coils - 24 hr standing26/03/91 10 6.58 8.01 8.01 8.55 8.06 7.95 7.44 Solder Coils - 24 hr standing27/03/91 11 6.47 7.97 8.05 8.05 7.96 7.95 7.39 Faucets - 24 hr standing28/03/91 12 6.54 7.95 8.05 7.45 8.30 8.30 7.5502/04/91 17 6.67 8.33 8.40 7.76 8.36 8.40 7.7303/04/91 18 6.84 7.72 7.77 8.00 7.94 7.75 7.21 Plumbing Coils - 24 hr standing04/04/91 19 6.54 8.01 8.15 8.03 8.47 8.16 7.5405/04/91 20 6.64 8.00 7.95 8.42 7.90 7.78 7.32 Plumbing Coils - 24 hr standing06/04/91 21 6.60 7.34 7.17 8.03 7.43 7.50 7.22 Faucets - 24 hr standing08/04/91 23 6.59 7.83 7.92 7.67 7.90 8.01 7.4909/04/91 24 6.74 7.83 7.88 8.28 7.78 7.68 7.28 Plumbing Coils - 24 hr standing10/04/91 25 6.49 7.78 7.81 8.11 7.59 7.59 7.17 Faucets - 24 hr standing11/04/91 26 6.60 7.77 7.77 8.22 7.65 7.61 7.22 Solder Coils - 24 hr standing13/04/91 28 6.56 7.83 7.93 7.62 8.05 8.00 7.5218/04/91 33 6.51 7.77 7.80 7.76 8.08 8.11 7.4923/04/91 38 6.57 7.95 7.85 7.89 7.78 7.95 7.4424/04/91 39 6.74 7.81 7.80 8.08 7.77 7.70 7.19 Plumbing Coils - 24 hr standing25/04/91 40 6.59 7.69 7.60 8.12 7.58 7.55 7.09 Solder Coils - 24 hr standing26/04/91 41 6.38 7.68 7.79 8.33 7.65 7.65 7.20 Faucets - 24 hr standing27/04/91 42 6.52 7.72 7.88 7.84 7.90 7.92 7.43189Inhibitor Chemical Testing at Seymour Dam^ Appendix PpH Measurements - Treated SamplesTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 729/04/91 44 6.58 8.10 7.86 7.99 7.80 7.80 7.3806/05/91 51 6.65 8.33 8.96 9.23 7.97 8.43 7.8708/05/91 53 6.52 8.04 7.82 9.30 8.11 7.97 7.4209/05/91 54 6.73 7.85 7.62 8.27 7.81 7.71 7.25 Plumbing Coils - 24 hr standing10/05/91 55 6.75 7.69 7.69 9.05 7.62 7.55 7.03 Solder Coils - 24 hr standing10/05/91 55 6.61 7.60 7.55 8.45 7.56 7.55 7.03 Faucets - 24 hr standing13/05/91 58 6.52 7.88 7.76 7.85 7.75 7.77 7.2414/05/91 59 6.56 7.67 7.66 8.32 7.58 7.51 7.02 Solder Coils - 24 hr standing15/05/91 60 6.75 7.72 7.61 8.03 7.55 7.61 7.09 Plumbing Coils - 24 hr standing15/05/91 60 6.55 7.60 7.54 8.13 7.54 7.58 7.07 Faucets -24 hr standing17/05/91 62 6.54 8.18 8.43 8.14 8.22 8.25 7.5721/05/91 66 6.48 7.80 7.60 7.61 7.85 8.06 7.4822/05/91 67 6.62 7.84 7.73 8.55 7.71 7.76 7.21 Solder Coils - 24 hr standing23/05/91 68 6.81 7.79 7.62 8.24 7.76 7.91 7.36 Plumbing Coils - 24 hr standing23/05/91 68 6.41 7.58 7.50 8.23 7.55 7.64 7.16 Faucets - 24 hr standing25/05/91 70 6.56 7.90 7.70 7.91 8.08 8.12 7.5327/05/91 72 6.50 7.98 7.70 7.90 7.99 7.93 7.4028/05/91 73 6.78 7.79 7.68 8.24 7.73 7.67 7.23 Plumbing Coils - 24 hr standing29/05/91 74 6.52 7.83 6.64 8.45 7.64 7.63 7.17 Solder Coils - 24 hr standing29/05/91 74 6.47 7.65 7.65 8.28 7.67 7.68 7.15 Faucets - 24 hr standing31/05/91 76 6.50 8.05 7.76 7.99 8.09 8.21 7.4003/06/91 79 6.51 7.89 7.64 7.65 7.93 7.86 7.1304/06/91 80 6.63 7.80 7.62 8.44 7.66 7.63 7.00 Solder Coils - 24 hr standing05/06/91 81 6.76 7.74 7.62 8.17 7.66 7.66 7.08 Plumbing Coils - 24 hr standing05/06/91 81 6.39 7.52 7.46 8.17 7.51 7.57 7.02 Faucets -24 hr standing06/06/91 82 6.52 7.79 7.61 7.92 8.04 7.96 7.3508/06/91 84 6.49 7.87 7.68 7.63 8.04 7.97 7.3210/06/91 86 6.49 7.63 7.52 7.66 7.82 7.74 7.3111/06/91 87 6.50 7.68 7.53 . 8.27 7.54 7.51 7.16 Solder Coils - 24 hr standing12/06/91 88 6.74 7.66 7.58 8.13 7.61 7.59 7.18 Plumbing Coils - 24 hr standing12/06/91 88 6.35 7.42 7.34 8.02 7.35 7.41 6.94 Faucets - 24 hr standing14/06/91 90 6.46 7.88 7.60 7.88 7.84 7.85 7.2218/06/91 94 6.45 8.28 7.63 7.79 8.62 8.39 7.4719/06/91 95 6.50 8.05 7.69 8.34 8.21 7.90 7.4421/06/91 97 6.46 7.71 7.57 7.98 7.82 7.71 7.6724/06/91 100 6.51 7.87 7.71 8.16 7.79 7.68 7.2725/06/91 101 6.61 7.68 7.65 8.53 7.53 7.50 7.13 Solder Coils - 24 hr standing26/06/91 102 6.74 7.73 7.62 8.47 7.62 7.57 7.16 Plumbing Coils - 24 hr standing26/06/91 102 6.43 7.67 7.55 8.42 7.52 7.47 7.08 Faucets - 24 hr standing27/06/91 103 6.54 7.86 7.70 7.94 7.80 7.75 7.3502/07/91 108 6.50 7.75 7.53 8.01 7.66 7.66 7.2503/07/91 109 6.52 7.59 7.61 7.90 7.59 7.55 7.2605/07/91 111 6.50 7.97 7.96 7.95 7.82 7.72 7.51190Inhibitor Chemical Testing at Seymour Dam^ Appendix PpH Measurements - Treated SamplesTreated SamplesDateDaysFromStartLoop Number1 2 3 4 5 6 7 Comment08/07/91 114 6.52 7.88 7.84 7.74 7.68 7.62 7.1009/07/91 115 6.58 7.76 7.69 8.48 7.56 7.46 7.13 Solder Coils - 24 hr standing10/07/91 116 6.68 7.78 7.64 8.34 7.63 7.55 7.17 Plumbing Coils - 24 hr standing10/07/91 116 6.32 7.76 7.58 8.46 7.62 7.56 7.15 Faucets - 24 hr standing12/07/91 118 6.44 7.90 7.98 7.86 7.85 7.97 7.4215/07/91 121 6.49 8.03 7.92 8.11 7.84 7.71 7.4417/07/91 123 6.46 7.94 7.85 8.07 7.80 7.77 7.3819/07/91 125 6.43 8.06 8.16 8.22 8.07 8.03 7.4522/07/91 128 6.42 7.65 7.70 8.09 7.33 7.53 7.1423/07/91 129 6.50 7.60 7.51 8.50 7.49 7.57 7.01 Solder Coils - 24 hr standing24/07/91 130 6.68 7.61 7.53 8.41 7.50 7.69 7.13 Plumbing Coils - 24 hr standing24/07/91 130 6.40 7.59 7.52 8.35 7.71 7.63 7.11 Faucets - 24 hr standing26/07/91 132 6.70 7.96 7.85 8.05 7.85 7.71 7.2329/07/91 135 6.52 8.01 8.03 8.23 8.06 7.73 7.3531/07/91 137 6.52 8.00 7.96 8.27 8.32 7.95 7.3502/08/91 139 6.54 7.83 7.84 7.88 8.18 8.02 7.3306/08/91 143 6.44 7.98 7.93 7.92 8.22 7.94 7.3407/08/91 144 6.50 7.85 7.71 8.48 7.83 7.87 7.25 Solder Coils - 24 hr standing08/08/91 145 6.69 7.71 7.56 8.22 7.75 7.83 7.18 Plumbing Coils - 24 hr standing08/08/91 145 6.35 7.82 7.58 8.33 7.89 8.20 7.31 Faucets - 24 hr standing12/08/91 149 6.48 8.05 8.03 7.67 8.45 8.47 7.5814/08/91 151 6.48 7.99 7.84 7.63 8.55 8.14 7.5215/08/91 152 6.49 8.20 8.11 8.26 8.39 8.35 7.8119/08/91 156 6.51 7.76 7.84 8.13 7.63 7.86 7.5120/08/91 157 6.51 7.70 7.49 8.70 7.51 7.79 7.52 Solder Coils - 24 hr standing21/08/91 158 6.69 7.61 7.32 8.43 7.54 7.78 7.51 Plumbing Coils - 24 hr standing21/08/91 158 7.90 7.76 8.68 7.69 8.01 7.40 Faucets - 24 hr standing23/08/91 160 6.48 8.34 8.02 8.63 7.99 8.27 7.5226/08/91 163 6.46 8.04 8.14 8.47 8.03 7.94 7.4928/08/91 165 6.52 7.70 7.82 8.16 7.87 8.01 7.4203/09/91 171 6.26 7.96 7.89 7.56 8.04 7.46 8.0004/09/91 172 6.34 8.03 8.18 8.05 7.89 7.31 7.3906/09/91 174 6.27 7.88 8.31 7.75 8.41 8.66 7.5809/09/91 177 6.37 8.46 8.44 8.58 8.16 8.76 7.8010/09/91 178 6.38 8.15 7.85 8.79 7.74 7.64 7.38 Solder Coils - 24 hr standing11/09/91 179 6.79 7.96 7.81 8.60 7.83 7.68 7.48 Plumbing Coils - 24 hr standing11/09/91 179 6.28 7.77 7.67 8.63 7.71 7.53 7.32 Faucets - 24 hr standing13/09/91 181 6.29 7.81 7.85 7.78 7.85 7.76 7.4716/09/91 184 6.40 8.42 8.08 8.25 8.19 7.88 7.6618/09/91 186 6.55 8.56 8.59 8.36 8.32 7.64 7.2920/09/91 188 6.46 8.25 8.32 8.45 8.12 7.97 7.9427/09/91 195 6.46 7.87 8.40 7.80 7.67 8.05 7.0330/09/91 198 6.51 7.86 7.73 7.86 7.71 7.82 8.46191Inhibitor Chemical Testing at Seymour Dam^ Appendix PpH Measurements - Treated SamplesTreated SamplesDateDaysFromStartLoop Number1 2 3 4 5 6 7 Comment01/10191 199 6.63 7.60 7.49 8.05 7.54 7.53 7.20 Solder Coils - 24 hr standing02/10/91 200 6.90 7.79 7.72 8.41 7.81 7.67 7.19 Plumbing Coils - 24 hr standing02/10/91 200 6.37 7.83 7.85 8.61 7.99 7.68 7.34 Faucets - 24 hr standing04/10/91 202 6.47 8.10 8.54 8.05 8.41 8.26 7.8807/10/91 205 6.51 8.00 7.93 7.97 8.13 8.22 7.5009/10/91 207 6.53 8.09 8.10 7.76 7.92 8.29 8.1111/10/91 209 6.52 7.85 7.85 7.79 8.42 8.41 7.8715/10/91 213 6.55 8.05 7.98 7.77 8.25 8.25 7.7316/10/91 214 6.30 7.20 7.26 7.22 7.48 7.34 7.1421/10/91 219 6.42 7.85 7.89 7.93 8.22 8.12 7.4022/10/91 220 6.63 7.59 7.46 8.05 7.44 7.42 7.06 Solder Coils - 24 hr standing22/10/91 220 6.79 7.73 7.55 8.31 7.61 7.50 7.13 Plumbing Coils - 24 hr standing23/10/91 221 6.38 7.66 7.55 8.34 7.63 7.45 7.02 Faucets - 24 hr standing25/10/91 223 6.44 7.79 7.85 7.64 7.52 7.54 7.3228/10/91 226 6.49 8.29 8.36 7.96 8.68 7.81 7.7730/10/91 228 6.47 8.07 8.23 7.84 8.37 8.12 7.7901/11/91 230 6.48 7.90 8.12 7.94 8.30 7.97 7.4704/11/91 233 6.52 8.07 8.28 8.31 8.63 8.00 7.8005/11/91 234 6.66 7.68 7.61 8.55 7.54 7.48 7.10 Solder Coils - 24 hr standing05/11/91 234 6.77 7.67 7.60 8.44 7.56 7.61 7.20 Plumbing Coils - 24 hr standing06/11/91 235 6.63 7.86 7.80 8.71 7.68 7.68 7.32 Faucets - 24 hr standing08/11/91 237 6.63 7.98 8.01 8.15 8.14 7.89 7.5412/11/91 241 6.55 7.91 8.01 8.24 7.78 7.75 7.3215/11/91 244 6.51 7.92 7.89 7.90 7.73 7.73 7.3918/11/91 247 6.52 7.93 7.96 8.02 7.86 7.74 7.4319/11/91 248 