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The effect of zinc orthophosphate and pH/alkalinity adjustment on copper and lead levels in drinking… Churchill, Diane M. 1997

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THE EFFECT OF ZINC ORTHOPHOSPHATE AND pH/ALKALINITY ADJUSTMENT ON COPPER AND LEAD LEVELS IN DRINKING WATER  by Diane M. Churchill BSN, The University of British Columbia, 1979  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE  REQUIREMENTS  FOR THE DEGREE OF MASTER OF APPLIED SCIENCE  in THE FACULTY OF GRADUATE STUDIES Department of Civil Engineering  We accept this theses as conforming to the required standard  THE UNIVERSITY OF BRITISH COLUMBIA MAY 1997 © Diane M. Churchill, 1997  In presenting this thesis in partial fulfillment of the requirements for an advanced degree at the University of British Columbia I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the Head of my Department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission.  Department of Civil Engineering University of British Columbia .2324 Main Mall Vancouver, B.C. V6T 1W5  Date: MAY 1997  ABSTRACT  A twelve month pilot plant study was conducted to evaluate the relative ability of various corrosion control treatments to reduce metal leaching from typical household plumbing materials. A pipe loop system with seven loops, each consisting of lead/tin soldered copper piping, coils of lead/tin solder material and brass faucets, was used to test six treatment options and a control. pH and alkalinity were adjusted by the addition of lime (Ca(OH) ) and sodium bicarbonate (NaHC0 ) respectively, and two 2  3  different doses of zinc orthophosphate were tested. Treated water samples, that had been left standing in the pipe loop system for a predetermined time period of eight or sixteen hours, were drawn at regular intervals and measured for lead, copper, and zinc. The results led to the following conclusions. There were some small reductions of lead and copper in the pH/alkalinity loops; however, overall, when compared to the control loop, pH/alkalinity treatment appeared to exacerbate metal leaching in standing samples. Metal levels in the treated loops were very unstable, with some spikes of very high concentrations. It is thought that these high spikes were a result of, not just leached metals, but sloughing off the scale that forms during flowing conditions. The instability of the scale may be related to the high variability of the pH that occurred in the treated loops. The control loop which had relatively stable metal concentrations and no episodes of extremely high metal spiking, maintained a relatively stable pH.  The zinc orthophosphate showed good results and was consistently effective at reducing lead and copper levels to below that of the control. The two different standing times showed little difference in the levels of metals that were leached into the water from the pH/alkalinity loops and the lower dose zinc orthophosphate loop. The exception to this, however, was the higher dose zinc orthophosphate loop, which had higher copper and zinc levels at the longer standing time.  iii  Table Of Contents ABSTRACT  ii  LIST OF TABLES  viii  LIST OF FIGURES  ix  ACKNOWLEDGMENTS  xi  DEDICATION  xii  1. INTRODUCTION  1  1.1. Greater Vancouver Water District Background Information  1  1.2. GVWD Water Quality Characteristics  4  1.3. Impacts of Corrosion 1.3.1. Health 1.3.2. Economics 1.3.3. Other Impacts  8 8 13 15  1.4. Regulatory Concerns 1.4.1. United States 1.4.2. Canada  15 16 17  1.5. Premise Plumbing 1.5.1. Copper Piping 1.5.2. Lead Solder 1.5.3. Brass Faucets 1.5.4. Galvanized Pipe 1.5.5. Plastic Pipe  18 18 19 19 20 20  1.6. Summary  21  2. STU DY OBJ ECTIVES  22  2.1. Previous Study  22  2.2. Objectives  24  3. THEORETICAL BACKGROUND  25  3.1. Basic Corrosion Theory  25  iv  3.2. Factors Influencing Corrosion  3.2.1. 3.2.2. 3.2.3. 3.2.4.  Water Quality Environmental factors Materials and workmanship Age of plumbing  3.3. Types of Corrosion  3.3.1. Copper Corrosion 3.3.2. Lead Corrosion 3.4. Corrosion Control  3.4.1. Calcium Carbonate Precipitation 3.4.2. pH /Alkalinity Adjustment 3.4.3. Zinc Orthophosphate  29  29 33 36 36 37  38 42 44  45 45 47  3.5. Health Factors  49  4. EXPERIMENTAL METHODS  52  4.1. Introduction  52  4.2. Pilot Plant Description  53  4.2.1. Pipe Loop Description 4.2.2. Chemical Treatment Set-up 4.3. Operational Procedures  4.3.1. 4.3.2. 4.3.3. 4.3.4. 4.3.5. 4.3.6.  Pre-treatment Procedures Regular Routines Monitoring ZOP Dosing Preparation of Chemicals Sampling Routine for Metals Determination Quality Control and Data Analysis  53 56 58  58 59 60 61 62 65  5. RESULTS AND DISCUSSION  66  5.1. Copper Concentrations in Standing Water Samples  66  5.1.1. Plumbing Coils 5.1.2. Solder Coil 5.1.3. Faucets 5.2. Lead Concentrations in Standing Water Samples  5.2.1. Solder Coils 5.2.2. Plumbing Coils 5.2.3. Faucets 5.3. Zinc Concentrations in Standing Water Samples  66 68 74 76  76 82 84 86  v  5.4. Eight vs. Sixteen Hour Standing Times 5.4.1. Lead Levels 5.4.2. Copper Levels 5.4.3. Zinc Levels  91 91 91 95  5.5. Comparison of Water Treatments  98  5.6. Water Quality Parameters 5.6.1. pH 5.6.2. Alkalinity 5.6.3. Temperature 5.6.4. Conductivity  102 102 105 105 108  5.7. Quality Control  109  5.8. Unexpected Problems  110  6. SUMMARY DISCUSSION  111  6.1. General  111  6.2. ZOP Treatment  111  6.3. pH/Alkalinity Treatment  115  6.4. Standing Time Effects  115  7. CONCLUSIONS AND RECOMMENDATIONS  117  7.1. Conclusions  117  7.2. Recommendations  118  7.3. Further Study  120  8. REFERENCES  122  APPENDICES  131  A . GVWD Seymour Water Physical and Chemical Analysis  132  B. Virchem 939 Material Safety Data Sheet  133  c. Phosphorus Content  135  D. Copper Levels - Plumbing Coils  136  E. Copper Levels - Solder Coils  138  F. Copper Levels - Faucets  140  G. Lead Levels - Solder Coils  142  H. Lead Levels - Plumbing Coils  144  i.  Lead Levels - Faucets  146  j.  Zinc Levels - Plumbing Coil  148  K. Zinc Levels - Faucets  150  L. Zinc Levels - Solder Coils  152  M. Flowing Water pH Measurements  154  N. Standing Sample pH Measurements  163  o. Alkalinity Measurements  169  p. Temperature Measurements  182  Q. Comparison of Two Temperature Ranges Temperature Data  192  R. Conductivity Measurements  195  s. Quality Control Samples  205  T. Unexpected Incidents  215  vi  LIST OF TABLES  1.1 Corrosion Indices for Several Soft, Low Alkalinity Water Sources  7  4.1 Treatment Set-up  57  5.1 Total Copper Reductions  68  5.2 Copper Reductions in Plumbing Coils  68  5.3 Copper Reductions in Solder Coils  72  5.4 Copper Reductions in Faucets  74  5.5 Lead Reductions in Solder Coils  82  5.6 Lead Reductions in Faucets  84  5.7 Average pH  102  5.8 Average Alkalinity  105  v  LIST OF FIGURES 1.1 Greater Vancouver Water Supply 1.2 Seymour Falls Dam 3.1 Corrosion Cell 4.2 Pipe Loop System Schematic 5.1 Plumbing Coils - pH/Alkalinity Loop Copper Levels 5.2 Plumbing Coils - ZOP Loop Copper Levels 5.3 Plumbing Coils - Average Copper Levels 5.4 Solder Coils - Average Copper Levels 5.5 Faucets - Average Copper Levels 5.6 Solder Coils - pH/Alkalinity Loop Lead Levels 5.7 Solder Coils - ZOP Loop Lead Levels 5.8 Solder Coils - Average Lead Levels 5.9 Solder Coils - Decline in Lead Levels Over Time 5.10 Plumbing Coils - Average Lead Levels 5.11 Faucets - Average Lead Levels 5.12 Faucets - Average Zinc Levels  5.13 Average Zinc - ZOP Loops  88  5.14 Plumbing Coils - Zinc - ZOP Loops  89  5.15 Solder Coils - Lead - Eight vs. Sixteen Hour Samples  92  5.16 Plumbing Coils - Copper - Eight vs. Sixteen Hour Samples  93  5.17 Faucets - Copper - Eight vs. Sixteen Hour Samples  94  5.18 Faucets - Zinc - Eight vs. Sixteen Hour Samples  96  5.19 Plumbing Coils - Zinc - Eight vs. Sixteen Hour Samples  97  5.20 Relative Metal Mobility  99  5.21 Total Copper Average  100  5.22 Total Lead Average  101  5.23 Average pH  103  5.24 Comparison of Two Temperature Ranges -Copper  106  5.25 Comparison of Two Temperature Ranges - Lead  107  5.26 Average Lead - Pre vs. Post Treatment  113  5.27 Average Copper - Pre vs. Post Treatment  114  a.  ACKNOWLEDGMENTS This work was funded by the Greater Vancouver Regional District and by an NSERC Operating Grant awarded to Dr. Mavinic. The receipt of the funds is greatly appreciated. My special thanks to Dr. Don Mavinic, my thesis advisor, for his helpful advice, encouragement, and continuing support. Thank you to Doug Neden of the GVRD and Dr. Ken Hall at UBC for reviewing this thesis. Many thanks to Bill Horwood and the Seymour Dam custodial crew, Dennis and Clyde at the guard house, and the operations staff at the Seymour Watershed for all of their assistance. Thank you to Dennis Beattie and the GVRD chlorination crew for their assistance at the pilot plant. Thank you to Susan Harper, Paula Parkinson, and Jufang Zhou for their assistance and expert advice at the UBC Environmental Engineering Laboratory. Susan did all of the graphite furnace AAS lead measurements and the phosphorus determinations were done by Jufang and Paula. I would finally like to give heartfelt thanks to Sheila Churchill for all her help and expert assistance with the computer.  xi  DEDICATION  This work is gratefully dedicated to  Dr. Nicola James and David Boulding  xi  1.  INTRODUCTION 1.1.  Greater Vancouver Water District Background Information  The Greater Vancouver Water District (GVWD) supplies potable water to eighteen communities with a combined population of about 1.7 million people. The District is located in the south-west corner of the province of British Columbia and is comprised of the city of Vancouver and its neighboring municipalities. The water sources, treatment facilities and transmission network are maintained by the GVWD. The water is collected from the Capilano, Seymour and Coquitlam watersheds, an area of about 585 square kilometers, located in the Coast Mountains, immediately north of the Greater Vancouver area. Figure 1.1 shows the Greater Vancouver water supply sources and systems. The water is impounded by three major dams, Cleveland Dam on the Capilano River, Seymour Falls Dam on the Seymour River (Figure 1.2) and Coquitlam Dam on the Coquitlam River and smaller dams at Burwell Lake, Palisade Lake and Loch Lomond. Additional storage is provided by 18 service reservoirs, ranging in size from 4.5 million liters to 136 million liters, and 5 storage tanks. Twelve permanent pumping stations and over 500 kilometers of supply mains distribute the water. The water is chlorinated at the source to a 10 minute residual of approximately 0.9 to 1.1 mg/L. The GVWD distributes the water in lined steel mains. It is then distributed within the municipalities through a variety of pipes, including PVC pipe,  1  Figure 1.1 Greater Vancouver Water Supply  2  Figure 4.1 Seymour Falls Dam NO ENIRY | -  uSEYMOUR FALLS DAM 245 m '1,4 r/  SEYMOUR RIVER HATCHERY  /  (  \  / VI  BURRARD INLET Second Narrows Bridge  BURNABY  lined and unlined cast iron, and lined ductile iron. The raw source water is normally of high quality with chlorine disinfection being the only form of treatment currently practiced. Increasing concerns over water quality, which does not meet national drinking water guidelines, led the GVWD to initiate a comprehensive study to develop the Water Quality Improvement Plan (WQIP 1990). The study identified four main issues: 1. Potential waterborne disease in source water. 2. Bacterial regrowth through the distribution system. 3. Turbidity levels that exceed 5 NTU, thereby reducing effectiveness of disinfection. 4. The corrosive nature of the water. The ultimate objective of the WQIP is to provide water which meets the guidelines for Canadian drinking water quality (Health Canada 1996). This thesis addresses the concern over the corrosive nature of our water and is a component of the GVWD corrosion control initiative.  1.2.  GVWD Water Quality Characteristics  The GVWD's protected watersheds produce high quality water with low levels of chemical contaminants. The inherent characteristics of the raw source water of the GVWD, cause the water to be highly corrosive in nature.  4  The hydrological, geographical and geological characteristics of the Coast Mountains, in which the water catchment areas are located, have an important effect on the water quality. The surface water sources are fed by a high amount of rainfall and snowmelt runoff. Extensive areas of the marine west coast of British Columbia, particularly westerly exposures and higher elevations, receive in excess of 2500 mm of precipitation, making them by far the wettest parts of Canada (Valentine et al. 1978). The morphology of the watershed allows only short contact time with soil, due to the steep slopes and high ratios of water surface area to land. The high amount of rainfall, with significant runoff, provides little opportunity for dissolution of soil minerals. The soils themselves lack the minerals, limestone and other carbonate materials which provide buffering agents that help reduce a water's acidity. The bedrock is comprised mainly of poorly soluble, hard granite rock with low amounts of the buffering agents which, when dissolved, produce alkalinity. These factors produce a very soft, acidic water with little buffering ability. Acid precipitation can contribute to lowering the pH of surface waters. Sulfur and nitrogen oxides entering the atmosphere are the major cause of acid precipitation. Major sources of these include: natural contributions from, sulfate in sea salts, and sulfur and nitrogen oxides from biological processes in coastal areas and on land; and anthropogenic sources from combustion of fossil fuels (Manahan 1990). The acid rain problem in the mainland coast of British Columbia (B.C.) is much less pronounced than that found in other areas of North America. B.C., because of its geography, is located upwind of most sources of acidic deposition generated outside our province (Province of B.C. 1992) and sulfur emissions are low relative to 5  most other cities of similar size because natural gas is used, rather than coal or oil for almost all heating installations (GVRD 1991). Chlorination of water, for disinfection, lowers the pH of distributed water even further, as well as consuming alkalinity. All these factors contribute to producing a water that is characteristically of low pH, low alkalinity, low hardness and low mineral content. Appendix A lists average values for the physical and chemical analysis of GVWD raw water. Many of these measured values are characteristic of a corrosive water. Corrosion indices are commonly used to measure the relative corrosiveness of a water. With soft waters, the traditional indices may not accurately predict a waters corrosiveness but they can provide an indication of potential for corrosiveness. Data from the EES study (1990), of corrosion indices for several soft, low alkalinity water sources, indicate that GVWD waters may potentially be among the most corrosive in North America. Table 1.1 compares the corrosion indices for GVWD and several other soft, low alkalinity waters. The factors which influence corrosion are discussed further in Section 3.2.  6  Table 1.1 Corrosion Indices of Several Soft, Low Alkalinity Water Sources Aggressiveness Index  Larson's Ratio  Buffer intensify  7.5  1.0  0.1  -2.4  9.5  0.4  0.1  7.0  -3.1  8.6  •  0.0  12  7.1  -3.1  9.0  0.4  0.1  Wachusett Res  8  6.7  -3.2  8.5  Belllngham  LK Whatcom  21  7.3  -2.2  9.7  0.4  0.1  Beaumont, TX  Naches River  25  6.5  -2.5  9.2  -  -  GVWD  Seymour  3.4  6.1  -4.8  7.2  0.8  0.11  GVWD  Capilano  2.5  6.1  -5.1  7.0  1.0  0.08  GVWD  Coquitlam  1.8  5.9  -5.5  6.6  1.2  0.07  -  <6.5  <1.0  <10.0  >0.5  <0.2  City  Source  Alkalinity mg/L CaCO,  pH  Langeller Index  Seattle  Tolt River  5  6.6  -4.5  Seattle  Cedar River  20  7.5  San Francisco  Hetch Hetchy  6  Portland  Bull Run  Boston  Recognized CorrosMty  Data from EES (1990)  0.0  1.3.  Impacts of Corrosion  Water is a powerful solvent and as a result, as it is conveyed through the distribution system, the quality of the water can change. Because of its solvent quality, all water is corrosive to some degree. Waters of low pH and low alkalinity, however, are commonly associated with high rates of internal corrosion of water distribution systems (Richards and Moore 1984; Edwards, Ferguson, and Reiber 1994; Ferguson 1985). This can lead to unacceptable levels of corrosion byproducts being introduced into drinking water. The primary materials which may be released from typical piping and plumbing, because of corrosion, are: lead, copper, zinc, cadmium, iron and asbestos. The corrosion process can lead to impacts on health, economics, aesthetics and on the environment.  1.3.1. Health A principal concern about corrosion in water distribution systems is the possibility that its by-products will have deleterious effects on the health of the consumer. The following section discusses the potential health impacts of the primary materials released by corrosion.  1.3.1.1. Lead The most potentially serious impact, from a health perspective, is the release of lead into drinking water as a result of corrosion. The predominant sources of lead  8  in a distribution system are; the commonly used, lead solder, which is used to join copper piping, brass and bronze faucets, and can contain 2-8 % lead; and the less commonly found, but still in use in North America, lead service lines, lead goosenecks, valves and gaskets found in water treatment plants or distribution mains. Lead is acutely toxic to humans and is considered by the U.S. EPA to be a significant health threat (Engleson 1992). Acute lead poisoning in humans occurs rarely today but subchronic and chronic lead poisoning is common, especially among urban children (DWHETF 1989). Chronic, low level exposure can be associated with elevated blood pressure, neurological deficits, problems with reproduction, growth and development, blood synthesis and vitamin D metabolism (Lippmann 1992). Lead is widely distributed throughout the environment. Populations are exposed to lead in air, food, water and other environmental sources such as paint, pesticides, tobacco and soil. Lead is a cumulative poison and there is a very narrow range between lead exposure of the average North American and exposure that is considered excessive (Mahaffey, McKinney, and Reigart 1992). Lead will affect all individuals at sufficiently high exposure level but studies have demonstrated that infants and young children are more susceptible than adult females who are more susceptible than adult males. As well, infants and young children have been shown to absorb ingested lead more readily than do older children and adults (Mahaffey, McKinney, and Reigart 1992). Of major concern today are recent findings of the permanent, subtle effects of lead on the behavior and intelligence of infants and young children from low level, chronic exposure. 9  (DWHETF 1989; Needleman et al. 1990). For populations living in soft water areas, the concentration of lead in drinking water is not the only concern. It has been shown that, for individuals living in regions with soft water, their blood lead levels are significantly higher in comparison to individuals in hard water regions, even if the concentration of lead at the tap is similar (de Mora and Harrison 1984; Thomas et al. 1981). This may be due to the decrease in bioavailability of lead in hard waters. While there is ample data on the lead concentrations found in drinking water, further study is required to determine the physical and chemical forms present. This is important because the speciation of ingested lead influences the efficiency of absorption from the gastrointestinal tract. Some forms of metals are practically insoluble and thus are not well absorbed. Particle associated metals do not pose the same threat to humans or animals as do the more soluble forms. The adverse impact of metals also depends on the composition of the mixture of trace elements in which the metals are found. Harrison and Laxen (1980), in a study on the physiochemical speciation of lead in drinking water, suggested that the forms they found in drinking water may well be more available for absorption than the lead bound in foodstuffs. The relative contribution of drinking water to the average daily intake of lead is estimated to be approximately 10% for children and 11 % for adults (Health Canada 1996). The contribution that drinking water makes, however, to the overall human lead burden is still not well known.  10  1.3.1.2. Cadmium Cadmium is also a toxin to humans. Galvanized steel plumbing has cadmium as a known contaminant which can be released into drinking water through corrosion. The major sources of cadmium, however, are from diet and cigarettes. Cadmium can affect all body systems at sufficiently high levels, the most sensitive organ being the kidney. The Drinking Water Health Effects Task Force (1989) states that "drinking water is generally believed to contribute only slightly to the daily amount of ingested cadmium. The risk of additional exposure resulting from corrosion is believed to be minimal". In GVWD waters, measured at the tap, cadmium concentrations are below the level of concern (EES 1990).  1.3.1.3. Asbestos Asbestos in drinking water can occur from naturally occurring asbestos in raw water supplies and from corrosion of asbestos cement pipes in distribution systems. Asbestos is a known carcinogen.when inhaled and so there is concern regarding the possibility for carcinogenicity when ingested. While studies have not confirmed any correlation between ingestion and carcinogenicity the EPA has, however, proposed a maximum contaminant level in water of 7.0 million fibers per liter (MFL), of fibers longer than 10 microns.  1.3.1.4. Copper, Zinc, and Iron Copper, zinc, and iron are essential nutrients to humans. Toxicity to humans is evident only at extremely high levels of intake (DWHETF 1989).  11  Copper is not toxic to humans until quantities that are 40-135 times greater than their nutritional requirement are ingested (NAS 1982). The gastrointestinal (G.I.) tract provides an excellent barrier against toxicity, as copper is absorbed poorly. In addition, ingestion of high doses of copper,(concentrations above 15 mg/L) is irritating to the G.I. tract and will cause nausea, diarrhea and vomiting. This helps provide protection against acute copper poisoning. Patients with Wilson's disease, however, a rare, inherited disorder of copper metabolism, can be adversely affected by the estimated average intake of copper. Generally, though, the potential for toxicity from the levels of copper found in drinking water is extremely low. Copper in drinking water, in fact, contributes to our daily requirement for copper which, in adults, is estimated at 2-3 mg/day and is not always achieved in western diets which are estimated at 1.0 - 2.5 mg Cu/day (NAS 1982). Copper is vital for our metabolism and maintenance of health. In addition, it is also known to act as a bactericide and fungicide. Studies have shown that copper pipe is more resistant to growth of some waterborne opportunistic pathogens, including Legionella , than other tubing materials (Schofield and Locci 1985). Unless foods are carefully selected, it is difficult to meet the 15 mg/day recommended dietary allowance for zinc. This is due in part because of the low bioavailability of zinc in many foods. As well, zinc has low potential for toxicity when ingested because its absorption is regulated by the body. Zinc is extremely important to nutritional health and provides a protective action against cadmium and lead by acting as a metabolic antagonist of these metals. Normally, drinking water contributes less than 5% of the dietary requirement and the highest observed water 12  concentrations might contribute up to 20% of the daily human requirement (NAS 1982). Iron deficiency is common, possibly because of increased consumption of refined foods and decreased use of iron cookware. Iron deficiency anemia is a widespread health problem in the U.S., particularly among children and women of child bearing age (Kreutler and Czajka-Narins 1987). Athletes, as well, are prone to low level iron deficiency. Too much iron, though, can lead to toxicity. Iron poisoning can occur in conjunction with a genetic condition called haemochromatosis, in which iron is overabsorbed. Small children have been poisoned following ingestion of large quantities of iron tablets (Kreutler and Czajka-Narins 1987). The recommended daily allowance for iron is 10 mg/day for men and 18 mg/day for women. Studies have not confirmed the level to which trace metals in drinking water contribute to our nutritional health, and other than lead, there is little research on the impact of long term exposure to low levels of metals from drinking water. It is important, then, to continue to monitor the levels and potential health impact of metals which occur due to corrosion and other processes and not overlook the nutritional deficiency problems that might be encountered if they were eliminated completely.  1.3.2. Economics Corrosive waters cause significant economic impacts. The major impacts are the direct costs for replacement, maintenance and repair of plumbing systems in  13  residential, commercial and industrial buildings, due to premature pipe failure. Corrosion causes failure of water piping as a result of leakage or loss of hydraulic capacity from build-up of corrosion products. Corrosive water can cause pitting and tuberculation of galvanised steel, unlined steel and cast iron pipe. After only 20-30 years of service, tuberculation can plug up galvanised steel plumbing. Corrosion in copper piping can cause general corrosion (thinning) and pitting. In the Greater Vancouver Regional district, the life of copper plumbing is only 20-35 years with some failures occurring at 3-10 years (EES 1990). The most severe problem with copper piping occurs in hot water recirculating systems used in commercial buildings and apartment complexes. The piping typically requires replacement after 12-15 years. The GVWD Corrosion Control Initiative (EES 1990) estimated the cost associated with accelerated deterioration and premature pipe replacement in the region to be over $720 million over 75 years or approximately $1400 per dwelling unit. The Seattle, Washington Water Department estimated the cost of corrosion damaged residential plumbing systems approached $8 million annually (Reiber, Ferguson and Benjamin 1991). Costs, due to corrosion for interior plumbing systems were found to be significantly higher than those for the distribution system. The Seattle Water Department study found that costs for consumer plumbing and piping were ten times higher for initial capital and twenty times higher for annual maintenance than distribution system corrosion costs (Ryder 1980). In addition to these costs, there are many indirect costs that are associated with corrosion.  1 4  1.3.3. Other Impacts Corrosion can cause aesthetic impacts. The by-products of corrosion can affect the taste and appearance of water. Red, blue or green tinted water can occur and staining of fixtures, clothes, and even hair, can result. The staining of fixtures increases the use of cleaning substances which may be toxic to the environment. Metals in water can cause bitter, astringent, metallic tasting water. Bad taste complaints can be triggered at concentrations of copper between 1.5 and 2.0 mg/L.  Corrosion can make disinfection of water supplies more difficult as micro-organisms can find protection in corrosion products. In addition, these organisms can cause problems such as bad tastes, odors and slimes in the water and contribute to additional corrosion. While increased levels of copper and zinc in the water are not likely a human health concern, they may have a negative impact on the environment. Copper and zinc are especially toxic to fish and so the levels going into receiving waters, via the sanitary sewer system are of concern.  