6.58 7.52 7.56 8.35 7.45 7.48 7.01 Solder Coils - 24 hr standing19/11/91 248 6.73 7.69 7.60 8.50 7.50 7.58 7.17 Plumbing Coils - 24 hr standing20/11/91 249 6.38 7.65 7.61 8.59 7.44 7.54 7.00 Faucets - 24 hr standing22/11/91 251 6.35 7.92 7.91 8.15 7.96 7.81 7.4325/11/91 254 6.40 8.01 8.00 8.27 8.13 7.97 7.5027/11/91 256 6.42 8.10 7.94 8.19 8.01 8.23 7.5229/11/91 258 6.62 8.34 8.25 8.24 8.13 8.13 7.7202/12/91 261 6.40 8.14 8.06 8.45 7.95, 7.94 7.4703/12/91 262 6.56 7.69 7.68 8.58 7.55 7.52 7.13 Solder Coils - 24 hr standing03/12/91 262 6.80 7.80 7.71 8.54 7.62 7.71 7.24 Plumbing Coils - 24 hr standing04/12/91 263 6.42 7.82 7.74 8.70 7.61 7.65 7.22 Faucets -24 hr standing06/12/91 265 6.56 8.18 8.14 8.26 8.06 7.89 7.4809/12/91 268 6.47 8.16 _ 7.99 8.23 7.99 7.83 7.4711/12/91 270 6.42 7.96 7.85 8.15 7.94 7.85 7.4613/12/91 272 6.50 8.13 7.99 8.11 8.08 7.85 7.5016/12/91 275 6.53 8.29 7.90 8.39 8.07 7.93 7.4317/12/91 276 6.61 7.97 7.85 8.69 7.74 7.80 7.22 Solder Coils - 24 hr standing17/12/91 276 6.87 7.85 7.74 8.58 7.73 7.87 7.28 Plumbing Coils - 24 hr standing192Inhibitor Chemical Testing at Seymour Dam^ Appendix PpH Measurements - Treated SamplesTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 718/12/91 277 6.41 7.69 7.70 8.99 7.53 7.64 7.07 Faucets - 24 hr standing22/12/91 281 6.47 8.17 8.55 8.26 7.79 7.49 7.1230/12/91 289 6.48 7.93 8.12 7.75 7.57 8.15 7.4906/01/92 296 6.47 8.01 7.96 7.83 8.08 7.82 7.4613/01/92 303 6.58 8.04 7.90 8.02 8.07 8.42 7.5614/01/92 304 7.98 7.92 8.78 7.71 7.74 7.31 Solder Coils - 24 hr standing14/01/92 304 6.81 7.84 7.78 8.54 7.70 7.73 7.24 Plumbing Coils - 24 hr standing15/01/92 305 6.53 7.96 7.84 8.79 7.73 7.78 7.31 Faucets - 24 hr standing20/01/92 310 6.46 8.15 7.98 8.13 8.07 8.07 7.5727/01/92 317 6.55 8.38 8.25 8.48 8.53 8.16 7.8204/02/92 325 6.35 8.05 7.97 8.60 8.04 7.74 7.4317/02/92 338 6.54 8.34 8.11 8.43 7.77 8.13 7.9218/02/92 339 6.18 7.78 7.70 8.56 7.37 7.44 6.92 Solder Coils - 24 hr standing18/02/92 339 6.44 7.51 7.51 8.38 7.40 7.45 6.96 Plumbing Coils - 24 hr standing19/02/92 340 6.40 7.87 7.83 8.83 7.63 7.69 7.19 Faucets - 24 hr standing24/02/92 345 6.49 8.30 8.24 8.40 7.71 8.25 7.7803/03/92 353 6.53 7.76 7.81 8.18 8.01 7.83 7.3310/03/92 360 6.71 7.86 7.84 8.19 8.25 7.92 7.7411/03/92 361 6.57 8.00 8.00 8.64 7.75 7.75 7.35 Solder Coils - 24 hr standing11/03/92 361 6.71 7.77 7.68 8.38 7.68 7.76 7.28 Plumbing Coils - 24 hr standing12/03/92 362 6.49 8.23 7.67 8.54 7.77 7.47 7.30 Faucets - 24 hr standingAverage pH LevelsLoop Number3^4 5 6NtrwirMi .i'ilm 6. Ram I EaumingtionammimmajurmggentagatmprammrowmagV aximun 6.7 mammawin :.6: MM.=T immum 6.^• =EOMWA=UMWWMI aim ist II 1 mil 6. giejamgaski.= .6' MEMOeviation gagnig I.^6 EOMEgmminmuY axmiunMTH 6E11 1 17:11i;f4mtrarrrimmimmaimagiwir6.^INMmagWMimuOMummaggRawmuummawgm6. • 6mejmeiEmut. D eviation MU I.^6 I.^6 IIWEImumummgmV aximun 6.7 MINmawmuimamaimum=mum MinniiSIMilaMMBIlMAN 6-I rrrtzTem I : W 6. 11WAMEMIIILLIJIMIIIIMIII=piris carTtrminmignagnumimiwieigluElmV aximun 6.6 OMMEWnjEJIngMUMSmunum 6.^: 7. :^1 , ..,193Inhibitor Chemical Testing at Seymour Dam^ Appendix QAlkalinity Measurements, mg/LPre-treatmentDateLoop NumberComment1 2 3 4 5 6 712/02/91 7.25 7.00 4.96 4.88 4.96 5.08 4.80 Plumbing Coils - 8 hr standing13/02/91 2.86 2.41 2.59 2.52 2.69 3.09 2.2513/02/91 6.91 4.72 4.27 5.10 4.05 5.06 5.13 Plumbing Coils - 8 hr standing18/02/91 2.80 2.81 1.80 2.47 2.42 2.60 2.41 Faucets - 8 hr standing18/02/91 3.78 3.77 3.60 3.37 3.28 3.56 3.22 Solder Coils - 8 hr standing27/02/91 5.85 5.97 5.49 5.68 5.53 5.59 4.92 Plumbing Coils - 24 hr standing27/02/91 3.41 2.62 2.52 2.82 2.69 2.78 2.59 Faucets - 24 hr standing02/03/91 4.96 5.44 4.85 5.62 5.25 5.14 5.38 Plumbing Coils - 24 hr standing02/03/91 3.75 3.97 3.92 3.48 3.47 3.67 3.51 Solder Coils - 24 hr standingAlkalinity Measurements, mg/L - Treated SamplesTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 716/03/91 0 3.02 18.44 18.73 17.60 20.42 20.99 14.0617/03/91 1 3.08 18.16 _17.87 18.09 18.80 20.91 11.8019/03/91 3 3.33 18.66 18.66 19.72 20.71 12.0120/03/91 4 3.21 18.66 18.51 18.44 19.43 10.0321/03/91 5 3.07 18.02 18.23 17.95 18.51 19.57 10.1022/03/91 6 3.38 20.21 19.43 20.28 20.49 21.2023/03/91 7 3.48 20.21 19.86 18.66 22.54 11.3725/03/91 9 6.24 19.50 23.32 22.47 22.05 12.72 Plumbing Coils -24 hr standing26/03/91 10 4.19 20.63 20.56 22.33 20.63 21.62 9.04 Solder Coils - 24 hr standing27/03/91 11 3.99 20.00, 21.05 20.84 20.70 21.69 8.90 Faucets - 24 hr standing28/03/91 12 3.61 20.53 18.51 22.54 21.62 11.2402/04/91 17 3.82 20.21 21.76 19.72 21.84 22.61 11.8003/04/91 18 6.45 21.05 22.47 24.09 21.27 24.59 Plumbing Coils - 24 hr standing04/04/91 19 3.82 20.63 22.33 20.84 21.91 12.2205/04/91 20 4.50 20.63 21.34 20.42 20.78 8.69 Plumbing Coils -24 hr standing06/04/91 21 4.20 9.89 14.06 13.07 7.21 Faucets - 24 hr standing*08/04/91 23 3.67 19.08 18.93 18.58 20.49 21.69 10.8109/04/91 24 6.16 21.05 19.57 23.03 21.34 20.42 11.45 Plumbing Coils - 24 hr standing10/04/91 25 4.16 25.44 20.63 23.39 20.70 20.70 8.12 Faucets - 24 hr standing11/04/91 26 4.30 19.22 19.29 20.63 19.01 7.91 Solder Coils - 24 hr standing13/04/91 28 3.43 19.29 20.56 19.93 20.42 10.6018/04/91 33 3.52 18.51 18.59 17.95 19.65 20.92 10.7423/04/91 38 3.63 19.15 18.80 19.43 18.59 20.63 10.6024/04/91 39 7.45 19.36 20.14 21.84 20.42 20.49 9.20 Plumbing Coils - 24 hr standing25/04/91 40 4.35 18.94 18.37 20.49 18.66 19.01 13.14 Solder Coils - 24 hr standing26/04/91 41 4.05 20.42 22.68 20.00 7.77 Faucets - 24 hr standing27/04/91 42 3.76 18.94 20.21 20.56 20.92 9.8929/04/91 44 3.60 19.65 18.80 18.44 18.94 19.93 7.60194Inhibitor Chemical Testing at Seymour Dam^ Appendix QAlkalinity Measurements, mg/L - Treated SamplesTreated SamplesDateDaysFromStartLoop Number1 2 3 4 5 6 7 Comment06/05/91 51 4.00 20.49 23.46 25.93 19.57 21.90 9.8208/05/91 53 3.55 20.01 19.01 26.57 20.78 21.20 9.3309/05/91 54 6.86 20.63 19.36 25.65 23.11 21.55 12.23 Plumbing Coils - 24 hr standing10/05/91 55 5.16 20.85 20.21 27.98 20.00 19.22 8.33 Solder Coils - 24 hr standing10/05/91 55 19.01 19.29 23.25 17.73 18.33 Faucets - 24 hr standing13/05/91 58 3.61 19.29 18.80 18.37 18.59 19.50 8.2014/05/91 59 4.30 18.73 17.95 21.55 18.51 18.30 7.28 Solder Coils - 24 hr standing15/05/91 60 6.78 19.29 18.80 20.21 19.08 20.00 Plumbing Coils -24 hr standing15/05/91 60 3.98 19.15 18.51 21.48 19.08 18.94 7.28 Faucets - 24 hr standing17/05/91 62 3.51 19.60 21.20 19.73 20.13 21.06 10.0721/05/91 66 3.42 18.67 17.33 17.60 19.13 21.33 8.9322/05/91 67 4.54 20.00 18.73 21.60 19.07 19.33 8.40 Solder Coils - 24 hr standing23/05/91 68 7.00 20.33 19.67 21.53 20.00 20.67 9.20 Plumbing Coils -24 hr standing23/05/91 68 4.40 19.13 20.33 18.40 19.33 7.60 Faucets - 24 hr standing25/05/91 70 3.63 19.87 19.07 20.07 21.40 22.73 10.2027/05/91 72 3.56 19.53 18.93 19.53 19.87 19.40 9.3328/05/91 73 7.10 20.53 20.67 22.20 22.53 20.20 10.60 Plumbing Coils - 24 hr standing29/05/91 74 4.31 20.13 11.20 21.73 18.60 19.27 7.93 Solder Coils - 24 hr standing29/05/91 74 3.93 19.20 19.80 22.07 19.73 20.33 7.87 Faucets - 24 hr standing31/05/91 76 3.67 19.07 19.07 19.47 20.13 20.67 9.8003/06/91 79 3.87 19.60 18.67 18.73 19.67 19.80 9.3304/06/91 80 5.68 19.80 19.80 22.00 19.33 20.13 8.07 Solder Coils - 24 hr standing05/06/91 81 7.72 20.67 21.00 22.47 19.73 21.67 8.67 Plumbing Coils - 24 hr standing05/06/91 81 3.98 18.87 18.47 20.80 19.00 20.00 7.47 Faucets - 24 hr standing06/06/91 82 4.01 20.13 18.67 20.53 21.60 22.27 10.2008/06/91 84 3.78 19.87 19.47 19.67 20.73 21.13 9.1310/06/91 86 3.78 18.80 18.67 19.00 20.87 20.40 10.0011/06/91 87 4.32 19.47 19.53 21.33 19.13 19.67 13.27 Solder Coils - 24 hr standing12/06/91 88 8.11 20.73 20.67 22.60 20.87 22.07 11.00 Plumbing Coils - 24 hr standing12/06/91 88 3.96 17.93 18.47 20.67 18.67 18.73 7.00 Faucets - 24 hr standing14/06/91 90 3.82 20.53 19.00 19.00 20.60 21.07 9.0718/06/91 94 3.77 21.07 18.80 19.87 22.13 22.00 10.4019/06/91 95 3.87 21.06 19.20 21.53 21.60 21.33 10.5321/06/91 97 3.88 20.07 19.80 21.47 21.07 21.53 14.4024/06/91 100 4.01 20.73 19.67 21.20 20.80 20.60 10.0025/06/91 101 4.92 20.47 19.60 22.80 19.93 19.47 8.53 Solder Coils - 24 hr standing26/06/91 102 