1.4.  Regulatory Concerns  The potential risks from drinking water are a high priority when it comes to human health concerns. A reliable supply of wholesome water is vital to our way of life and to life itself. Everyone drinks water and because so many potentially toxic substances could contaminate drinking water and because we could be exposed to  15  them for such long periods, even up to a lifetime, the safety of drinking water is a paramount public health issue. Standards for drinking water exist all over the world to protect the public health.  1.4.1. United States As a result of tighter scrutiny and new research findings there is an increased awareness of the presence and potential impacts of corrosion products in drinking water. This has led the U.S. EPA to promulgate the lead and copper rule in 1991 which mandates standards for lead and copper at the consumers tap. With current studies that show the risks of chronic low level lead exposure are greater than previously thought, the regulations regarding lead at the tap have become more stringent. Currently, the regulations state that the values for the concentration of lead and copper at the tap must be less than or equal to 0.015 mg/L for lead and less than or equal to 1.3 mg/L for copper (Pontius 1994). These values are termed action levels and trigger responses such as public notification, public education and commencement of a study to optimize corrosion control. Under the new regulations, treatment is called for when 10% of standing water samples taken at the tap exceed the action levels. In addition to the EPA lead and copper rule, lead solder has been phased out of use in copper plumbing since 1982 and 1986 amendments to the Safe Drinking Water Act ban all future use of lead solders, flux and pipes in public water systems and buildings (DWHETF 1989).  16  1.4.2. Canada In Canada, there is no federal legislation governing drinking water standards. There are only guidelines which are not legally enforceable. Guidelines for drinking water quality are published by Health Canada (Health Canada 1996). They set maximum acceptable concentrations (MAC) for substances that are known or suspected to cause adverse health effects and aesthetic objectives (AO) for certain substances or characteristics which can affect consumer acceptance. In British Columbia, the Provincial Ministry of Health is responsible for the provision and quality of drinking water. The applicable guidelines and recommendations for water quality are taken from Guidelines for Canadian Drinking Water Quality (Health Canada 1996). In response to the concern over lead corrosion, the 1989 revision of the British Columbia Plumbing Code eliminates the use of lead/tin solder (Ministry Municipal Affairs 1989). The following are the Canadian drinking water guideline levels (Health Canada 1996) for contaminants that can occur in drinking water from corrosion.  Lead  0.01 mg/L MAC (on a flushed sample)  Copper  < 1.0 mg/L AO  Zinc  < 5.0 mg/L AO  Cadmium  0.005 mg/L MAC  Iron  < 0.30 mg/L AO  17  Asbestos  1.5.  "Assessment of data indicates no need to set a numerical guideline"  Premise Plumbing  Metallic corrosion products in tap water can originate from water mains, service lines and interior premise plumbing. Unlike most distribution systems, however, the piping found in household, commercial and industrial buildings is generally more susceptible to internal corrosion. This is because it is of much narrower diameter, thinner walled, is unlined and frequently has large sections of piping in which water can be stagnant for hours. In addition, with small diameter pipes the surface area to volume ratio is high and when metals are released into small bore tubing there is little opportunity for their dilution. The materials commonly found in interior premise plumbing are copper piping, lead solder, galvanized piping, polyvinyl chloride pipe and brass valves and faucets.  1.5.1. Copper Piping Copper is currently the dominant material used in domestic water systems in North America. (EES 1990; Sorg and Bell 1986). Copper is a relatively noble metal which gives it a high degree of corrosion resistance in most natural environments. Copper has good machinability and workability and hence ease of installation, making for low installation costs. Its bactericidal and fungicidal qualities contribute to our health, as does its status as an essential nutrient. In addition, copper is seen as environmentally friendly due to its potential to be 100% recycled.  18  Under certain conditions, though, copper can corrode at a rate which leads to premature failure of piping and elevated levels of copper in the water. In a study conducted in the Greater Vancouver Regional District (GVRD), for example, Singh and Mavinic (1991) found that, under certain building and plumbing conditions, the copper levels found in the drinking water exceeded the US EPA maximum contaminant level of 1.0 mg/L in 73% of the samples.  1.5.2. Lead Solder Lead has always been a popular metal with plumbers because of its flexibility, durability and long life. It generally has a very low corrosion rate and is easy to work with. Lead pipe has been used for centuries to convey drinking water. It was used extensively in some U.S. cities, at the beginning of the 19 century, for lead th  and lead lined service pipes. In the past 20 years the predominant use of lead in interior plumbing has been 50/50 lead-tin solder. While failure of the solder from excessive corrosion is not a problem, numerous studies have shown that lead solder contributes significant levels of lead to drinking water (Reiber 1991; Singh and Mavinic 1991; Birden et al. 1985). In fact, compared to other possible sources of lead, lead based solder has been found to be the most significant source of lead at the tap (Lee et al. 1989; and Schock 1985).  1.5.3. Brass Faucets Brass or bronze alloys of copper, which generally contain 3-8% lead, are the principal materials used in plumbing fixtures such as faucets and valves. Numerous  19  studies have shown that chrome plated brass faucets can be a significant source of lead, zinc and copper contamination of drinking water, particularly upon standing (Schock and Neff 1988; Samuels and Meranger 1984; and Mattson 1980). Lee et al. (1989) found that brass faucets contributed an average of one third of the lead in one liter first draw standing samples.  1.5.4. Galvanized Pipe Galvanized steel (an alloy of iron) is subject to corrosion of zinc, (the coating used in the galvanizing process), as well as cadmium and lead which are impurities that occur in the process. Given the appropriate conditions, once the zinc layer has corroded away, the pipe can corrode like iron. Galvanized steel corrosion is characterized by pits and tubercles which cause blockage of pipe and eventually restrict water flow. In the GVWD, galvanized steel, which was the material of choice for residential plumbing until 30 years ago, has mostly been replaced with copper tube due to corrosion.  1.5.5. Plastic Pipe Plastic pipe, which is becoming more popular as a plumbing material is immune to corrosion. Other advantages include the inert properties of the material, low friction flow factors and its light weight and ease of installation (Sorg and Bell 1986). Potential disadvantages may be its combustibility in the event of fire with possible release of gases; and health concerns raised, regarding leaching of additives from stabilizers, such as lead and tin, and joining cements. Studies have found that  20  levels of leached materials are well below those that have been associated with adverse effects in experimental animals (Environmental Health Directorate 1983).  1.6.  Summary  The household and building plumbing systems typically found in the GVRD are the major contributors of lead and copper to the region's drinking water. Currently, in the GVRD, plastic pipe is replacing copper for plumbing systems in many new buildings. Lead solder is no longer used in new construction or repair of plumbing systems. However, older piping in municipal distribution systems is failing due to corrosion, causing major economic impacts on communities and increasing the risk of contamination of the water. Most buildings and residences in the region still have copper piping and lead solder. New buildings with plastic pipe still use brass faucets. Lead and copper levels, measured randomly, at the tap, in the regions' households and buildings have been shown to exceed recommended levels. Because of the nature of GVWD water, until older distribution piping, and household and building plumbing systems have been replaced, and safe materials that resist corrosion are found, corrosion control will be an important issue in providing safe drinking water.  21  2.  STUDY OBJECTIVES  2.1.  Previous Studies  Region-wide studies initiated by the GVWD, as part of the GVWD Corrosion Control Initiative (EES 1990), involved: home tap sampling programs to characterize the levels of lead, copper, and zinc that occur; sampling for lead in regional school drinking water fountains; and a service and plumbing pipe condition sampling program. The results confirmed that corrosion of metal piping was a problem in the area, especially in household plumbing, and that lead and copper levels frequently exceeded Canadian drinking water guidelines. In other studies, preliminary tap water sampling programs conducted by Millette and Mavinic (1988), and Singh and Mavinic (1991), indicate that elevated levels of copper, in the first study, and lead and copper, in the second, occur with significant frequency in the homes that were tested in the GVWD area. The Corrosion Control Initiative continued with a pilot scale study by Economic and Engineering Services (EES) (1990). They studied corrosion control by treating water with pH and alkalinity adjustment and comparing the effects of disinfection with chloramine versus chlorine on corrosion The study concluded that by disinfecting with chloramine instead of chlorine and adjusting pH and alkalinity to 88.5 and 20 mg/L as C a C 0 respectively, copper corrosion could be reduced by 603  22  80 percent and lead corrosion could be reduced by 10-60 percent, over the levels occurring from the water currently delivered by the GVWD. It was recommended that further pilot testing examine chemical inhibitors as an adjunct to pH and alkalinity adjustments. MacQuarrie (1993), in his follow-up study, tested the chemical corrosion inhibitors zinc orthophosphate, type N sodium silicate, and a commercial blend of the two, in water with adjusted pH and alkalinity and disinfected with chloramine. Weight loss determinations from the copper and cast iron pipe coupon inserts indicated that corrosion was inhibited in the copper coupons by all the treatments, particularly the zinc orthophosphate; however, in the cast iron coupons, the inhibitors provided negligible additional benefit over that obtained from pH/alkalinity adjustment alone. In comparing the inhibitors with respect to the level of metals leached into standing water samples from the copper and lead pipe loop system, the results were less definitive. Generally, the lowest lead levels occurred with the untreated raw water and the lowest copper levels from simple pH/alkalinity adjustment. The chemical inhibitors appeared to exacerbate metal leaching in some cases. MacQuarrie recommended further study of zinc orthophosphate and sodium silicate in relation to the effect of the length of standing time and of different pH/alkalinity adjustments on their efficacy. He also recommended a study to determine optimum dosage levels for the corrosion inhibitors.  23  2.2.  Objectives  Since drinking water regulations focus on meeting concentration limits, the focus of this study was on metal levels in drinking water, rather than the rates of corrosion. The studies cited above indicate that copper corrosion in the GVWD could be reduced by pH/alkalinity adjustment and that, of the chemical inhibitors, zinc orthophosphate was particularly effective at reducing copper corrosion. More study on further reducing metal levels was indicated. The metals of concern in this study were lead and copper. The objectives of this study were, within the limitations of the pilot plant pipe loop set up, to: •  Compare the effectiveness of different pH/alkalinity applications on copper and lead levels found in standing water samples.  •  Determine if the chemical inhibitor zinc orthophosphate (ZOP) is effective at reducing copper and lead levels and compare effectiveness of two different doses of ZOP.  •  Determine if different standing times (8 and 16 hours) have an effect on the metal levels and /or the effectiveness of ZOP.  24  THEORETICAL BACKGROUND  3.  3.1.  Basic Corrosion Theory  By virtue of the reduction of ore by the smelting and manufacturing process, metals are left in an unstable state relative to their environment. As a result, processed metals corrode in an attempt to reach the more stable forms of metal ions, salts, oxides and hydroxides, which are found in nature. Virtually all the common metal household or building plumbing materials will oxidize and dissolve to some extent in potable waters. All metals, eventually, undergo corrosion in contact with water but the rate varies widely and can be affected by the water quality and the type and quality of metal. The rates of corrosion, fortunately, are normally very slow so metals exposed to water may endure for long periods of time. In aqueous environments, corrosion occurs via establishment of an electrochemical corrosion cell which is set up on the metal surface, as shown in Figure 3.1. The electrochemical cell is initiated by a potential difference between components of the corroding metal and/or between the metal and the solution around it. Such a situation may develop for several reasons: •  From the connection of dissimilar metals.  •  Surface heterogeneity in the metal structure, for example differences in crystal 25  structure, surface imperfections, scales and traces of impurities. •  Potential difference between the water, which is an electrolyte solution, and the metal surface. This potential is the result of the tendency of a metal to go to the equilibrium state with the electrolyte. The reaction will proceed until the metal is in equilibrium with the electrolyte solution containing ions of this metal.  Figure 3.1 Corrosion Cell !  Anode  !  Cathode  The cell is composed of an anode, cathode, arvextemal circuit and an internal circuit. The anode and cathode are separate sites on the metal surface which have a difference in electrical potential between them. Oxidation and dissolution of the metal takes place at the anode, where the following oxidation reaction occurs, representing a loss of electrons by the metal: M <-> M  2+  + 2e"  The metal acts as the external circuit (electron conductor) transporting electrons to  26  the cathodic area. Reduction occurs at the cathode where an oxidizing agent (electron acceptor), such as oxygen, for example, must accept the released electrons: 0 + 2H 0 + 4e" - » 40H" 2  2  In waters of low pH hydrogen ions can also accept electrons, i.e. 2H + 2e" -> H +  2  The electrolyte solution (the water in contact with the metal), acts as the internal circuit to conduct ions between the anode and cathode. The different reactions are linked by the transfer of electrons through the metal. The rates of electron transfer are dependent on the electrochemical potential of the system, which is a measure of the relative attraction for electrons. Electrons are transferred from the lower activity electrode (anode) to the higher activity electrode (cathode). The oxidizing agents compete for the electrons depending on their relative electrode potentials, and in addition, the higher the concentration of the oxidant the higher the driving force for corrosion. Another factor that affects the rate of corrosion is the rate of diffusion of the electron acceptor to the site of the cathode. Since the rates of electrochemical processes are related to the electrical potential at the metal-solution interface, factors which influence the potential can hasten or reduce the rate of corrosion. As previously stated, the rate of corrosion of the metals used in most potable waters is normally slow enough not to be problematic.  27  However, various factors, which influence the electrochemical potential, can hasten the rate of corrosion excessively. Two principal types of electrochemical corrosion cells are of concern in water distribution systems (Uhlig 1971). The first, the concentration cell, is a corrosion cell which involves a single metal. If two parts of the metal are exposed to different concentrations of aqueous solution species, this can drive the corrosion reaction. Corrosion will occur until the concentration of species that are involved in the corrosion reaction equalizes. Common species involved in the reaction are the major electron acceptors such as dissolved oxygen, hydrogen ions, or a disinfectant residual. The second type of corrosion cell is a galvanic cell, which results from the contact of two different metals. The difference in electromotive potential between two metals can be greater than the potentials arising from concentration cells so corrosion can occur at a higher rate. This is seen, for example, when a more active (less noble) metal like lead is in contact with a less active (more noble) metal like copper. The copper serves as the cathode (site for electron consumption reactions), while the more electronegative lead based solder serves as the oxidation site (anode) and point of metal release. The driving force is the difference in demand for electrons by the different metals and then subsequent transfer to an electron acceptor in the water.  28  3.2.  Factors Influencing Corrosion  Certain qualities of water, properties of plumbing materials, operating conditions and other environmental factors can increase the rate of corrosion. How all these factors influence corrosion, however, is not completely understood. In addition, these factors may influence corrosion differently with different metals and under different environmental conditions.  3.2.1. Water Quality The following water quality characteristics are some of the most important factors influencing corrosion. 3.2.1.1. pH pH is a measure of the hydrogen ions (H ) present in the water: (the lower the pH, +  the higher the concentration of hydrogen ions). A low (acidic) pH can enhance corrosion by affecting the stability, solubility and protective qualities of passive films on the metal surface. Hydrogen ions can act as an oxidizing agent in the cathodic reaction and can influence the rate of transport of the chemicals involved in the corrosion cell reactions.  3.2.1.2. Alkalinity Alkalinity is the capacity of a water to accept protons (i.e. H ). Generally, the basic +  species responsible for alkalinity in water are the bicarbonate ion (HC0 "), the 3  carbonate ion (C0 ). 3  2  a r |  d the hydroxide ion (OH") i.e.  29  HCCV + H - » C 0 + H 0 +  2  2  C 0 " + H -> HCO3" 3  2  +  OH" + H - » H 0 +  2  Waters of low alkalinity provide little buffering capability (resistance to change in pH) and so significant drops in pH can occur under conditions such as when chlorine or other water treatment chemicals are added. In addition, the bicarbonate and carbonate present in a water affect many corrosion reactions, including the ability to form protective metallic carbonate coatings or scales on pipe surfaces. High levels of carbonate, though, can cause formation of strong soluble complexes with metals which can accelerate corrosion or cause high levels of metal leaching (Schock and Gardels 1983; and Edwards, Schock and Meyer 1996).  3.2.1.3. Dissolved Oxygen Oxygen, a powerful oxidizing agent, may accelerate corrosion by participating in cathodic reduction reactions. It particularly accelerates corrosion of ferrous materials. Oxygen also reacts with the hydrogen gas (H ) that is released in 2  cathodic reactions and removes the protective hydrogen film at the cathode. For water that is near saturation, as GVWD water is, dissolved oxygen may not be the rate limiting factor of copper corrosion. Reiber (1989), in an electrochemical study of copper, found that the oxygen concentration did not become rate limiting until a level of below 6 mg/L; above this concentration, corrosion rates were relatively unaffected. Dissolved oxygen may also help retard corrosion by forming protective  30  metal oxide films on the metal. 3.2.1.4. Chlorine Chlorine is also a strong oxidizing agent and so can act directly on the cathodic reaction as an electron acceptor, accelerating corrosion. When chlorine is added to waters of low alkalinity for disinfection, it further reduces the pH of the water and consumes alkalinity.  3.2.1.5. Hardness A water is referred to as hard or soft depending on the concentration of certain metallic ions in the water. Calcium and magnesium cause the greatest portion of the hardness occurring in natural waters. Hardness can contribute to corrosion resistance by formation of a protective calcium carbonate (CaC0 ) lining on pipe 3  walls. Soft waters of low pH and low alkalinity are thought incapable of forming this protective scale.  3.2.1.6. Other Major Water Constituents Other common constituents found in natural waters can also have an influence on corrosion. For example: The primary anions in potable waters, including; chloride, nitrate, sulfate, and natural organic matter (NOM), can have important influences on initiating or preventing corrosion. Some mechanisms by which they act include their combination with dissolved metal to form strong acids, interference with the  31  formation of a protective oxide film or by altering the properties of the film that forms (AWWARF 1985). High nitrate concentrations may result in nitrate reduction substituting for oxygen reduction in corrosion reactions (El-Kot and Al-Suhybani 1987). Natural organic matter is an important component of potable waters that may significantly affect corrosion processes. NOM is primarily composed of humic and fulvic acids, which are negatively charged compounds that contain oxygenated, aromatic, carbohydrate and aliphatic acid-derived groups. Water treatment processes generally attempt to remove NOM because of the problems it can cause with disinfection by-products. However, NOM may provide an important inhibitory effect on corrosion (Korshin, Perry, and Ferguson 1996). It may reduce corrosion through several mechanisms including promoting formation of more protective metal oxide films and calcium carbonate scales and, inhibiting cathodic or anodic reactions. NOM has also been found to promote corrosion at certain concentration ranges, however, (Korshin, Perry, and Ferguson 1996), and may also increase corrosion by soluble complex formation (Edwards, Ferguson, and Reiber 1994). The amount of total dissolved solids (TDS) in water determines the electrical conductivity of the water and so will have an impact on the electrochemical corrosion reactions. Stone et al. (1987) showed that increases in conductivity up to about 200 uS/cm increased copper corrosion rates significantly.  32  3.2.2. Environmental factors 3.2.2.1. Microbially Influenced Corrosion Microbially influenced corrosion (MIC) is an important, complex form of metal corrosion. The primary promoter of MIC is a biofilm of microbial, algal or fungal origin. The chemical makeup of the biofilm is directly related to its corrosive influences, and exopolymers have been identified as the main components of most biofilms (Sequeira 1995). Some of the mechanisms by which biofilms can induce corrosion are: Nitrifying bacteria can produce acidity, via conversion of ammonia to nitrites and nitrates and consume oxygen, producing oxygen concentration cells that cause localized corrosion and pitting (Lee, O'Connor, and Banerji 1980). Iron bacteria are well known to cause corrosion by deriving energy from oxidation of ferrous iron (AWWARF 1985). Peng, Park and Patenaude (1994), in their study, suggested that sulfate-reducing bacteria are the most important anaerobic bacteria influencing microbial corrosion. They promote corrosion by reduction of sulfate to sulfide which then reacts with the metal ions produced at the anode. The authors found that C a C 0 precipitation played a significant role in influencing the microbial 3  corrosion tendency. The effects of sulfate concentration and bacteria on biocorrosion were significant only for a water of low alkalinity and undersaturated with C a C 0 . Peng, Park and Patenaude (1994) summarized the role of 3  microorganisms in influencing corrosion in metal structures thus: "By formation of the concentration cell on a metal surface:; production of high concentration of corrosive metabolites; removal of the corrosion reaction product, enhancing the  33  kinetic forward reaction; reduction of the protective influence of surface film; increase in electrolytic concentration at surface sites, favoring electron transfer; and mediation of the oxidation of reduced species". The main effect of these mechanisms is produced by microbially mediated enzymes which catalyse the specific corrosion reaction steps (Sequeira 1995). 3.2.2.2. Flow, Velocity and Stagnation The effect of the velocity of the water flowing through plumbing and piping systems has varied influences on corrosion. High water velocity can cause erosion of the protective surface scales or the pipe material itself. It occurs primarily as a result of faulty pipe design or workmanship which allows high velocities (AWWARF 1985). In cold potable water supplies the AWWARF (1985) recommends limiting upper velocity to about 6 fps (2 m/s). Pisigan and Singley (1987) in studying flow rate effects on corrosion of mild steel and copper found that corrosion rates of both metals increased as flow rates increased in both laboratory loop studies and field studies and suggested that the increase in corrosion could be attributed to the increase in turbulence and mechanical stress or the erosion effect. However, Stone et al (1987) found no change in corrosion rate at high or low flow rates, which suggests that differences in water quality, environmental, and hydraulic conditions affect the influence of flow rate. In some waters, higher velocity can aid in the formation of protective films by increasing the amount of protective materials that come into contact with the pipe surface (AWWARF 1985). Extremely slow or stagnant flows can also increase  34  corrosion by increasing the contact time of corrosive waters with the pipe material, allowing increased time for corrosion reactions and leaching of metals into the water. Stagnation time is of particular concern in household plumbing because of the long periods that water may be left standing in pipes. This allows longer time for corrosion reactions to occur and pH can decrease further in stagnant water. Stagnation time can also affect efficacy of corrosion inhibitors (AWWARF 1985). 3.2.2.3. Temperature Because the rates of chemical reactions increase proportionately to the rise in temperature it is thought that, in general, higher water temperatures will increase corrosion. In studying the effects of building specifics on trace metal contamination of drinking water, Singh and Mavinic (1991) concluded that the high temperatures of hot water recirculation systems, found in high rise buildings, contributed to accelerating corrosion. To some extent corrosion may be a seasonal problem. One Seattle study found that for aged surfaces the corrosion rate of copper and zinc increased up to 50 percent when the temperature changed from 10 to 25 °C (Stone et al. 1987). In low alkalinity waters, with their poor buffering ability, pH can decrease with increasing temperatures. Under most circumstances, the solubility of the calcium carbonate film decreases with increasing temperature but, in low alkalinity waters, the decrease in pH caused by increased temperature can cause dissolution of the protective film (AWWA 1990).  