7.73 20.73 21.07 24.33 21.00 23.60 13.53 Plumbing Coils -24 hr standing26/06/91 102 4.02 20.20 19.33 22.13 19.00 19.47 7.93 Faucets -24 hr standing27/06/91 103 4.00 20.80 20.00 21.40 20.87 22.13 9.6002/07/91 108 3.93 19.47 18.93 20.67 19.20 20.33 9.8003/07/91 109 4.08 19.06 19.33 21.40 20.00 20.13 10.0705/07/91 111 4.03 20.40 21.47 20.00 20.53 20.13 11.3308/07/91 114 3.88 20.73 20.80 20.33 20.06 19.73195Inhibitor Chemical Testing at Seymour Dam^ Appendix QAlkalinity Measurements, mg/L - Treated SamplesTreated SamplesDateDaysFromStartLoop Number1 2 3 4 5 6 7 Comment09/07/91 115 4.71 20.60 20.60 22.80 19.67 20.00 8.60 Solder Coils - 24 hr standing10/07/91 116 7.53 21.40 21.67 23.13 22.53 20.33 12.53 Plumbing Coils - 24 hr standing10/07/91 116 4.20 21.00 19.67 22.47 20.20 19.93 8.67 Faucets - 24 hr standing12/07/91 118 4.04 20.47 20.47 20.47 20.73 21.87 11.0015/07/91 121 4.12 20.60 20.53 21.07 20.20 20.73 11.1317/07/91 123 4.10 21.07 21.00 21.87 21.07 21.73 10.9319/07/91 125 4.07 22.20 23.13 22.60 22.80 22.80 11.2022/07/91 128 4.11 20.73 21.00 21.93 19.00 21.20 11.3323/07/91 129 4.71 20.53 20.73 23.33 22.00 24.40 8.40 Solder Coils - 24 hr standing24/07/91 130 8.25 21.73 23.60 24.67 32.07 10.20 Plumbing Coils -24 hr standing24/07/91 130 4.54 21.07 20.60 23.87 21.60 22.20 9.40 Faucets - 24 hr standing26/07/91 132 4.71 22.13 22.06 22.27 22.67 22.47 10.6029/07/91 135 4.46 20.67 20.27 20.67 21.00 20.13 11.3331/07/91 137 4.35 20.33 20.47 20.87 21.20 21.13 9.0602/08/91 139 4.96 20.27 19.67 20.07 21.47 21.87 10.0006/08/91 143 4.75 21.33 20.67 20.93 22.00 22.07 11.5307/08/91 144 5.10 21.46 20.47 23.20 21.73 22.87 9.87 Solder Coils - 24 hr standing08/08/91 145 11.80 22.07 23.60 23.80 24.67 24.47 16.33 Plumbing Coils -24 hr standing08/08/91 145 4.70 21.73 20.87 22.80 21.87 23.46 10.60 Faucets - 24 hr standing12/08/91 149 4.82 21.47 21.33 19.60 22.60 23.40 11.7314/08/91 151 4.66 21.40 21.00 19.47 23.20 22.93 10.3315/08/91 152 4.60 21.40 21.73 21.40 22.67 24.13 11.0019/08/91 156 4.75 9.80 10.00 9.60 9.93 10.47 9.47 *20/08/91 157 5.38 10.00 10.13 12.60 10.67 12.33 11.20 Solder Coils - 24 hr standing*21/08/91 158 8.33 11.33 10.93 12.67 12.47 13.67 15.07 Plumbing Coils - 24 hr standing*21/08/91 158 21.60 23.20 23.07 20.53 21.60 11.50 Faucets - 24 hr standing23/08/91 160 4.56 22.87 20.73 24.53 21.93 23.07 10.0026/08/91 163 4.63 21.73 21.40 22.73 22.40 22.13 10.4028/08/91 165 4.70 21.13 21.87 22.40 22.53 22.73 10.6003/09/91 171 2.40 18.80 18.20 17.40 18.47 16.80 9.0004/09/91 172 2.51 18.67 19.20 18.60 18.20 15.93 8.8706/09/91 174 2.58 18.67 19.40 17.33 20.00 21.13 9.5309/09/91 177 2.68 18.80 19.07 19.80 18.13 21.13 10.4710/09/91 178 3.13 19.00 18.80 21.53 19.20 19.33 9.47 Solder Coils - 24 hr standing11/09/91 179 5.60 19.67 20.13 22.73 20.53 21.40 10.27 Plumbing Coils - 24 hr standing11/09/91 179 3.23 19.00 19.33 21.33 19.07 18.73 7.86 Faucets - 24 hr standing13/09/91 181 3.21 16.47 16.33 16.53 16.93 17.26 9.8716/09/91 184 3.24 19.13 18.87 19.13 18.47 18.87 7.6018/09/91 186 3.31 21.20 21.40 20.27 21.27 21.27 10.6720/09/91 188 3.65 21.27 21.40 21.47 20.47 20.80 11.8727/09/91 195 3.78 20.67 21.87 20.00 18.93 21.93 8.0730/09/91 198 3.93 20.27 19.47 19.73 19.67 21.40 14.6701/10/91 199 4.43 21.87 21.07 24.13 21.13 22.00 9.87 Solder Coils - 24 hr standing196Inhibitor Chemical Testing at Seymour Dam^Appendix QAlkalinity Measurements, mg/L - Treated SamplesTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 702/10/91 200 8.97 23.40 23.93 25.80 27.53 26.93 16.07 Plumbing Coils - 24 hr standing02/10/91 200 4.31 21.06 21.33 23.53 22.07 21.53 9.60 Faucets -24 hr standing04/10/91 202 4.15 21.20 22.07 21.00 22.20 23.00 12.7307/10/91 205 4.35 21.53 20.73 21.07 22.07 23.00 10.2709/10/91 207 4.47 21.53 21.53 20.27 20.80 23.00 19.0011/10/91 209 4.37 21.27 21.00 20.53 22.73 23.67 12.4015/10/91 213 4.57 22.13 22.13 20.73 23.20 23.60 13.7316/10/91 214 4.54 21.80 21.87 21.73 24.20 23.80 13.1321/10/91 219 4.14 24.07 24.00 24.33 25.53 27.27 11.4022/10/91 220 4.83 25.27 23.40 27.40 23.20 24.00 10.87 Solder Coils - 24 hr standing22/10/91 220 8.69 26.80 26.33 27.73 32.60 31.40 19.20 Plumbing Coils -24 hr standing23/10/91 221 4.45 20.47 20.40 23.33 21.80 21.00 7.73 Faucets - 24 hr standing25/10/91 223 4.19 19.00 19.20 18.20 18.33 18.73 11.2028/10/91 226 4.02 19.87 20.07 18.80 21.67 19.87 14.4730/10/91 228 4.03 19.07 19.20 18.00 20.13 20.60 11.6001/11/91 230 3.83 18.20 19.27 18.87 19.40 19.53 10.3304/11/91 233 4.15 18.33 19.20 19.47 20.00 19.27 12.4005/11/91 234 4.66 19.20 18.80 22.87 19.53 20.47 9.93 Solder Coils - 24 hr standing05/11/91 234 7.12 19.67 19.93 21.87 20.80 22.27 12.33 Plumbing Coils - 24 hr standing06/11/91 235 5.08 18.07 18.33 21.53 17.93 18.47 8.73 Faucets - 24 hr standing08/11/91 237 4.39 19.27 19.27 19.67 19.60 20.47 12.0712/11/91 241 3.89 18.53 19.06 19.47 18.73 19.67 9.2715/11/91 244 3.60 19.93 19.73 20.13 19.67 19.80 9.8018/11/91 247 3.04 19.27 19.27 19.53 19.73 19.53 9.3319/11/91 248 3.69 21.13 20.07 23.47 19.73 20.87 9.13 Solder Coils - 24 hr standing19/11/91 248 6.17 20.27 22.87 22.73 29.60 23.80 11.93 Plumbing Coils - 24 hr standing20/11/91 249 3.29 18.33 18.40 21.53 17.87 18.53 4.80 Faucets -24 hr standing22/11/91 251 2.78 18.87 18.93 19.47 19.07 19.53 8.9325/11/91 254 2.77 18.67 18.53 19.33 19.27 19.53 8.5327/11/91 256 2.84 18.53 18.53 18.80 19.47 21.13 8.3329/11/91 258 4.05 21.80 21.27 20.93 20.33 21.06 12.2702/12/91 261 2.83 19.27 19.33 20.20 19.27 19.13 8.9303/12/91 262 3.74 19.27 18.80 22.33 18.53 19.53 7.73 Solder Coils - 24 hr standing03/12/91 262 5.87 20.47 20.13 22.67 20.07 21.00 8.40 Plumbing Coils -24 hr standing04/12/91 263 3.18 18.40 18.13 20.80 17.93 18.53 7.67 Faucets - 24 hr standing06/12/91 265 3.46 20.53 20.87 21.20 20.80 21.27 9.3309/12/91 268 3.14 20.13 19.93 20.33 20.33 20.27 10.0711/12/91 270 2.86 19.07 19.53 20.13 20.27 20.73 10.1313/12/91 272 3.00 19.40 19.40 19.40 19.9316/12/91 275 3.56 20.53 18.87 20.47 19.73 20.27 7.4717/12/91 276 4.46 18.93 18.73 18.67 20.73 6.27 Solder Coils - 24 hr standing17/12/91 276 5.68 20.33 20.00 22.20 19.93 23.67 7.13 Plumbing Coils - 24 hr standing18/12/91 277 3.12 16.87 18.80 23.47 16.93 17.87 6.20 Faucets - 24 hr standing197Inhibitor Chemical Testing at Seymour Dam^ Appendix QAlkalinity Measurements, mg/L - Treated SamplesTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 722/12/91 281 2.98 18.67 19.87 18.67 17.93 18.00 8.6030/12/91 289 3.09 18.87 19.20 17.93 17.67 20.60 9.8006/01/92 296 3.13 19.47 19.07 18.67 20.00 19.33 9.8713/01/92 303 3.88 20.13 19.33 20.07 20.53 21.07 10.4014/01/92 304 3.94 18.93 19.67 22.53 19.60 20.27 8.27 Solder Coils - 24 hr standing14/01/92 304 5.67 20.93 21.87 23.00 20.87 21.27 8.33 Plumbing Coils - 24 hr standing15/01/92 305 3.44 20.00 20.27 23.67 20.27 20.33 7.60 Faucets -24 hr standing20/01/92 310 3.16 19.87 19.80 19.87 20.40 20.67 10.5327/01/92 317 3.01 19.73 19.53 20.40 20.40 19.67 10.0004/02/92 325 2.31 17.80 18.87 20.07 18.33 17.67 7.3317/02/92 338 2.80 18.73 18.53 19.47 18.80 20.00 10.2718/02/92 339 2.57 18.13 17.40 21.07 17.67 18.20 6.40 Solder Coils - 24 hr standing18/02/92 339 4.32 18.87 19.07 21.33 21.73 19.87 8.93 Plumbing Coils - 24 hr standing19/02/92 340 2.69 17.60 17.87 22.20 17.60 18.00 6.73 Faucets - 24 hr standing24/02/92 345 2.80 17.87 19.13 19.33 17.93 20.00 10.8003/03/92 353 3.23 18.33 18.73 18.93 19.00 18.87 7.9310/03/92 360 3.93 20.20 19.73 20.40 20.80 20.67 10.2711/03/92 361 3.73 20.07 19.53 22.80 20.33 20.60 11.47 Solder Coils - 24 hr standing11/03/92 361 5.56 22.13 22.20 22.80 21.73 22.47 11.67 Plumbing Coils - 24 hr standing12/03/92 362 2.74 20.87 16.07 22.06 19.33 15.47 9.87 Faucets - 24 hr standingAverage Alkalinities, mLoop Number1.6 Raj .6715-mremlmaitimintAgmAtimhozmag4•.615IMMIKRAMENIMMEMajimagumunimmuiweljamiRan6101171FMTIT■ rillto^ eviation .° 6INELImigem=mum1 WW1 6E1 IWT1 6. 6audnig:javg .6rassummitagttalingigIBM : EMItd I eviationV aximum wag 6.: I minim .61MIABUCHITAWMimmum WM1151.1LUMIMIRPMFarIRM EH! : ravamgmupizuInsmigmilejtatientimgmeinEmmaEautd 1 eviation15 rrummig. .6: mujo-. 