35  3.2.3. Materials and workmanship The quality of the manufacturing processes used for common plumbing materials, such as galvanized and copper pipe, will affect their corrosion resistance. Poorly designed or poorly installed domestic plumbing systems can promote corrosion. For example, well made solder joints should have minimal solder exposure to the inner pipe bore to minimize surface area in contact with the water. Installation practices that avoid producing areas where water can stagnate or cause turbulent flows will reduce the potential for corrosion. Avoidance of different metals in a system will reduce galvanic corrosion.  3.2.4. Age of plumbing The age of the plumbing materials has been found to be an important factor in the rate of corrosion and amount of leaching of metals. Many studies indicate significant reductions in the level of lead and copper as plumbing ages (Reiber 1991; Birden, Calabrese, and Stoddard 1985; and Neuman 1995). Lee, Becker, and Collins (1989), found plumbing age to be the most significant site factor to influence lead levels at the tap. Singh and Mavinic (1991), in studying the significance of building specifics on trace metal concentrations in drinking water in the GVWD, found that, while age appeared to have a marginal effect on lead levels, it strongly influenced copper concentrations in first flush cold water samples. Running hot water samples, though, indicated that age was very significant in the levels of copper and lead found in samples from high-rise buildings.  36  Many metals, in particular lead, exhibit a high initial rate of corrosion that is substantially reduced through the passivation process. Under most water quality conditions, lead/tin solder surfaces also passivate rapidly (Reiber 1991). The mechanism that is thought to provide protection as plumbing ages is the natural build-up of a dense, adherent metal oxide film on the metal surface. This passivating film, consisting in part of corrosion by-products, protects by physically shielding the underlying metal from electrolyte contact reducing the overall corrosion rate. Normal aging, though, takes months or years to form a mature surface scale. In monitoring the corrosion rate of copper in the low alkalinity, low pH, low mineral content water of Seattle, Reiber, Ferguson, and Benjamin (1987), found that the oxide film layer on aged copper surfaces provided substantial protection. Compared with new copper plumbing, the oxide film on aged surfaces reduced the corrosion rate by about 50 percent.  3.3.  Types of Corrosion  There are many types and classifications of internal corrosion in water distribution systems which are discussed in such references as AWWA (1990), MacQuarrie (1993) and AWWARF (1985). The corrosion of copper and lead in low pH, low alkalinity waters is the focus of this study, so this paper will limit discussion of types of corrosion related to these factors.  37  3.3.1. Copper Corrosion 3.3.1.1. Uniform Waters of low pH and low alkalinity are commonly associated with high, uniform copper corrosion rates (Edwards, Ferguson, and Reiber 1994). Uniform corrosion causes the rate of metal loss to be relatively uniform over the metal surface causing thinning of the metal. This type of corrosion can cause high corrosion by-product release and so unacceptable levels of copper can be introduced into drinking water and blue-green water and staining can occur. Uniform corrosion results from the formation of a concentration cell on the copper surfaces, with the distribution of anodic and cathodic sites being very close to each other. The sites can also shift about the surface so that any site on the metal surface may be anodic one instant and cathodic the next.  3.3.1.2. Pitting Pitting corrosion is localized corrosion that forms pits in the pipe surface. It can occur at random and, with little metal loss, cause rapid failure of plumbing from holes. It occurs on surfaces that are not completely protected with scale, such as sites with surface imperfections, eroded areas or sites with non protective surface deposits. The pit is initiated at the anodic site and continues to develop because of the large cathodic area surrounding the anode. Unlike corrosion of ferrous metals, pitting of copper is less common and seen under limited conditions (Reiber 1989). Pitting of copper is typically seen with hard waters of low pH (Edwards, Ferguson,  38  and Reiber 1994), however, pitting has been shown to occur in copper plumbing in the Greater Vancouver Water District (EES 1990). 3.3.1.3. Influencing factors The pH of water is a critical factor in uniform and localized corrosion of copper in soft, low mineralized water (AWWARF 1985). Copper will corrode at high rates at pH <6.0 and usually corrodes slowly at pH >8.0. If pH is too low, uniform corrosion is favored and at pH >8.0 soft water pitting may occur (Edwards, Ferguson, and Reiber 1994). pH is thought to influence the type of scale that forms and in addition influence the fundamental corrosion reactions. A higher pH decreases the solubility of copper oxide solids, enhancing the build-up of an oxide film. Hilburn (1983), postulated that an elevated pH can also reduce copper corrosion by decreasing the driving force of the hydroxyl ions away from the copper surface, diminishing the cathodic half cell reaction, and so inhibiting the overall rate of corrosion. The influence of the other major ions, found in potable waters, on copper corrosion rates are more subtle and not completely understood. The cations: calcium, magnesium, sodium, and potassium do not participate directly in the mechanism of copper corrosion and so generally it has been thought that they do not influence the rate of corrosion (AWWARF 1985). However, in a literature review of copper corrosion studies, Edwards, Ferguson, and Reiber (1994), found evidence from practical experiences, which suggests that hardness ions have beneficial effects on corrosion. The authors cited a study by Ives and Rawson (1962), which found  39  benefits from calcium under conditions well below calcium carbonate saturation. The mechanism is not well understood but calcium is believed to assist in corrosion buffering reactions at the pipe surface (AWWA 1990). The anions: chloride, sulfate and bicarbonate are known to affect corrosion and generally, sulfate, and especially chloride, are thought to increase copper corrosion and bicarbonate to inhibit it (AWWARF 1985). Different studies on copper corrosion confirm the importance of pH but show various results for other factors. For example: A study of Seattle's low alkalinity, low pH, low mineral content water (Reiber Ferguson and Benjamin 1987) found that a significant relationship existed between copper corrosion rate and pH, particularly for aged surfaces with a heavy oxide layer, but less so for relatively clean copper surfaces typical of new plumbing. The study, which determined how instantaneous copper corrosion rates are affected by short-term variations in selected water quality parameters, found, though, that chlorine was more important in predicting copper corrosion rates. They found a strong positive correlation of corrosion rate with free chlorine residual for fresh copper surfaces, with corrosion rates on aged surfaces being substantially less. The study also found that conductivity appeared to be of little importance to copper corrosion in low alkalinity waters. In studying the effect of anions on the characteristics of the protective oxide film that forms on copper tubing, Shalaby, Al-Kharafi, and Said (1990), found that sulfate ions promoted the formation of a highly porous oxide scale with severe general corrosion below the scale. Hemispherical pits developed from the chloride solution  40  underneath a layer of cuprous oxide and chloride crystals. The smooth, well compacted scales formed in the 15 ppm bicarbonate solution indicated that the film formed was quite protective. As well, the addition of 15 mg/L H C 0 . anions to the 3  60 mg/L CI" solution produced a corrosion morphology similar to that developed in the bicarbonate solution alone. The results indicate that bicarbonate ions do not play a role in initiation of corrosion in soft tap water, while sulfate and chloride ions are the main cause of corrosion in this type of water. From their literature review and simple experiments Edwards, Ferguson, and Reiber (1994), summarized that even though short term experiments, on which current copper corrosion theory is based, indicate chloride is more aggressive towards copper than sulfate, long term effects are not well understood. They concluded that practical observations indicate that chloride is less corrosive and sulfate more corrosive to copper. Some recent studies have demonstrated that, over the short term, chloride appears to increase corrosion tendencies; however a scale forms that clearly passivates copper surfaces over longer term. In contrast, systems with sulfate exhibited aggressive behavior over the longer term (Edwards, Rehring and Meyer 1994; Edwards and Ferguson 1993) Contrary to conventional belief about the efficacy of alkalinity (or bicarbonate) to reduce copper corrosion, recent work has found that higher bicarbonate concentrations exacerbate copper corrosion rates and by-product release under certain conditions (Edwards, Meyer and Rehring 1994; Edwards, Schock, and Meyer 1996). Results show that, above about pH 8.1, the presence of bicarbonate  41  tends to passivate copper surfaces and decrease corrosion rates. However, below about pH 8.1, bicarbonate is increasingly aggressive at higher alkalinities (>100 mg/L as CaC0 ). Under appropriate conditions bicarbonate is believed to act as a 3  complexing agent, reacting with copper ions to form soluble complexes, and so decreasing the likelihood that a passivating, solid copper corrosion by-product film will form on the copper surface.  3.3.2. Lead Corrosion 3.3.2.1. Types In the Greater Vancouver water district, lead comes in contact with drinking water mainly via lead based solders and brass or bronze fixtures. Lead pipe, lead goosenecks or service lines, which are virtually pure lead, are not normally used. Corrosion of pure lead occurs by establishment of a concentration cell on the lead surface. In the case of solders and lead containing brass and bronze, under appropriate conditions, the direct contact of dissimilar metals with different electrode potentials causes galvanic corrosion to occur. A major factor in the high corrosion rate of solder is the small ratio of the surface area of the lead, which acts as the anode, to that of copper (the cathode) (Singley 1994).  3.3.2.2. Influencing factors Theoretical studies on speciation and solubility of lead in water indicate that, for low  42  alkalinity waters, lead levels are very pH sensitive with lead solubility decreasing rapidly as pH increases and minimum lead solubility .occurring at pH values in excess of pH 8.5 (AWWARF 1985). The most important factor influencing corrosion and uptake of lead is the solubility of its corrosion products which is governed mainly by pH, alkalinity and temperature (Schock 1989). Studies have shown the effects of temperature on increasing lead solubility (deMora and Harrison 1984; Singh and Mavinic 1991) Corrosion of lead pipe can be influenced by other water quality factors. The presence of electron acceptors, such as: dissolved oxygen, hydrogen ions, and chlorine residual may hasten corrosion. The strong effect of pH on lead solubility has been well documented (Lee, Becker, and Collins; Schock 1989; deMora and Harrison 1984). Unlike pure lead, though, except for pH, water quality has little effect on galvanic corrosion, which occurs with solders and alloys of lead (Singley 1994). Reiber (1991), found pH had a significant effect on galvanic current. He found pH to be an important parameter in determining the rate and extent of passivation of the solder surface and related it to the solubility of the protective lead and tin oxide scales. He found at lower pH values (5 and 6) the degree of passivation is substantially less than at values of pH 7 and higher. Chlorine has been shown to accelerate the rate of corrosion on copper surfaces (Reiber 1989), and so has been a factor of concern with the solder/copper couple. However, Reiber (1991), found chlorine residuals are of little importance to the galvanic corrosion process. He found that the addition of free chlorine residuals in the range 0 to 3 mg/L as C l can stimulate galvanic 2  corrosion in the short term but the effect is transient and does not appear to alter 43  long-term corrosion rates. Lee, Becker, and Collins (1989), found pH was the only water quality factor that appeared to influence lead levels at the tap. pH values  3  8.0 provided superior lead control compared to lower values. Free chlorine residuals at levels <1.0 mg/L to >5.0 mg/L had no apparent effect on the amount of lead contributed from plumbing materials, nor did alkalinity, calcium or hardness. The American Water Works Company (AWWC 1995), in a survey of 24 large water utilities and 66 medium sized systems found that calcium, alkalinity, temperature and specific conductance had no effect on lead levels measured at the tap. The two parameters that directly impacted lead at the tap were pH and corrosion inhibitor dose.  3.4.  Corrosion Control  Corrosion cannot be eliminated completely by practical means, so the goal of corrosion control is to reduce or inhibit corrosion to appropriate levels, taking into account cost effectiveness, benefits to human health and impacts on the environment. In addition to proper materials selection and good system design for domestic plumbing systems, the easiest and most practical way to reduce corrosion is through water quality adjustment at the source. Corrosion control through water quality adjustment involves interference in the chain of corrosion cell reactions. This usually consists of promoting formation of a passivating film to provide a barrier which limits transport of metallic species into the solution (mostly by solubility limitation) and limits the diffusion of oxidizing agents to the pipe surface.  44  Chemical treatment of potable water, however, is limited to small concentrations of non toxic substances.  3.4.1. Calcium Carbonate Precipitation As previously mentioned, all waters are corrosive to metal but hard waters can provide protection against corrosion by the natural deposition of a, relatively, insoluble, film on the metal surface. The film or scale is largely formed by precipitation of calcium carbonate. Traditionally, corrosion control for most water supplies involves adjusting water quality parameters, such as pH, so as to promote the formation of a thin calcium carbonate film. In soft waters, the water is not saturated enough with calcium carbonate to naturally form this protective film. In addition, it is not practical in the low pH, low alkalinity, waters of the GVWD to achieve, by water quality adjustment, the levels of calcium and carbonate alkalinity necessary for calcium carbonate precipitation and scale protection.  3.4.2. pH /Alkalinity Adjustment pH/alkalinity adjustment is the most common method of corrosion control for water distribution systems. For a number of low alkalinity, low pH waters, pH/alkalinity adjustment alone has proved effective at reducing copper and lead levels to below regulatory levels (Vinci and Sarapata 1992; O'Brien 1993; Judge 1994; Reiber, Ferguson, and Benjamin 1987, citing a series of pilot studies in Seattle). Alkalinity is added to provide buffering ability, which is necessary to maintain stable pH conditions. For very low alkalinity waters, soda ash (Na C0 ) or sodium 2  3  45  bicarbonate (NaHC0 ) are the preferred chemicals (AWWA 1990), because they 3  also contribute carbonate or bicarbonate ions. Bicarbonate has been shown to have beneficial effects in corrosion control in field studies (Johnson, et al. 1993; Judge 1994; Vinci and Sarapata 1992). O'Brien (1993) in a pipe loop study of lead pipe, found adjustment of pH to 8.0 - 8.5 and alkalinity to 25 mg/L (using bicarbonate) resulted in 90 percent reduction in lead corrosion. Alkalinity addition alone, gave over 80 percent reduction. As discussed previously, some studies have shown that under certain conditions, and at higher concentrations bicarbonate may be involved in increasing corrosion, however, the extremely low alkalinity, low mineral content waters of the GVWD would not be expected to have problems with the formation of carbonate complexes that increase metal solubility. While the literature generally recommends, for corrosion control, an optimum pH of 9 for lead and pH 8 for copper, the effective pH for any given water is very specific to its water quality characteristics and the impact pH may have on other water processes. For low alkalinity waters the AWWA (1990) recommends, for minimum lead solubility, a pH of about 9.8 in the presence of about 20 to 30 mg/L of alkalinity. Vinci and Sarapata (1992), using theoretical chemical equilibria data, calculated that by adjusting water with a normal pH of 6 and alkalinity of 5 mg/L to pH 8 and alkalinity 30 mg/L, lead solubility is reduced almost 50 fold. Similarly for copper, adjusting to pH 8 and alkalinity 30 mg/L, a 56 fold decrease in copper solubility is obtained. Judge (1994), in a full scale corrosion control program, reported that, the addition of sodium bicarbonate to increase alkalinity to 40 ppm and sodium hydroxide to increase pH to 7.8 was effective at reducing copper and lead levels, at the tap, to  46  below MCL's in low alkalinity, low pH water.  3.4.3. Zinc Orthophosphate Results of a recent corrosion study in the GVWD (MacQuarrie 1993), indicate that pH/alkalinity adjustment alone may not be sufficient to consistently reduce metal levels, at the tap, to acceptable levels. In this study, it was determined that, of the three chemical corrosion inhibitors tested, zinc orthophosphate (ZOP) would likely provide the best adjunct to corrosion control of lead leaching and possibly copper corrosion. Numerous studies confirm the efficacy of zinc orthophosphate at reducing lead levels (Maloney , Temkar, and Scholze 1993; Neuman 1995; Porter and Ferguson 1995; Becker and Moser 1993; Lee, Becker, and Collins 1989). It is generally believed that, ZOP is more effective in controlling lead corrosion than copper corrosion. However, one study has found good results in reducing copper corrosion (Reiber 1989). Zinc orthophosphate does not change the corrosive characteristics of the water but reduces corrosion by formation of a very thin, (in the 2-10 micron range), protective, barrier film on the metal surface. Phosphate inhibitors are thought to also function to some degree by inhibiting anodic reactions and may be aided by the presence of zinc, calcium, or magnesium to interfere with the cathodic reduction of oxygen at the metal surface (Ryder and Wagner 1985). The mechanism of the formation of the barrier film is poorly understood. Reiber (1989) states that conventional wisdom regarding the mechanism suggests that the phosphates react and precipitate the oxidized metal species at the corrosion surface, to form a hard, insoluble, metal-phosphate film. Nancollas (1983) proposes  47  that phosphates may also combine with oxygen at the surface of the metal and form a crystalline lattice structure that anchors the precipitated species. It is thought that the precipitation can be improved by cations like calcium or zinc and lead to a denser layer (Ryder and Wagner 1985). Porter and Ferguson (1995), using 50:50 lead/tin solder coupons, found that the coupons exposed to orthophosphate passivated sooner and achieved a greater level of passivation than the coupons exposed to untreated water. The untreated solder coupons corroded at roughly three to five times the rate of coupons exposed to orthophosphate. Examination of the coupons revealed that orthophosphate exposed coupons had a hard, thin, grey scale quite different from the soft, powdery scales found in the coupons exposed to untreated tap water. The water quality characteristics of the source water have a significant role in the effectiveness of corrosion inhibitors. The manufacturer of the zinc orthophosphate product used in this study (Virchem 939), suggests that ZOP is effective over a wide pH range (6.5 to 8.5) but performs better within certain ranges for different materials (7.5 to 8.5 for copper and lead). As the pH of the water approaches 8.5, ZOP can come out of solution, increasing turbidity and reducing corrosion control. This occurs at high alkalinity as well (TPC 1992). Reiber (1989 and 1991) found that orthophosphate is very sensitive to changes in pH, on copper and solder surfaces, suggesting that because of the minimal quantity of scale, the electrochemical effects associated with a pH shift are very strong. He found that the protective films are labile in low pH waters. Exposure to pH < 6.0 degrades the film, destroying its protective qualities within hours, both for young and well aged surfaces. Dodrill and 48  Edwards (1995), in examining data from a AWWA water utility survey, found that in some pH and alkalinity categories orthophosphates appeared to adversely affect copper and lead release. For utilities with alkalinity of 30-74 mg/L as C a C 0 , at pH 3  values > 7.4, orthophosphate inhibitors had significant adverse effects on lead levels. The best lead results using phosphate inhibitors occurred only in the lowest alkalinity category (< 30 mg/L) at all pH values. Above pH 7.80, the addition of phosphate inhibitors had disparate effects on copper release and at pH > 8.40 and alkalinity < 30 mg/L, there were significant adverse effects for copper corrosion. The best copper results with phosphate inhibitors were from utilities with pH <7.80 and alkalinity > 90 mg/L.  3.5.  Health Factors  One of the primary goals of corrosion control treatment is to reduce or prevent the formation of corrosion by-products which leach into the water and thereby potentially impact health. The benefits of corrosion control, both economic and in terms of human health, must be weighed against the possible toxicity of the corrosion inhibitors added to the water. The main substances added to water for corrosion control are sodium and calcium hydroxide, sodium and calcium carbonate, sodium and zinc ortho and polyphosphates, sodium silicate and carbon dioxide. The residuals in the finished water that result from addition of these chemicals are calcium, phosphorus, sodium, zinc and silicates, which are all normal constituents of the body and of food. The  49  Drinking Water Health Effects Task Force (1989) states that "these chemicals are believed to present essentially no health risk at the levels found in drinking water". The positive health effects of zinc have been discussed (Section 1.3.2.4). Calcium and phosphorus in drinking water may, as well, provide health benefits. Populations living in hard water areas are known to have lower rates of cardiovascular disease than those in soft water areas (NAS 1980; WHO 1984). While the mechanism of protection is unknown, one theory is that it may be related to the presence of specific ions such as calcium and magnesium. Calcium is an essential nutrient with an recommended daily allowance (RDA) of 800 mg /day for men and 1200 mg/day for women, with no upper limit set (Kreutler, and Czajka-Narins 1987). The average calcium concentration in potable waters is 26 mg/l and so contributes only 5-10% of the adult RDA (NAS 1980). Phosphorus, in the form of phosphate, is common to most foods and foodstuffs and has an RDA of 1200 mg/day. In addition to being essential nutrients, it is known that in the presence of calcium, phosphates, and zinc, some metals, such as lead, are much less well absorbed when ingested (Kimbrough 1990; Kreutler, and Czajka-Narins 1987). Increased sodium in drinking water may be of concern to individuals who restrict sodium intake because of evidence that high dietary intakes of sodium may play a role in the development of hypertension. However, a recent analysis (Midgley et al. 1996), to update evidence on the effect of dietary sodium restriction on lowering blood pressure, concluded that the evidence does not support current recommendations for universal dietary sodium restriction. In addition, the low intake  50  of sodium from.drinking water, relative to that from food, would not likely be responsible for a significant additional effect. There is, at present, no upper limit guideline value for sodium in drinking water based on health risk. While generally believed non toxic, toxicology studies on corrosion additives have been conducted (Bull and Craun 1977), but there is little research available on the long term health impacts, be they beneficial or potentially harmful, of addition of these substances to drinking water. While not the primary emphasis of EPA health effects research on drinking water contaminants, the EPA has indicated a need for a study of the impact of non disinfectant chemical additives, such as substances added to adjust such characteristics as pH and water hardness (Hauchman 1992). Knocke et al. (1993) present in their paper important issues surrounding risk assessment of metals and metalloids in drinking water. Among many risk assessment issues discussed, they identify the need for research on the relative source contribution of drinking water to overall exposure from specific inorganic compounds; the long term risks of exposure by the levels typically detected in drinking water; and also note that "because inadequate intake of an essential trace element can induce a deficiency, it is important to consider both the essential requirement and the toxicity of these chemicals". It would appear that the benefits of corrosion control, by the reduction of toxicologically significant substances, such as lead, and the introduction of nutritionally beneficial minerals, outweigh the possible risks from corrosion additives.  51  4.  EXPERIMENTAL METHODS  4.1.  Introduction  The process of internal corrosion is extremely complex and is influenced by many interdependent interactions such as: the many chemical interactions that govern the solubility of metals and the formation and type of protective scale formed, the qualities of the water and the properties of the plumbing materials. Because these interactions have not been adequately studied or quantified and because there will always be differences in water qualities in different waters studied, predictions about what specifically causes a particular corrosion problem and the best way to control it cannot be reliable. Conventional indexes commonly used to assess the corrosive tendency of a water (e.g. Langelier index or Larson's ratio) have been found to be poor predictors of the degree of metal leaching that could occur in a given water (Edwards, Schock, and Meyer 1996). Subsequently, evaluation of effective methods for corrosion control must be studied on a site specific basis. This study was conducted under pilot plant conditions, using a flow through pipe loop system. The use of a pilot testing facility avoids the risk of affecting the water being supplied to the public and allows partial simulation of the home plumbing environment and the use of the raw source water of the region. Pipe loop systems have commonly been used to evaluate a variety of corrosion related parameters (Mackoul, Nelson, and Toussaint 1995; MacQuarrie 1993; Maloney, Temkar, and  52  Scholze 1993; EES 1990), such as: corrosion rates, metal leaching potential and corrosion control treatment. The pipe loop system used for this study allowed for measurement of metal leaching from typical household plumbing materials and demonstrated relative performance of alternate treatment approaches.  