6Dinam•.Ipmnrmrnmigammejtamirmemnignugg.6 1MaltamiresamugumsnEriimam 6.18 MITMTM11.11/RialLESimi.6I rirtrZWY1 : rm•T:opsa ma■ 1:gurtitteaugunjujnagum1Egyi•Eulto D eviation•immum ' ^' • :1* On 06/04/91 and 19-21/08/91 the circuit breaker feeding NaH( 03, V939, and TPC 223 wasthrown which accounts for the low alkalinities in some loops on those dates.198Inhibitor Chemical Testing at Seymour Dam^ Appendix RChloramine Measurements, mg/LTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 716/03/91 0 0.0 2.5 2.5 2.4 2.4 2.4 2.417/03/91 1 0.0 2.4 2.4 2.5 2.4 2.4 2.419/03/91 3 0.0 2.5 2.5 2.4 2.4 2.5 2.420/03/91 4 0.0 2.5 2.4 2.4 2.5 2.5 2.421/03/91 5 0.0 2.5 2.4 2.5 2.5 2.5 2.522/03/91 6 0.0 2.5 2.4 2.5 2.5 2.5 2.423/03/91 7 0.0 2.5 2.5 2.3 2.4 2.4 2.425/03/91 9 0.0 0.0 0.0 0.0 <0.1 <0.1 <0.1 Plumbing Coils - 24 hr standing26/03/91 10 0.0 1.3 1.3 1.8 1.8 2.0 2.0 Solder Coils - 24 hr standing27/03/91 11 0.0 2.4 2.4 2.3 2.4 2.2 2.3 Faucets -24 hr standing28/03/91 12 0.0 2.5 2.5 2.5 2.6 2.4 2.302/04/91 17 0.0 2.5 2.5 2.4 2.5 2.5 2.403/04/91 18 0.0 0.2 0.3 0.1 0.3 0.0 0.2 Plumbing Coils - 24 hr standing04/04/91 19 0.0 2.5 2.5 2.6 2.6 2.6 2.505/04/91 20 0.0 1.7 1.7 1.8 1.7 1.9 1.9 Plumbing Coils - 24 hr standing*06/04/91 21 0.0 2.2 2.2 2.1 2.1 2.0 2.1 Faucets -24 hr standing08/04/91 23 0.0 2.5 2.4 2.4 2.4 2.4 2.409/04/91 24 0.0 0.2 0.3 0.1 0.2 <0.1 0.2 Plumbing Coils -24 hr standing10/04/91 25 0.0 1.2 1.1 1.2 1.8 1.8 1.8 Faucets - 24 hr standing11/04/91 26 0.0 1.6 1.8 1.9 1.8 1.8 1.9 Solder Coils - 24 hr standing13/04/91 28 0.0 2.5 2.5 2.5 2.5 2.5 2.518/04/91 33 0.0 2.3 2.3 2.4 2.4 2.4 2.423/04/91 38 0.0 2.5 2.6 2.6 2.6 2.6 2.624/04/91 39 0.0 0.2 0.3 0.1 0.3 0.1 0.2 Plumbing Coils - 24 hr standing25/04/91 40 0.0 1.5 1.3 1.7 1.3 1.6 Solder Coils - 24 hr standing26/04/91 41 0.0 2.1 2.5 2.0 2.4 2.3 1.8 Faucets -24 hr standing27/04/91 42 0.0 2.6 2.8 2.7 2.8 2.7 2.729/04/91 44 0.0 2.6 2.6 2.5 2.5 2.5 2.406/05/91 51 0.0 2.2 2.2 2.2 2.2 2.2 2.208/05/91 53 0.0 2.4 2.5 2.5 2.5 2.4 2.509/05/91 54 0.0 0.1 0.2 0.0 0.2 0.0 0.0 Plumbing Coils - 24 hr standing10/05/91 55 0.0 1.2 1.1 1.0 1.2 1.3 1.2 Solder Coils - 24 hr standing10/05/91 55 0.0 2.3 2.3 2.3 2.3 2.3 2.2 Faucets -24 hr standing13/05/91 58 0.0 2.4 2.4 2.3 2.3 2.4 2.314/05/91 59 0.0 1.2 1.2 1.3 1.5 1.6 1.5 Solder Coils - 24 hr standing15/05/91 60 0.0 0.0 0.1 0.0 0.1 0.0 0.1 Plumbing Coils - 24 hr standing15/05/91 60 0.0 2.2 2.2 2.2 2.3 2.3 2.2 Faucets - 24 hr standing17/05/91 62 0.0 2.4 2.4 2.4 2.4 2.4 2.421/05/91 66 0.0 2.3 2.3 2.3 2.3 2.4 2.322/05/91 67 0.0 1.4 1.4 1.4 1.4 1.5 1.4 Solder Coils - 24 hr standing23/05/91 68 0.0 0.0 0.1 0.0 0.1 0.0 0.2 Plumbing Coils - 24 hr standing23/05/91 68 0.0 2.2 2.2 2.2 2.2 2.2 2.2 Faucets -24 hr standing199Inhibitor Chemical Testing at Seymour Dam^ Appendix RChloramine Measurements, mg/LTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 725/05/91 70 0.0 2.4 2.3 2.5 2.4 2.4 2.427/05/91 72 0.0 2.3 2.4 2.4 2.4 2.3 2.328/05/91 73 0.0 0.1 0.1 0.0 0.1 0.1 0.1 Plumbing Coils - 24 hr standing29/05/91 74 0.0 1.3 1.2 1.4 1.2 1.6 1.4 Solder Coils - 24 hr standing29/05/91 74 0.0 2.4 2.5 2.4 2.5 2.4 2.3 Faucets - 24 hr standing31/05/91 76 0.0 2.3 2.3 2.3 2.3 2.3 2.303/06/91 79 0.0 2.4 2.3 2.3 2.3 2.2 2.204/06/91 80 0.0 1.2 1.1 1.4 1.2 1.6 1.3 Solder Coils - 24 hr standing05/06/91 81 0.0 <0.1 0.0 <0.1 0.1 0.1 0.1 Plumbing Coils - 24 hr standing05/06/91 81 0.0 2.2 2.0 2.2 2.1 2.2 2.2 Faucets - 24 hr standing06/06/91 82 0.0 2.3 2.3 2.3 2.4 2.4 2.408/06/91 84 0.0 2.3 2.4 2.3 2.3 2.3 2.410/06/91 86 0.0 2.3 2.3 2.3 2.3 2.3 2.411/06/91 87 0.0 1.1 1.1 1.4 1.4 1.6 1.5 Solder Coils - 24 hr standing12/06/91 88 0.0 0.0 0.1 0.0 0.1 0.1 <0.1 Plumbing Coils - 24 hr standing12/06/91 88 0.0 2.0 2.1 2.1 2.1 2.1 2.0 Faucets - 24 hr standing14/06/91 90 0.0 2.3 2.3 2.3 2.2 2.3 2.218/06/91 94 0.0 2.3 2.3 2.3 2.3 2.3 2.319/06/91 95 0.0 2.7 2.6 2.6 2.6 2.7 2.621/06/91 97 0.0 2.5 2.5 2.5 2.5 2.6 2.724/06/91 100 0.0 2.4 2.5 2.4 2.4 2.4 2.425/06/91 101 0.0 1.3 1.1 1.5 1.4 1.6 1.6 Solder Coils - 24 hr standing26/06/91 102 0.0 <0.1 0.1 0.0 0.1 0.0 0.0 Plumbing Coils -24 hr standing26/06/91 102 0.0 2.3 2.4 2.3 2.3 2.3 2.3 Faucets - 24 hr standing27/06/91 103 0.0 2.5 2.5 2.5 2.5 2.4 2.502/07/91 108 0.0 2.4 2.5 2.4 2.4 2.4 2.303/07/91 109 0.0 2.4 2.3 2.4 2.4 2.4 2.405/07/91 111 0.0 2.5 2.6 2.5 2.5 2.5 2.508/07/91 114 0.0 2.5 2.5 2.3 2.3 2.4 2.409/07/91 115 0.0 1.3 1.3 1.6 1.4 1.8 1.7 Solder Coils - 24 hr standing10/07/91 116 0.0 <0.1 <0.1 0.0 0.1 0.1 0.0 Plumbing Coils - 24 hr standing10/07/91 116 0.0 2.2 2.3 2.3 2.3 2.3 2.3 Faucets - 24 hr standing12/07/91 118 0.0 2.5 2.4 2.5 2.5 2.5 2.515/07/91 121 0.0 2.4 2.5 2.5 2.6 2.6 2.617/07/91 123 0.0 2.6 2.5 2.5 2.6 2.6 2.519/07/91 125 0.0 2.6 2.6 2.6 2.6 2.6 2.622/07/91 128 0.0 2.6 2.5 2.4 2.5 2.5 2.423/07/91 129 0.0 1.1 1.1 1.7 1.4 2.2 1.6 Solder Coils -24 hr standing24/07/91 130 0.0 <0.1 0.1 <0.1 0.1 0.1 0.1 Plumbing Coils - 24 hr standing24/07/91 130 0.0 2.4 2.3 2.3 2.3 2.3 2.3 Faucets - 24 hr standing26/07/91 132 0.0 2.6 2.6 2.5 2.5 2.5 2.629/07/91 135 0.0 2.6 2.6 2.6 2.6 2.5 2.6200Inhibitor Chemical Testing at Seymour Dam^ Appendix RChloramine Measurements, mg/LTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 731/07/91 137 0.0 2.6 2.6 2.6 2.5 2.5 2.502/08/91 139 0.0 2.5 2.5 2.5 2.5 2.5 2.506/08/91 143 0.0 2.7 2.6 2.6 2.7 2.5 2.607/08/91 144 0.0 1.3 1.3 1.8 1.7 2.0 1.8 Solder Coils - 24 hr standing08/08/91 145 0.0 0.1 0.1 0.0 0.1 0.0 0.0 Plumbing Coils - 24 hr standing08/08/91 145 0.0 2.5 2.5 2.6 2.5 2.5 2.4 Faucets -24 hr standing12/08/91 149 0.0 2.4 2.4 2.4 2.3 2.3 2.314/08/91 151 0.0 2.6 2.5 2.5 2.7 2.6 2.615/08/91 152 0.0 2.7 2.6 2.6 2.6 2.5 2.619/08/91 156 0.0 2.6 2.8 2.7 2.7 2.7 2.620/08/91 157 0.0 1.4 1.4 1.9 1.7 2.1 1.9 Solder Coils - 24 hr standing21/08/91 158 0.0 0.0 0.1 0.0 0.0 0.1 0.0 Plumbing Coils -24 hr standing21/08/91 158 0.0 2.5 2.5 2.5 2.5 2.4 2.4 Faucets -24 hr standing23/08/91 160 0.0 2.7 2.7 2.7 2.7 2.8 2.826/08/91 163 0.0 2.8 2.8 2.8 2.8 2.9 2.928/08/91 165 0.0 2.7 2.7 2.7 2.7 2.8 2.803/09/91 171 0.0 2.6 2.6 2.7 2.6 2.6 2.604/09/91 172 0.0 2.6 2.6 2.5 2.5 2.5 2.506/09/91 174 0.0 2.6 2.6 2.5 2.6 2.5 2.409/09/91 177 0.0 2.5 2.6 2.6 2.6 2.6 2.610/09/91 178 0.0 1.6 1.5 1.7 1.8 1.8 1.8 Solder Coils - 24 hr standing11/09/91 179 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Plumbing Coils - 24 hr standing11/09/91 179 0.0 2.6 2.5 2.5 2.5 2.6 2.4 Faucets -24 hr standing13/09/91 181 0.0 2.6 2.6 2.6 2.6 2.6 2.616/09/91 184 0.0 2.5 2.5 2.4 2.4 2.4 2.518/09/91 186 0.0 2.6 2.6 2.5 2.6 2.6 2.520/09/91 188 0.0 2.6 2.5 2.5 2.6 2.5 2.527/09/91 195 0.0 2.7 2.6 2.7 2.7 2.6 2.630/09/91 198 0.0 2.6 2.6 2.6 2.6 2.6 2.501/10/91 199 0.0 1.2 1.1 1.8 1.4 1.9 1.8 Solder Coils - 24 hr standing02/10/91 200 0.0 0.0 0.1 0.0 0.0 0.0 0.0 Plumbing Coils - 24 hr standing02/10/91 200 0.0 2.5 2.5 2.5 2.4 2.5 2.3 Faucets - 24 hr standing04/10/91 202 0.0 2.7 2.7 2.7 2.7 2.7 2.707/10/91 205 0.0 2.5 2.5 2.5 2.5 2.5 2.509/10/91 207 0.0 2.5 2.5 2.5 2.5 2.5 2.511/10/91 209 0.0 2.5 2.5 2.4 2.4 2.3 2.415/10/91 213 0.0 2.6 2.6 2.6 2.6 2.6 2.516/10/91 214 0.0 2.6 2.6 2.6 2.5 2.6 2.621/10/91 219 0.0 2.8 2.8 2.9 2.9 3.1 3.122/10/91 220 0.0 1.3 1.3 2.0 1.3 1.9 1.7 Solder Coils - 24 hr standing22/10/91 220 0.0 0.0 0.1 0.0 0.0 0.0 0.0 Plumbing Coils -24 hr standing23/10/91 221 0.0 2.4 2.8 2.7 3.1 3.0 2.6 Faucets - 24 hr standing201Inhibitor Chemical Testing at Seymour Dam^ Appendix RChloramine Measurements, mg/LTreated SamplesDateDaysFromStartLoop Number1 2 3 4 5 6 7 Comment25/10/91 223 0.0 2.6 2.5 2.5 2.6 2.5 2.528/10/91 226 0.0 2.6 2.6 2.6 2.6 2.7 2.630/10/91 228 0.0 2.6 2.6 2.6 2.6 2.6 2.601/11/91 230 0.0 2.6 2.5 2.5 2.5 2.5 2.504/11/91 233 0.0 2.6 2.6 2.7 2.5 2.6 2.505/11/91 234 0.0 1.6 1.4 2.1 1.7 2.0 1.9 Solder Coils - 24 hr standing05/11/91 234 0.0 <0.1 0.1 <0.1 0.1 0.1 <0.1 Plumbing Coils - 24 hr standing06/11/91 235 0.0 2.4 2.4 2.4 2.4 2.4 2.4 Faucets -24 hr standing08/11/91 237 0.0 2.7 2.7 2.6 2.6 2.7 2.712/11/91 241 0.0 2.6 2.6 2.6 2.6 2.6 2.615/11/91 244 0.0 2.5 2.5 2.6 2.4 2.5 2.418/11/91 247 0.0 2.5 2.5 2.5 2.5 2.5 2.519/11/91 248 0.0 1.5 1.4 1.9 1.5 1.8 1.7 Solder Coils - 24 hr standing19/11/91 248 0.0 0.0 0.1 0.1 0.0 <0.1 0.0 Plumbing Coils -24 hr standing20/11/91 249 0.0 2.5 2.5 2.5 2.4 2.5 2.4 Faucets - 24 hr standing22/11/91 251 0.0 2.4 2.5 2.5 2.5 2.5 2.525/11/91 254 0.0 2.6 2.6 2.6 2.5 2.6 2.627/11/91 256 0.0 2.6 2.5 2.5 2.6 2.6 2.629/11/91 258 0.0 2.5 2.5 2.5 2.5 2.6 2.502/12/91 261 0.0 2.5 2.5 2.5 2.5 2.5 2.503/12/91 262 0.0 1.5 1.6 1.9 1.6 1.3 1.8 Solder Coils - 24 hr standing03/12/91 262 0.0 0.0 0.1 <0.1 <0.1 0.0 0.1 Plumbing Coils - 24 hr standing04/12/91 263 0.0 2.2 2.3 2.3 2.3 2.3 2.1 Faucets -24 hr standing06/12/91 265 0.0 2.6 2.6 2.6 2.5 2.6 2.609/12/91 268 0.0 2.6 2.6 2.6 2.6 2.5 2.611/12/91 270 0.0 2.5 2.6 2.5 2.6 2.5 2.513/12/91 272 0.0 2.5 2.5 2.5 2.5 2.5 2.516/12/91 275 0.0 2.6 2.6 2.5 2.6 2.6 2.617/12/91 276 0.0 1.7 1.7 2.1 1.7 0.4 1.8 Solder Coils - 24 hr standing17/12/91 276 0.0 0.0 0.1 0.1 <0.1 0.0 0.0 Plumbing Coils -24 hr standing18/12/91 277 0.0 2.3 0.7 2.5 2.3 2.3 2.2 Faucets -24 hr standing22/12/91 281 0.0 2.5 2.4 2.4 2.5 2.4 2.430/12/91 289 0.0 2.4 2.4 2.4 2.4 2.4 2.406/01/92 296 0.0 2.5 2.5 2.5 2.5 2.4 2.413/01/92 303 0.0 2.5 2.5 2.4 2.5 2.5 2.514/01/92 304 0.0 1.7 1.7 2.0 1.8 1.0 Solder Coils - 24 hr standing14/01/92 304 0.0 0.0 0.1 0.1 <0.1 0.0 0.1 Plumbing Coils -24 hr standing15/01/92 305 0.0 2.6 2.5 2.6 2.6 2.6 2.6 Faucets -24 hr standing20/01/92 310 0.0 2.5 2.5 2.5 2.5 2.5 2.527/01/92 317 0.0 2.5 2.6 2.5 2.5 2.5 2.504/02/92 325 0.0 2.4 2.5 2.5 2.4 2.5 2.517/02/92 338 0.0 2.5 2.5 2.4 2.5 2.5 2.4202Inhibitor Chemical Testing at Seymour Dam^ Appendix RChloramine Measurements, mg/LTreated SamplesDateDaysFromStartLoop NumberComment1 2 3 4 5 6 718/02/92 339 0.0 1.1 1.7 2.0 1.7 2.1 2.0 Solder Coils - 24 hr standing18/02192 339 0.0 0.0 0.1 0.1 0.0 0.1 0.1 Plumbing Coils - 24 hr standing19/02/92 340 0.0 2.4 2.3 2.4 2.3 2.3 2.3 Faucets - 24 hr standing24/02/92 345 0.0 2.5 2.5 2.4 2.5 2.5 2.403/03/92 353 0.0 2.5 2.4 2.5 2.4 2.4 2.410/03/92 360 0.0 2.6 2.5 2.5 2.5 2.4 2.411/03/92 361 0.0 1.6 1.6 2.0 1.7 2.1 1.8 Solder Coils - 24 hr standing11/03/92 361 0.0 <0.1 0.1 0.1 0.1 0.1 0.1 Plumbing Coils - 24 hr standing12/03/92 362 0.0 2.1 1.4 1.4 1.9 1.3 1.4 Faucets - 24 hr standing* Levels for Plumbing Coils for 05/04/91 not included in averages because theyare so much higher than all the other measured levels for the Plumbing Coils.Average Chloramine Levels, mg/LLoop Number1 2 3 4 5 6 7Non Standing 0.0 2.5 2.5 2.5 2.5 2.5 2.5Std Deviation 0.0 0.1 0.1 0.1 0.1 0.1 0.1Maximum 0.0 2.8 2.8 2.9 2.9 3.1 3.1Minimum 0.0 2.2 2.2 2.2 2.2 2.2 2.2P Coil - 24 Hr St 0.0 0.1 0.1 0.0 0.1 0.1 0.1Std Deviation 0.0 0.1 0.1 0.1 0.1 0.1 0.1Maximum 0.2 0.3 0.1 0.3 0.1 0.2 0.0Minimum 0.0 0.0 0.0 0.0 0.0 0.0 0.0S Coil - 24 Hr St 0.0 1.4 1.4 1.7 1.5 1.7 1.7Std Deviation 0.0 0.2 0.2 0.3 0.2 0.4 0.2Maximum 0.0 1.7 1.8 2.1 1.8 2.2 2.0Minimum 0.0 1.1 1.1 1.0 1.2 0.4 0.0Faucet - 24 Hr St 0.0 2.3 2.2 2.3 2.3 2.3 2.2Std Deviation 0.0 0.3 0.5 0.3 0.2 0.3 0.3Maximum 0.0 2.6 2.8 2.7 3.1 3.0 2.6Minimum 0.0 1.2 0.7 1.2 1.8 1.3 1.4203Inhibitor Chemical Testing at Seymour Dam^ Appendix SCopper Coupons - Bacteriological ResultsHeterotrophic Plate Count, CFU/in2ExposureTimeLoop Number1 2 3 4 5 6 73 Months (a) 1.8E+06 8.5E+01 1.5E+05 1.0E+03 1.7E+02 7.1E+02 3.6E+053 Months (2) (b) 2.1E+05 7.8E+03 3.0E+05 6.4E+02 1.0E+04 8.4E+02 3.0E+066 Months (c) 1.2E+06 1.2E+06 2.2E+04 2.4E+03 1.2E+04 2.6E+02 2.4E+036 Months (2) (d) 5.6E+04 8.5E+03 1.3E+05 1.2E+04 6.2E+04 4.5E+05 7.2E+039 Months (e) 1.2E+06 9.5E+01 4.3E+02 1.4E+03 8.0E+01 8.6E+05 1.1E+059 Months (2) (f) 2.7E+05 5.7E+04 1.2E+06 2.1E+03 1.2E+05 3.3E+03 1.4E+0512 months (g) 4.6E+05 2.4E+03 1.8E+05 4.9E+03 6.2E+05 1.2E+06 6.0E+05Averages 7.4E+05 1.8E+05 2.8E+05 3.5E+03 1.2E+05 3.6E+05 6.0E+05Plate Count Relative to Raw Water 1.00 0.25 0.38 0.005 0.16 0.48 0.81Total Coliform Bacteria, MPN/100 mlExposureTimeLoop Number1 2 3 4 5 6 73 Months (a) <2 <2 <2 <2 <2 <2 <23 Months (2) (b) <2 <2 <2 <2 <2 <2 <26 Months (c) <2 <2 <2 <2 <2 <2 <26 Months (2) (d) <2 <2 <2 <2 <2 <2 <29 Months (e) <2 <2 <2 <2 <2 <2 <29 Months (2) (f) <2 <2 <2 <2 <2 <2 <212 months (g) <2 <2 <2 <2 <2 <2 <2Averages <2 <2 <2 <2 <2 <2 <2Total Conforms Relative to Raw Water^1 1 1 1 1 1 1(a) Exposed 15/03/91 to 17/06/91(warmer)(b) Exposed 18/12/91 to 16/03/92 (colder)(c) Exposed 15/03/91 to 16/09/91(warmer)(d) Exposed 16/09/91 to 16/03/92 (colder)(e) Exposed 15/03/91 to 18/12/91(wanner)(f) Exposed 17/06/91 to 16/03/92 (colder)(g) Exposed 15/03/91 to 16/03/92204Inhibitor Chemical Testing at Seymour Dam^ Appendix SCast Iron Coupons - Bacteriological ResultsHeterotrophic Plate Count, CFU/in2ExposureTimeLoop Number1 2 3 4 5 6 73 Months (a) 5.5E+07 7.7E+07 1.9E+08 7.2E+07 1.7E+08 3.8E+06 4.6E+083 Months (2) (b) 1.9E+07 1.1E+08 7.6E+08 5.4E+07 3.5E+08 4.0E+08 3.2E+086 Months (c) 4.0E+07 3.8E+07 2.9E+07 1.7E+07 8.3E+07 6.8E+07 3.5E+076 Months (2) (d) 4.3E+06 1.8E+07 5.7E+08 8.7E+06 2.9E+08 2.2E+08 2.5E+089 Months (e) 1.5E+07 3.0E+07 5.3E+07 4.9E+06 5.1E+07 8.8E+07 1.3E+089 Months (2) (f) 7.0E-F06 9.4E-F06 4.3E+08 8.8E+06 4.9E+08 1.1E+08 2.4E+0812 months (g) 4.0E+06 1.1E+08 3.0E+08 9.9E+06 1.9E+08 6.7E+07 1.1E+07Averages 2.1E+07 5.6E+07 3.3E+08 2.5E+07 2.3E+08 1.4E+08 2.1E+08Plate Count Relative to Raw Water 1.00 2.72 16.16 1.21 11.25 6.63 10.02Total Conform Bacteria, MPN/100 mlExposureTimeLoop Number1 2 3 4 5 6 73 Months (a) 9 <2 <2 <2 <2 <2 <23 Months (2) (b) 22 <2 <2 <2 <2 <2 <26 Months (c) 34 <2 <2 <2 4 <2 <26 Months (2) (d) 23 <2 <2 <2 <2 <2 <29 Months (e) 13 <2 <2 <2 <2 <2 <29 Months (2) (f) 30 <2 <2 <2 <2 <2 <212 months (g) 30 <2 <2 <2 <2 <2 <2Averages 23 <2 <2 <2 <2 <2 <2Total Coliforms Relative to Raw Water 1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1(a) Exposed 15/03/91 to 17/06/91(warmer)(b) Exposed 18/12/91 to 16/03/92 (colder)(c) Exposed 15/03/91 to 16/09/91(warmer)(d) Exposed 16/09/91 to 16/03/92 (colder)(e) Exposed 15/03/91 to 18/12/91 (warmer)(1) Exposed 17/06/91 to 16/03/92 (colder)(g) Exposed 15/03/91 to 16/03/92205Inhibitor Chemical Testing at Seymour Dam^ Appendix TQuality Control SamplesThe following samples were measured by the GVWD laboratory as a check onanalyses done at the UBC laboratory.Total Phosphorus Silica as Si02SampleDate LoopGVWDMeasureUBCMeasureUBCRelative toGVWDSampleDate LoopGVVVDMeasureUBCMeasureUBCRelative toGVWD09/04/91 3 0.16 0.019 0.12 09/04/91 4 18 17.659 0.9818/04/91 5 0.13 0.154 1.18 18/04/91 2 3.2 3.386 1.0623/04/91 7 0.32 0.39 1.22 23/04/91 3 4 4.44 1.1129/04/91 6 0.34 0.385 1.13 29/04/91 1 3.20 3.118 0.9708/05/91 1 <0.005 0.007 1.40 08/05/91 3 3.7 3.829 1.0315/05/91 7 0.35 0.408 1.17 15/05/91 4 16 15.025 0.9423/05/91 2 <0.005 0.005 1.00 23/05/91 7 2.9 2.636 0.9128/05/91 4 <0.005 0.006 1.20 28/05/91 5 2.9 2.767 0.9504/06/91 5 0.101 0.135 1.34 04/06/91 3 3.7 3.556 0.9611/06/91 6 0.301 0.398 1.32 11/06/91 4 16 15.759 0.9819/06/91 3 0.2 0.019 0.10 19/06/91 2 2.9 2.91 1.0026/06/91 1 <0.005 0.005 1.00 26/06/91 3 3.7 3.686 1.0003/07/91 2 <0.005 0.007 1.40 03/07/91 5 2.8 2.868 1.0210/07/91 7 0.3 0.337 1.12 10/07/91 4 17 16.598 0.9817/07/91 5 0.13 0.142 1.09 17/07/91 3 3.6 3.766 1.0524/07/91 6 0.32 0.384 1.20 24/07/91 4 15 13.833 0.9231/07/91 7 0.3 0.33 1.10 31/07/91 3 3.8 3.779 0.9908/08/91 3 0.15 0.022 0.15 08/08/91 1 3 3.271 1.0914/08/91 4 <0.005 0.01 2.00 14/08/91 7 3.1 3.564 1.1521/08/91 2 0.007 0.008 1.14 21/08/91 6 3.1 3.34 1.0828/08/91 5 0.16 0.216 1.35 28/08/91 4 20 17.861 0.8904/09/91 6 0.42 0.476 1.13 04/09/91 3 4.1 4.183 1.0211/09/91 7 0.317 0.386 1.22 11/09/91 4 15 13.908 0.9318/09/91 3 <0.005 0.039 7.80 18/09/91 2 3.5 3.437 0.9802/10/91 1 <0.005 0.009 1.80 02/10/91 5 3.6 3.481 0.9709/10/91 7 0.402 0.52 1.29 09/10/91 4 16 14.583 0.9116/10/91 6 0.404 0.478 1.18 16/10/91 2 3.9 3.904 1.0023/10/91 5 0.053 0.055 1.04 23/10/91 3 4.6 4.858 1.0630/10/91 3 0.177 0.036 0.20 30/10/91 7 3.8 4.064 1.0706/11/91 7 0.308 0.368 1.19 06/11/91 4 16 14.773 0.9215/11/91 4 <0.005 0.004 0.80 15/11/91 6 3.6 3.706 1.0320/11/91 5 0.083 0.123 1.48 20/11/91 4 14 13.821 0.9927/11/91 2 0.007 0.008 1.14 27/11/91 1 3.1 3.618 1.1704/12/91 3 0.183 0.025 0.14 04/12/91 3 4.3 4.558 1.0611/12/91 7 0.35 0.368 1.05 11/12/91 7 2.8 3.979 1.4218/12/91 6 1.2 1.265 1.05 18/12/91 6 2.9 3.798 1.3130/12/91 5 0.12 0.063 0.53 30/12/91 5 3.4 3.783 1.1106/01/92 4 <0.005 0.002 0.40 06/01/92 4 12 13.839 1.1513/01/92 3 0.23 0.03 0.13 13/01/92 3 4.5 