4.2.  Pilot Plant Description  The GVWD Corrosion Control Pilot Water Treatment Plant is located at Seymour Falls Dam, which impounds Seymour Lake. It is approximately 11 miles from the mouth of Seymour River, which empties into Burrard Inlet (see Figure 1.2). The pilot plant is housed in bays within the dam. In one bay the pipe loop system is located, while the lab equipment required for water analysis is in an adjacent bay.  4.2.1. Pipe Loop Description Figure 4.2 shows a schematic diagram of the pipe loop system. The pipe loop setup allowed for seven parallel, independent, pipe loops, through which water could flow. The water source for operation of the pipe loop system is raw water flow from Seymour Lake which was reduced in pressure and regulated to allow for constant pressure to the pilot plant. Globe valves were used to regulate the flow rate to the pipe loops to 15 L/min., which resulted in a velocity of about 2.6 fps (0.79 m/s) through the copper plumbing coils. This velocity is similar to that in household plumbing and is the same as that used in previous corrosion control studies at this pilot plant. Each of the seven globe valves were followed by rotameters, used to monitor the instantaneous flow rate.  Figure 4.2 Pipe Loop System Schematic  Prsaaure reguSator Pressure Gats valve 50.8 mm  -da Pump discharge  y a h w  va«v«  r  A B Static mixer  Rotameter Corroeometer Static Water meter Globe  Loop<  chemicals which were used to provide each of the seven water treatments. Treatment number one was the raw water control, so loop number one did not have any injection ports. In-line static mixers were located following the injection ports to ensure rapid mixing of the treatment chemicals with water. On each line, following the static mixers, was a sampling tap used to take samples for daily monitoring and water quality analysis. Following this, on each loop was a length of straight PVC pipe. Downstream of the PVC pipe, each pipe loop was comprised of three sections of different household plumbing materials: a coil of copper plumbing, a coil of lead solder and a brass faucet. Water could be isolated in each section and allowed to remain stagnant for the desired standing time, after which samples could be drawn from each section for analysis. The copper plumbing section consisted of an 84 foot (25.6 meter) coil of half inch, type L soft copper tubing which was joined every 4 feet with 50/50 lead-tin solder. This was intended to represent typical household plumbing. Immediately downstream of each copper coil was a plastic, one liter canister holding a coil of 50/50 lead-tin solder material, of approximately 500 g weight. When water was flowing through the system, it circulated through the canisters and the coils in them so that the coils were always submerged in water. The outlet of each pipe loop was the third section, a two-handled, cast brass mixing faucet, typical of those used in household plumbing fixtures. The faucets  55  discharged the water into vats containing granular activated carbon so that the water was filtered before being discharged into the Seymour River. An electronic timer allowed automatic start-up and shutdown of the pipe loop system. It controlled the electric activated ball valve which allowed water flow to commence and the start-up for the chemical feed pumps which delivered the appropriate treatments to each loop. Manual operation was also possible.  4.2.2. Chemical Treatment Set-up The pipe loop system allowed for seven different water treatment applications. The chemical feed system delivered the specified chemicals to the injection ports on each pipe loop set. The treatment chemical solutions were stored in Nalgene chemical vats. The feed lines from these vats were made of norprene tubing and the chemicals were delivered via variable speed Masterflex L/S peristaltic pumps. Four pH/alkalinity combinations and two different doses of zinc orthophosphate (ZOP) were evaluated. The two loops with ZOP also had the pH and alkalinity raised to promote its efficacy. The pH was raised by addition of lime (Ca(OH) ) and 2  alkalinity was raised by addition of sodium bicarbonate (NaHC0 ). The zinc 3  orthophosphate used was a commercial preparation from Technical Products Corporation of Portsmouth, VA., called Virchem 939. It comes in liquid form with a zinc content of 7.3 percent and phosphate content of 21.7%. The material safety data sheet appears in Appendix B. Each of the seven identical pipe loops had a different water treatment application as  56  follows: •  Loop number one was the control treatment so no chemicals were applied and only raw source water flowed through the loop.  •  Loop two had the pH raised to 8 and the alkalinity raised to 20 mg/L as C a C 0 .  •  Loop three had the pH raised to 8 and the alkalinity raised to 30 mg/L as C a C 0 .  •  Loop four had the pH raised to 9 and the alkalinity raised to 20 mg/L as C a C 0 .  •  Loop five had the pH raised to 9 and the alkalinity raised to 30 mg/L as CaCOg.  •  Loop six had zinc orthophosphate applied at a dose of 0.37 mg/L as Zn. In  3  3  3  addition, the pH was raised to 7 and the alkalinity to 20 mg/L as C a C 0 . 3  •  Loop seven had zinc orthophosphate applied at a dose of 1.0 mg/L as Zn. In addition the pH was raised to 7.5 and the alkalinity to 20 mg/L as C a C 0 . 3  Table 4.1 summarizes the treatment set up. Table 4.1 Treatment Set-up Loop Number  1  2  3  4  5  6  7  PH  control  8.0  8.0  9.0  9.0  7.0  7.5  control  20  30  20  30  20  20  -  -  -  -  0.37  1.00  Alkalinity (mg/L CaC0 ) 3  i  ZOP (mg/L Zn)  -  57  4.3.  Operational Procedures  4.3.1. Pre-treatment Procedures Prior to commencement of the water treatment applications the pipe loop system was flushed with raw source water. This was to flush out chemicals used from previous studies. The system was flushed, with the water flowing at full velocity, for one week . It was then decided to run an acidic solution through the pipe loops to dissolve the scale that may have built up from previous use. A 1 % solution of nitric acid was batched and fed through the pipe loops to bring the water flowing through the pipes to a pH of about 4. The pipe loops were flushed with this solution for about one hour then the system was shut down and the acidic water was left standing in the pipes for 20 hours. This was repeated three times on three successive days. Following this procedure, the pipe loop system was flushed with raw source water for 11 days. Following this, pre-treatment standing water samples were drawn before the study commenced. Eight hour standing water samples were drawn from the copper coils, the canisters containing lead solder, and the faucets on each of the seven loops. Each sample was measured for the concentration of copper, lead and zinc present. This allowed one to determine background levels for comparison to treated water samples and to determine if the seven different loops had approximately the same metal levels in raw water conditions. Finally, immediately prior to the study commencing, loop 6 and loop 7 were passivated with a high dose of ZOP for ten days, six hours a day, as recommended by the Technical Products representative.  58  The dose applied was 1.5 mg/L as Zn to both loops.  4.3.2. Regular Routines The pilot plant was in operation seven days a week for the one year duration of the study. The electronic timer automatically commenced the water flow and chemical feed daily, which ran for a total of six hours each day. The velocity through the half inch (12.5 mm) copper plumbing coils was 2.6 fps (0.79 m/s). This velocity produced a flow rate of 1.59 US gpm (6 L/min) and resulted in a total output of about 573 US gallons (2,166 L) daily. The same velocity was used in the previous two studies at this pilot plant and falls within the range of velocities used in studies in Seattle and Portland (EES 1990). To monitor and maintain proper functioning of the pipe loop system and to ensure target levels for pH and alkalinity were being maintained the system was monitored on a regular basis so that mechanical, and electrical problems were promptly corrected, and water quality parameters and chemical feed rates were monitored and adjustments make as necessary. The following daily routine was followed: • The flow rate was determined from the rotameters of each loop and the globe valves adjusted as necessary to maintain flow at 1.6 gpm (6 L/min). •  One liter flowing water samples were drawn from each loop from the sampling taps located downstream of the chemical injection ports.  •  The temperature of the flowing water was measured.  • A 150 ml portion of each of the seven water samples was heated to 25° C in a 59  water bath, (as recommended by Standard Methods (APHA et al.1989), so that all measurements were done at a fixed temperature), for use for the following measurements: •  Conductivity of each sample was measured at 25°C using a Hanna Model 8733 conductivity meter which had been calibrated at 25°C.  •  pH of each sample was measured at 25°C using a Horiba Model D-13 pH meter which was calibrated using three standards at 25°C.  •  Alkalinity of each sample was determined at 25°C in accordance with Standard Methods, 17 Edition (APHA et al., 1989), 2320 B "Titration Method", 5.b. th  "Potentiometric titration of low alkalinity". 4.3.3. Monitoring ZOP Dosing Since the ZOP concentration could not be measured daily, to ensure accurate dosing, the volume of the prepared ZOP was checked daily to ensure the correct volume had infused. In addition, approximately every two weeks, after each new vat of ZOP was batched, flowing water samples from loop 1, loop 6 and loop 7 were collected for phosphorus determination at the UBC environmental lab. Results are found in Appendix C. To obtain the samples, 300 ml flowing water was taken from loop 1,6 and 7 in glass BOD bottles which had previously been rinsed with hot 10% HCI. The samples were immediately acidified with 0.3 ml of concentrated HCI to give a 0.1 percent HCI matrix. Phosphorus was measured in accordance with Standard Methods, 17 Edition (APHA et al., 1989), 4500-P F "Automated Ascorbic th  60  Acid Reduction Method" using a Latchet Quikchem autoanalyzer, with a detection limit of 10ug/Lfor P.  4.3.4. Preparation of Chemicals The water treatment chemicals were prepared and mixed in large Nalgene chemical vats, as required, approximately every two weeks. The chemicals were prepared as follows: •  Zinc orthophosphate (Virchem 939) The specific gravity of the Virchem 939 concentrate was 1.4 and the vat concentration was 2500 mg/L as product, so the required dilution was 560:1. Usually 200 L was prepared at a time so 349 mL of product was added to the vat, then water added with good mixing.  •  Sodium Bicarbonate Sodium bicarbonate (99% purity, as supplied by GVRD) was prepared in a mixing vat, mixed with an electric mixer for several hours then transferred to the chemical feed solution vat. The vat concentration was 30 g/L. Usually 300 L was prepared, so at 99% purity 9090 g of soda bicarbonate was added.  •  Slaked Lime Slaked lime (95% purity, as supplied by GVRD), was prepared in a mixing vat, mixed with an electric mixer for approximately 24 hours, (because of its low solubility), then allowed to settle for a day before being transferred to the feed  61  vat. The vat concentration was 1 g/L. Usually 400 L was prepared, so at 95% purity 421 g lime was added.  4.3.5. Sampling Routine for Metals Determination At approximately three week intervals, following the appropriate standing time, water samples were taken from the copper plumbing coils, the lead solder canisters, and the faucets, of each pipe loop, so that the concentration of leached metals could be determined. The original plan for the study was to evaluate samples which had been standing, or stagnating, in the pipe loops for an eight hour period, and then, in the second half of the term of the study, examine sixteen hour standing samples. The purpose of this was to compare the results of different standing times. After seven months of the twelve month term of the study, the metal leaching in the eight hour standing time samples had still not appeared to stabilize so it was decided to continue taking eight hour samples and commence taking sixteen hour samples on alternate weeks. The sampling procedure was as follows: • The treated water was allowed to flow through the pipe loops for three hours. •  While water was still flowing the water was isolated in the copper coils, the solder coil canisters and in the faucets by turning off the faucets and the valves leading to them and shutting the inlet and outlet valves of the copper coils and plastic canisters.  •  The system was then shut down for an eight or sixteen hour period, depending  62  on which standing time was being tested, so that the water could stagnate in the pipe loops. Following the appropriate standing time samples were drawn from the plumbing coils, the solder canisters and the faucets. One 1L and two 500 mL samples were taken from the stopcock on each plumbing coil. The 1 L samples were used for temperature, conductivity, pH and alkalinity and turbidity measurements as per the daily routine. The 500 mL samples were used for metals content determination. Water from each canister, in which the lead solder coils were submerged, was collected in a 750 mL container for daily routine measurements and 250 mL was collected in a separate container for metals content determination. From the faucets, a first draw, 250 mL sample was collected for metals determination then a 1 L sample was taken for the routine measurements. Following collection, all samples for metals determination were immediately acidified with concentrated nitric acid to a 2.5 percent matrix. The samples for metals determination were brought to the UBC environmental lab where they were acid digested, in accordance with Standard Methods, 17  th  Edition (APMA et al. 1989), 3030 E "Nitric Acid Digestion". A 100 mL of each water sample was boiled, with 5 mL concentrated HN0 , to a volume of about 20 3  mL. Each sample was then diluted to 100 mL with de-ionized water. Each sample was then analyzed for copper, lead and zinc. Copper, zinc and the  63  higher lead levels were determined on a Thermo Jarrel Ash Video 22 Atomic Absorption Spectrophotometer, (with detection limits of 0.01 mg/L; 0.005 mg/L; and 0.05 mg/L, respectively), in accordance with Standard Methods, 17  th  Edition (APHA et al. 1989), 3111 B "Direct Air-Acetylene Flame Method". The low level lead samples were determined on a Perkin-Elmer HGA-500 graphite furnace Atomic Absorption Spectrophotometer, (with a detection limit of 1 u.g/L for lead), in accordance with Standard Methods, 17 Edition (APHA et al. th  1989), 3113 B "Electrothermal Atomic Absorption Spectrometric Method". To ensure that the chance of metal contamination was minimized all materials used were acid washed. Previous to each sample collection the sample bottles were thoroughly washed with metal-free nonionic detergent, then given a deionized rinse. They were then filled with 10% nitric acid and allowed to stand for at least eight hours, and then thoroughly rinsed with deionized water and capped. At the same time that each set of samples was drawn, control blanks were prepared, using deionized water, and acidified. The blanks were carried through every step of analysis, including digestion, and measured for all metals determinations, and then the necessary corrections to the results were applied. During metals analysis for all sample sets, a midpoint check standard and calibration blank were analyzed at the beginning, the end and after each set of ten water samples. A number of samples were analyzed in duplicate for each set of samples to establish precision.  64  4.3.6. Quality Control and Data Analysis In addition to the above items discussed, regarding quality control, a number of samples were randomly selected from the standing water samples collected throughout the study, and sent to the GVRD laboratory for metals analysis. This outside measure was used to verify results obtained at the UBC environmental laboratory. Microsoft Excel for Windows 95, Version 7.0 by Microsoft Corporation ©1985-1995 was used for data analysis, plotting of results and statistical analysis. Tests used for statistical analysis included determination of averages, standard deviations and confidence intervals, for each series of data, results for which are documented in the appropriate appendices. Statistical significance was determined using a one tailed student's t-test. The t-test returns the probability that two sample means are equal. The null hypothesis was rejected at the 5% level. If the observed significance level, or probability (P value), was less than 5% (P<05) the result was considered statistically significant. If the probability was less than 1 % (P<01) the result was considered highly, statistically significant. P values are given within the text when statistical significance is identified.  65  5.  RESULTS AND DISCUSSION  5.1.  Copper Concentrations in Standing Water Samples  5.1.1. Plumbing Coils The actual measured copper levels in standing water samples from the plumbing coils are presented in Appendix D. These data are represented graphically in Figures 5.1 and 5.2. The average copper levels, from all treated samples, of each loop, are compared in Figure 5.3. Table 5.1 summarizes the total copper reduction for each pipe loop. The total percent reduction in copper for each pipe loop was calculated from the average of the copper concentrations from the plumbing coil, solder coil, and faucet. Figure 5.3 indicates that loops six and seven, the zinc orthophosphate loops, achieved the lowest average copper levels, in the plumbing coils. Loops six and seven were compared, statistically, to the control using a one tailed t-test, to test the null hypothesis. At the observed significance level of P=.05, for loop six, the difference is not significant; however, for loop seven, at P=.007, there is a highly, significant difference from the control. Over the term of the study, average copper levels in loops six and seven, of the plumbing coils, were reduced by 18 and 25 percent, respectively, relative to their pretreatment levels (Table 5.2). These reductions were not high, and only loop seven's reduction was significant  66  (P=.03). Pre-treatment copper levels in the plumbing coils were quite low, however, averaging 0.95 mg/L, which is below the EPA action level of 1.3 mg/L, so one would not expect to see large reductions with treatment. Loop four was the only pH/alkalinity loop that had any reduction in average copper concentration from pretreatment levels. The t-test probability of P=.28 indicates that the average copper level for loop four was not statistically different than the control, however. The remaining pH/alkalinity loops appeared to exacerbate copper leaching, to well above pretreatment levels, and the control loop level. Some very high copper levels were encountered. The highest levels were from loop two, which had an average copper level of 4.15 mg/L, well above the 1.25 mg/L average for the control loop. All loops, except the control loop, periodically experienced high concentrations in the form of spikes. The spikes occurred less frequently and were of lower concentrations in the ZOP loops. As can be seen in Figure 5.2, the control loop maintained fairly steady copper concentrations with no decreasing trend in concentrations over the term of the study.  67  Table 5.1 Total Copper Reduction In Each Pipe Loop Plumbing Coil+Solder Coil+Faucet Average Concentration Loop Number  Average Concentration mg/L  Percent Reduction  Before Treatment  After Treatment  1  0.36  0.57  -58%  2  0.42  1.42  -238%  3  0.41  0.69  -68%  4  0.51  0.37  27%  5  0.36  0.75  -108%  6  0.41  0.32  22%  7  0.43  0.29  33%  Table 5.2 Copper Reductions in Plumbing Coils Loop Number  Average Concentration mg/L  Percent Reduction  Before Treatment  After Treatment  1  0.76  1.25  -64%  2  0.97  4.15  -327%  3  0.95  1.95  -105%  4  1.19  1.09  8%  5  0.77  2.17  -182%  6  0.97  0.80  18%  7  1.04  0.78  25%  N e g a t i v e r e d u c t i o n m e a n s a n i n c r e a s e in c o n c e n t r a t i o n  Figure 5.1 Plumbing Coils-Copper Levels pH/Alk Adjusted Loops-8 and 16 Hour Samples 12  Days From Start CO CD  Figure 5.2 Plumbing Coils-Copper Levels ZOP Treated Loops-8 and 16 Hour Samples 4.5  Days From Start  O  Figure 5 . 3  Plumbing Coils-Average Copper Levels 8 and 16 Hour Samples  4.5  3.5  E  3  ha  0>  a a o  2.5  a>  cn ro  > <  2 1.5  0.5  Control  Loop 2  Loop 3  Loop 4  Loop 5  Loop 6  Loop 7  5.1.2. Solder Coil The actual measured copper levels in standing water samples from the solder coils are presented in Appendix E. Table 5.3 summarizes the copper reductions. Table 5.3 Copper Reductions in Solder Coils Loop Number  Average Cu Concentration mg/L  Percent Reduction  Before Treatment  After Treatment  1  0.09  0.15  - 67%  2  0.09  0.05  44%  3  0.10  0.06  40%  4  0.13  0.02  85%  5  0.12  0.04  67%  6  0.08  0.03  63%  7  0.08  0.03  63%  The copper measured from the solder coil samples would originate from background copper in the flowing water from the upstream, copper plumbing coils. The average copper levels in the treated loops were all well below that of the control loop, as illustrated in Figure 5.4. The significance level for all treated loops, compared to the control, was less than 1%, which indicates the difference was highly, statistically significant. This may indicate that all the treated waters provided some beneficial effect at reducing copper levels, under flowing conditions. Loop four had the lowest average copper level and the best reduction in copper levels of all the  72  Figure 5 . 4 Solder Coils-Average Copper Levels 8 and 16 Hour Samples 0.18  CO  loops. The zinc orthophosphate loops did not appear to provide any better protection than the pH/alkalinity loops.  5.1.3. Faucets The actual measured copper levels in standing water samples from the faucets are presented in Appendix F. Table 5.4 summarizes the reductions of copper in the faucets. The copper in the standing faucet samples would be the combined contributions of, background copper in the flowing waters from the upstream, copper plumbing coils, and the copper leached from the faucets during standing. Table 5.4 Copper Reductions in Faucets Loop Number  Average Cu Concentration mg/L  Percent Reduction  Before Treatment  After Treatment  1  0.23  0.30  - 30%  2  0.21  0.06  71%  3  0.19  0.05  74%  4  0.22  0.01  95%  5  0.19  0.04  79%  6  0.18  0.11  39%  7  0.17  0.07  59%  The brass faucets appeared to respond much better to the treated waters than did  74  Figure 5 . 5 Faucets-Average Copper Levels 8 and 16 Hour Samples 0.35  , 95% Confidence Intervals  en  the copper plumbing coils. Figure 5.5 indicates that the average copper levels for all treated loops were well below that of the untreated control loop, and all were highly statistically significant with a P value < 0 1 . As with the plumbing coils, loop four had the lowest average copper concentration. The average reductions in copper levels, for the pH/alkalinity loops, were better in the faucets, than the solder coil samples (Tables 5.4 and 5.3). This may indicate that pH/alkalinity treatment provided some protection to faucets under standing conditions, as well as flowing. The control loop showed no reduction in average copper concentration. The control loop copper concentrations were fairly stable, so it is interesting to note that there was an increase in average copper concentration from pretreatment levels in the control loop, for the plumbing coils, solder coils and faucets.  5.2.  Lead Concentrations in Standing Water Samples  5.2.1. Solder Coils The actual measured lead levels in standing water samples, from the lead/tin solder coils are presented in Appendix G. These data are represented graphically in Figures 5.6 and 5.7. The average lead levels for each loop, from all the treated samples, are compared in Figure 5.8. Table 5.5 summarizes the average reduction in lead concentration, for each treatment, in the pipe-loop solder coils, over the term of the study. From Figure 5.6 and Figure 5.8 it would appear that all pH/alkalinity treatments exacerbated lead leaching, since all samples have lead concentrations higher than  76  Figure 5 . 6  Solder Coils-Lead Levels  p H / A l k Adjusted Loops-8 and 16 Hour Samples  Days From Start  Figure 5.7  Solder Coils-Lead Levels  Z O P T r e a t e d L o o p s - 8 and 16 Hour S a m p l e s 4  Days From Start  CO  Figure 5.8 Solder Coils-Average Lead Levels 8 and 16 Hour Samples  those of the control loop. In addition, all average concentrations for the treated loops were statistically, highly, significantly different (P=<.01) from the control. Lead levels for these loops are highly variable, especially for loop four, which had spikes of lead concentrations up to 12 mg/L. Loop four, which was adjusted to pH 9, had significantly higher average lead levels than loop two (P=.0002) and three (P=.04), which were adjusted to pH 8. In this case, it may not be useful to compare the lead levels from the treated loops to the control loop, since, the treated loops were acidified prior to this study commencing, to remove chemicals used in the previous study. Loop one was the control loop in both studies and had no access for treatment or chemical injection. This factor may have resulted in the control loop having an aged surface and the treated loops a fresh surface. A new surface is known to corrode faster than an aged surface and to be more sensitive to changes in pH, for lead/tin solder (Reiber 1991). Table 5.5 shows that lead leaching was reduced, somewhat, from pre-treatment levels, in loops two and three. Figures 5.7 and 5.8 show that, ZOP consistently produced the lowest lead concentrations, compared to the pH/alkalinity loops. Compared to the control loop, however, the difference in lead levels in loops six and seven were not statistically significant (P=.396 and P=.053, respectively). Over the term of the study, average lead concentrations were reduced by 72% and 83% in the ZOP loops. Figure 5.6 also shows that, towards the last few months of the study, all lead levels were decreasing dramatically. Figure 5.9 demonstrates the decline in average lead levels in the last four months of the study, for all of the treated loops. The observed  80  Figure 5.9  D e c l i n e in L e a d L e v e l s O v e r T i m e  A v e r a g e L e a d L e v e l s at 0 - 4 m o n t h s , 4 - 8 m o n t h s a n d 8 - 1 2 Solder Coils-Average Lead  months  significance level for the difference in average lead levels at 0-4 months and 8-12 months was less than 5% for all treated loops, and so indicates that the decline was statistically significant. Table 5.5 Lead R e d u c t i o n s in S o l d e r C o i l s  Loop Number  Average Pb Concentration mg/L  Percent Reduction  Before Treatment  After Treatment  1  1.86  0.73  61%  2  3.16  1.98  37%  3  5.02  3.38  33%  4  5.08  4.81  5%  5  2.94  3.71  - 26%  6  2.44  0.68  72%  7  2.49  0.43  83%  5.2.2. Plumbing C o i l s  The actual measured lead levels, in standing water samples from the copper plumbing coils, with lead/tin soldered joints, are presented in Appendix H. The lead concentrations in the plumbing coils were extremely low and often below detectable limits, in all loops. This may be due to simple depletion of leachable metal. Figure 5.10 shows that loop six had the lowest average lead level but it was not statistically significant (P=.27). Percent reductions in lead levels could not be determined, as most pre-treatment samples were below detectable limits. 82  Figure 5 . 