4.496 1.0020/01/92 2 <0.005 0.008 1.60 20/01/92 2 3.3 3.716 1.1327/01/92 1 <0.005 0.007 1.40 27/01/92 1 3.4 3.889 1.1404/02/92 7 0.23 0.337 1.47 04/02/92 7 2.1 2.483 1.1819/02/92 1 0.006 0.01 1.67 19/02/92 1 1.9 3.027 1.5924/02/92 2 <0.005 0.009 1.80 24/02/92 2 2.9 3.483 1.2003/03/92 3 0.22 0.016 0.07 03/03/92 3 3.6 5.15 1.4310/03/92 3 0.19 0.092 0.48 10/03/92 3 3.5 5.238 1.50206Inhibitor Chemical Testing at Seymour Dam^ Appendix TQuality Control Samples - FaucetsThe following faucet samples were measured by the GVWD laboratory as a check onanalyses done at the UBC laboratory.SampleDate LoopTotal Copper, mg/L Total Zinc, mg/L Total Lead, mg/LGYVVDMeas.UBCMeas.UBCRelative toGYVVDGV'WDMeas.UBCMeas.UBCRelative toGVWDGVVVDMeas.UBCMeas.UBCRelative toGVWD27/03/91 7 0.11 0.05 0.45 0.47 0.47 1.00 0.027 0.020 0.7406/04/91 2 0.38 0.35 0.92 0.23 0.24 1.04 0.190 0.158 0.8310/04/91 5 0.09 0.05 0.56 0.22 0.25 1.14 0.030 0.036 1.2026/04/91 1 0.62 0.28 0.260 0.250 0.9610/05/91 3 0.08 0.16 2.00 0.07 0.01 0.14 0.017 0.011 0.6515/05/91 6 0.05 0.01 0.20 0.41 0.45 1.10 0.014 0.013 0.9323/05/91 4 0.05 0.00 0.00 0.06 0.06 1.00 0.032 0.037 1.1629/05/91 1 0.69 0.64 0.93 0.30 0.26 0.87 0.093 0.130 1.4026/06/91 3 0.10 0.08 0.80 0.08 0.05 0.63 0.023 0.025 1.0909/07/91 4 0.07 0.05 0.71 0.11 0.08 0.73 0.034 0.047 1.3824/07/91 5 0.11 0.11 1.00 0.21 0.19 0.90 0.027 0.030 1.1108/08/91 6 0.03 <0.01 0.33 0.41 0.39 0.95 0.008 <0.010 1.2501/10/91* 1 0.41 0.37 0.90 0.27 0.24 0.89 0.033 0.033 1.0001/10/91** 7 0.06 0.04 0.67 0.28 0.25 0.89 0.009 0.009 1.0023/10/91* 2 0.17 0.13 0.76 0.08 0.07 0.88 0.035 0.043 1.2323/10/91** 4 0.04 0.01 0.25 0.02 0.02 1.00 0.020 0.024 1.2006/11/91* 2 0.14 0.08 0.57 0.07 0.04 0.57 0.025 0.022 0.8806/11/91** 1 0.05 0.03 0.60 0.07 0.05 0.71 0.006 0.012 2.0020/11/91* 7 0.08 0.03 0.38 0.49 0.49 1.00 0.009 0.008 0.8920/11/91** 5 0.04 0.05 1.25 0.08 0.11 1.38 0.005 0.006 1.2004/12/91 5 0.12 0.12 1.00 0.22 0.19 0.86 0.021 0.025 1.1918/12/91 6 0.13 0.08 0.62 0.51 0.52 1.02 0.008 0.011 1.3815/01/92 4 0.07 0.02 0.29 0.14 0.12 0.86 0.025 0.029 1.1619/02/92 5 0.07 0.02 0.29 0.17 0.16 0.94 0.010 0.009 0.9012/03/92 5 0.08 0.04 0.50 0.18 0.14 0.78 0.009 0.007 0.78* Filtered samples** Digested samples. All samples after 20/11/91 were digested.207Inhibitor Chemical Testing at Seymour Dam^ Appendix TQuality Control Samples - Plumbing CoilsThe following samples were measured by the GVWD laboratory as a check onanalyses done at the UBC laboratory.SampleDate LoopTotal Copper, mg/L Total Zinc, mg/L Total Lead, mg/LGVWDMeas.UBCMeas.UBCRelative toGVWDG'VVVDMeas.UBCMeas.UBCRelative toGVWDGVWDMeas.UBCMeas.UBCRelative toGVWD25/03/91 5-2 2.08 1.96 0.94 0.38 0.44 1.16 0.026 0.026 1.0003/04/91 1-1 0.90 0.87 0.97 0.04 0.02 0.50 0.020 0.022 1.1009/04/91 3-2 1.17 1.11 0.95 0.02 0.01 0.50 0.011 0.012 1.0924/04/91 4-1 2.68 0.02 0.016 0.012 0.7509/05/91 2-2 0.91 0.87 0.96 0.01 <0.01 1.00 0.018 <0.01 0.5614/05/91 6-1 1.97 1.95 0.99 0.60 0.61 1.02 0.045 0.049 1.0922/05/91 7-2 0.81 0.78 0.96 0.17 0.18 1.06 0.035 0.052 1.4928/05/91 3-1 1.01 0.99 0.98 0.01 <0.01 1.00 0.004 <0.01 2.5004/06/91 4-2 0.46 0.44 0.96 <0.01 <0.01 1.00 0.017 0.012 0.7111/06/91 5-1 1.95 2.03 1.04 0.22 0.18 0.82 0.008 <0.01 1.2525/06/91 7-1 10.00 10.26 1.03 1.06 1.03 0.97 0.140 0.180 1.2909/07/91 4-2 0.38 0.32 0.84 0.01 <0.01 1.00 0.023 0.023 1.0023/07/91 6-2 0.64 0.62 0.97 0.54 0.50 0.93 0.003 <0.01 3.3307/08/91 1-2 1.97 1.92 0.97 0.01 <0.01 1.00 0.023 0.021 0.9120/08/91 5-1 3.30 3.13 0.95 0.56 0.52 0.93 0.029 0.028 0.9710/09/91 3-2 1.10 1.05 0.95 <0.01 <0.01 1.00 0.008 0.005 0.6301/10/91* 4-2 0.24 0.24 1.00 <0.01 <0.01 1.00 0.019 0.021 1.1101/10/91** 1-1 1.18 1.18 1.00 0.06 0.05 0.83 0.009 0.014 1.5622/10/91* 1-1 0.16 0.16 1.00 <0.01 0.04 4.00 0.003 0.001 0.3322/10/91** 5-2 15.60 15.50 0.99 0.55 0.44 0.80 0.049 0.027 0.5505/11/91* 6-2 0.08 0.06 0.75 0.21 0.20 0.95 0.001 0.003 3.0005/11/91** 3-1 0.50 0.46 0.92 0.02 0.00 0.00 0.004 0.037 9.2519/11/91* 7-1 0.12 0.14 1.17 0.30 0.30 1.00 0.008 0.008 1.0019111/91** 5-2 17.30 18.16 1.05 1.00 0.97 0.97 0.047 0.049 1.0403/12/91 7-2 0.38 0.33 0.87 0.46 0.43 0.93 0.940 0.081 0.0917/12/91 2-2 0.43 0.36 0.84 0.02 0.03 1.50 0.003 0.003 1.0014/01/92 4-2 0.24 0.33 1.38 0.02 0.01 0.50 0.004 0.002 0.5018/02/92 5-1 7.94 7.98 1.01 0.89 0.90 1.01 0.160 0.135 0.8411/03/92 5-1 1.51 1.44 0.95 0.23 0.25 1.09 0.038 0.026 0.68* Filtered samp es** Digested samples. All samples after 20/11/91 were digested.208Inhibitor Chemical Testing at Seymour Dam^ Appendix TQuality Control Samples - Solder CoilsThe following samples were measured by the GVWD laboratory as a check onanalyses done at the UBC laboratory.SampleDate LoopTotal Copper, mg/L Total Zinc, mg/L Total Lead, mg/LGVWDMeas.UBCMeas.UBCRelative toGVWDGVWDMeas.UBCMeas.UBCRelative toGVVVDGVWDMeas.UBCMeas.UBCRelative toGVVVD26/03/91 3 0.16 0.09 0.56 0.04 <0.01 0.25 3.50 3.72 1.0605/04/91 6 0.21 0.17 0.81 0.90 0.94 1.04 3.01 3.10 1.0311/04/91 4 0.06 0.03 0.50 0.03 0.01 0.33 3.65 3.73 1.0224/04/91 5 0.53 0.54 5.07 5.02 0.9909/05/91 1 0.14 0.20 1.43 0.01 <0.01 1.00 1.47 1.53 1.0414/05/91 7 0.21 0.17 0.81 0.58 0.62 1.07 5.49 5.75 1.0522/05/91 2 0.05 <0.01 0.20 0.04 0.03 0.75 3.11 3.27 1.0528/05/91 6 0.13 0.12 0.92 0.84 0.80 0.95 1.90 1.53 0.8104/06/91 3 0.13 0.09 0.69 0.02 <0.01 0.50 6.19 6.16 1.0011/06/91 4 0.08 0.05 0.63 0.03 <0.01 0.33 15.60 14.60 0.9425/06/91 4 0.14 0.12 0.86 0.03 0.02 0.67 21.90 22.20 1.0109/07/91 5 0.19 0.17 0.89 0.52 0.49 0.94 12.60 14.92 1.1823/07/91 7 0.62 0.62 1.00 0.94 0.90 0.96 14.90 17.44 1.1707/08/91 4 0.13 0.08 0.62 0.02 <0.01 0.50 15.20 15.44 1.0210/09/91 1 0.28 0.24 0.86 <0.01 <0.01 1.00 3.57 2.91 0.8201/10/91* 3 0.03 0.02 0.67 0.01 <0.01 1.00 0.44 0.30 0.6801/10/91** 1 0.30 0.26 0.87 0.06 0.06 1.00 1.46 1.20 0.8222/10/91* 6 0.03 0.01 0.33 0.25 0.22 0.88 0.05 0.20 4.4422/10/911* 3 0.14 0.11 0.79 0.10 0.07 0.70 7.10 6.10 0.8605/11/91* 4 0.03 0.02 0.67 <0.01 <0.01 1.00 0.27 0.50 1.8505/11/91** 5 0.46 0.43 0.93 0.34 0.28 0.82 6.58 4.30 0.6519/11/91* 4 <0.02 0.07 3.50 0.01 0.04 4.00 0.34 0.28 0.8219/11/91** 3 0.19 0.15 0.79 0.10 0.10 1.00 14.60 15.30 1.0503/12/91 6 0.07 0.05 0.71 1.56 1.57 1.01 1.35 1.30 0.9617/12/91 2 0.11 0.03 0.27 0.03 0.02 0.67 15.60 15.20 0.9714/01/92 7 0.08 0.06 0.75 0.84 0.83 0.99 4.79 4.80 1.0018/02/92 5 0.17 0.11 0.65 0.31 0.27 0.87 6.21 6.10 0.9811/03/92 3 0.65 0.02 0.03 0.03 0.02 0.67 2.89 2.24 0.78* Filtered samples** Digested samples. All samples after 20/11/91 were digested.209Inhibitor Chemical Testing at Seymour Dam^ Appendix UPHOSPHORUS CONTENT, mg/L (Average of Two Samples)DateLoop NumberAvgLoopsLoop 3Dosemg,/L0.000Loop 5Dosemg/L0.000Loop 6Dosemg/L0.000Loop 7Dosemg/L0.0001 2 3 4 5 6 7 1,2 & 415/02/91* 0.011 0.012 0.009 0.010 0.007 0.002 0.004 0.00818/03/91** 0.003 0.006 0.075 0.004 0.480 1.313 1.313 0.027 0.048 0.452 1.285 1.28628/03/91 0.017 0.011 0.027 0.002 0.137 0.301 0.370 0.015 0.012 0.122 0.286 0.35502/04/91 0.004 0.008 0.010 0.004 0.138 0.357 0.377 0.006 0.004 0.132 0.351 0.37110/04/91 0.011 0.011 0.019 0.010 0.141 0.354 0.344 0.013 0.006 0.128 0.340 0.33018/04/91 0.006 0.005 0.017 0.014 0.154 0.394 0.420 0.012 0.005 0.141 0.381 0.40723/04/91 0.018 0.093 0.024 0.007 0.131 0.384 0.390 0.016 0.008 0.115 0.368 0.37429/04/91 0.007 0.016 0.039 0.012 0.156 0.385 0.389 0.019 0.020 0.136 0.365 0.36908/05/91 0.007 0.013 0.019 0.006 0.147 0.385 0.370 0.010 0.008 0.136 0.374 0.35915/05/91 0.002 0.003 0.035 0.008 0.172 0.411 0.408 0.015 0.020 0.157 0.396 0.39323/05/91 0.005 0.005 0.025 0.005 0.128 0.355 0.348 0.012 0.014 0.116 0.344 0.33628/05/91 0.010 0.010 0.034 0.006 0.171 0.351 0.380 0.016 0.018 0.154 0.334 0.36304/06/91 0.012 0.010 0.037 0.009 0.135 0.373 0.346 0.019 0.018 0.116 0.354 0.32711/06/91 0.005 0.010 0.040 0.009 0.150 0.398 0.379 0.018 0.022 0.132 0.380 0.36119/06/91 0.002 0.006 0.019 0.010 0.161 0.377 0.365 0.010 0.009 0.150 0.367 0.35426/06/91 0.005 0.003 0.026 0.001 0.107 0.326 0.305 0.011 0.015 0.096 0.315 0.29403/07/91 0.003 0.007 0.024 0.005 0.107 0.327 0.288 0.011 0.014 0.097 0.316 0.27810/07/91 0.006 0.008 0.024 0.004 0.131 0.401 0.337 0.011 0.013 0.120 0.389 0.32517/07/91 0.006 0.006 0.013 0.003 0.142 0.358 0.311 0.007 0.006 