1 0 Plumbing Coils-Average Lead Levels 8 and 16 Hour Samples 0.025  CO CO  5.2.3. Faucets T h e actual m e a s u r e d lead levels, in standing water s a m p l e s from the b r a s s faucets a r e p r e s e n t e d i n A p p e n d i x I. low; h o w e v e r ,  Figure 5.11  L e a d c o n c e n t r a t i o n s in the f a u c e t s w e r e a l s o quite  s h o w s that all t r e a t e d l o o p s h a d s i g n i f i c a n t l y lower  a v e r a g e lead levels than the control loop.  Table 5.6  P v a l u e s for all t r e a t e d l o o p s w e r e <.001.  s h o w s that all o f the t r e a t e d l o o p s a c h i e v e d c o m p a r a b l e r e d u c t i o n s in  lead.  Table 5.6 Lead Reductions in Faucets Loop Number  Average Pb Concentration mg/L  Percent Reduction  Before Treatment  After Treatment  1  0.004  0.150  - 275%  2  0.008  0.002  75%  3  0.012  0.002  83%  4  0.011  0.001  91%  5  0.011  0.001  91%  6  0.014  0.001  93%  7  0.011  0.002  82%  84  0.037 0.025  ,  Figure 5 . 1 1 Faucets-Average Lead Levels 8 and 16 Hour Samples  A  0.02 -  E  0.015  T3 to 0) /  < D C COD  v_  >  <  0.01  95% Confidence Intervals  00  5.3.  Zinc Concentrations in Standing Water Samples  The actual measured zinc levels in the standing water samples from the plumbing coils, faucets and solder coils are presented in Appendices J,K, and L, respectively. Of the plumbing materials tested, brass faucets would potentially provide the highest source of zinc. Again, the faucets appeared to respond well to treatment. The faucets from the pH/alkalinity treated loops all had average zinc levels <0.03 mg/L, well below the control average of 0.08 mg/L, as shown in Figure 5.12. Loop four zinc levels were below detectable limits. Figure 5.13 compares average zinc levels, in the plumbing coil, solder coil and faucet for loops six and seven, the ZOP loops. For the faucets and solder coils, the average level of zinc is somewhat higher, but roughly approximates, the feed rate of zinc to those loops (0.37mg/L to loop six and 1.0 mg/L to loop seven). The plumbing coil of loop seven, however, has an average zinc concentration more than double that of the feed rate. In addition, the standard deviations are all higher in loop seven than in loop six, which would indicate more variability in the zinc concentrations for loop seven. Figure 5.14 graphically demonstrates the actual zinc concentrations in the plumbing coils for loop six and seven, over the term of the study. As the graph shows, loop seven frequently had high concentrations of zinc in the form of spikes. In loop six, the concentrations were much more stable, and as shown in Figure 5.13, average concentrations were similar to those found in the  86  Figure 5.12 Faucets-Average Zinc Levels 8 and 16 Hour Samples  Control  Loop 2  Loop 3  Loop 4  Loop 5  Figure 5 . 1 3 Average Zinc Levels Z O P L o o p s - 8 and 16 Hour Samples  faucets and solder coils. Since the plumbing coils are upstream of the brass faucets, the only likely source for the high zinc levels is from the ZOP. The high concentrations are possibly caused by the inhibitor precipitating out before forming a protective scale or the already formed scale could be sloughing off. These processes may be related to the dose of inhibitor, pH, and/or alkalinity. TPC, the manufacturer of Virchem 939, the ZOP formulation used in the study, has stated that as the pH approaches 8.5 or at high alkalinities, ZOP comes out of solution, reducing effectiveness. In these waters, ZOP may be more sensitive to changes in pH and alkalinity. Another observation one can make from Figure 5.14 is that the very high zinc concentrations occurred in the last half of the study, possibly indicating that a scale had built up on the pipe surface and was sloughing off. There may be a narrow range of effective dose for ZOP and the dose may need to be adjusted as necessary as conditions change.  90  5.4.  Eight vs. Sixteen Hour Standing Times  5.4.1. Lead Levels Figure 5.15 compares average lead levels at eight and sixteen hour standing times. Statistically there was no difference for any of the loops; P values ranged from 15% to 40%. Lee, Becker, and Collins (1989), in measuring lead at the tap from lead service pipes, found that the largest increment of lead increase occurred in the first two hours, but continued to increase for up to six hours and sometimes longer. It is likely in this study that, after eight hours of standing, the majority of the leaching would have occurred. ZOP, which is thought to be less effective under long standing time conditions, was, in this case, just as effective after sixteen hours as it was after eight hours.  5.4.2. Copper Levels Results are somewhat different for copper. Figure 5.16 compares average copper levels at eight and sixteen hour standing times. Loop three had an increase in copper, that was statistically significant (P=.045), at the longer standing time; however, this does not appear to be a trend for the pH/alkalinity loops. The sixteen hour samples from loop seven had an average copper concentration more than three times greater than the eight hour samples, and the difference was highly, statistically significant (P=.001).  91  Figure 5.15  Solder Coils-Average Lead Levels 8 vs 16 Hour Samples  Figure 5 . 1 6 Plumbing Coils-Average Copper Levels 8 vs 16 Hour Samples  Figure 5.17  Faucets-Average Copper Levels 8 vs 16 Hour Samples  0.40 95%  t o  Confidence Intervals  Copper levels in the faucets did not appear to be affected by the longer standing time, as shown in Figure 5.17.  5.4.3. Zinc Levels Figure 5.18 compares average zinc levels from loop six and seven faucets, at eight and sixteen hour standing times. Loop seven, again, had a significantly (P=.025) higher average metal concentration at the longer standing time. In Figure 5.19 average zinc levels from the plumbing coils are compared at the two standing times. The loop seven zinc level at the longer standing time was also significantly (P=.016) higher. These consistently higher levels at sixteen hours standing, for loop seven, indicate that at the higher dose ZOP is affected by standing time.  95  Figure 5 . 1 8  F a u c e t s - A v e r a g e Zinc Levels  8 vs 16 Hour S a m p l e s 1.8 95% Confidence Intervals  1.6 -f  1.4 +  i !  1.2 -f  96  Figure 5.19  Plumbing Coils-Average Zinc Levels 8 vs 16 Hour Samples  5.5.  Comparison of Water Treatments  Figure 5.20 graphically demonstrates the overall, relative performance of each treatment. The graph shows the overall average from the plumbing coil, solder coil, and faucet, for copper, lead and zinc (minus the ZOP dose), for each loop. Of the treated loops the ZOP loops had the lowest average concentrations of leached metals. In comparing the pH/alkalinity loops, loop 4 had the lowest, overall copper (Figure 5.21) and loop 2, the lowest overall lead (Figure 5.22). However, when the relative performance of each treatment is considered, it is not possible to determine an optimum treatment regime, between the pH/alkalinity options, or between the ZOP options.  98  Figure 5.20 Relative Metal Mobility PC+SC+F Average for Copper, Lead, and Zinc 2.5  • Avg Zn minus ZOP H Average Pb M Average Cu PC=Plumbing Coils SC=Solder Coils F=Faucets  Control to CO  Loop 2  Loop 3  Loop 4  Loop 5  Loop 6  Loop 7  Figure 5.21 Total Copper Average Plumbing Coil + Faucet + Solder Coil  Control  Loop 2  Loop 3  Loop 4  Loop 5  Figure 5.22 Total Lead Average Plumbing Coil + Faucet + Solder Coil  5.6.  Water Quality Parameters  5.6.1. pH The flowing water pH's were measured as part of regular water quality monitoring, to guide adjustment of chemical feed rates, so as to maintain the target pH for each loop. They are tabulated in Appendix M. The pH's from the standing samples are tabulated in Appendix N. The observations from the pH measurements are: The average pH, for the flowing water samples, in each loop, was very close to the target pH, being within 0.02 - 0.07 of a unit. (Table 5.7). However, the targeted pH's Table 5.7 Average pH  Loop Number:  1  2  3  4  5  6  7  Target p H  control  8.0  8.0  9.0  9.0  7.0  7.5  Average pH Flowing water  6.30  8.05  8.05  9.02  9.02  7.07  7.53  Solder coils-standing samples  6.26  7.20  7.34  8.61  8.72  6.88  7.08  Plumbing coils-standing samples  6.34  7.06  7.23  8.42  8.53  6.86  7.04  Faucets-standing samples  6.26  7.01  7.17  8.02  8.05  6.79  6.94  were fairly difficult to maintain and required almost daily adjustment of the lime feed  102  Figure 5.23 Average pH 9.5  I  |' i ! ! '»j j!!! 1  (  1  1,  Target  8.5  pH/Alkalinity:  • Control • pH 8/Alk20 11 pH 8/Alk30 11 pH 9/Alk 20 B p H 9/Alk 30 UpH 7/Alk20 • pH7.5/Alk 20  I Q. 0) O)  re  > <  7.5  6.5  6 Loop 5  o CO  Loop 6  Loop 7  rate. This is reflected in the range and standard deviations for the treated loops, which were quite high compared to the control. Figure 5.23 compares the standard deviations of the average pH's for loops one to seven. The graph illustrates that it was more difficult to maintain pH at 8 than it was at 9. This can be explained by the lower buffer intensity that occurs at pH 8 (Benefield, Judkins, and Weand 1982). In the ZOP loops, the lower pH of loop six, was easier to maintain and had less variability than loop seven. Table 5.7 shows the average pH for flowing and standing water sample. The average pH's from standing samples were all lower than the flowing water pH's, except for the control loop, in which the pH's were comparable in standing and flowing water. Many reactions could be occurring which would lower pH in standing samples. For example: Cu + 1/2H 0 -> 1/2Cu 0 + H + e" 2  +  2  As corrosion releases metal ions into solution they could react with and use up hydroxyl ions, for example: Cu° + OH" - » 1/2Cu 0 + 1/2H 0 2  PbO + Pb  2+  2  + 20H" - » P b 0 + H 0 + Pb 2  2  2+  C 0 could be produced via oxidation of organic matter, and would not be free to 2  escape into the atmosphere because the pipe-loop is a closed system.  104  5.6.2. Alkalinity The measured alkalinities are tabulated in Appendix O. Table 5.8 gives the averages for the measured, flowing water alkalinities and their standard deviations. Table 5.8 Average Alkalinity  Loop Number  1  2  3  4  5  6  7  T a r g e t Alkalinity  control  20.0  30.0  20.0  30.0  20.0  20.0  A v e r a g e Alkalinity  3.85  20.2  30.3  21.2  30.2  20.5  20.6  Standard Deviation  0.51  2.26  3.61  2.53  3.15  2.61  3.32  As with pH, the average alkalinities were quite close to the target values. The standard deviations indicate the difficulty maintaining target values, and were greater for the higher alkalinities and the higher dose of ZOP. Alkalinity was added to the treatment loops in an attempt to buffer the pH. Even though the standard deviations for pH were high, Figure 5.23 indicates that the higher alkalinity dose may have provided increased buffering as the pH standard deviations were lower in the 30 mg/L as C a C 0 alkalinity loops. 3  5.6.3. Temperature The raw water temperatures, which were measured regularly over the term of the study, and the standing water sample temperatures, can be found in Appendix P. The temperature varied from a high of 17.5 °C when the study began in August, to a  105  Figure 5 . 2 4 Comparison of T w o Temperature Ranges Plumbing Coils-Average Copper Levels 1 2 - 1 7 and 2 - 7 Degrees Centigrade  Figure 5 . 2 5 Comparison of T w o Temperature Ranges Solder Coils-Average Lead Levels 1 2 - 1 7 and 2 - 7 Degrees Centigrade  low of 2°C in January and then back up to a high of 16°C in August when the study ended. The standing temperatures reached a high of 22°C. Figures 5.24 and 5.25 compare average metal levels, at two different temperature ranges, for copper and lead. The metal levels appear to be comparable at the two different temperature ranges, and, except for two exceptions, the t-test showed no statistical difference. The exception, in loop 5, Figure 5.25, cannot be explained; however, the higher lead level occurred in the lower temperature range, so would not be a result of temperature effect. The other exception was in loop 7, Figure 5.25. The higher dose ZOP loop had a higher average lead level at the higher temperature range, which was statistically significant (P=.04). This may indicate that the effects of ZOP are sensitive to temperature, especially at higher doses. Ryder and Wagner (1985) have stated that the action of corrosion inhibitors is quite temperature dependent.  5.6.4. Conductivity The routine conductivities measured over the course of the study are tabulated in Appendix R. Conductivity varies with the number and type of ions the solution contains. In the low alkalinity, low mineral waters of the GVWD, conductivity is low, with an average in the control loop of 13 |iS/cm. The addition of the chemicals in the treated loops would, of course, increase the conductivity level, depending on the concentration and chemical added. This proved useful as a monitoring mechanism because alterations in feed rate of the chemicals would be reflected by the conductivity measured for a particular loop. High conductivity can be an factor influencing corrosion but the conductivities measured in this study were low, the  108  highest being about 70 uS/cm. Reiber, Ferguson and Benjamin (1987) have found in studies that conductivity appears to be of little importance to copper corrosion in low alkalinity waters.  5.7.  Quality Control  Appendix S compares the results of the metals analysis performed by the GVRD laboratory to those obtained at the UBC Environmental laboratory. For copper analysis most results are comparable. Eighty percent of copper measurements in the faucets and plumbing coils are within a 20% error margin. The much lower copper concentrations in the solder coils had a larger margin of error. The copper measured from the solder coils, however, are not an important indicator of copper leaching. In general, the UBC results tended to be lower than the GVRD results. Ninety-three percent of the UBC results were lower for copper. Lead results from the solder coils are comparable between UBC and GVRD analysis. Ninety-two percent of the values were within a 15% error margin. As with copper, the UBC lead results tended to be lower, with 88% of UBC results lower than GVRD results. The low level lead results from the faucets and plumbing coils, which were measured on the graphite furnace, were very low, with many being below detectable limits. The GVRD results were, on average, 50% higher than UBC. The possible high level of error could be because results are so close to the detection limit.  109  Zinc levels were also quite low, being close to detection limits. The faucets and plumbing coils had 60% of results within a 20% error margin. The remaining 40% of the UBC results were an average of 58% of the GVRD results.  5.8.  Unexpected Problems  During the course of this study there were an number of unplanned incidents which may have had an influence on outcomes of the study. The dates of these incidents did not appear to coincide with episodes of high metal spiking. Fortunately, due to the long term nature of the study, and the ability to resolve problems quickly, any impact would likely not be significant. The incidents were recorded and can be found in Appendix T.  110  6.  SUMMARY DISCUSSION  6.1.  General  The general objective of this study was to determine which corrosion control techniques tested would most effectively reduce lead and copper concentrations in drinking water from household piping and plumbing. While a pipe loop study allows testing using actual raw, source water and the types of materials that are used in household plumbing, the metal levels obtained will not directly equate with those that would be found in the actual distribution system; in addition, it cannot predict how effective the treatments will be at meeting recommended lead and copper levels at the tap. However, this type of study can provide information on the relative effectiveness of various treatments for corrosion control.  6.2.  ZOP Treatment  Overall, the zinc orthophosphate corrosion inhibitor provided the most effective treatment for reducing copper and lead concentrations in standing water samples. Compared to the pH/Alkalinity loops, loops six and seven consistently had; the highest reductions in metal levels; the lowest, average metal levels; and the most stable concentrations, with less spiking of metal concentrations. Studies have shown that ZOP is not as effective in reducing copper corrosion as it is lead corrosion. This appeared to be the case in this study. Overall, reductions  111  were better for lead than for copper. From Figure 5.9 it can be seen that, in the last four months of the study, the average lead levels in loops six and seven were well below the pH/alkalinity loops, as well as the control loops. In addition, the average lead levels from the treated samples showed good reductions compared to the average pretreatment levels in these loops (Figure 5.26). Average copper levels in the ZOP loops were lower than the control; however, the difference between the ZOP loops and the pH/alkalinity loops was not as great for copper as it was for lead. In addition, as Figure 5.27 shows, there was little reduction in copper from pretreatment levels. The small reductions for copper may be due to the low concentrations measured, even before treatment began. Copper spiking also occurred more frequently than lead spiking in the ZOP loops. The one concern with ZOP was the high levels of zinc that occurred in loop seven. The plumbing coil had spikes of zinc up to 6 mg/L, much higher than the feed rate of 1.0  mg/L ZOP as Zn.  In comparing the two doses of ZOP it was found that, in most cases, the average concentrations of metals were comparable in both loops. The average lead level in the solder coils was somewhat less in loop seven, the higher ZOP dose, than loop six. However, the major difference between the two doses was that loop seven lead levels dropped much sooner than loop six lead levels did, as seen in Figure 5.9. Initially the higher dose of ZOP may have promoted development of a protective film more quickly than the lower dose. The best dose of ZOP is probably variable and will require adjustment depending on the length of time it has been applied, water  112  Figure 5 . 2 6 Solder Coils-Average Lead Reduction Pre Treatment vs Post Treatment  Figure 5.27 Plumbing Coils-Average Copper Reduction Pre Treatment vs Post Treatment  quality conditions and the age of the pipe surface.  6.3.  pH/Alkalinity Treatment  The pH/alkalinity treatments generally appeared to exacerbate metal leaching in standing water samples. Average copper and lead levels in the pH/alkalinity loops were all higher than the control levels. Only lead levels in loops two and three had any reduction from pretreatment levels (Figure 5.26). It appears that the scale that forms under these conditions, on a fresh pipe surface, is not as stable as the metal oxide scale that likely was present on the control loop. The concurrent high standard deviations for pH and alkalinity that occurred in the treated loops may indicate that the treated loops were more sensitive to the variations in pH, than to the pH value itself. Reiber (1989), found that fresh copper surfaces were highly sensitive to pH. Johnson et al (1993) concluded that a steady pH is probably the most important factor in achieving consistent corrosion control results. There was no pH/alkalinity combination which could be identified that provided the lowest overall metal levels. There was a decline in lead levels, over time, for all loops, which may show benefits for pH/alkalinity treatment in the field, over the long term.  6.4.  Standing Time Effects  In general, there was no difference in metal levels at the longer (16 hour) standing  115  time. pH/alkalinity loops had similar results at eight and sixteen hour standing times. However, loop seven had higher average copper and zinc concentrations at the longer standing time. This may be related to the higher dose of ZOP, the higher variability in zinc and copper concentrations in this loop and/or the greater variability in pH that occurred. Although metal levels for flowing water samples were not measured, the results from the solder coils and faucets give some indication of the metal levels that would occur under flowing conditions. Johnson (1993) concluded that there apparently was a difference in the chemistry of corrosion control between flowing and standing conditions. This variation was evidenced by fluctuations in pH for standing water compared with flowing water and also the effectiveness of pH/alkalinity at decreasing copper in flowing water. This study had similar results. The copper levels in the treated solder coil and faucet samples were all significantly below the control loop, even for pH/alkalinity treatment, and the same was true for lead in the faucets. In these examples the pH/alkalinity treatments were just as effective as ZOP.  116  CONCLUSIONS AND RECOMMENDATIONS  7.1.  Conclusions  The objectives of this study were: 1. Compare the relative effectiveness of different pH/alkalinity applications at reducing copper and lead levels in standing water samples. 2. Determine if zinc orthophosphate is effective at reducing copper and lead levels and compare effectiveness of two different doses of zinc orthophosphate. 3. Determine if different standing times affect metal levels or the effectiveness of ZOP. The results of this study have lead to the following conclusions: •  pH/alkalinity treatment did not appear to be effective at reducing metal levels, below those of the control, in standing water samples.  •  In comparing pH/alkalinity loops it was not possible to identify an optimum pH/alkalinity combination for reducing both metals. Loops two (pH 8/alkalinity 20 mg/L) and three (pH 8/alkalinity 30 mg/L) provided the best reductions in lead, and loop four (pH 9/alkalinity 30 mg/L) had the lowest average copper.  •  pH/alkalinity treatment did appear to provide some corrosion protection under flowing conditions.  117  •  The longer standing time of sixteen hours did not appear to increase metal levels above that of the shorter standing time of eight hours, in the pH/alkalinity loops.  •  Lead concentrations were decreasing dramatically, in all pH/alkalinity loops, in the last four months of the study.  •  ZOP was effective at reducing lead as well as copper concentrations in standing water samples; however, it was somewhat less effective at reducing copper leaching than it was lead.  •  The higher dose ZOP lowered lead levels much sooner in to the term of the study than the lower dose ZOP. Overall, the reductions in metals were comparable with both inhibitor doses.  •  The higher ZOP dose had higher copper and zinc levels at the longer standing time, and also had some problems with spiking of zinc concentrations, at both standing times.  7.2.  Recommendations  While pH/alkalinity treatment did not appear to be effective under pilot plant conditions, there may be benefits to the use of pH/alkalinity adjustment in the field. The pH/alkalinity treatment used in this study did have some positive effects. It was very effective at reducing metal levels in the faucets and apparently, under flowing water conditions. pH/alkalinity adjustment is also considered to be a "natural"  118  method of corrosion control and so would probably have better public acceptance than chemical corrosion inhibitors. pH/alkalinity adjustment is relatively inexpensive, and has been proven to work in many field studies and in actual use in distribution systems. Pilot plant results do not always reflect how a treatment will respond in the distribution system in the long term. One must also consider that, in the study, the pH/alkalinity treatments were applied to a fresh copper surface, due to flushing of the system with acid before the study began. This type of surface is known to be more sensitive to pH and to variation in pH. In the field one would be more likely to encounter aged plumbing surfaces. This study suggests that maintenance of a stable pH is important in reducing metal levels. Maintaining a stable pH at a lower value may prove to be easier, as at pH 7 there is a much higher buffer intensity than at pH 8 or 9, for the bicarbonate buffering system; and in addition, the lower pH may be more beneficial for other water treatment considerations. Zinc orthophosphate in the distribution system may effectively reduce metal levels and have an additional, positive impact on human health, from the addition of zinc, but there are other impacts that must be considered. With use of ZOP there is potential for elevated zinc levels which cannot be tolerated by waste treatment plants. Zinc is toxic to fish and so any additional zinc going into receiving waters must be monitored and could be problematic. Increased levels of phosphorus, from ZOP, may affect disinfection of drinking water and an increase in phosphorus content of waste waters could increase the risk of  119  eutrophication of receiving waters. The perception of the public, while not necessarily correct, may be that the addition of a chemical inhibitor to the drinking water could only cause negative impacts on health, e.g. "If it's toxic to fish then it must be toxic to humans". Before ZOP is used in the distribution system public education and study of its impact on the environment must be considered. Given these concerns with ZOP, and its additional cost, it is recommended that pH/alkalinity adjustment be used first, in the distribution system, to determine its effects. Meanwhile, further study of zinc and non zinc orthophosphate inhibitors could be done. Because there is no ideal corrosion inhibitor it is important to consider all methods to reduce corrosion and its impacts. For example: Education of the public to increase awareness of sources of exposure to lead and how to reduce them; replacement of any lead containing materials in the distribution system; and, the quality of piping and plumbing materials used should be considered, and the importance of good plumbing practice and design emphasized, to minimize metal leaching.  7.3.  Further Study  The literature on this subject stresses the need for a great deal more study in all areas concerning inhibitor use and internal corrosion control in water distribution systems. Further study, in the GVWD, may be useful is such areas as:  120  Further study using pH/alkalinity adjustment at lower and higher pH values. Study on how to maintain a more stable pH in systems using pH/alkalinity adjustment. Study of the effects of pH/alkalinity adjustment on aged plumbing surfaces. Field studies using pH/alkalinity adjustment. Further study of zinc orthophosphate, including: determining optimum pH, how to avoid zinc spiking, effectiveness under different conditions such as fresh and aged plumbing surfaces, and low and high flow conditions. Trials of non zinc orthophosphate inhibitors. These are thought to require higher levels of phosphorus for effectiveness which must be considered. If orthophosphate inhibitors are considered, then, as MacQuarrie (1993) suggests, the effect of phosphates on bacterial regrowth needs to be more closely examined. Study of the interactions between, and effects of, corrosion inhibitors and disinfection chemicals. Continue to monitor results of further study on: the impacts of metals on health; the chemical and physical forms that these metals take in various domestic waters, and their availability for absorption; and the relative contribution of metals from drinking water as compared to other sources.  121  REFERENCES Al-Kharafi, F.M., H.M. Shalaby, and V.K. Gouda. "Pitting of copper under laboratory and field conditions". British Corrosion Journal, Vol. 24, No. 4 (1989), pp 284-290. APHA, AWWA, WPCF (American Public Health Association, American Water Works Association, Water Pollution Control Federation). Standard Methods for the Examination of Water and Wastewater. 17 ed. American Public Health Association. 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Geneva, (1984).  130  Appendices Append x A  GVWD Seymour Water Physical and Chemical Analysis  Append x B  Virchem 939 Material Safety Data Sheet  Append x C  Phosphorus Content  Append x D  Copper Levels - Plumbing Coils  Append x E  Copper Levels - Solder Coils  Append x F  Copper Levels - Faucets  Append x G  Lead Levels - Solder Coils  Append x H  Lead Levels - Plumbing Coils  Append x 1 Lead Levels - Faucets Append x J  Zinc Levels - Plumbing Coil  Append x K  Zinc Levels - Faucets  Append x L  Zinc Levels - Solder Coils  Append x M  Flowing Water pH Measurements  Append x N  Standing Sample pH Measurements  Append x O  Alkalinity Measurements  Append x P  Temperature Measurements  Append x Q  Comparison of Two Temperature Ranges - Temperature Data  Append x R  Conductivity Measurements  Append x S  Quality Control Samples  Append x T  Unexpected Incidents  Appendix A GVWD Seymour Water - Physical and Chemical Analysis Seymour Intake/Raw Water  Parameters Measured Total Alkalinity as C a C 0 Aluminum  3  ( m g IL)  D i s s o l v e d (mg/L)  3.7 < 0 . 0 2 - 0 . 0 8 (median 0 . 0 5 )  C a l c i u m (mg/L)  1.76  C a r b o n Inorganic Total (mg/L)  1.1  C a r b o n Organic Total (mg/L)  1.6  C a r b o n T o t a l (mg/L)  2.7  Chloride (mg/L)  0.5  Color  13-25  Apparent  (median 17)  Conductivity (nmohs/cm)  16  Copper  <0.001 - 0 . 0 0 2 (median <0.001  (mg/L)  <0.05  Fluoride (mg/L) Hardness as C a C 0  5.10  3  0.16  Iron ( m g / L ) Magnesium  (mg/L)  0.17  Manganese  (mg/L)  <0.01 - 0 . 0 2 (median 0 . 0 1 )  Nitrogen - A m m o n i a  (mg/L)  <0.02 - 0 . 0 2 (median <0.02)  Nitrogen - Nitrate (mg/L)  0.09  Nitrogen - Nitrite (mg/L)  <0.01  PH  6.2  Residue Total Dissolved (mg/L)  16  Residue Total Fixed (mg/L)  12  Residue Total Volatile (mg/L)  6  Residue Total (mg/L)  18  Silica a s S i 0  3.2  2  (mg/L)  Sulfate (mg/L)  2.0  Turbidity  0 . 1 - 8 . 1 (med. 0 . 6 ) (avg. 1.4)  (NTU)  Data from EES (1990) These figures represent the average or median of a number of analyses throughout the year of 1 9 8 8 . Methods and terms are those of "Standard Methods for the Examination of Water and Waste Water" 1 6 ' " Edition 1 9 8 5 . Less than (<) means not detectable by technique used for determination.  132  Appendix B TICMMICAV PSOOUCTI  eo«».  iM< l O M O O N K v O PCATJMOUTX. VIAOlNIA 13J04  VIRCHEM* 939  M A T E R I A L SAFETY DATA SHEET ./nlormaiion Telephone 8O4n».$O09  Emergency Telephone: 804/399-5004  CHEMTREC Telephone 800/424-9300  I. IDENTIFICATION »t»i*onSAti  V I R C H E M * 939  P»03UCT N A U E .  Proprietary Acidic  CMiuc*iM*ut.Liquid  *Corrosive  o.oT.SHIPPINGNAME,  .corrosive Liquid,  Applicable  no  F o r m u l a t i incouuu E P A R E O *  oot M*iARO«x*ss:  •OUI N O * C (I  Phosphate  v-939  IYNOMVUS  PMYSOU.  Zinc  only  POINT  No  mm HQ,  FREEZING POINT  t o drum  Clear,  STATE  VAPOR PRESSURE  Not  A T jo*C. m m M © .  UMNO.  n.o.3.  zinc  Zri3(P0 )2 4  Not Applicable 7779-90-0  CAS**  Orthophosphate  shipment  water white,  than  1760  CAS MA**  odorless  liquic  SPECIFIC GRAVITY  (M o«i| }  sovuaiirrv  data  Less  <C  material  J u n e , 1989  7.2°C  IN W A T E R at. %  Soluble  VOUCHES VC1UME %  Not  Applicable  Not  Applicable  EVAPORATION HATE [ftuty A e t i a t * • t )  Applicable  1.40 <? 70°F  *  0.8  III. HAZARDOUS COMPONENTS GREATER THAN 1% MATERIAL Zinc  TLV  PEL No  Compounds  data  No  *****  NON-HAZARDOUS COMPONENTS  CAS. No.  data  *****  %  7779-90-0  16-31  *****  69-84  r e p o r t i n g r e q u i r e m e n t s o f S e c t i o n .113 - T i t l e I I I o f t h e S u p e r f u n d Amendments a n d R e a u t h o r i z a t i o n A c t o f 1 9 8 6 a n d 4 0 CFR P a r t 3 7 2 . CAAQNoccNcirv  fjot  listed  b y N T P , I ARC,  o r 0SHA.  IV. FIRE AND EXPLOSION HAZARD DATA rLAUUA81llTY  Non-flammable  NOPUAV  EXTINGUISHING  SPECIAI  *i«E  fOHTlNO P«OCJ0u»tJ  Not  UNUSUAL AXD  rmt  AGENT  Not  liquid  Applicable  Applicable  None  tmosiON r» A L A M O S  V. REACTIVITY DATA jTAjinrv  COMOITIONS TO A V O I O  Stable INCOUPATABIllTV  as a c i d  Aluminum, z i n c , m i l d  AIAHOOUS C O u e u j t l O x  OR M A / A A D O U f 0(C0UPOSII<0N  Treat  ">O0IX'S  - Avoid  scrong  s c e e l , scrong  bases  caustic  materials.  None.  To the oeat ol our knowledge, tho information contained heroin is accural*. However, Technical Product! Corp. itiumti no liability whatsoever f r the accuracy or completeness of the Information. Final determination of the sultapiiity of any malarial la the sola reaoon. SiDillty of lr»8 U38/. All materials may prssenl unknown health hazards and should bo used with caution. Although carta'" hazards art described herein, ws cannot ousraniea trial thejo are ths only hazards wnicn eiisi 0  133  P«OO«CTN»MI  Material Safety Data Sheet  VIRCHEM* 9 3 9  Appendix B  VI. HEALTH HAZARD DATA  '•'  1  •cuHfwiCTtwi»osu«( Slightly Slightly  .\«AL  No s p e c i f i c  CONTACT  t*€  May  C-BON.C Of  EJ°OSuBE  OTrlEO DATA  N  I o  specific  I No s p e c i f i c  data  • data  toxic.  S»IN CONTACT  4 I O N  1 nv  toxic.  May c a u s e s k i n  information.  irritation.  ,  cause eve i n j u r y .  No s p e c i f i c  information.  No s p e c i f i c  information.  M t * l t M  E M E R G E N C E AN O F I R S * AID P R O C E D U R E S  Srt»LLOWiNG  No s p e c i f i c  SKIN  Flush  .INHALATION  EVES  area  information. with  copious  Remove t o f r e s h a i r . Flush  area  with  Consult  amounts o f w a t e r  Consult  copious  a physician. f o r 15 m i n u t e s .  Consult  a physician.  a physician.  '-\  amounts o f w a t e r f o r 15 m i n u t e s . (  Consult  a physician.  VII. SPILL OR LEAK PROCEDURES S T E P S T O 86 T A K E N * M A T E R I A L 1? RELEASED OS SPiLLEO  WASTE  DISPOSAL METnOO  F l u s h area w i t h l a r ^ e prevent contamination  quantities of water. S p i l l s s h o u l d be c o n t a i n e d t o o f s u r f a c e and g r o u n d w a t e r s u p p l i e s .  n i s p o s a l s h o u l d be i n a c c o r d a n c e w i t h r e g a r d i n g z i n c and p h o s p h a t e .  federal,  s t a t e and l o c a l  regulations  VIII. SPECIAL PROTECTION INFORMATION RESPIRATORY PROTECTION  PROTECTIVE GLOVES  VENTILATION  None. E r f  Rubber None .  _ HANOI i N G *'<0  gloves.  PROTECTION  fOO'PUENT  Chemical workers  goggles.  Eyewash  safety  fountain,  shower.  tX. SPECIAL PRECAUTIONS STORING  S t o r e i n polye'.'. l e n e , F R P , epr.xv, r u b b e r - l i n e d m i l d stainless steel containers. OTMER  None.  steel, or  134  Appendix C Phosphorus Content Date  Phosphorus mg/L Loop 1  Loop 6  control  0.45 mg P/L  26/08/92  0.004  0.207  0.587  10/09/92  0.008  0.328  1.048  1 6/09/92  n/d  0.386  1.178  25/09/92  0.003  0.368  1.093  09/10/92  n/d  0.482  0.851  23/10/92  0.005  0.134  0.862  30/10/92  0.017  0.221  0.946  12/11/92  0.017  0.471  0.909  08/12/92  0.004  0.290  1.093  21/12/92  0.002  0.394  1.114  11/01/93  0.016  0.286  1.164  02/02/93  n/d  0.245  1.355  1 9/02/93  n/d  0.388  1.593  05/03/93  0.020  0.496  1.377  22/03/93  0.012  0.518  1.018  05/04/93  0.009  0.560  0.952  1 9/04/93  0.004  0.256  1.190  07/05/93  0.015  0.324  1.132  20/05/93  0.014  0.198  1.228  01/06/93  0.003  0.489  0.839  1 6/06/93  0.004  0.543  0.858  29/06/93  0.003  0.504  0.902  09/07/93  0.014  0.516  0.164*  23/07/93  n/d  0.402  0.113  08/08/93  n/d  0.303  0.120  Average  0.009  0.372  0.947  Applied  Dosage:  Loop 7  1.35 mg P/L  * Z 0 P applied dose-loop 7 decreased to 0 . 4 5 m g P/L  135  Appendix D Copper Levels - Plumbing Coils Date  Days From Start  Standing Time (Hours)  Loop Number:  Copper Concentration mg/L  1  2  3  4  5  6  7  Pre - t r e a t m e n t S a m p l e s 0407/92  0  8  0.67  0.71  1.2  1.14  0.48  0.76  1.02  14/07/92  0  8  0.86  1.22  0.7  1.24  1.05  1.19  1.07  0.76  0.97  0.95  1.19  0.77  0.97  1.04  Average  Treated Samples 26/08/92  12  8  1.03  1.86  0.39  1.11  0.24  0.48  0.46  01/09/92  18  8  0.91  1.15  1.01  0.49  0.69  0.42  0.28  16/09/92  33  8  0.97  1.6  0.27  0.16  0.66  1.6  1.15  30/09/92  47  8  0.86  5.31  0.8  1.25  1.31  0.35  0.31  21/10/92  68  8  1.14  3.73  2.64  0.65  4.89  2.48  0.32  18/11/92  96  8  1.11  0.76  1.54  1.97  7.47  0.44  0.11  25/11/92  103  8  0.95  1.02  0.57  0.36  0.27  0.28  0.14  09/12/92  117  8  0.97  0.81  0.64  1.19  0.96  0.34  0.4  06/01/93  145  8  0.84  4.71  0.72  1.31  2.63  0.38  0.29  28/01/93  167  8  1.83  11.36  1.89  2.1  4.93  0.43  0.3  19/02/93  189  8  1.44  6.34  2.83  1.56  7.13  0.3  0.83  08/03/93  206  8  1.45  0.85  0.99  0.49  0.63  0.47  0.83  19/03/93  217  16  1.58  3.86  2.43  0.22  0.74  0.36  0.80  02/04/93  231  16  3.38  6.12  1.59  0.19  2.42  0.33  0.84  08/04/93  237  8  1.06  5.87  1.36  0.79  0.16  0.23  0.17  1 8/04/93  247  16  1.22  8.57  3.61  0.82  1.64  4.14  1.01  07/05/93  266  16  0.99  6.03  1.97  0.83  1.70  0.28  1.84  14/05/93  273  8  0.83  4.2  1.11  0.21  0.8  0.31  0.64  136  Appendix D Copper Levels - Plumbing Coils Date  Days From Start  Standing Time (Hours)  Loop Number:  Copper Concentration mg/L  1  2  3  4  5  6  7  Treated Samples 11/06/93  301  16  1.21  3.95  5.94  1.31  2.73  0.70  1.95  18/06/93  308  8  1.29  7.64  3.15  3.03  1.96  3.71  0.62  30/06/93  320  16  0.96  3.15  1.36  2.01  1.04  0.37  0.93  14/07/93  334  8  1.22  2.95  2.43  1.3  1.43  0.34  0.5  21/07/93  341  16  1.52  5.53  2.15  1.58  2.33  0.41  2.38  06/08/93  357  8  1.3  3.89  4.8  0.29  1.18  0.29  0.14  10/08/93  361  16  1.17  2.59  2.62  2.01  4.36  0.67  2.27  Average concentration  1.25  4.15  1.95  1.09  2.17  0.80  0.78  Minimum value  0.83  0.76  0.27  0.16  0.16  0.23  0.11  M a x i m u m value  3.38  11.36  5.94  3.03  7.47  4.14  2.38  Standard Deviation  0.51  2.68  1.38  0.75  2.05  1.06  0.67  9 5 % Confidence Interval  0.20  1.05  0.54  0.29  0.80  0.42  0.26  137  Appendix E Copper Levels - Solder Coils Date  Days From Start  Copper concentration mg/L  Standing Time (Hours)  Loop Number:  1  2  3  4  5  6  7  Pre - treatment Samples 01/07/92  0  8  0.11  0.09  0.13  0.13  0.15  0.08  0.09  14/07/92  0  8  0.07  0.08  0.06  0.12  0.08  0.07  0.07  0.09  0.09  0.10  0.13  0.12  0.08  0.08  Average  Treated Samples 26/08/92  12  8  0.14  0.11  0.08  0.09  0.12  0.10  0.11  01/09/92  18  8  0.09  0.01  0.09  0.12  0.10  0.06  0.12  01/10/92  33  8  0.20  0.02  0.04  0.02  0.05  0.01  0.06  01/11/92  47  8  0.10  0.05  0.13  0.04  0.25  n/d  0.13  01/12/92  68  8  0.13  0.05  0.14  0.02  0.04  0.02  0.02  01/13/92  96  8  0.09  n/d  0.02  n/d  0.08  0.03  0.02  25/11/92  103  8  0.07  0.02  0.08  0.01  0.05  0.13  0.01  09/12/92  117  8  0.10  0.03  0.03  n/d  n/d  0.01  n/d  06/01/93  145  8  0.09  0.03  0.05  n/d  n/d  0.01  0.01  28/01/93  167  8  0.10  0.09  0.03  0.01  0.01  0.02  0.02  19/02/93  189  8  0.12  0.04  0.10  n/d  n/d  0.02  0.01  08/03/93  206  8  0.17  0.07  0.07  0.03  0.06  0.08  0.08  19/03/93  217  16  0.19  0.02  0.04  n/d  0.01  0.01  n/d  02/04/93  231  16  0.12  0.03  0.05  n/d  0.02  0.03  n/d  08/04/93  237  8  0.20  0.06  0.40  0.01  n/d  n/d  n/d  18/04/93  247  16  0.26  0.22  0.32  0.12  0.08  0.16  0.08  07/05/93  266  16  0.14  0.03  0.01  n/d  0.02  0.01  n/d  14/05/93  273  8  0.13  0.03  0.04  n/d  n/d  0.01  0.01  11/06/93  301  16  0.16  0.04  0.02  n/d  n/d  0.01  n/d  138  Appendix E Copper Levels - Solder Coils Date  Days From Start  Copper concentration mg/L  Standing Time (Hours)  1  Loop Number:  2  3  4  5  6  7  Treated Samples 1 8/06/93  308  8  0.19  0.05  0.03  n/d  n/d  n/d  n/d  30/06/93  320  16  0.19  0.06  0.03  0.01  0.02  0.02  0.01  14/07/93  334  8  0.17  0.03  0.02  n/d  n/d  n/d  n/d  21/07/93  341  16  0.20  0.08  0.03  n/d  n/d  0.02  0.02  06/08/93  357  8  0.19  0.05  0.02  n/d  0.03  0.03  0.03  10/08/93  361  16  0.23  0.15  0.14  0.03  0.04  0.05  0.04  Average concentration  0.15  0.05  0.08  0.02  0.04  0.03  0.03  M i n i m u m value  0.07  0.00  0.01  0.00  0.00  0.00  0.00  M a x i m u m value  0.26  0.22  0.40  0.12  0.25  0.16  0.13  Standard Deviation  0.05  0.05  0.09  0.04  0.06  0.04  0.04  9 5 % Confidence Interval  0.02  0.02  0.04  0.01  0.02  0.02  0.02  139  Appendix F Copper Levels - Faucets Date  Days From Start  Standing Time (Hours)  Copper Concentration mg/L  1  Loop Number:  2  3  4  5  6  7  Pre - Treatment Samples 16/07/92  0  8  0.22  0.22  0.16  0.2  0.18  0.17  0.18  29/07/92  0  8  0.24  0.19  0.21  0.24  0.19  0.19  0.16  0.23  0.21  0.19  0.22  0.19  0.18  0.17  Average  Treated Samples 26/08/92  12  8  1.21  0.05  0.07  0.02  0.04  0.04  0.05  01/09/92  18  8  0.17  0.05  0.04  0.02  0.01  0.05  0.08  16/09/92  33  8  0.21  0.06  0.03  n/d  0.08  0.14  0.01  30/09/92  47  8  0.49  0.05  0.05  0.01  0.09  0.13  0.01  21/10/92  68  8  0.21  0.07  0.09  0.01  0.11  0.18  0.06  18/11/92  96  8  0.23  0.04  0.05  n/d  0.06  0.21  0.07  25/11/92  103  8  0.15  0.05  0.04  0.01  0.02  0.16  0.08  09/12/92  117  8  0.16  0.05  0.04  0.01  0.05  0.19  0.09  06/01/93  145  8  0.19  0.04  0.03  n/d  0.03  0.15  0.10  28/01/93  167  8  0.35  0.05  0.05  n/d  0.04  0.15  0.14  19/02/93  189  8  0.22  0.03  0.03  n/d  0.02  0.09  0.08  08/03/93  206  8  0.27  0.02  0.05  n/d  0.02  0.10  0.11  19/03/93  217  16  0.31  0.03  0.06  n/d  0.02  0.15  0.08  02/04/93  231  16  0.19  0.06  0.04  n/d  0.04  0.15  0.08  08/04/93  237  8  0.21  0.07  0.03  n/d  0.02  0.10  0.03  1 8/04/93  247  16  0.18  0.06  0.08  n/d  0.05  0.14  0.06  07/05/93  266  16  0.25  0.04  0.04  n/d  0.04  0.09  0.06  14/05/93  273  8  0.47  0.03  0.03  n/d  0.01  0.07  0.01  11/06/93  301  16  0.27  0.11  0.10  n/d  0.02  0.09  0.04  140  Appendix F Copper Levels - Faucets Date  Days From Start  Standing Time (Hours)  Loop Number:  Copper Concentration mg/L  2  1  3  4  5  6  7  Treated Samples 18/06/93  308  8  0.27  0.07  0.01  n/d  n/d  0.01  n/d  30/06/93  320  16  0.26  0.1  0.07  n/d  0.05  0.1  0.04  14/07/93  334  8  0.28  0.03  n/d  n/d  n/d  0.03  0.06  21/07/93  341  16  0.34  0.10  0.07  0.02  0.06  0.09  0.13  06/08/93  357  8  0.32  0.10  0.07  0.02  0.06  0.08  0.14  10/08/93  361  16  0.33  0.08  0.08  0.02  0.09  0.10  0.13  Average concentration  0.30  0.06  0.05  0.01  0.04  0.11  0.07  M i n i m u m value  0.15  0.02  0.00  0.00  0.00  0.01  0.00  M a x i m u m value  1.21  0.11  0.10  0.02  0.11  0.21  0.14  Standard Deviation  0.21  0.02  0.02  0.01  0.03  0.05  0.04  9 5 % C o n f i d e n c e Interval  0.08  0.01  0.01  0.00  0.01  0.02  0.02  Total Copper Concentrations - Plumbing Coils + Faucets + Solder Coils mg/L Loop Number  control  2  3  4  5  6  7  S u m of Copper Concentrations  42.54  106.66  52.07  27.88  56.31  23.74  22.03  A v e r a g e Concentration  0.57  1.42  0.69  0.37  0.75  0.32  0.29  M i n i m u m value  0.07  0.00  0.00  0.00  0.00  0.00  0.00  M a x i m u m value  3.38  11.36  5.94  3.03  7.47  4.14  2.38  0.58  2.47  1.19  0.67  1.55  0.70  0.52  0.13  0.56  0.27  0.15  0.35  0.16  0.12  Standard  Deviation  9 5 % Confidence Interval  141  Appendix G Lead Levels - Solder Coils Date  Days  Standing  From  Time  Start  (Hours)  Lead Concentrations m g / L  1  Loop Number:  2  3  4  5  6  7  Pre - treatment Samples 01/07/92  0  8  1.92  3.14  4.05  3.48  3.22  1.83  2.39  14/07/92  0  8  1.80  3.17  5.98  6.67  2.65  3.04  2.59  1.86  3.16  5.02  5.08  2.94  2.44  2.49  Average  Treated Samples 26/08/92  12  8  0.84  7.15  7.05  7.32  4.19  3.86  3.44  01/09/92  19  8  0.46  2.02  7.22  11.86  1.92  1.60  2.15  16/09/92  34  8  0.79  1.62  5.11  3.94  1.70  0.35  0.92  30/09/92  48  8  0.8  1.10  6.59  4.32  2.99  0.32  0.82  21/10/92  69  8  1.02  2.66  5.03  4.57  4.41  0.87  n/d  18/11/92  97  8  0.51  1.04  2.06  2.69  6.07  0.51  0.43  25/11/92  104  8  0.47  1.58  4.19  4.27  5.53  0.69  0.29  09/12/92  118  8  0.62  3.40  4.19  10.84  10.61  0.74  0.16  06/01/93  146  8  0.33  2.63  6.07  8.85  6.87  0.52  0.15  28/01/93  168  8  0.69  3.49  4.58  6.38  2.23  0.90  0.20  19/02/93  189  8  0.43  1.51  2.49  6.73  2.66  0.54  0.11  08/03/93  206  8  0.48  2.99  3.41  9.08  5.76  1.00  0.31  19/03/93  217  16  1.78  1.22  3.59  2.32  3.20  0.07  n/d  02/04/93  231  16  0.66  1.56  2.65  3.24  4.53  0.60  0.21  08/04/93  237  8  1.03  1.23  3.69  4.46  4.64  0.15  0.01  1 8/04/93  247  16  1.68  4.22  5.15  11.58  8.11  2.05  0.38  07/05/93  266  16  1.43  1.37  1.32  2.67  3.65  0.39  0.14  14/05/93  273  8  0.64  0.81  1.80  3.86  0.86  0.21  0.11  04/06/93  294  16  0.45  0.69  1.24  1.71  2.77  0.26  n/d  18/06/93  308  8  0.85  1.37  2.13  4.14  1.15  0.07  0.08  142  Appendix G Lead Levels - Solder Coils Date  Days From Start  Standing Time (Hours)  Loop Number:  Lead Concentrations mg/L  1  2  3  4  5  6  7  Treated Samples 30/06/93  320  16  0.37  0.73  0.53  0.97  5.61  0.26  0.06  14/07/93  334  8  0.49  0.70  1.15  1.26  0.76  0.45  0.03  21/07/93  341  16  0.51  1.76  1.08  1.44  0.99  0.30  0.39  06/08/93  357  8  0.26  0.52  1.01  0.82  0.74  0.19  0.21  10/08/93  362  16  0.57  2.16  1.05  1.01  0.83  0.13  0.20  Average concentration  0.73  1.98  3.38  4.81  3.71  0.68  0.43  M i n i m u m value  0.26  0.52  0.53  0.82  0.74  0.07  0.00  M a x i m u m value  1.78  7.15  7.22  11.86  10.61  3.86  3.44  Standard Deviation  0.40  1.45  2.07  3.40  2.55  0.81  0.77  9 5 % C o n f i d e n c e Interval  0.16  0.57  0.81  1.33  1.00  0.32  0.30  143  Appendix H Lead Levels - Plumbing Coils Date  Days  Lead Concentration m g / L  Standing  From  Time  Start  (Hours)  1  Loop Number:  2  3  4  5  6  7  Pre - treatment Samples 2/7/92  0  8  n/d  n/d  n/d  n/d  n/d  n/d  n/d  14/07/92  0  8  n/d  n/d  n/d  n/d  n/d  n/d  n/d  Treated Samples 26/08/92  12  8  n/d  n/d  n/d  n/d  n/d  n/d  n/d  01/09/92  18  8  n/d  n/d  n/d  n/d  n/d  n/d  n/d  16/09/92  33  8  n/d  n/d  n/d  n/d  n/d  0.005  n/d  30/09/92  47  8  n/d  n/d  n/d  n/d  n/d  n/d  n/d  21/10/92  68  8  n/d  n/d  0.005  n/d  0.024  0.005  n/d  18/11/92  96  8  n/d  n/d  n/d  n/d  n/d  n/d  n/d  25/11/92  103  8  0.001  0.001  n/d  0.002  0.002  n/d  n/d  09/12/92  117  8  0.002  n/d  n/d  0.002  0.002  n/d  0.002  06/01 /93  145  8  n/d  0.005  0.001  0.007  0.149  n/d  0.004  28/01/93  167  8  0.027  0.019  0.005  0.011  0.039  0.005  0.006  19/02/93  189  8  0.004  0.025  0.023  0.012  0.060  n/d  0.01  08/03/93  206  8  0.003  0.006  0.008  0.007  0.008  n/d  0.007  19/03/93  217  16  0.003  0.018  0.015  0.002  0.005  0.001  0.007  02/04/93  231  16  0.020  0.018  0.008  0.001  0.012  n/d  0.016  08/04/93  237  8  0.004  0.024  0.009  0.008  0.003  n/d  0.007  18/04/93  247  16  0.006  0.022  0.014  0.006  0.01  0.023  0.008  07/05/93  266  16  0.004  0.029  0.008  0.006  0.012  n/d  0.012  14/05/93  273  8  0.002  0.016  0.008  0.002  0.009  n/d  0.005  11/06/93  301  16  0.005  0.045  0.055  0.015  0.046  0.005  0.019  18/06/93  308  8  0.005  0.023  0.012  0.026  0.018  0.025  0.003  1 4 4  Appendix H Lead Levels - Plumbing Coils Date  Days  Standing  From  Time  Start  (Hours)  Loop Number:  Lead Concentration m g / L  2  1  3  4  5  6  7  Treated Samples 30/06/93  320  16  0.001  0.001  n/d  0.009  n/d  n/d  0.002  14/07/93  334  8  0.002  n/d  n/d  n/d  n/d  0.003  0.002  21/07/93  341  16  0.004  0.006  n/d  0.002  n/d  n/d  0.002  06/08/93  357  8  0.003  0.016  0.023  0.004  0.007  n/d  n/d  10/08/93  361  16  0.003  0.007  0.008  0.016  0.018  0.001  0.02  Average concentration  0.004  0.011  0.008  0.006  0.017  0.003  0.005  Minimum value  0.000  0.000  0.000  0.000  0.000  0.000  0.000  Maximum value  0.027  0.045  0.055  0.026  0.149  0.025  0.020  Standard Deviation  0.006  0.012  0.012  0.006  0.032  0.007  0.006  95% Confidence Interval  0.002  0.005  0.005  0.003  0.012  0.003  0.002  n/d means not detectable by the techniques used for determination  145  Appendix i Lead Levels - Faucets Date  Days From Start  Lead Concentration mg/L  Standing Time (Hours)  1  Loop Number:  2  3  4  5  6  7  Pre - Treatment Samples 16/07/92  0  8  0.008  0.008  0.009  0.009  0.009  0.011  0.009  29/07/92  0  8  n/d  0.008  0.014  0.012  0.012  0.016  0.013  0.008  0.008  0.012  0.011  0.011  0.014  0.011  Average  Treated Samples 26/08/92  12  8  0.144  n/d  n/d  n/d  n/d  n/d  n/d  01/09/92  18  8  n/d  n/d  n/d  n/d  n/d  n/d  n/d  16/09/92  33  8  0.005  0.007  n/d  n/d  n/d  n/d  n/d  30/09/92  47  8  0.049  n/d  n/d  n/d  n/d  n/d  n/d  21/10/92  68  8  0.006  n/d  n/d  n/d  n/d  n/d  n/d  18/11/92  96  8  0.003  n/d  n/d  n/d  n/d  n/d  n/d  25/11/92  103  8  0.008  n/d  n/d  n/d  n/d  n/d  n/d  09/12/92  117  8  n/d  n/d  n/d  n/d  n/d  n/d  0.002  06/01/93  145  8  0.014  n/d  n/d  n/d  n/d  n/d  0.004  28/01/93  167  8  0.054  0.004  0.003  n/d  n/d  0.004  0.011  19/02/93  189  8  0.014  n/d  n/d  n/d  0.003  0.003  n/d  08/03/93  206  8  0.012  0.003  0.003  0.003  0.002  0.003  0.004  19/03/93  217  16  0.017  0.004  0.005  0.002  0.002  0.003  n/d  02/04/93  231  16  0.128  0.004  0.003  0.002  0.002  0.003  0.002  08/04/93  237  8  0.015  0.008  0.004  0.002  n/d  n/d  n/d  1 8/04/93  247  16  0.014  n/d  n/d  n/d  n/d  n/d  n/d  07/05/93  266  16  0.060  0.002  0.002  0.001  n/d  0.002  0.004  14/05/93  273  8  0.015  n/d  n/d  n/d  n/d  n/d  n/d  11/06/93  301  16  0.014  0.007  0.011  0.004  0.004  0.008  0.008  146  Appendix I Lead Levels - Faucets  Date  Days From Start  Standing  Lead Concentration m g / L  Time (Hours)  Loop Number:  1  2  3  4  5  6  7  Treated Samples 1 8/06/93  308  8  0.017  0.004  0.002  n/d  n/d  n/d  n/d  30/06/93  320  16  0.010  n/d  n/d  n/d  n/d  n/d  n/d  14/07/93  334  8  0.003  n/d  n/d  n/d  n/d  n/d  n/d  21/07/93  341  16  0.003  0.004  n/d  n/d  n/d  n/d  0.002  06/08/93  357  8  0.015  0.006  0.004  0.004  0.003  0.003  0.007  10/08/93  361  16  0.017  0.005  0.004  0.002  0.006  0.002  0.004  A v e r a g e concentration  0.024  0.002  0.002  0.001  0.001  0.001  0.002  M i n i m u m value  0.000  0.000  0.000  0.000  0.000  0.000  0.000  M a x i m u m value  0.128  0.008  0.011  0.004  0.006  0.008  0.011  Standard Deviation  0.033  0.003  0.003  0.001  0.002  0.002  0.003  9 5 % Confidence Interval  0.013  0.001  0.001  0.001  0.001  0.001  0.001  n/d means not detectable by the techniques used for determination  T o t a l Lead C o n c e n t r a t i o n s - Plumbing C o i l s + F a u c e t s + S o l d e r C o i l s mg/L  Loop Number  control  2  3  4  5  6  7  Sum of Lead Concentrations  18.87  49.87  84.62  120.49  93.23  17.13  10.98  Average Concentration  0.25  0.66  1.13  1.61  1.24  0.23  0.15  Minimum value  0.00  0.00  0.00  0.00  0.00  0.00  0.00  Maximum value  1.78  7.15  7.22  11.86  10.61  3.86  3.44  Standard Deviation  0.41  1.25  1.99  2.99  2.28  0.56  0.48  95% Confidence Interval  0.09  0.28  0.45  0.68  0.52  0.13  0.11  147  Appendix J Zinc Levels - Plumbing Coils  Date  Days  Standing  From  Time  Start  (Hours)  Loop Number:  Zinc Concentration m g / L  1  2  3  4  5  6  7  Pre - treatment 5/7/92  0  8  0.04  0.03  0.03  0.03  0.04  0.06  0.08  14/07/92  0  8  n/d  n/d  n/d  n/d  n/d  0.02  0.01  0.04  0.03  0.03  0.03  0.04  0.04  0.05  Average  Treated Samples 26/08/92  12  8  n/d  n/d  n/d  n/d  n/d  0.48  1.03  01/09/92  18  8  n/d  n/d  n/d  n/d  n/d  0.47  1.04  16/09/92  33  8  n/d  n/d  n/d  n/d  n/d  0.86  1.68  30/09/92  47  8  n/d  0.02  n/d  n/d  n/d  0.45  0.87  21/10/92  68  8  n/d  n/d  n/d  n/d  0.04  0.74  1.10  18/11/92  96  8  n/d  n/d  n/d  0.01  0.13  0.47  0.63  25/11/92  103  8  n/d  n/d  n/d  n/d  n/d  0.47  1.13  09/12/92  117  8  n/d  n/d  n/d  0.01  0.01  0.46  1.86  06/01/93  145  8  n/d  n/d  n/d  n/d  0.03  0.46  1.41  28/01/93  167  8  n/d  0.01  n/d  n/d  0.03  0.42  1.16  19/02/93  189  8  n/d  n/d  n/d  0.02  0.06  0.31  2.66  08/03/93  206  8  n/d  n/d  n/d  n/d  n/d  0.46  4.62  19/03/93  217  16  n/d  n/d  n/d  n/d  n/d  0.51  2.29  02/04/93  231  16  n/d  n/d  n/d  n/d  n/d  0.54  2.80  08/04/93  237  8  n/d  n/d  n/d  n/d  n/d  0.45  1.02  18/04/93  247  16  n/d  n/d  n/d  n/d  0.01  1.46  3.13  07/05/93  266  16  n/d  n/d  n/d  n/d  n/d  0.50  6.26  14/05/93  273  8  n/d  n/d  n/d  n/d  0.01  0.52  3.83  11/06/93  301  16  n/d  n/d  n/d  n/d  n/d  0.40  3.79  '  148  Appendix J Zinc Levels - Plumbing Coils  Date  Days  Standing  From  Time  Start  (Hours)  Zinc Concentration m g / L  1  Loop Number:  2  3  4  5  6  7  Treated Samples 18/06/93  308  8  n/d  n/d  n/d  n/d  n/d  0.97  2.39  30/06/93  320  16  n/d  n/d  n/d  n/d  n/d  0.46  2.42  14/07/93  334  8  n/d  n/d  n/d  n/d  0.01  0.52  0.81  21/07/93  341  16  n/d  n/d  n/d  0.01  0.02  0.57  1.85  06/08/93  357  8  n/d  n/d  n/d  n/d  n/d  0.39  0.44  10/08/93  361  16  n/d  n/d  n/d  0.01  0.03  0.13  1.86  A v e r a g e concentration  0.00  0.00  0.00  0.00  0.02  0.54  2.08  M i n i m u m value  0.00  0.00  0.00  0.00  0.00  0.13  0.44  M a x i m u m value  0.00  0.02  0.00  0.02  0.13  1.46  6.26  Standard Deviation  0.00  0.00  0.00  0.01  0.03  0.25  1.40  9 5 % Confidence Interval  -  0.00  -  0.00  0.01  0.10  0.55  n/d means not detectable by the techniques used for determination  149  Appendix K Zinc Levels - Faucets Date  Days  Standing  From  Time  Start  (Hours)  Loop Number:  Zinc Concentration m g / L  1  2  3  4  5  6  7  Pre - treatment Samples 15/07/92  0  8  0.09  0.14  0.06  0.12  0.12  0.14  0.10  29/07/92  0  8  0.13  0.20  0.12  0.20  0.18  0.19  0.13  0.11  0.17  0.09  0.16  0.15  0.17  0.12  Average  Treated Samples 26/08/92  12  8  0.21  0.05  0.04  n/d  0.02  0.65  1.26  01/09/92  18  8  0.06  0.04  0.02  n/d  n/d  0.53  1.28  16/09/92  33  8  0.06  0.03  0.01  n/d  0.05  0.65  1.48  30/09/92  47  8  0.09  0.02  0.03  n/d  0.06  0.51  1.21  21/10/92  68  8  0.09  0.02  0.03  n/d  0.10  0.62  1.07  18/11/92  96  8  0.08  0.01  0.01  n/d  0.05  0.67  1.09  25/11/92  103  8  0.04  n/d  n/d  n/d  0.03  0.53  1.44  09/12/92  117  8  0.05  0.01  0.01  n/d  0.06  0.54  1.26  06/01/93  145  8  0.08  n/d  n/d  n/d  0.02  0.54  1.17  28/01/93  167  8  0.11  0.02  0.01  n/d  0.02  0.40  0.96  19/02/93  189  8  0.07  0.01  0.01  . n/d  0.01  0.46  1.02  08/03/93  206  8  0.03  n/d  n/d  n/d  n/d  0.57  1.37  19/03/93  217  16  0.12  n/d  n/d  n/d  0.03  0.76  1.70  02/04/93  231  16  0.08  n/d  n/d  n/d  0.03  0.74  1.78  08/04/93  237  8  0.04  0  n/d  n/d  0.03  0.61  1.25  1 8/04/93  247  16  0.05  0.01  n/d  n/d  0.05  0.77  1.79  07/05/93  266  16  0.06  n/d  n/d  n/d  0.03  0.64  1.79  14/05/93  273  8  0.05  n/d  n/d  n/d  n/d  0.62  1.49  11/06/93  301  16  0.08  0.02  0.03  n/d  n/d  0.58  1.73  150  Appendix K Zinc Levels - Faucets Date  Days  Standing  From  Time  Start  (Hours)  Loop Number:  Zinc Concentration m g / L  1  2  3  4  5  6  7  Treated Samples 18/06/93  308  8  0.04  n/d  n/d  n/d  n/d  0.5  1.12  30/06/93  320  16  0.07  0.03  n/d  n/d  0.01  0.64  2.02  14/07/93  334  8  0.25  0.02  n/d  n/d  n/d  0.58  0.46  21/07/93  341  16  0.10  0.03  n/d  n/d  0.02  0.66  0.95  06/08/93  357  8  0.07  0.02  0.02  n/d  0.03  0.45  0.74  10/08/93  361  16  0.10  0.03  0.01  n/d  0.06  0.25  0.77  0.08  0.02  0.01  0.00  0.03  0.58  1.29  Minimum value  0.03  0.00  0.00  0.00  0.00  0.25  0.46  M a x i m u m value  0.25  0.05  0.04  0.00  0.10  0.77  2.02  Standard Deviation  0.05  0.01  0.01  0.00  0.03  0.12  0.38  0.02  0.01  0.00  -  0.01  0.05  0.15  Average  95%  concentration  Confidence Interval  n/d means not detectable by the techniques used for determination  151  Appendix L Zinc Levels - Solder Coils Date  Days  Standing  From  Time  Start  (Hours)  Zinc Concentration m g / L  1  Loop Number:  2  3  4  5  6  7  Pre - treatment Samples 01/07/92  0  8  0.01  n/d  n/d  n/d  n/d  n/d  0.01  14/07/92  0  8  n/d  n/d-  n/d  n/d  n/d  n/d  n/d  Treated Samples 26/08/92  12  8  0.05  0.01  0.02  0.01  0.02  0.53  1.35  01/09/92  18  8  0.04  0.04  0.04  0.04  0.05  0.53  1.46  16/09/92  33  8  0.02  0.02  0.01  0.02  0.03  0.54  1.49  30/09/92  47  8  0.03  n/d  n/d  n/d  0.01  0.46  1.20  21/10/92  68  8  0.03  0.01  0.02  0.01  0.01  0.49  0.99  18/11/92  96  8  0.01  0.01  n/d  0.01  0.02  0.48  1.03  25/11/92  103  8  n/d  n/d  n/d  n/d  0.01  0.40  1.24  09/12/92  117  8  n/d  n/d  0.01  n/d  n/d  0.36  1.14  06/01/93  145  8  n/d  n/d  n/d  n/d  n/d  0.38  