0.135 0.351 0.30424/07/91 0.006 0.005 0.016 0.005 0.158 0.384 0.352 0.009 0.007 0.149 0.375 0.34331/07/91 0.003 0.000 0.014 0.002 0.147 0.414 0.330 0.006 0.008 0.141 0.408 0.32408/08/91 0.004 0.007 0.022 0.003 0.171 0.419 0.368 0.010 0.012 0.162 0.409 0.35914/08/91 0.022 0.008 0.031 0.010 0.172 0.423 0.365 0.021 0.010 0.151 0.402 0.34421/08/91 0.004 0.008 0.035 0.006 0.164 0.372 0.365 0.015 0.020 0.149 0.357 0.35028/08/91 0.007 0.008 0.036 0.006 0.216 0.375 0.359 0.016 0.020 0.200 0.359 0.34304/09/91 0.025 0.015 0.038 0.043 0.077 0.476 0.428 0.035 0.003 0.041 0.440 0.39211/09/91 0.009 0.008 0.024 0.006 0.051 0.441 0.386 0.013 0.011 0.038 0.428 0.37318/09/91** 0.009 0.012 0.039 0.011 0.126 1.313 1.189 0.020 0.019 0.106 1.293 1.17002/10/91 0.009 0.009 0.024 0.005 0.031 , 0.449 0.395 0.013 0.012 0.019 0.437 0.38309/10/91 0.008 0.012 0.032 0.008 0.038 0.449 0.520 0.016 0.016 0.022 0.433 0.50416/10/91 0.004 0.006 0.033 0.004 0.029 0.478 0.401 0.014 0.020 0.016 0.464 0.38723/10/91 0.002 0.002 0.025 0.004 0.055 0.508 0.383 0.010 0.015 0.045 0.498 0.37330/10/91 0.009 0.009 0.036 0.003 0.029 , 0.392 0.381 0.016 0.020 0.013 0.376 0.36506/11/91 0.007 0.009 0.032 0.004 0.038 0.380 0.368 0.014 0.018 0.023 0.366 0.35415/11/91 0.006 0.008 0.035 0.004 0.136 0.387 0.375 0.015 0.020 0.121 0.372 0.36020/11/91 0.003 0.006 0.028 0.005 0.123 0.398 0.391 0.012 0.016 0.111 0.386 0.38027/11/91 0.010 0.008 0.030 0.005 0.129 0.384 0.373 0.015 0.015 0.114 0.369 0.35804/12/91 0.005 0.005 0.025 0.004 0.136 0.410 0.359 0.011 0.014 0.125 0.399 0.34811/12/91 0.010 0.010 0.026 0.006 0.118 0.364 0.368 0.014 0.012 0.104 0.350 0.35418/12/91** 0.008 0.007 0.055 0.002 0.367 1.265 1.182 0.022 0.034 0.345 1.243 1.16130/12/91 0.009 0.006 0.021 0.006 0.063 0.349 0.320 0.012 0.009 0.051 0.337 0.30806/01/92 0.006 0.007 0.038 0.002 0.109 0.393 0.342 0.015 0.023 0.093 0.377 0.32713/01/92 0.007 0.007 0.030 0.003 0.106 0.379 0.335 0.013 0.017 0.093 0.366 0.32220/01/92 0.008 0.008 0.045 0.004 0.110 0.378 0.332 0.019 0.026 0.091 0.359 0.31327/01/92 0.007 0.008 0.035 0.005 0.112 0.343 0.338 0.016 0.020 0.097 0.327 0.32204/02/92 0.009 0.009 0.038 0.004 0.116 0.370 0.337 0.017 0.021 0.099 0.353 0.32019/02/92 0.010 0.008 0.032 0.009 0.137 0.409 0.355 0.017 0.015 0.120 0.392 0.33824/02192 0.005 0.009 0.048 0.005 0.111 0.381 0.343 0.019 0.029 0.092 0.362 0.32403/03/92 0.001 0.002 0.016 0.000 0.097 0.318 0.303 0.005 0.010 0.092 0.313 0.29710/03/92 0.018 0.016 0.092 0.011 0.140 0.368 0.363 0.040 0.052 0.099 0.327 0.323Overall Averages, mg/L 0.015 0.015 0.105 0.373 0.350* Pre-treatment levels. Average is for all loops.** Indicates that inhibitor dosage in Loops 3, 5, 6 and 7 were tripled for initial passivation as recommended by themanufacturer. These dosage levels were not included in the averages.210Inhibitor Chemical Testing at Seymour Dam^ Appendix VSILICA CONTENT, mg/L (Average of Two Samples)DateLoop NumberAvgLoopsLoop 3Dosemg/LLoop 4Dosemg/L1 2 3 4 5 6 7 1,2&5-715/02/91* 2.455 2.517 2.533 2.478 2.529 2.493 2.560 2.509 0.000 0.00018/03/91** 3.156 3.055 3.903 17.786 3.070 3.188 3.148 3.123 0.780 14.66328/03/91 3.320 3.271 4.314 19.898 3.354 3.361 3.406 3.342 0.971 16.55602/04/91 3.543 3.414 4.275 17.123 3.436 3.512 3.378 3.456 0.818 13.66610/04/91 3.402 3.322 4.177 17.659 3.343 3.400 3.499 3.393 0.784 14.26518/04/91 3.298 3.386 4.532 15.824 3.537 3.516 3.451 3.437 1.095 12.38623/04/91 3.395 3.587 4.440 15.343 3.619 3.715 3.600 3.583 0.856 11.75929/04/91 3.118 3.145 3.906 14.564 3.117 3.300 3.251 3.186 0.720 11.37808/05/91 3.154 3.118 3.829 15.566 3.010 3.072 3.027 3.076 0.753 12.49015/05/91 2.854 2.858 3.615 15.025 2.832 2.847 2.890 2.856 0.759 12.16923/05/91 2.652 2.610 3.367 13.369 2.589 2.649 2.636 2.627 0.740 10.74128/05/91 2.851 2.845 3.649 15.075 2.767 2.931 2.824 2.843 0.806 12.23104/06/91 2.869 2.761 3.556 14.470 2.732 2.974 2.847 2.836 0.719 11.63311/06/91 2.959 2.942 3.858 15.759 2.910 3.010 2.999 2.964 0.894 12.79519/06/91 2.929 2.910 3.678 13.783 2.836 2.922 2.911 2.902 0.776 10.88126/06/91 2.960 2.924 3.686 15.569 2.833 3.005 2.987 2.941 0.744 12.62703/07/91 2.929 2.892 3.723 14.274 2.868 2.993 2.952 2.926 0.797 11.34810/07/91 2.924 2.897 3.789 16.598 2.945 3.065 2.974 2.961 0.828 13.63717/07/91 3.082 2.918 3.766 14.477 2.877 3.065 3.064 3.001 0.765 11.47624/07/91 3.016 3.015 3.704 13.833 2.965 3.052 3.047 3.019 0.685 10.81431/07/91 3.052 3.111 3.997 15.015 2.962 3.176 3.180 3.096 0.901 11.91908/08/91 3.271 3.279 4.191 14.956 3.257 3.338 3.290 3.287 0.904 11.66914/08/91 3.397 3.368 4.307 13.835 3.390 3.573 3.564 3.458 0.849 10.37721/08/91 3.273 3.260 4.209 15.838 3.265 3.340 3.341 3.296 0.913 12.54328/08/91 3.624 3.565 4.272 17.861 3.546 3.747 3.741 3.644 0.627 14.21604/09/91 3.327 3.286 4.183 14.468 3.228 3.363 3.331 3.307 0.876 11.16111/09/91 3.369 3.323 4.193 13.908 3.271 3.403 3.358 3.345 0.848 10.56318/09/91** 3.475 3.437 4.819 14.100 3.459 3.731 3.670 3.554 1.264 10.54502/10/91 3.616 3.511 4.334 14.945 3.481 3.633 3.615 3.571 0.763 11.37409/10/91 3.916 3.907 4.672 14.583 3.821 3.966 3.985 3.919 0.753 10.66416/10/91 3.959 3.904 4.822 15.440 3.936 4.128 4.154 4.016 0.805 11.42323/10/91 3.998 4.025 4.858 16.062 4.000 4.065 4.083 4.034 0.824 12.02730/10/91 4.009 3.921 4.857 15.246 3.926 4.157 4.064 4.015 0.842 11.23106/11/91 3.865 3.777 4.774 14.773 3.737 3.871 3.843 3.818 0.955 10.95415/11/91 3.760 3.623 4.550 13.383 3.623 3.706 3.671 3.676 0.874 9.70620/11/91 3.462 3.391 4.370 13.821 3.169 3.441 3.467 3.386 0.984 10.43527/11/91 3.618 3.542 4.639 13.731 3.601 3.783 3.756 3.660 0.979 10.07104/12/91 3.655 3.525 4.558 14.024 3.454 3.778 3.695 3.621 0.937 10.40311/12/91 3.772 3.710 4.830 15.470 3.619 3.926 3.979 3.801 1.029 11.66918/12/91** 3.572 3.498 5.452 16.011 3.533 3.798 3.755 3.631 1.821 12.38030/12/91 3.816 3.713 4.513 13.877 3.783 3.800 3.636 3.749 0.764 10.12806/01/91 3.650 3.625 4.533 13.839 3.559 3.635 3.797 3.653 0.880 10.18613/01/92 3.678 3.605 4.496 14.127 3.534 3.723 3.687 3.645 0.851 10.48220/01/92 3.680 3.716 4.681 15.010 3.721 3.859 3.853 3.766 0.915 11.24427/01/92 3.889 3.767 4.753 14.836 3.768 3.896 3.893 3.842 0.911 10.99404/02/92 2.410 2.446 3.346 13.177 2.367 2.557 2.483 2.452 0.894 10.72519/02/92 3.027 3.201 3.876 13.893 3.060 3.399 3.365 3.210 0.666 10.68224/02/92 3.522 3.483 4.501 14.405 3.401 3.493 3.473 3.474 1.026 10.93103/03/92 4.349 4.266 5.150 17.079 4.203 4.438 4.402 4.331 0.819 12.74810/03/92 4.044 4.329 5.238 18.119 4.237 4.418 4.395 4.284 0.954 13.835Overall Averages, mg/L 3.390 0.845 11.731* Pre-treatment levels. Average is for all loops.** Indicates that inhibitor dosage in Loop 3 was tripled for initial passivation as reconunended by the manufacturer.These dosage levels were not included in the averages.211Inhibitor Chemical Testing at Seymour Dam^ Appendix WIncidents Which May Have Impacted The Outcome Of The ExperimentThe following are copies of comments from the experiment notes.DATE^ITEM28/03/91 Discovered that the Pump feeding TPC 223 in Loop 3 was set toolow by about 20 percent. Pump was reset to the correct setting.06/04/9130/04/9106/05/91Circuit breaker for the outlet for the pumps that feed NaHCO3,Virchem 939 and TPC 223 was open. For how long is not known;could be as long as 2 days.Plant shut down at 10:00 to install Corrosometer probes. Allowed24 hours for PVC soldered welds to set. Plant restarted at 10:15on 01/05/91.Plant ran continuously from startup (by others) on 01/05/91 tilabout 10:00 on 03/05/91 when it shut down automatically probablybecause of GAC filter headloss. The timer was not set, so flowwas continuous. It then sat idle until today because I was away forthe week and there was no one to check on the plant in myabsence. All chemicals except HC1 ran out. Chemicals wererebatched and the plant was restarted at 11:05 today.After rebatching chemicals it was noticed that the pH in Loops 3and 4 were quite high (8.96 and 9.23 respectively). This couldhave been due to poor mixing and a higher concentration ofinhibitor (both of which are basic) being on the bottom near thepump intake. Care will be taken to ensure proper mixing in future.While backwashing the GAC filters, one of the perforated