1.11  28/01/93  167  8  0.14  0.05  0.04  0.02  0.05  0.43  0.99  19/02/93  189  8  0.03  0.02  0.03  0.01  0.01  0.40  1.14  08/03/93  206  8  n/d  n/d  0.02  0.01  0.04  0.63  3.67  19/03/93  217  16  n/d  0.02  0.01  0.0.1  n/d  0.51  1.05  02/04/93  231  16  0.01  0.01  0.02  n/d  n/d  0.56  1.20  08/04/93  237  8  0.01  0.01  0.02  n/d  n/d  0.51  1.12  18/04/93  247  16  n/d  n/d  n/d  0.02  0.03  1.00  3.60  07/05/93  266  16  n/d  n/d  n/d  n/d  n/d  0.47  1.45  14/05/93  273  8  n/d  n/d  0.01  0.01  n/d  0.50  2.06  11/06/93  301  16  0.02  0.01  0.02  0.01  0.03  0.42  0.85  18/06/93  308  8  0.01  n/d  n/d  n/d  n/d  0.46  1.43  152  Appendix L Zinc Levels - Solder Coils Date  Days  Zinc Concentration m g / L  Standing  From  Time  Start  (Hours)  Loop Number:  1  2  3  4  5  6  7  Treated Samples 30/06/93  320  16  0.02  0.03  0.03  0.02  0.01  0.44  1.13  14/07/93  334  8  0.01  n/d  n/d  n/d  n/d  0.45  0.45  21/07/93  341  16  n/d  n/d  n/d  n/d  n/d  0.47  0.41  06/08/93  357  8  0.02  0.02  n/d  n/d  0.01  0.38  0.46  10/08/93  361  16  n/d  n/d  0.01  0.01  0.01  0.16  0.43  0.02  0.01  0.01  0.01  0.01  0.48  1.30  M i n i m u m value  n/d  n/d  n/d  n/d  n/d  0.16  0.41  M a x i m u m value  0.14  0.05  0.04  0.04  0.05  1.00  3.67  Standard Deviation  0.03  0.01  0.01  0.01  0.02  0.14  0.80  0.01  0.01  0.01  0.00  0.01  0.05  0.31  Average  95%  concentration  Confidence Interval  n/d means not detectable by the techniques used for determination  153  Appendix M pH Measurements - Flowing Water Date  Days From Start  Loop Number:  pH Measurements  1  2  3  4  5  6  7  Pre - treatment 01/07/92  6.39  6.43  6.45  6.49  6.51  6.50  6.51  14/07/92  6.62  6.65  6.65  6.68  6.75  6.72  6.72  29/07/92  6.32  6.30  6.35  6.34  6.35  6.35  6.35  Treated Flowing Water Target pH:  control  8.0  8.0  9.0  9.0  7.0  7.5  14/08/92  0  6.30  7.83  7.75  8.84  8.62  7.03  7.23  1 7/08/92  3  6.23  7.70  8.01  8.86  8.91  6.93  7.41  18/08/92  4  6.34  8.53  8.27  9.05  8.75  7.20  7.38  19/08/92  5  6.34  8.26  8.42  9.06  8.90  7.25  7.50  20/08/92  6  6.49  8.70  8.61  9.09  8.91  7.35  7.47  21/08/92  7  6.37  8.27  8.04  9.21  9.13  7.26  7.66  25/08/92  11  6.11  8.06  8.40  8.94  8.91  7.07  7.46  27/08/92  13  6.45  8.20  8.56  9.05  8.97  7.08  7.48  28/08/92  14  6.42  8.83  8.61  9.25  9.14  7.16  8.04  31/08/92  17  6.31  8.90  8.22  9.24  9.21  7.12  7.22  01/09/92  18  6.25  7.77  8.15  9.13  8.86  7.00  7.63  03/09/92  20  6.22  8.68  8.40  9.47  9.23  7.37  7.68  04/09/92  21  6.28  9.10  8.59  9.56  9.45  7.36  8.68  05/09/92  22  6.60  9.42  8.88  9.56  9.78  8.13  8.85  08/09/92  25  6.53  8.77  8.94  9.62  9.56  8.58  7.30  10/09/92  27  6.53  8.73  8.99  9.23  9.35  8.09  7.62  11/09/92  28  6.53  7.94  8.12  9.01  9.18  7.34  7.60  14/09/92  31  6.56  8.16  8.13  8.85  9.10  7.25  7.41  1 5/09/92  32  6.50  7.73  8.17  8.71  9.03  7.18  7.40  16/09/92  33  6.62  8.01  8.28  9.00  9.15  7.33  7.51  154  Appendix M pH Measurements - Flowing Water  Date  pH Measurements  Days From Start  Loop Number:  1  2  3  4  5  6  7  Treated Flowing Water 1 7/09/92  34  6.54  8.62  8.37  9.09  9.16  7.29  7.44  18/09/92  35  6.52  7.38  8.19  8.93  9.12  7.22  7.48  21/09/92  38  6.50  7.37  8.78  8.82  8.97  7.17  7.33  22/09/92  39  6.61  7.89  7.73  8.98  9.12  7.18  7.74  23/09/92  40  6.57  7.42  7.95  8.46  8.78  7.28  7.47  24/09/92  41  6.55  7.46  7.78  8.67  8.95  7.24  7.68  25/09/92  42  6.50  7.46  7.86  8.70  8.85  7.00  7.42  28/09/92  45  6.38  7.38  7.91  8.62  8.71  7.01  7.21  29/09/96  46  6.47  8.47  8.25  8.87  8.96  7.16  7.50  30/09/92  47  6.50  7.74  8.15  8.11  8.62  7.14  7.28  01/10/92  48  6.48  7.62  8.03  8.81  8.61  7.01  7.26  02/10/92  49  6.37  7.51  7.43  8.22  8.75  7.03  7.23  05/10/92  52  6.24  8.75  8.23  8.90  8.91  6.99  7.31  06/10/92  53  6.52  8.66  8.36  9.24  9.17  7.20  8.14  07/10/92  54  6.53  7.93  8.33  9.32  9.07  7.21  8.22  08/10/92  55  6.45  8.36  7.64  8.94  8.76  7.02  7.34  09/10/92  56  6.38  9.10  7.74  9.03  8.82  7.02  7.43  13/10/92  60  6.40  8.05  7.34  9.07  8.80  7.23  7.59  15/10/92  62  6.45  8.25  8.34  9.47  9.37  6.90  8.60  16/10/92  63  6.43  8.82  8.37  9.41  9.47  7.01  8.30  19/10/92  66  6.42  8.47  7.97  9.43  9.18  7.02  7.50  20/10/92  67  6.40  8.53  8.02  9.36  9.29  6.96  8.65  21/10/92  68  6.39  7.52  8.22  9.09  9.13  6.98  7.27  22/10/92  69  6.30  7.57  7.53  8.77  9.02  6.96  7.37  155  Appendix M pH Measurements - Flowing Water Date  Days From Start  Loop Number:  pH Measurements  1  2  3  4  5  6  7  Treated Flowing Water 23/10/92  70  6.35  7.32  7.62  8.97  8.96  6.98  7.41  26/10/92  73  6.25  7.61  7.68  8.86  8.90  7.01  7.36  27/10/92  74  6.24  8.26  7.86  9.11  9.07  7.00  7.41  28/10/92  75  6.23  8.51  7.37  8.94  9.04  6.97  7.47  29/10/92  76  6.24  8.71  7.84  9.07  9.00  6.99  7.48  30/10/92  77  6.15  7.56  7.57  8.57  8.84 .  6.92  7.45  03/11/92  81  6.02  7.50  8.15  8.91  8.72  6.77  7.15  04/11/92  82  6.25  8.60  8.31  9.14  9.00  7.03  7.52  05/11/92  83  6.31  8.01  7.88  9.19  9.06  7.00  7.42  06/11/92  84  6.25  8.36  9.00  9.07  8.85  6.94  7.50  09/11/92  87  6.09  8.73  7.57  8.85  9.00  6.84  7.57  10/11/92  88  6.12  8.74  8.19  8.89  8.98  6.88  7.70  12/11/92  90  6.26  7.96  8.15  9.22  9.32  7.02  7.84  13/11/92  91  6.28  7.88  8.01  9.00  9.09  7.04  7.63  16/11/92  94  6.16  7.88  8.01  8.94  8.93  6.98  7.95  17/11/92  95  6.26  7.77  7.90  9.00  9.01  6.96  7.40  18/11/92  96  6.20  8.17  7.91  9.05  8.88  7.00  7.60  19/11/92  97  6.28  8.21  8.24  9.18  9.07  7.02  7.44  20/11/92  98  6.23  8.16  8.70  9.17  9.19  6.96  7.63  23/11/92  101  6.16  8.23  7.42  9.21  9.19  6.88  7.86  24/11/92  102  6.24  8.23  8.63  9.16  9.21  6.96  7.72  25/11/92  103  6.26  7.53  8.06  8.96  9.08  7.00  7.25  26/11/92  104  6.25  7.95  7.56  9.23  9.24  7.00  7.84  27/11/92  105  6.30  7.63  8.68  9.25  9.24  7.00  7.67  156  Appendix M pH Measurements - Flowing Water  Date  Days  pH Measurements  From Start Loop Number:  1  2  3  4  5  6  7  Treated Flowing Water 30/11/92  108  6.25  9.08  8.02  9.31  9.22  6.98  7.44  02/12/92  110  6.29  8.62  8.30  9.20  9.31  6.91  7.20  03/12/92  111  6.30  8.89  8.35  9.17  9.38  7.04  7.63  04/12/92  112  6.32  8.49  8.00  9.07  9.08  7.34  7.59  07/12/92  115  6.33  7.61  8.20  9.11  9.14  6.96  7.58  08/12/92  116  6.02  7.63  7.84  8.83  9.00  6.86  7.36  09/12/92  117  6.32  7.68  7.77  8.85  8.90  7.12  7.20  10/12/92  118  6.29  7.97  8.11  9.11  9.14  6.96  7.50  11/12/92  119  6.32  8.19  7.38  9.10  9.15  7.09  7.33  14/12/92  122  6.29  8.40  7.88  9.24  9.20  6.91  7.66  17/12/92  125  6.27  8.60  7.33  9.00  9.04  7.18  7.45  18/12/92  126  6.34  7.20  8.31  8.95  8.95  6.98  7.41  22/12/92  130  6.29  8.02  8.12  9.00  9.00  6.92  7.40  23/12/92  131  6.32  8.31  7.63  9.02  9.03  7.17  7.41  24/12/92  132  6.31  7.90  8.27  9.00  8.90  7.15  7.35  28/12/92  136  6.30  7.46  7.38  8.90  9.03  6.90  7.30  30/12/92  138  6.13  6.91  7.78  8.77  8.77  6.96  7.20  31/12/92  139  6.25  7.62  8.27  8.88  8.86  7.22  7.40  04/01/93  143  6.21  8.26  7.50  8.75  8.90  6.88  7.39  05/01/93  144  6.32  7.32  7.86  8.80  8.83  6.97  7.47  06/01/93  145  6.38  7.53  7.80  8.78  8.71  7.10  7.37  07/01/93  146  5.86  8.12  7.82  8.92  8.93  7.01  7.51  12/01/93  151  6.20  8.46  8.04  9.08  9.27  7.16  7.54  13/01/93  152  6.20  7.46  8.00  8.97  9.03  6.95  7.73  157  Appendix M pH Measurements - Flowing Water  Date  Days  pH Measurements  From Start Loop Number:  1  2  3  4  5  6  7  Treated Flowing Water 14/01/93  153  6.24  8.30  8.09  8.97  9.00  7.00  7.36  15/01/93  154  6.21  7.39  8.06  8.76  8.80  6.97  7.26  19/01/93  158  6.16  8.35  8.57  9.02  8.97  7.00  7.41  20/01/93  159  6.20  7.97  8.68  9.00  8.97  7.00  7.58  21/01/93  160  6.19  7.73  7.80  8.96  9.00  7.02  7.51  22/01/93  161  6.16  7.32  7.70  8.86  8.82  6.97  7.30  25/01/92  164  6.12  7.12  7.61  8.55  8.58  6.86  7.31  27/01/93  166  6.12  7.51  7.57  8.54  8.74  6.89  7.38  28/01/93  167  6.11  7.06  7.13  7.54  7.77  6.83  7.18  29/01/93  168  6.11  7.65  7.76  9.08  9.02  6.82  7.46  01/02/93  171  6.03  7.62  8.50  9.20  8.99  6.86  7.38  03/02/93  173  6.18  8.43  7.97  9.06  8.91  6.87  7.44  04/02/93  174  6.14  8.35  8.40  8.98  8.95  6.93  7.46  08/02/93  178  6.19  8.54  8.65  9.29  9.05  7.00  7.51  09/02/93  179  6.11  7.97  7.90  9.06  8.95  6.88  7.24  10/02/93  180  6.21  9.38  8.92  9.86  9.45  8.56  8.96  11/02/93  181  6.17  7.31  8.11  9.11  9.19  6.95  7.44  16/02/93  186  6.11  7.26  7.68  8.96  8.95  6.88  7.23  18/02/93  188  6.22  8.16  8.23  9.18  9.16  6.97  7.54  1 9/02/93  189  6.07  7.82  7.83  9.04  9.05  6.88  7.28  22/02/93  192  6.15  8.22  8.21  9.00  8.73  7.04  7.70  24/02/93  194  6.08  8.01  7.52  8.71  8.68  6.96  7.01  25/02/93  195  5.96  7.50  6.95  8.89  8.90  6.61  7.50  01/03/93  199  5.92  8.20  8.00  9.28  8.91  6.73  7.20  158  Appendix M pH Measurements - Flowing Water  Date  Days  pH Measurements  From Start  1  Loop Number:  2  3  4  5  6  7  Treated Flowing Water 03/03/93  201  5.95  7.68  8.28  9.12  8.92  6.81  7.48  05/03/93  203  6.24  8.67  8.69  9.11  9.06  7.22  8.14  08/03/93  206  6.22  8.79  8.28  9.10  9.06  7.07  7.81  09/03/93  207  6.22  8.14  8.64  9.25  9.12  7.02  7.93  12/03/93  210  6.25  8.26  8.40  9.17  9.14  7.19  7.45  15/03/93  213  6.21  8.62  7.95  9.15  9.17  7.05  7.66  17/03/92  215  6.24  8.41  8.22  9.18  9.07  7.02  7.66  18/03/93  216  6.19  7.93  7.98  9.04  9.06  7.22  7.43  19/03/93  217  6.23  7.54  7.53  8.99  8.95  6.89  7.13  23/03/93  221  6.27  8.76  8.86  9.28  8.96  7.32  7.87  24/03/93  222  6.29  8.73  8.55  9.26  9.07  7.26  7.56  25/03/93  223  6.33  8.46  8.16  9.17  9.11  7.23  7.70  26/03/93  224  6.38  8.40  8.32  9.25  9.14  7.28  7.70  29/03/93  227  6.33  8.05  8.50  9.33  9.20  7.06  7.61  31/03/93  229  6.31  8.07  8.29  9.15  9.19  7.08  7.47  01/04/93  230  6.30  7.95  7.73  9.03  8.95  7.00  7.46  06/04/93  235  6.33  8.20  7.70  9.22  9.29  7.07  7.75  08/04/93  237  6.41  8.19  7.54  8.95  9.06  7.02  7.38  16/04/93  245  6.48  7.96  8.38  9.17  9.14  7.08  7.66  17/04/93  246  6.37  7.67  7.94  9.11  9.23  6.98  7.36  19/04/93  248  6.31  8.38  8.28  9.13  9.05  7.00  7.55  22/04/93  251  6.28  7.88  7.86  9.11  8.93  7.44  7.35  27/04/93  256  6.18  7.52  7.59  8.98  8.86  6.82  7.29  29/04/93  258  6.29  7.73  7.88  8.74  9.05  6.88  7.38  159  Appendix M pH Measurements - Flowing Water  Date  pH Measurements  Days From Start  Loop Number:  1  2  3  4  5  6  7  Treated Flowing Water 03/05/93  262  6.32  8.64  8.45  9.00-  9.09  7.33  7.47  05/05/93  264  6.32  8.46  8.45  8.89  8.91  8.32  9.07  06/05/93  265  6.31  8.26  8.36  9.02  8.89  7.16  7.54  07/05/93  266  6.36  7.30  7.40  8.82  8.91  7.03  7.34  11/05/93  270  6.28  7.84  7.64  8.99  8.91  7.34  7.51  12/05/93  271  6.37  7.84  7.93  8.93  9.00  7.07  7.49  14/05/93  273  6.41  8.22  8.05  9.04  9.03  7.08  7.68  18/05/93  277  6.26  7.88  8.11  9.04  9.01  6.93  7.50  20/05/93  279  6.26  7.84  7.78  8.86  9.00  6.92  7.62  21/05/93  280  6.33  8.40  8.33  9.20  9.06  7.00  7.53  27/05/93  286  6.31  7.86  8.11  9.11  9.09  6.91  7.51  28/05/93  287  6.30  8.20  7.95  9.20  9.21  7.00  7.42  04/06/93  294  6.34  8.15  8.13  9.20  9.16  7.04  7.54  08/06/93  298  6.43  9.30  8.16  9.30  9.33  7.03  8.37  09/06/93  299  6.36  9.24  8.84  8.87  9.10  7.04  7.22  10/06/93  300  6.36  7.23  8.08  9.06  9.10  7.12  7.65  11/06/93  301  6.42  7.01  7.40  8.70  9.10  7.05  7.34  1 5/06/93  305  6.29  8.33  7.95  8.88  9.11  7.04  7.27  16/06/93  306  6.22  8.07  8.05  9.01  9.07  7.01  7.37  17/06/93  307  6.31  8.16  7.80  9.02  9.14  6.93  7.53  18/06/93  308  6.35  7.13  7.57  8.88  8.87  7.01  7.50  22/06/93  312  6.24  8.40  7.72  8.93  8.96  6.90  7.37  23/06/93  313  6.34  7.43  7.93  9.10  8.94  7.03  7.53  24/06/93  314  6.30  7.51  7.83  9.08  9.00  7.24  7.37  160  Appendix M pH Measurements - Flowing Water  Date  Days  pH Measurements  From Start Loop Number:  1  2  3  4  5  6  7  Treated Flowing Water 25/06/93  315  6.32  7.45  7.90  9.01  9.09  6.95  7.63  29/06/93  319  6.26  7.57  8.00  8.95  8.75  6.86  7.40  01/07/93  321  6.30  7.92  7.87  8.84  8.96  7.22  7.35  05/07/93  325  6.27  7.64  7.62  8.86  8.90  6.93  7.34  06/07/93  326  6.35  7.62  7.84  8.91  8.92  6.95  7.14  07/07/93  327  6.32  8.06  8.08  8.98  9.16  7.14  7.18  09/07/93  329  6.24  7.73  7.86  9.12  8.95  6.85  7.56  12/07/93  332  6.28  8.43  8.04  9.01  8.88  7.10  7.23  13/07/93  333  6.33  7.74  7.83  8.70  8.95  7.12  7.18  14/07/93  334  6.39  7.76  8.13  9.20  9.21  7.24  7.29  1 5/07/93  335  6.40  8.30  8.28  9.17  9.19  7.01  7.35  19/07/93  339  6.22  7.74  8.04  8.85  8.93  6.85  7.27  20/07/93  340  6.26  7.73  7.70  8.78  8.81  6.94  7.30  22/07/93  342  6.34  7.79  7.65  8.83  8.76  7.20  7.64  23/07/93  343  6.31  7.37  8.00  9.00  8.81  6.87  7.30  27/07/93  347  6.33  8.09  8.12  9.13  9.14  6.85  7.32  28/07/93  348  6.37  8.33  8.03  8.94  8.96  7.41  7.78  29/07/93  349  6.41  7.92  8.18  9.23  9.19  6.94  7.57  30/07/93  350  6.27  7.80  8.06  9.14  9.07  6.97  7.37  03/08/93  354  6.30  8.49  8.17  9.10  9.15  7.02  7.45  04/08/93  355  6.36  7.71  8.27  9.06  9.07  7.00  7.52  05/08/93  356  6.37  8.14  7.90  9.16  9.03  7.04  7.51  06/08/93  357  6.36  7.86  7.63  9.13  9.10  7.20  7.71  09/08/93  360  6.32  8.38  7.97  9.13  8.87  6.90  7.57  161  Appendix M pH Measurements - Flowing Water Date  Days From Start  pH Measurements  6  7  9.0  7.0  7.5  9.02  9.02  7.07  7.53  6.95  7.54  7.77  6.61  7.01  9.42  9.00  9.86  9.78  8.58  9.07  0.13  0.50  0.38  0.25  0.20  0.26  0.32  0.02  0.07  0.05  0.04  0.03  0.04  0.05  Loop Number:  1  2  Target pH  control  8.0  8.0  9.0  Average pH  6.30  8.05  8.05  Minimum value  5.86  6.91  Maximum value  6.62  Standard Deviation 95% Confidence Interval  3  4  5  Treated Flowing Water  162  Appendix N pH Measurements - Standing Water Samples Sampling Date  Days  Comments  pH Measurements  From Start Loop Number:  1  2  3  4  5  6  7  Pre - treatment Samples 01/07/92  6.39  6.43  6.45  6.49  6.51  6.50  6.51  Solder coils/8 hr standing  03/07/92  6.57  6.62  6.53  6.71  6.72  6.76  6.62  Plumbing coils/8 hr standing  14/07/92  6.45  6.48  6.51  6.53  6.49  6.54  6.52  Solder coils/8 hr standing  14/07/92  6.72  6.77  6.69  6.78  6.73  6.73  6.68  Plumbing coils/8 hr standing  15/07/92  6.54  6.54  6.52  6.63  6.50  -  6.52  Faucets/8 hr standing  29/07/92  6.32  6.30  6.35  6.34  6.35  6.35  6.35  Faucets/8 hr standing  Treated Samples 25/08/92  26/08/92  01/09/92  16/09/92  30/09/92  11  12  18  33  47  6.11  8.06  8.40  8.94  8.91  7.07  7.46  Flowing water  6.38  7.13  7.05  8.25  7.54  6.98  6.88  Faucets/8 hr standing  6.32  8.30  7.42  9.24  8.40  7.28  6.96  Solder coils/8 hr standing  6.45  7.62  7.37  8.80  8.15  7.10  6.84  Plumbing coils/8 hr standing  6.25  7.77  8.15  9.13  8.86  7.00  7.63  Flowing water  6.32  7.12  7.19  8.58  8.20  7.00  6.80  Faucets/8 hr standing  6.28  7.25  7.33  8.81  8.31  7.00  6.82  Solder coils/8 hr standing  6.35  7.15  7.21  8.80  8.38  6.98  6.79  Plumbing coils/8 hr standing  6.62  8.01  8.28  9.00  9.15  7.33  7.51  Flowing water  6.12  6.97  7.28  8.02  8.52  6.81  6.64  Solder coils/8 hr standing  6.15  6.99  6.95  7.60  7.82  6.75  6.52  Faucets/8 hr standing  6.20  6.86  7.08  8.00  8.28  6.71  6.51  Plumbing coils/8 hr standing  6.50  7.74  8.15  8.11  8.62  7.14  7.28  Flowing water  6.41  7.37  7.29  8.37  8.45  6.95  6.92  Solder coils/8 hr standing  6.45  7.20  7.09  7.62  7.57  6.92  6.87  Faucets/8 hr standing  6.49  7.21  7.09  7.92  8.03  6.90  6.98  Plumbing coils/8 hr standing  163  Appendix N pH Measurements - Standing Water Samples Sampling Date  Days  pH Measurements  Comments  From Start Loop Number:  1  2  3  4  5  6  7  Treated Samples 21/10/92  18/11/92  25/11/92  09/12/92  06/01/93  28/01/93  68  96  103  117  145  167  6.39  7.52  8.22  9.09  9.13  6.98  7.27  Flowing water  6.25  6.94  6.98  8.70  8.96  6.72  6.82  Solder coils/8 hr standing  6.20  6.83  6.85  8.11  8.03  6.66  6.67  Faucets/8 hr standing  6.09  6.85  6.80  8.50  8.70  6.58  6.90  Plumbing coils/8 hr standing  6.20  8.17  7.91  9.05  8.88  7.00  7.60  Flowing water  6.08  7.05  7.12  8.76  8.69  6.63  6.88  Solder coils/8 hr standing  6.04  6.86  6.91  8.09  7.58  6.57  6.66  Faucets/8 hr standing  6.07  6.94  6.96  8.49  8.54  6.72  6.96  Plumbing coils/8 hr standing  6.26  7.53  8.06  8.96  9.08  7.00  7.25  Flowing water  6.07  7.09  7.26  8.99  9.11  6.87  7.04  Solder coils/8 hr standing  6.23  7.11  7.20  8.78  8.80  6.80  6.80  Faucets/8 hr standing  6.27  7.12  7.38  8.95  9.00  6.81  6.89  Plumbing coils/8 hr standing  6.32  7.68  7.77  8.85  8.90  7.12  7.20  Flowing water  6.15  7.04  7.28  8.84  8.97  6.73  6.93  Solder coils/8 hr standing  6.20  6.98  7.18  8.65  8.42  6.76  6.79  Faucets/8 hr standing  6.28  6.95  7.19  8.70  8.73  6.77  6.87  Plumbing coils/8 hr standing  6.38  7.53  7.80  8.78  8.71  7.10  7.37  Flowing water  6.15  7.04  7.33  8.32  8.64  6.78  7.01  Solder coils/8 hr standing  6.20  6.94  7.18  7.86  8.09  6.65  6.85  Faucets/8 hr standing  6.19  6.82  7.19  8.17  8.47  6.67  6.93  Plumbing coils/8 hr standing  6.11  7.06  7.13  7.54  7.77  6.83  7.18  Flowing water  5.89  6.73  6.95  7.00  7.55  6.52  6.70  Solder coils/8 hr standing  5.98  6.65  6.88  6.95  7.34  6.43  6.60  Faucets/8 hr standing  6.03  6.65  6.90  7.19  7.75  6.52  6.73  Plumbing coils/8 hr standing  164  Appendix N pH Measurements - Standing Water Samples Sampling Date  Days  Comments  pH Measurements  From Start Loop Number:  1  2  3  4  5  6  7  Treated Samples 19/02/93  08/03/93  189  206  6.07  7.82  7.83  9.04  9.05  6.88  7.28  Flowing water  -  -  -  -  -  -  -  Solder coils/8 hr standing  -  pH meter  -  -  -  Faucets/8 hr standing  -  not working  -  -  -  Plumbing coils/8 hr standing  6.22  8.79  8.28  9.10  9.06  7.07  7.81  Flowing water  6.15  8.12  7.60  9.16  8.98  6.97  7.60  Solder coils/8 hr standing  6.19  7.51  7.31  8.79  8.67  6.93  7.49  Faucets/8 hr standing  6.32  7.74  7.48  9.03  8.64  6.99  7.52  Plumbing coils/8 hr standing  1 8/03/93  216  6.19  7.93  7.98  9.04  9.06  7.22  7.43  Flowing water  19/03/93  217  6.23  7.54  7.53  8.99  8.95  6.89  7.13  Solder coils/1 6hr standing  6.15  7.12  7.20  8.21  7.85  6.80  6.93  Faucets/16 hr standing  6.30  7.32  7.24  8.62  8.48  6.87  7.06  Plumbing coils/16 hr standing  6.30  7.95  7.73  9.03  8.95  7.00  7.46  Flowing water  6.29  7.15  7.23  9.00  8.99  6.88  7.14  Solder coils/8 hr standing  6.30  7.00  7.08  8.28  8.20  6.77  7.02  Faucets/8 hr standing  6.34  6.99  7.05  8.84  8.72  6.87  7.20  Plumbing coils/8 hr standing  6.41  8.19  7.54  8.95  9.06  7.02  7.38  Flowing water  -  -  -  -  -  -  -  Solder coils/8 hr standing  01/04/93  08/04/93  230  237  -  pH meter  -  -  -  Faucets/8 hr standing  -  not working  -  -  -  Plumbing coils/8 hr standing  165  Appendix N pH Measurements - Standing Water Samples Sampling Date  Days  Comments  pH Measurements  From Start Loop Number:  1  2  3  4  5  6  7  Treated Samples 17/04/93  247  18/04/93  6.37  7.67  7.94  9.11  9.23  6.98  7.36  Flowing water  6.41  7.31  7.41  9.02  8.88  6.88  7.26  Solder coils/1 6hr standing  6.29  7.03  7.20  8.33  8.27  6.81  7.11  Faucets/16 hr standing  6.37  7.03  7.34  8.78  8.67  6.98  7.22  Plumbing coils/16 hr standing  06/05/93  265  6.31  8.26  8.36  9.02  8.89  7.16  7.54  Flowing water  07/05/93  266  6.36  7.30  7.40  8.82  8.91  7.03  7.34  Solder coils/1 6hr standing  -  7.12  7.28  8.00  8.12  6.91  7.22  Faucets/16 hr standing  6.40  7.15  7.31  8.54  8.61  7.00  7.31  Plumbing coils/16 hr standing  6.41  8.22  8.05  9.04  9.03  7.08  7.68  Flowing water  6.30  7.26  7.43  8.96  9.00  6.95  7.55  • Solder coils/8 hr standing  6.32  7.13  7.27  8.53  8.43  6.95  7.43  Faucets/8 hr standing  6.32  7.14  7.28  8.72  8.80  6.95  7.43  Plumbing coils/8 hr standing  14/05/93  273  10/06/93  300  6.36  7.23  8.08  9.06  9.10  7.12  7.65  Flowing water  11/06/93  301  6.42  7.01  7.40  8.70  9.10  7.05  7.34  Solder coils/16hr standing  6.38  6.94  7.32  7.76  8.46  6.91  7.16  Faucets/16 hr standing  6.63  7.04  7.39  8.37  8.90  7.10  7.29  Plumbing coils/16 hr standing  29/06/93  319  6.26  7.57  8.00  8.95  8.75  6.86  7.40  Flowing water  30/06/93  320  6.36  6.94  7.47  8.16  8.70  6.88  7.10  Solder coils/1 6hr standing  6.33  6.85  7.27  7.42  7.84  6.76  7.00  Faucets/16 hr standing  6.55  7.00  7.44  8.10  8.51  6.98  7.14  Plumbing coils/16 hr standing  166  Appendix N pH Measurements - Standing Water Samples Sampling Date  Days  pH Measurements  Comments  From Start Loop Number:  1  2  3  4  5  6  7  Treated Samples 14/07/93  334  6.39  7.76  8.13  9.20  9.21  7.24  7.29  Flowing water  6.38  7.01  7.60  8.55  8.93  6.96  7.15  Solder coils/8 hr standing  6.36  6.96  7.49  7.92  8.47  6.86  7.12  Faucets/8 hr standing  6.55  7.03  7.53  8.17  8.68  6.97  7.04  Plumbing coils/8 hr standing  20/07/93  340  6.26  7.73  7.70  8.78  8.81  6.94  7.30  Flowing water  21/07/93  341  6.29  6.97  7.38  8.22  8.37  6.87  7.18  Solder coils/16hr standing  6.30  6.85  7.28  7.45  7.73  6.74  7.03  Faucets/16 hr standing  6.48  6.93  7.34  8.04  8.35  6.89  7.15  Plumbing coils/16 hr standing  6.36  7.86  7.63  9.13  9.10  7.20  7.71  Flowing water  6.40  7.02  7.48  8.37  8.70  6.87  7.20  Solder coils/8 hr standing  6.39  7.00  7.32  7.70  8.11  6.80  6.89  Faucets/8 hr standing  6.48  6.93  7.32  8.25  8.59  6.87  7.14  Plumbing coils/8 hr standing  06/08/93  357  09/08/93  360  6.32  8.38  7.97  9.13  8.87  6.90  7.57  Flowing water  10/08/93  361  6.32  6.98  7.41  8.44  8.69  6.77  7.06  Solder coils/1 6hr standing  6.29  6.89  7.20  7.55  7.57  6.61  6.89  Faucets/1 6 hr standing  6.40  6.87  7.21  8.33  8.68  6.78  7.04  Plumbing coils/1 6 hr standing  167  Appendix N pH Measurements - Standing Water Samples  pH - Statistics  Loop 1  Loop 2  Loop 3  Loop 4  Loop 5  Loop 6  Loop 7  Solder Coils - Standing Water Samples Average pH  6.26  7.20  7.34  8.61  8.72  6.88  7.08  Minimum value  5.89  6.73  6.95  7.00  7.55  6.52  6.64  Maximum value  6.42  8.30  7.60  9.24  9.11  7.28  7.60  Standard Deviation  0.138  0.374  0.169  0.494  0.357  0.157  0.247  95% Confidence Interval  0.057  0.156  0.071  0.207  0.149  0.066  0.103  Faucets - Standing Water Samples Average pH  6.26  7.01  7.17  8.02  8.05  6.79  6.94  Minimum value  5.98  6.65  6.85  6.95  7.34  6.43  6.52  Maximum value  6.45  7.51  7.49  8.79  8.80  7.00  7.49  Standard Deviation  0.118  0.173  0.161  0.488  0.400  0.143  0.246  95% Confidence Interval  0.050  0.072  0.067  0.204  0.167  0.060  0.103  Plumbing Coils - Standing Water Samples Average pH  6.34  7.06  7.23  8.42  8.53  6.86  7.04  Minimum value  6.03  6.65  6.80  7.19  7.75  6.52  6.51  Maximum value  6.63  7.74  7.53  9.03  9.00  7.10  7.52  Standard Deviation  0.160  0.250  0.189  0.427  0.289  0.155  0.237  95% Confidence Interval  0.067  0.104  0.079  0.179  0.121  0.065  0.099  168  Appendix O Alkalinity Measurements Date  Days  mg/L  Start Loop N u m b e r :  Comments  Alkalinity  From  1  2  as C a C 0  4  3  3  5  6  7  Pre - treatment 14/07/92  4.80  5.35  4.83  4.76  4.83  4.79  4.86  14/07/92  5.33  5.32  5.57  5.47  5.08  5.07  4.88  14/07/92  6.76  7.33  6.50  7.34  7.00  7.17  6.67  29/07/92  4.97  4.64  4.67  4.70  4.73  4.71  4.85  Flowing water Solder coils/8 hr standing Plumbing coils/8 hr Faucets/8 hr standing  Treated S a m p l e s Target Alkalinity:  con-  20  30  20  30  20  20  trol 14/08/92  0  4.21  20.0  30.0  23.3  29.3  18.0  23.7  17/08/92  3  4.18  19.0  27.7  22.5  27.7  17.0  24.7  18/08/92  4  4.31  21.2  31.0  23.0  32.3  21.8  15.4  19/08/92  5  4.28  20.7  32.7  23.0  29.7  23.5  23.7  20/08/92  6  4.40  22.0  33.7  23.3  30.0  24.3  22.7  21/08/92  7  4.31  20.5  27.0  24.0  32.0  22.7  23.5  25/08/92  11  3.64  20.0  30.8  22.7  30.3  21.8  22.2  4.55  16.7  19.3  20.0  20.0  16.7  9.00  4.55  25.8  19.1  35.7  21.7  27.3  9.17  7.50  31.5  20.3  36.7  25.2  21.7  8.30  26/08/92  12  27/08/92  13  4.29  21.0  31.2  23.2  31.7  18.2  21.3  28/08/92  14  4.29  22.8  32.0  26.0  34.5  22.7  26.0  31/08/92  17  4.21  21.0  28.7  24.3  23.7  17.5  11.0  01/09/92  18  4.22  18.7  28.7  24.0  27.7  17.7  21.7  4.60  15.8  19.3  20.8  22.7  15.0  8.00  3.84  16.0  18.5  21.7  21.3  16.0  8.00  6.14  18.3  20.2  21.8  21.3  16.7  8.50  Faucets/8 hr standing Solder coils/8 hr standing Plumbing coils/8 hr standing  Faucets/8 hr standing Solder coils/8 hr standing Plumbing coils/8 hr standing  169  Appendix O Alkalinity Measurements Date  Days  m g / L as C a C 0  Start Loop Number:  Comments  Alkalinity  From  1  2  3  4  3  5  6  7  Treated Samples 03/09/92  20  4.16  18.7  28.0  24.5  32.0  24.0  19.7  04/09/92  21  4.13  20.5  29.0  25.0  34.3  22.0  26.0  05/09/92  22  4.33  19.7  25.7  21.3  30.0  21.7  24.2  08/09/92  25  4.37  17.8  31.0  23.7  27.3  25.3  13.8  10/09/92  27  4.28  17.3  34.0  .17.8  28.5  22.3  19.7  11/09/92  28  4.13  16.0  28.7  19.3  27.8  18.0  21.4  14/09/92  31  4.31  18.0  29.3  19.8  28.3  21.0  18.7  1 5/09/92  32  4.27  17.7  30.3  20.3  28.7  19.8  20.6  1 6/09/92  33  4.55  18.7  29.3  20.3  29.2  20.5  19.3  4.53  16.3  20.8  17.8  23.8  16.3  7.17  Solder coils/8 hr standing  4.55  16.3  20.0  19.0  23.3  15.3  9.33  Faucets/8 hr standing  5.80  17.7  20.3  19.7  24.3  17.0  9.33  Plumbing coils/8 hr standing  1 7/09/92  34  4.42  20.2  30.0  20.8  29.5  21.8  18.8  18/09/92  35  4.48  17.0  27.7  20.7  29.8  20.3  19.3  21/09/92  38  4.33  17.2  50.0  20.2  29.3  18.5  18.3  22/09/92  39  4.60  17.3  24.0  20.0  29.7  21.0  20.3  23/09/92  40  4.83  17.8  32.5  19.3  29.3  25.0  21.0  24/09/92  41  4.79  17.8  28.2  20.3  28.8  22.7  22.0  25/09/92  42  4.78  19.0  30.8  21.3  29.7  16.8  19.5  28/09/92  45  4.29  18.0  29.8  20.5  28.7  21.3  16.8  29/09/96  46  4.50  19.8  31.7  21.5  28.8  21.0  19.8  30/09/92  47  4.37  18.5  33.5  19.8  28.7  19.3  16.3  5.1  18.3  20.8  21.0  24.7  15.8  10.0  Solder coils/8 hr standing  5.84  17.7  19.2  19.2  22.7  16.0  10.8  Faucets/8 hr standing  6.21  22.3  23.6  21.7  24.6  20.5  15.1  Plumbing coils/8 hr standing  170  Appendix O Alkalinity Measurements Date  Days  m g / L as C a C 0  Start Loop Number:  Comments  Alkalinity  From  1  2  3  4  3  5  6  7  Treated Samples 01/10/92  48  4.48  18.8  31.5  21.0  30.7  17.7  16.7  02/10/92  49  4.88  18.8  26.5  20.5  30.3  20.3  18.3  05/10/92  52  4.33  19.5  28.2  20.2  26.5  19.5  16.8  06/10/92  53  4.50  19.2  28.0  22.3  29.3  22.5  21.2  07/10/92  54  4.17  18.8  30.8  23.3  29.3  25.0  22.3  08/10/92  55  4.67  20.5  30.3  22.5  30.3  21.5  21.5  09/10/92  56  4.38  22.0  29.6  21.8  29.3  19.5  20.7  13/10/92  60  4.58  20.0  28.7  22.5  28.8  22.7  21.2  15/10/92  62  4.48  19.7  32.8  28.0  38.0  17.8  24.0  16/10/92  63  4.83  22.0  32.7  26.7  33.5  19.0  23.7  19/10/92  66  4.63  19.7  30.7  26.2  30.7  20.7  20.0  20/10/92  67  4.63  20.2  29.8  24.7  31.8  18.5  27.5  21/10/92  68  4.46  19.5  34.0  24.0  32.5  21.7  18.7  4.85  17.5  21.5  22.7  27.7  16.0  12.0  Solder coils/8 hr standing  4.63  16.3  19.7  24.3  26.0  16.0  13.0  Faucets/8 hr standing  6.38  20.8  21.2  23.2  28.7  19.8  19.0  Plumbing coils/8 hr standing  22/10/92  69  4.17  19.3  27.7  21.7  30.3  20.7  20.5  23/10/92  70  3.68  16.8  24.8  20.5  27.0  17.3  18.7  26/10/92  73  3.29  18.0  33.7  21.2  32.8  20.8  21.2  27/10/92  74  3.25  18.0  32.2  20.7  31.2  21.0  20.7  28/10/92  75  3.13  18.2  23.8  19.5  28.7  20.0  21.0  29/10/92  76  3.04  19.0  29.0  21.3  30.2  19.8  21.2  171  Appendix O Alkalinity Measurements Date  Days  m g / L as C a C 0  Start Loop Number:  Comments  Alkalinity  From  1  2  3  4  3  5  6  7  Treated Samples 30/10/92  77  3.00  17.5  28.7  19.2  29.3  18.8  21.2  03/11/92  81  3.00  17.0  32.2  20.3  27.3  18.0  17.7  04/11/92  82  