pipeson the smaller filter gave way which resulted in a loss of about 2/3of the GAC being lost from that filter. System was shut down andthe GAC replaced on 07/05/91. System was back on at 17:00 on07/05/91.10/05/91^High pH and alkalinity in Loop4 was due to the HC1 feed beingblocked. Line was replaced and feed then seemed OK.13/05/91^Lines to faucets for Loops 1 and 3 were leaking. Repaired.21/05/91^Circuit breaker for the outlet for the pumps that feed NaHCO3,Virchem 939 and TPC 223 was open again, since about P.M.19/05/91. Reset at 12:00 today.212Inhibitor Chemical Testing at Seymour Dam^ Appendix W04/06/91^Faucet on Loop 1 was almost totally clogged, and had been so forseveral weeks. Faucet screen was cleaned out and now runs freely.05/06/91^Feed pump for Ca(OH)2 to Loop 7 was off, for how long isunknown. The electrical plug was loose. Rectified.06/06/91^Feed pump for Ca(OH)2 to Loop 5 was off, for how long isunknown. Rectified.08/06/91^Feed pump for Ca(OH)2 to Loop 2 was off, for how long isunknown. Rectified.11/06/91^Power for CA(OH)2 feeds to Loops 2, 5, and 3 is out and have notbeen able to rectify. System shut down until A.M. 12/06/91. Therewas a blown fuse in the control panel.17/06/91^System shut down for removal and replacement of pipe coupons(three month or 94 days). New City of Vancouver test loopsinstalled. System kept down for 24 hours so PVC solder weldscould set. System back up A.M. 18/06/91.12/08/91^Discovered that the system had been shut down since 08/08/91.Power was never turned back on after having been shut off.19/08/91^Circuit breaker for the outlet for the pumps that feed NaHCO3,Virchem 939 and TPC 223 was open again. Reset at 10:15 today.21/08/91^Hose to the faucet for Loop 1 had popped off. Unable to obtain anisolated faucet sample for Loop 1 this time.26/08/91^HC1 feed hose to Loop 4 was crimped. Rectified.29/08/91^System was shut down at about midnight due to flooding (extremeheavy rain). The flooding kept me from going into the plant fortwo days and caused numerous minor problems which had to berectified, and some of the chemicals had to be rebatched. Systemwas back up and running at 15:00 on 01/09/91.03/09/91^Circuit breaker for the outlet for the pumps that feed NaHCO3,Virchem 939 and TPC 223 was open again. Reset at 10:10 today.Flow in Loops 1 and 4 was quite low ( Loop 1 - 2.9 USGPM andLoop 4 - 3.7 USGPM). Problem was due to the bypass valves forthose loops only being partially open. Rectified.213Inhibitor Chemical Testing at Seymour Dam^ Appendix WHave noticed that flow backs off in some loops overnight for noapparent reason. The only way to deal with this is to be sure andchech the flow the first thing each day.04/09/91^Pump feeding Virchem 939 to Loops 6 and 7 is not working eventhough the power light comes on. Problem may have occurredduring the flood but not discovered until today. Pump waschanged and sent in for repair.Feed pump for Ca(OH)2 was off, for how long is unknown.Power indicator light was on but the "INT/EXT" switch on theback was set to "EXT". Rectified.07/09/9110/09/9116/09/91Water was shut off at 10:45 for about 6 hours due to a leak in thegenerating room. Feed pumps were still on, though, so they ran bythemselves from 14:00 to 15:00. System was back to normalwhenthe timer came on again at 19:00.Used new KC1 solution to calibrate the Conductivity meter. Themeter required about a 20 percent upward adjustment, so the morerecent readings may be somewhat suspect.System shut down at 08:20 for removal and replacement of pipecoupons (6 months, or 184 days) and replacement. Virchem 939and TPC 223 dosage rates tripled and doubled respectively for thenext two days for initial passivation.18/09/91^Rebatched Virchem 939 and TPC 223 vats to give normal feedagain.27/09/91^After one week absence, discovered that flow in Loop 1 was low atabout 60 percent of the required level. No explanation for this.Valve was readjusted.30/09/91^Pump feeding Ca(OH)2 to Loop 7 was not working even thoughthe power light was on. How long is unknown. Pump replaced.01/10/91^Change in metals sampling protocol.  For the Solder Coilssamples, the water in the cannisters was shaken up as much aspossible to mix the sediment and suspend it and all of it waspoured into a two L container. The container was then shakenvigorously and one L was poured into a container for pH,alkalinity, etc., analysis. The remainder was poured into a 250 mlcontainer. The sample in the 250 ml container was divided in half,with half being filtered through a no. 42 Whatman filter. Finally,the two 125 ml samples were acidified and transported to UBC for214Inhibitor Chemical Testing at Seymour Dam^ Appendix Wmetals analysis. The solder canisters were cleaned out beforereplacing them on the system to minimize metals being carriedfrom one sample period to the next. The Plumbing Coil andFaucet samples were gathered the same way, but a portion of eachwas filtered through no. 42 Whatman filters and then both thefiltered and the unfiltered samples were acidified. Prior to metalsmeasurement, the unfiltered samples were digested.09/10/91^Main water valve was closed since 08/10/91, so the system ran foralmost 24 hours with no water, only chemicals flowing. Rectified.15/10/91^Water flow in Loop 1 was very low again. No apparent reason.Rectified.21/10/91^The water flow in all loops needed considerable adjustment. Thisseems to be an ongoing problem that seems to be getting worse.23/10/91^Again water flow needed considerable adjustment in all loops.25/10/91^Water flow needed adjustment, particularly Loop 1.05/11/91^Water flow has not required nearly as much adjustment lately,seems back to normal. Noticed that it was impossible to removeall the sediment from the solder coil cannisters. Some of it alwaysstays behind meaning that the metals determinations have anegative error.12/11/91^Ca(OH)2 feed line to Loop 5 was leaking. Repaired.20/11/91^Heavy rainfall for the last few days likely responsible for the lowerconductivity, pH, and alkalinity levels.26/11/91^System was not working at 09:35 due to auto shutoff. Probablecause was the float valve being bumped yesterday afternoon whileSCBV pers were washing anthricite in the large GAC filter.29/11/91^^Used new KC1 solution for Conductivity which could account forthe higher conductivity measurements today.02/12/91^Change in metals sampling protocol. The Solder Coil canisterswere flushed out to remove any sediment (significant amounts ofsediment were flushed from the canisters for Loops 5, 6, and 7)before they were isolated for the 24 our standing period. Thisshould help ensure that the metals measured are from the 24 hourstanding period only.215Inhibitor Chemical Testing at Seymour Dam^ Appendix W16/12/91^Power plug for the pumps feeding TPC 223 to Loop 3 andNaHCO3 to Loop 7 was out. Rectified.18/12/91Had planned to replace the third set of pipe coupons, but due to abreakdown in communications with GVRD lab staff the task waspostponed to Wed. The lines had all been loosened and drained,and had to be resealed and water flow restarted. Initial flow afterreconnection was very dirty, likely due to sloughing off of some ofthe biofilm.System shut down for removal and replacement of the third set ofpipe coupons (nine months or 277 days). Virchem 939 and TPC223 dosage rates tripled and doubled respectively for the next fourdays for initial passivation.HC1 feed line to Loop 4 was crimped. Rectified.22/12/91^Rebatched Virchem 939 and TPC 223 vats to give normal feedagain.04/02/92^HC1 feed line to Loop 4 was crimped. Rectified.06/02/91^System had been shut down since 04/02. Neglected to turn it backon that day. Back on at 08:15 today.16/03/92^System shut down for removal of all the remaining pipe coupons(12 month, duplicates of 3, 6, and 9 month; 366 days). Cu couponno. 37 was damaged on removal because it was stuck in itscontainer. Cu coupon no. 20 was also damaged because it fell onthe floor. Some epoxy scraped off both of these.Experiment terminated today. Plant allowed to run for a few daysto use up the remainder of the chemicals in the vats.216

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