3.04  19.7  30.7  21.3  28.3  20.5  19.2  05/11/92  83  3.17  17.5  28.2  21.0  29.7  18.0  17.3  06/11/92  84  3.18  24.8  43.0  21.0  28.0  17 7  18.7  09/11/92  87  2.88  19.2  25.3  19.7  27.8  20.2  19.6  10/11/92  88  2.97  19.5  30.0  19.8  28.3  18.6  20.5  12/11/92  90  3.17  18.2  29.3  21.7  30.7  23.0  21.0  13/11/92  91  3.21  18.7  27.8  20.5  29.6  21.3  19.7  16/11/92  94  3.17  19.3  30.7  21.7  30.2  17.8  21.3  17/11/92  95  -  18.0  28.7  21.3  29.3  21.3  18.3  18/11/92  96  3.25  19.0  29.2  22.0  29.3  21.0  20.5  -  16.3  21.2  21.2  24.7  16.0  12.2  Solder coils/8 hr standing  3.21  16.3  19.3  19.7  23.3  15.7  12.8  Faucets/8 hr standing  4.71  17.0  22.0  23.7  32.3  21.0  12.0  Plumbing coils/8 hr standing  :  19/11/92  97  2.58  19.0  29.3  22.7  29.3  21.2  18.0  20/11/92  98  3.17  19.5  33.3  23.0  30.7  19.7  20.7  23/11/92  101  3.29  19.3  24.7  23.0  30.8  20.0  21.7  24/11/92  102  3.29  19.5  32.5  21.3  30.3  20.3  21.5  25/11/92  103  3.21  18.2  28.7  21.7  30.5  19.7  14.8  3.42  16.8  22.5  22.2  27.3  15.7  12.3  Solder coils/8 hr standing  3.3  16.7  21.3  21.3  26.0  15.7  9.3  Faucets/8 hr standing  4.70  17.3  26.0  22.3  27.2  15.8  13.3  Plumbing coils/8 hr standing  3.33  18.3  25.8  22.3  32.7  22.7  24.8  26/11/92  104  172  Appendix O Alkalinity Measurements Date  Days  Alkalinity  From  m g / L as C a C 0  Start Loop Number:  Comments  1  2  3  4  3  5  6  7  Treated Samples 27/11/92  105  3.07  18.0  39.3  23.0  33.3  21.5  23.2  30/11/92  108  3.54  22.7  29.8  24.0  30.7  20.0  20.3  02/12/92  110  3.46  19.3  27.7  20.0  31.8  15.3  15.7  03/12/92  111  3.54  21.3  31.8  22.2  33.2  21.2  21.7  04/12/92  112  3.63  19.5  29.5  21.8  28.7  21.3  21.3  07/12/92  115  3.58  18.0  30.7  21.3  29.3  19.8  21.3  08/12/92  116  3.42  18.5  30.7  21.8  29.3  21.7  19.3  09/12/92  117  3.54  18.3  28.0  21.3  29.0  21.3  15.7  3.75  18.0  23.3  21.3  26.0  15.0  12.0  Solder coils/8 hr standing  2.71  16.2  22.7  21.5  24.5  14.8  9.30  Faucets/8 hr standing  4.92  16.8  23.8  22.7  26.7  15.7  11.5  Plumbing coils/8 hr standing  10/12/92  118  3.63  18.2  29.8  21.2  29.3  19.3  18.0  11/12/92  119  3.66  22.2  22.5  20.2  28.7  20.3  16.8  14/12/92  122  3.63  18.3  16.7  20.8  31.2  20.3  20.2  17/12/92  125  3.67  21.3  21.5  20.0  28.5  20.8  19.3  18/12/92  126  3.63  17.0  28.7  20.0  30.0  20.2  20.7  22/12/92  130  3.79  21.2  35.2  20.8  32.0  21.3  19.5  23/12/92  131  3.79  23.2  30.0  21.3  32.5  21.5  21.0  24/12/92  132  3.71  20.7  34.5  21.3  30.0  20.7  18.7  28/12/92  136  3.79  19.0  25.0  20.8  30.8  18.0  15.8  30/12/92  138  3.75  14.8  33.7  21.8  30.8  19.5  20.0  31/12/92  139  4.00  21.3  36.3  21.5  31.2  23.0  23.7  173  Appendix O Alkalinity Measurements Date  Days  m g / L as C a C 0  Start Loop Number:  Comments  Alkalinity  From  1  2  3  4  3  5  6  7  Treated Samples 04/01/93  143  3.96  24.5  28.7  20.2  30.2  18.8  21.8  05/01/93  144  3.96  18.8  30.5  18.8  30.0  19.3  22.2  06/01/93  145  3.88  19.3  30.7  19.5  28.7  20.3  19.0  4.17  17.0  26.2  12.7  28.3  15.7  14.7  Solder coils/8 hr standing  4.04  16.3  25.3  13.2  26.8  14.2  12.7  Faucets/8 hr standing  5.38  20.7  26.7  14.3  30.0  15.3  14.8  Plumbing coils/8 hr standing  07/01/93  146  3.63  22.2  29.7  19.5  30.0  20.8  20.2  12/01/93  151  4.04  21.0  28.3  24.2  35.2  22.7  24.0  13/01/93  152  4.04  19.7  30.7  23.3  29.7  18.5  24.3  14/01/93  153  4.08  24.5  31.8  19.3  30.2  20.7  20.3  15/01/93  154  4.00  19.3  30.8  18.0  28.7  19.7  16.3  19/01/93  158  3.92  24.8  37.3  21.2  32.0  22.3  20.8  20/01/93  159  4.00  24.0  40.0  20.5  32.0  22.0  24.0  21/01/93  160  3.96  20.7  29.5  20.0  31.5  20.7  22.7  22/01/93  161  4.04  20.0  29.3  20.2  29.2  20.7  20.7  25/01/92  164  4.29  20.0  31.7  20.2  29.8  21.0  23.5  27/01/93  166  3.90  20.3  28.5  18.3  29.0  18.8  23.3  28/01/93  167  3.80  18.7  25.3  18.0  27.3  20.2  22.8  4.17  15.3  24.7  12.3  26.7  14.3  13.3  Solder coils/8 hr standing  4.17  15.3  24.2  12.8  26.8  12.7  11.5  Faucets/8 hr standing  6.54  25.2  25.8  15.7  33.3  15.5  14.0  Plumbing coils/8 hr standing  3.92  20.8  30.2  22.5  30.8  18.7  21.0  29/01/93  168  174  Appendix O Alkalinity Measurements Date  Days  Alkalinity  From  m g / L as C a C 0  Start Loop Number:  Comments  1  2  3  4  3  5  6  7  Treated Samples 01/02/93  171  3.92  22.3  38.3  20.8  33.2  19.5  22.8  03/02/93  173  4.29  23.0  29.5  18.0  30.2  20.0  20.7  04/02/93  174  4.13  23.5  32.8  20.7  30.0  20.7  21.5  08/02/93  178  3.96  21.3  31.2  22.0  30.5  21.7  19.5  09/02/93  179  3.83  20.8  29.3  19.6  32.7  20.5  18.5  10/02/93  180  3.95  37.5  46.0  43.2  63.3  41.7  50.5  11/02/93  181  3.92  17.3  29.2  14.3  29.5  18.8  18.2  16/02/93  186  4.04  18.3  29.7  20.3  30.7  20.3  19.0  18/02/93  188  4.17  19.8  29.0  20.0  30.5  19.0  18.7  19/02/93  189  4.08  20.6  28.7  20.0  32.0  19.7  19.0 Solder coils/8 hr standing  pH meter not working  Faucets/8 hr standing  Unable to determine alkalinity  Plumbing coils/8 hr  22/02/93  192  4.00  20.8  30.3  18.7  24.2  18.2  19.7  24/02/93  194  4.42  21.8  29.2  19.3  29.0  23.3  16.0  25/02/93  195  4.13  21.0  29.3  18.6  28.7  17.7  25.7  01/03/93  199  3.75  20.3  30.2  21.7  27.0  20.7  20.0  03/03/93  201  4.08  19.5  33.3  20.2  28.8  21.0  20.0  05/03/93  203  3.58  20.0  31.3  18.0  28.0  20.3  20.2  08/03/93  206  3.33  21.7  28.5  19.7  28.5  18.7  19.3  3.63  16.3  26.0  15.3  25.3  16.5  17.7  Solder coils/8 hr standing  3.54  15.7  24.7  13.8  28.0  17.0  17.3  Faucets/8 hr standing  5.42  18.0  27.7  15.0  22.7  19.0  23.7  Plumbing coils/8 hr standing  175  Appendix O Alkalinity Measurements Date  Days  m g / L as C a C 0  Start Loop Number:  Comments  Alkalinity  From  1  2  3  4  3  5  6  7  Treated Samples 09/03/93  207  3.50  19.5  31.3  20.0  28.2  20.0  20.2  12/03/93  210  3.33  18.7  28.8  18.7  28.7  21.0  18.0  1 5/03/93  213  3.50  22.0  29.2  20.7  30.8  20.7  20.7  1 7/03/92  215  3.50  20.3  29.5  20.8  30.0  19.0  21.7  18/03/93  216  3.46  20.7  30.7  20.7  30.0  22.0  19.0  1 9/03/93  217  4.17  20.0  30.7  15.5  26.7  18.7  14.2  Solder coil/16 hr standing  3.79  18.7  29.8  15.2  27.3  19.3  16.2  Faucets/16 hr standing  6.33  36.0  33.7  16.7  28.0  20.2  18.7  Plumbing coils/16 hr standing  23/03/93  221  3.50  20.7  34.7  19.3  24.0  23.3  20.3  24/03/93  222  3.21  22.7  29.7  19.3  27.3  22.5  18.3  25/03/93  223  3.38  20.0  28.8  18.8  28.7  21.3  20.5  26/03/93  224  3.33  20.0  31.8  20.0  29.3  19.3  20.5  29/03/93  227  -  -  -  -  -  -  -  31/03/93  229  3.21  19.3  30.7  19.3  34.8  21.0  19.0  01/04/93  230  3.17  19.5  28.7  18.8  26.7  16.2  19.3  02/04/93  231  3.50  15.7  21.2  15.0  23.8  14.3  16.2  Solder coil/16 hr standing  3.58  16.0  21.3  14.3  24.0  14.5  17.3  Faucets/1 6 hr standing  6.00  23.3  23.3  16.0  27.3  15.6  19.7  Plumbing coils/16 hr standing  06/04/93  235  3.42  20.7  20.6  20.8  33.0  18.7  22.5  08/04/93  237  3.42  21.2  23.8  18.3  27.8  18.7  17.7  10/04/93  239  -  -  -  -  -  -  -  16/04/93  245  3.42  20.0  35.0  21.2  30.0  21.2  21.7  176  Appendix 0 Alkalinity Measurements Date  Days  m g / L as C a C 0  Start Loop N u m b e r :  Comments  Alkalinity  From  1  2  3  4  3  5  6  7  Treated S a m p l e s 1 7/04/93  246  3.25  18.8  28.5  19.8  34.2  18.0  18.2  1 8/04/93  247  3.46  17.3  25.2  16.7  26.2  17.3  16.7  3.63  16.2  25.0  15.7  26.7  17.0  16.7  5.08  23.0  29.0  17.2  28.7  20.0  19.6  1 9/04/93  248  3.29  23.2  33.7  21.5  30.0  21.2  21.2  22/04/93  251  3.50  21.7  32.3  21.3  28.8  29.0  20.2  27/04/93  256  3.33  19.3  28.2  22.0  29.3  17.0  20.0  29/04/93  258  3.29  19.3  29.3  19.0  29.3  14.5  19.3  03/05/93  262  3.00  21.3  30.5  19.0  29.3  21.8  19.5  05/05/93  264  2.90  21.3  34.0  20.8  28.3  23.7  25.5  06/05/93  265  3.10  20.3  28.8  20.8  28.2  16.8  19.8  07/05/93  266  3.46  16.2  23.3  14.0  25.0  16.5  18.0  -  16.2  22.3  14.0  25.5  16.7  19.7  4.92  22.0  25.8  15.8  27.8  17.3  21.3  11/05/93  270  3.29  19.8  28.3  20.7  30.2  24.0  20.0  12/05/93  271  3.42  19.0  30.7  20.7  30.5  19.3  20.2  14/05/93  273  3.50  21.3  31.2  22.3  29.0  20.8  22.5  3.71  16.0  24.7  15.0  28.0  17.5  20.2  3.67  14.5  23.0  13.2  22.7  20.5  22.2  5.00  19.5  26.5  13.8  28.0  17.5  26.2  18/05/93  277  3.33  19.8  31.2  21.7  31.2  19.2  20.5  20/05/93  279  3.27  20.3  26.7  21.2  29.8  18.0  21.6  Solder coil/1 6 hr standing Faucets/16 hr standing Plumbing coils/16 hr standing  Solder coil/1 6 hr standing Faucets/1 6 hr standing Plumbing coils/16 hr standing  Solder coils/8 hr standing Faucets/8 hr standing Plumbing coils/8 hr standing  177  Appendix O Alkalinity Measurements Date  Days  m g / L as C a C 0  Start Loop Number:  Comments  Alkalinity  From  1  2  3  4  3  5  6  7  Treated Samples 21/05/93  280  3.40  22.0  31.3  23.2  31.3  19.8  20.8  27/05/93  286  3.46  20.3  33.2  21.0  31.7  19.3  20.7  28/05/93  287  3.29  20.6  29.3  20.6  33.3  24.3  18.7  04/06/93  294  3.45  20.2  30.2  19.8  31.2  19.0  20.0  08/06/93  298  3.58  22.7  26.8  20.3  30.7  17.0  22.7  09/06/93  299  3.58  25.0  33.0  20.2  29.7  19.3  14.0  10/06/93  300  3.54  17.8  29.7  22.0  29.0  20.8  21.7  11/06/93  301  4.29  11.8  24.3  12.3  27.6  18.5  16.3  Solder coil/16 hr standing  4.08  11.3  23.7  14.0  29.2  18.3  18.5  Faucets/16 hr standing  6.0  15.0  28.5  14.0  32.0  20.0  21.7  Plumbing coils/1 6 hr standing  15/06/93  305  3.46  20.8  30.0  20.5  30.3  19.6  17.2  16/06/93  306  3.42  20.7  31.5  22.2  31.2  23.2  18.6  1 7/06/93  307  3.54  21.5  30.0  20.5  33.5  19.7  22.3  1 8/06/93  308  3.71  18.7  28.8  20.0  30.7  21.3  24.0  22/06/93  312  3.71  22.7  30.5  19.7  30.0  19.8  20.5  23/06/93  313  3.71  19.6  31.5  20.5  28.8  20.5  21.7  24/06/93  314  3.88  19.8  30.7  20.3  30.5  21.2  19.7  25/06/93  315  3.79  17.7  33.0  20.8  32.2  18.5  23.0  29/06/93  319  3.67  20.2  31.5  20.2  26.2  18.5  21.5  30/06/93  320  4.30  14.0  25.7  13.0  23.3  15.3  14.6  Solder coil/16 hr standing  4.25  10.8  26.0  10.6  24.0  15.8  14.8  Faucets/16 hr standing  4.92  15.3  27.7  13.7  25.7  16.7  15.3  Plumbing coils/16 hr standing  178  Appendix O Alkalinity Measurements Date  Days  Alkalinity  From  m g / L as C a C 0  Start Loop Number:  Comments  1  2  3  4  3  5  6  7  Treated Samples 01/07/93  321  3.88  22.0  28.0  20.2  29.8  21.7  18.8  05/07/93  325  3.92  22.0  29.2  21.2  29.5  19.2  20.3  06/07/93  326  4.00  19.5  30.0  21.2  31.7  19.0  20.7  07/07/93  327  4.00  21.7  30.8  19.0  34.8  21.7  19.7  09/07/93  329  4.13  20.8  31.7  19.8  31.8  18.0  27.8  1 2/07/93  332  4.25  23.0  31.2  22.0  29.2  22.0  21.3  1 3/07/93  333  4.25  20.0  28.3  17.0  29.5  22.0  17.2  14/07/93  334  4.42  20.5  29.2  23.0  32.0  21.2  19.3  4.88  11.7  25.3  12.2  23.6  16.5  15.8  Solder coils/8 hr standing  4.71  9.67  25.3  12.0  23.3  14.5  18.7  Faucets/8 hr standing  6.08  13.2  26.2  13.3  24.6  16.3  12.6  Plumbing coils/8 hr standing  1 5/07/93  335  4.29  23.0  32.0  23.3  31.2  19.7  21.2  19/07/93  339  4.13  21.2  32.0  22.0  30.5  18.0  20.3  20/07/93  340  4.25  20.5  29.8  18.7  29.8  19.7  19.8  21/07/93  341  4.79  11.0  25.3  11.3  23.3  18.0  16.3  Solder coil/16 hr standing  4.92  10.7  25.3  12.3  25.2  17.8  18.7  Faucets/16 hr standing  7.0  15.8  33.2  13.5  27.2  19.2  18.5  Plumbing coils/16 hr standing  22/07/93  342  4.42  21.0  28.5  21.3  29.2  26.5  24.5  23/07/93  343  4.42  17.3  31.8  21.3  30.3  18.7  19.3  27/07/93  347  4.54  21.2  32.0  18.0  33.2  18.0  19.3  28/07/93  348  4.54  22.5  31.8  22.6  30.2  24.5  23.6  29/07/93  349  4.83  20.7  32.0  16.0  33.0  20.8  21.5  179  Appendix O Alkalinity Measurements Date  Days  m g / L as C a C 0  Start Loop N u m b e r :  Comments  Alkalinity  From  1  2  3  4  3  5  6  7  Treated S a m p l e s 30/07/93  350  4.38  20.7  30.2  24.2  32.0  21.3  20.0  03/08/93  354  4.33  26.6  29.7  15.3  30.3  26.8  -  04/08/93  355  4.67  19.6  33.5  24.8  30.3  20.7  21.5  05/08/93  356  4.75  21.7  30.3  22.5  29.2  20.3  21.3  06/08/93  357  4.75  20.3  27.7  23.2  31.5  21.2  23.2  5.20  11.0  23.2  12.7  23.3  15.0  14.5  5.17  10.3  23.8  12.7  23.7  15.0  11.7  Faucets/8 hr standing  6.88  12.3  28.2  12.7  23.7  16.0  15.2  Plumbing coils/8 hr standing  Solder coils/8 hr standing  09/08/93  360  4.66  24.2  30.0  24.3  26.7  19.2  21.7  10/08/93  361  5.08  12.5  25.5  14.0  25.3  16.0  14.5  5.13  11.8  25.5  14.5  29.0  16.5  16.2  Faucets/16 hr standing  5.63  13.8  27.3  16.0  31.5  18.0  18.2  Plumbing coils/16 hr standing  Solder coil/16 hr standing  180  Appendix O Alkalinity Measurements Loop 1  Statistics  Loop 2  Loop 3  Loop 4  Loop 5  Loop 6  Loop 7  Alkalinity - Flowing Water control  20.0  30.0  20.0  30.0  20.0  20.0  Average  3.85  20.2  30.3  21.2  30.2  20.5  20.6  M i n i m u m value  2.58  14.8  16.7  14.3  23.7  14.5  11.0  M a x i m u m value  4.88  37.5  50.0  43.2  63.3  41.7  50.5  Standard Deviation  0.51  2.26  3.61  2.53  3.15  2.61  3.32  9 5 % Confidence Interval  0.07  0.33  0.52  0.37  0.46  0.8  0.41  Target Alkalinity CaC0  mg/L  3  Solder Coils - Standing Water S a m p l e s Average  4.23  16.0  23.6  17.1  25.2  16.8  13.9  Minimum value  3.42  11.0  18.5  11.3  21.3  14.3  7.17  M a x i m u m value  5.20  25.8  30.7  35.7  28.3  27.3  20.2  Standard Deviation  0.60  3.31  2.77  5.64  2.02  2.64  3.32  9 5 % Confidence Interval  0.26  1.38  1.16  2.36  0.84  1.10  1.39  Faucets - Standing Water S a m p l e s Average  4.19  14.8  23.0  16.1  25.0  16.1  14.3  M i n i m u m value  2.71  9.67  19.2  10.6  20.0  12.7  8.0  M a x i m u m value  5.84  18.7  29.8  24.3  29.2  20.5  22.2  Standard Deviation  0.76  2.67  2.83  3.86  2.32  1.76  4.11  9 5 % Confidence Interval  0.32  1.12  1.18  1.61  0.97  0.74  1.72  Plumbing Coils - Standing Water S a m p l e s Average  5.80  19.8  25.8  18.2  27.3  18.0  16.2  Minimum value  4.70  12.3  20.2  12.7  21.3  15.3  8.3  M a x i m u m value  7.50  36.0  33.7  36.7  33.3  21.7  26.2  Standard Deviation  0.80  5.74  3.74  5.55  3.19  2.06  4.88  9 5 % Confidence Interval  0.33  2.40  1.56  2.32  1.33  0.86  2.04  181  Appendix P Temperature Measurements  Date  Days From Start  Raw WaterFlowing  Treated WaterStanding Samples Solder Coils  Plumbing Coils  Faucets  Standing Time  23.0  8 hr.  Temperature - Degrees C 14/08/92  0  16.5  17/08/92  3  17.0  18/08/92  4  16.5  19/08/92  5  16.5  20/08/92  6  16.5  21/08/92  7  16.5  25/08/92  1 1  17.0  26/08/92  12  17.0  27/08/92  13  17.0  28/08/92  14  17.0  31/08/92  17  17.5  01/09/92  18  17.0  03/09/92  20  17.0  04/09/92  21  17.0  05/09/92  22  17.0  08/09/92  25  16.5  10/09/92  27  17.0  11/09/92  28  16.5  14/09/92  31  16.0  1 5/09/92  32  15.5  16/09/92  33  15.5  1 7/09/92  34  15.5  18/09/92  35  15.0  8 hr.  21.0  22.5  20.5  21.5  22.0  8 hr.  17.0  19.0  19.0  8 hr.  182  Appendix P Temperature Measurements Date  Days  Raw  From  Water-  Start  Flowing  Treated WaterStanding S a m p l e s Solder Coils  Plumbing Coils  Faucets  Standing Time  Temperature - Degrees C  21/09/92  38  15.5  22/09/92  39  15.5  23/09/92  40  15.0  24/09/92  41  15.0  25/09/92  42  14.5  28/09/92  45  13.5  29/09/96  46  13.5  30/09/92  47  13.5  01/10/92  • 48  13.5  02/10/92  ' 49  13.0  05/10/92  52  13.0  06/10/92  53  13.0  07/10/92  54  13.0  08/10/92  55  13.0  09/10/92  56  13.0  13/10/92  60  12.5  15/10/92  62  12.0  16/10/92  63  12.0  19/10/92  66  12.0  20/10/92  67  12.0  21/10/92  68  11.5  17.5  17.5  19.5  8 hr.  16.0  16.0  17.5  8 hr.  183  Appendix P Temperature Measurements Date  Days  Raw  From  Water-  Start  Flowing  Treated WaterStanding S a m p l e s Solder Coils  Plumbing Coils  Faucets  Standing Time  15.0  8 hr.  Temperature - Degrees C 22/10/92  69  12.0  23/10/92  70  11.0  26/10/92  73  10.0  27/10/92  74  10.0  28/10/92  75  10.5  29/10/92  76  10.0  30/10/92  77  10.0  03/11/92  81  9.0  04/11/92  82  9.0  05/11/92  83  9.0  06/11/92  84  8.5  09/11/92  87  8.0  10/11/92  88  8.0  12/11/92  90  8.0  13/11/92  91  7.5  16/11/92  94  7.5  17/11/92  95  7.5  18/11/92  96  7.5  19/11/92  97  7.0  20/11/92  98  7.0  23/11/92  101  7.0  12.5  13.5  184  Appendix P Temperature Measurements Date  Days  Raw  From  Water-  Start  Flowing  Treated WaterStanding S a m p l e s Solder Coils  Plumbing Coils  Faucets  Standing Time  Temperature - Degrees C 24/11/92  102  7.0  25/11/92  103  7.0  26/11/92  104  6.0  27/11/92  105  6.0  30/11/92  108  5.0  02/12/92  110  5.0  03/12/92  111  4.5  04/12/92  112  4.5  07/12/92  115  4.0  08/12/92  116  4.5  09/12/92  117  4.5  10/12/92  118  4.0  11/12/92  119  3.5  14/12/92  122  3.5  17/12/92  125  3.0  18/12/92  126  3.0  21/12/92  129  3.0  22/12/92  130  2.5  23/12/92  131  2.5  24/12/92  132  2.0  28/12/92  136  2.0  10.5  11.0  14.0  8 hr.  12.5  11.5  12.0  8 hr.  185  Appendix P Temperature Measurements Date  Days  Raw  From  Water-  Start  Flowing  Treated WaterStanding S a m p l e s Solder Coils  Plumbing Coils  Faucets  Standing Time  Temperature - Degrees C 30/12/92  138  2.5  31/12/92  139  2.5  04/01/93  143  2.5  05/01/93  144  2.0  06/01/93  145  2.0  07/01/93  146  2.0  12/01/93  151  2.0  13/01/93  152  2.0  14/01/93  153  -  15/01/93  154  2.0  19/01/93  158  2.0  20/01/93  159  2.0  21/01/93  160  2.5  22/01/93  161  2.0  25/01/92  164  2.0  27/01/93  166  2.0  28/01/93  167  2.0  29/01/93  168  2.0  01/02/93  171  2.0  03/02/93  173  2.5  04/02/93  174  3.0  6.0  6.5  8.5  8 hr.  7.0  7.0  10.0  8  hr.  186  Appendix P Temperature Measurements Date  Days  Raw  From  Water-  Start  Flowing  Treated WaterStanding S a m p l e s Solder Coils  Plumbing Coils  Faucets  Standing Time  Temperature - Degrees C 08/02/93  178  3.0  09/02/93  179  3.0  10/02/93  180  3.5  11/02/93  181  3.0  16/02/93  186  3.0  18/02/93  188  3.0  19/02/93  189  3.0  22/02/93  192  3.0  24/02/93  194  3.0  25/02/93  195  3.5  01/03/93  199  3.5  03/03/93  201  3.5  05/03/93  203  3.0  08/03/93  206  4.0  09/03/93  207  3.5  12/03/93  210  3.5  1 5/03/93  213  4.0  1 7/03/92  215  4.0  18/03/93  216  4.0  19/03/93  217  4.0  23/03/93  221  4.5  8.5  8.0  10.5  8 hr.  9.0  9.0  12.0  8 hr.  12.0  11.5  14.0  16 hr.  187  Appendix P Temperature Measurements Date  Days  Raw  From  Water-  Start  Flowing  Treated WaterStanding S a m p l e s Solder Coils  Plumbing Coils  Faucets  Standing Time  Temperature - Degrees C  24/03/93  222  4.5  25/03/93  223  4.5  26/03/93  224  4.5  29/03/93  227  4.5  31/03/93  229  5.0  01/04/93  230  5.0  02/04/93  231  5.0  06/04/93  235  5.5  08/04/93  237  5.5  10/04/93  239  5.5  16/04/93  245  6.0  1 7/04/93  246  6.0  18/04/93  247  6.0  1 9/04/93  248  6.0  22/04/93  251  -  27/04/93  256  6.0  29/04/93  258  6.5  03/05/93  262  7.0  05/05/93  264  6.5  06/05/93  265  6.5  07/05/93  266  6.5  11.0  10.5  13.0  16 hr.  11.5  12.0  15.0  8 hr.  12.0  11.0  13.5  16 hr.  12.0  11.5  14.0  16 hr.  188  Appendix P Temperature Measurements Date  Days  Raw  From  Water-  Start  Flowing  Treated WaterStanding S a m p l e s Solder Coils  Plumbing Coils ».  Faucets  Standing Time  Temperature - Degrees C  11/05/93  270  7.0  12/05/93  271  7.0  14/05/93  273  7.5  18/05/93  277  7.5  20/05/93  279  7.5  21/05/93  280  8.0  27/05/93  286  8.0  28/05/93  287  8.5  03/06/93  293  9.0  04/06/93  294  9.0  08/06/93  298  9.0  09/06/93  299  9.0  10/06/93  300  9.0  11/06/93  301  9.0  1 5/06/93  305  9.5  16/06/93  306  9.5  17/06/93  307  9.5  18/06/93  308  9.5  22/06/93  312  10.0  23/06/93  313  10.0  24/06/93  314  10.0  13.5  13.0  16.0  8 hr.  17.0  15.5  18.5  16 hr.  14.5  14.0  17.0  8 hr.  189  Appendix P Temperature Measurements Date  Days  Raw  From  Water-  Start  Flowing  Treated WaterStanding S a m p l e s Solder Coils  Plumbing Coils  Faucets  Standing Time  Temperature - Degrees C 25/06/93  315  10.0  29/06/93  319  10.0  30/06/93  320  10.0  01/07/93  321  10.5  05/07/93  325  11.0  06/07/93  326  11.0  07/07/93  327  11.0  09/07/93  329  11.5  12/07/93  332  11.5  13/07/93  333  11.5  14/07/93  334  12.0  1 5/07/93  335  12.0  19/07/93  339  12.5  20/07/93  340  12.5  21/07/93  341  12.5  22/07/93  342  12.5  23/07/93  343  13.0  27/07/93  347  13.0  28/07/93  348  13.5  29/07/93  349  13.5  16.0  15.5  17.5  16 hr.  16.0  16.0  18.5  8 hr.  17.0  16.0  18.0  16 hr.  190  Appendix P Temperature Measurements Date  Days  Raw  From  Water-  Start  Flowing  Treated WaterStanding S a m p l e s Solder Coils  Plumbing Coils  Faucets  Standing Time  Temperature - Degrees C  30/07/93  350  13.0  03/08/93  354  13.5  04/08/93  355  13.5  05/08/93  356  14.0  06/08/93  357  13.5  09/08/93  360  14.0  10/08/93  361  14.0  19.5  19.5  22.0  8 hr.  19.5  18.0  20.5  16 hr.  191  Appendix Q Comparison of Two Temperature Ranges Temperature Data - Lead Sampling Date  Flowing Water Temp. °C  Lead Concentration  Standing Water Temp. °C  mg/L  Solder Coil-Lead Levels - Temperature Range 12 - 17°C 26/08/92  17.0  21.0  0.84  7.15  7.05  7.32  4.19  3.86  3.44  Or/09/92  17.0  20.5  0.46  2.02  7.22  11.86  1.92  1.6  2.15  16/09/92  15.5  17.0  0.79  1.62  5.11  3.94  1.70  0.35  0.92  30/09/92  13.5  17.5  0.8  1.10  6.59  4.32  2.99  0.32  0.82  14/07/93  12.0  16.0  0.49  0.70  1.15  1.26  0.76  0.45  0.03  21/07/93  12.5  17.0  0.51  1.76  1.08  1.44  0.99  0.30  0.39  06/08/93  13.5  19.5  0.26  0.52  1.01  0.82  0.74  0.19  0.21  10/08/93  14.0  19.5  0.57  2.16  1.05  1.01  0.83  0.13  0.20  Average concentration  0.59  2.13  3.78  4.00  1.77  0.90  1.02  Minimum value  0.26  0.52  1.01  0.82  0.74  0.13  0.03  Maximum value  0.84  7.15  7.22  11.86  4.19  3.86  3.44  Standard Deviation  0.20  2.11  2.96  3.89  1.25  1.28  1.19  95% Confidence Interval  0.14  1.47  2.05  2.70  0.87  0.89  0.82  Solder Coil-Lead Levels - Temperature Range 2 - 7 °C 25/11/92  7.0  11.0  0.47  1.58  4.19  4.27  5.53  0.69  0.29  09/12/92  4.5  11.5  0.62  3.40  4.19  10.84  10.61  0.74  0.16  06/01/93  2.0  6.0  0.33  2.63  6.07  8.85  6.87  0.52  0.15  28/01/93  2.0  7.0  0.69  3.49  4.58  6.38  2.23  0.9  0.20  19/02/93  3.0  8.5  0.43  1.51  2.49  6.73  2.66  0.54  0.11  08/03/93  4.0  9.0  0.48  2.99  3.41  9.08  5.76  1.00  0.31  19/03/93  4.0  12.0  1.78  1.22  3.59  2.32  3.2  0.07  n/d  02/04/93  5.0  11.0  0.66  1.56  2.65  3.24  4.53  0.6  0.21  08/04/93  5.5  11.5  1.03  1.23  3.69  4.46  4.64  0.15  0.01  192  Appendix Q Comparison of Two Temperature Ranges Temperature Data - Lead continued Sampling Date  Flowing Water Temp. °C  Lead Concentration  Standing Water Temp. °C  mg/L  Solder Coil-Lead Levels - Temperature Range 2 - 7 °C 1 8/04/93  6.0  12.0  1.68  4.22  5.15  11.58  8.11  2.05  0.38  07/05/93  6.5  12.0  1.43  1.37  1.32  2.67  3.65  0.39  0.14  Average concentration  0.87  2.29  3.76  6.40  5.25  0.70  0.18  Minimum value  0.33  1.22  1.32  2.32  2.23  0.07  n/d  Maximum value  1.78  4.22  6.07  11.58  10.61  2.05  0.38  Standard Deviation  0.53  1.08  1.31  3.30  2.52  0.53  0.12  95% Confidence Interval  0.31  0.64  0.78  1.95  1.49  0.31  0.07  Temperature Data - Copper  Sampling Date  Flowing Water Temp. °C  Copper Concentration  Standing Water Temp. °C  mg/L  Plumbing Coil-Copper Levels - Temperature Range 12-17 °C 26/08/92  17.0  22.5  1.03  1.86  0.39  1.11  0.24  0.48  0.46  01/09/92  17.0  21.5  0.91  1.15  1.01  0.49  0.69  0.42  0.28  16/09/92  15.5  19.0  0.97  1.60  0.27  0.16  0.66  1.60  1.15  30/09/92  13.5  17.5  0.86  5.31  0.80  1.25  1.31  0.35  0.31  14/07/93  12.0  16.0  1.22  2.95  2.43  1.30  1.43  0.34  0.50  21/07/93  12.5  16.0  1.52  5.53  2.15  1.58  2.33  0.41  2.38  06/08/93  13.5  19.5  1.30  3.89  4.80  0.29  1.18  0.29  0.<14  10/08/93  14.0  18.0  1.17  2.59  2.62  2.01  4.36  0.67  2.27  Average concentration  1.12  3.11  1.81  1.02  1.53  0.57  0.94  Minimum value  0.86  1.15  0.27  0.16  0.24  0.29  0.14  Maximum value  1.52  5.53  4.80  2.01  4.36  1.60  2.38  Standard Deviation  0.22  1.66  1.52  0.65  1.31  0.43  0.91  95% Confidence Interval  0.15  1.15  1.05  0.45  0.91  0.30  0.63  193  Appendix Q Comparison of Two Temperature Ranges Temperature Data - Copper continued  Sampling Date  Flowing Water Temp. °C  Copper Concentration  Standing Water Temp. °C  mg/L  Plumbing Coil-Copper Levels - Temperature Range 2-7 °C 25/11/92  7.0  10.5  0.95  1.02  0.57  0.36  0.27  0.28  0.14  9/12/92  4.5  12.5  0.97  0.81  0.64  1.19  0.96  0.34  0.40  6/1/93  2.0  6.5  0.84  4.71  0.72  1.31  2.63  0.38  0.29  28/01/93  2.0  7.0  1.83  11.36  1.89  2.10  4.93  0.43  0.30  19/02/93  3.0  8.0  1.44  6.34  2.83  1.56  7.13  0.30  0.83  8/3/93  4.0  9.0  1.45  0.85  0.99  0.49  0.63  0.47  0.83  19/03/93  4.0  11.5  1.58  3.86  2.43  0.22  0.74  0.36  0.80  2/4/93  5.0  10.5  3.38  6.12  1.59  0.19  2.42  0.33  0.84  8/4/93  5.5  12.0  1.06  5.87  1.36  0.79  0.16  0.23  0.17  18/04/93  6.0  11.0  1.22  8.57  3.61  0.82  1.64  4.14  1.01  7/5/93  6.5  11.5  0.99  6.03  1.97  0.83  1.70  0.28  1.84  Average concentration  1.43  5.05  1.69  0.90  2.11  0.69  0.68  Minimum value  0.84  0.81  0.57  0.19  0.16  0.23  0.14  Maximum value  3.38  11.36  3.61  2.10  7.13  4.14  1.84  Standard Deviation  0.72  3.32  0.98  0.60  2.16  1.15  0.50  95% Confidence Interval  0.42  1.96  0.58  0.35  1.27  0.68  0.29  194  Appendix R Conductivity Measurements Date  Days From Start  Loop Number:  Comments  Conductivity - u S / c m  1  2  3  4  5  6  7  14/08/92  0  15.1  43.3  63.4  51.2  62.0  47.5  62.8  1 7/08/92  3  15.4  43.8  59.0  50.4  60.1  43.4  60.5  1 8/08/92  4  15.4  47.2  68.4  53.8  70.9  55.5  57.8  1 9/08/92  5  15.2  45.9  67.1  50.8  62.3  56.4  57.8  20/08/92  6  15.1  46.8  66.6  51.2  63.0  57.1  55.9  21/08/92  7  15.2  45.9  58.3  53.3  68.6  54.2  58.0  25/08/92  1 1  15.0  43.7  64.7  53.7  65.8  52.7  53.3  15.8  37.3  42.3  45.2  44.2  40.1  29.8  Faucets/8 hr standing  14.9  52.8  42.3  75.5  48.9  59.0  33.2  Solder coils/8 hr standing  17.3  60.7  43.9  72.7  52.0  49.2  30.5  Plumbing coils/8 hr standing  26/08/92  12  27/08/92  13  14.8  43.3  62.1  48.7  64.2  44.9  51.1  28/08/92  14  14.5  48.6  64.8  56.0  71.3  51.4  57.4  31/08/92  17  14.5  45.7  57.5  53.4  50.7  41.8  32.4  01/09/92  18  14.7  39.1  57.9  52.6  58.4  41.9  50.8  14.8  33.9  41.0  44.4  47.8  36.4  27.1  Faucets/8 hr standing  15.3  34.8  39.0  45.5  44.9  37.8  26.4  Solder coils/8 hr standing  16.5  36.6  39.7  45.0  45.8  37.5  26.7  Plumbing coils/8hr standing  03/09/92  20  13.9  41.4  55.3  55.8  65.9  52.7  47.1  04/09/92  21  14.3  45.1  59.1  58.4  72.8  50.8  56.3  05/09/92  22  14.2  42.9  53.0  47.2  66.0  48.3  50.2  08/09/92  25  14.0  38.4  61.3  53.1  59.2  54.3  38.5  10/09/92  27  14.1  37.7  67.9  41.4  60.8  50.2  49.6  11/09/92  28  14.0  35.3  57.1  42.4  58.4  42.6  49.8  14/09/92  31  14.4  37.7  57.2  41.7  57.7  47.7  46.1  195  Appendix R Conductivity Measurements Date  Days  Comments  Conductivity - u S / c m  From Start Loop Number:  1  2  3  4  5  6  7  1 5/09/92  32  14.5  37.2  59.8  42.6  58.0  46.8  48.7  16/09/92  33  14.4  38.3  56.2  42.9  57.5  46.0  46.5  14.5  34.8  43.6  37.3  48.8  38.5  27.9  Solder coils/8 hr standing  14.4  35.1  42.2  38.0  46.2  36.4  29.2  Faucets/8 hr standing  15.8  34.6  41.9  39.9  48.2  36.7  27.0  Plumbing coils/8 hr standing  1 7/09/92  34  14.7  40.0  56.3  44.3  59.2  48.9  44.9  18/09/92  35  14.5  35.3  52.6  42.5  58.1  45.4  45.8  21/09/92  38  14.5  34.6  89.3  41.0  56.2  41.5  42.7  22/09/92  39  14.2  35.6  45.1  40.1  57.5  45.4  45.2  23/09/92  40  14.6  35.9  58.9  39.5  55.4  53.1  46.4  24/09/92  41  14.6  35.6  52.3  40.3  54.8  47.3  47.6  25/09/92  42  14.9  37.2  54.7  41.9  55.6  38.6  43.4  28/09/92  45  14.8  36.2  54.2  40.5  53.5  46.0  39.8  29/09/96  46  14.6  38.9  57.2  42.7  54.9  45.1  44.5  30/09/92  47  14.6  37.0  61.1  38.8  53.1  42.7  38.8  14.8  35.2  39.5  39.2  46.0  34.5  27.9  Solder coils/8 hr standing  15.5  34.1  36.9  37.5  43.3  34.1  29.1  Faucets/8 hr standing  15.8  34.7  37.5  38.6  43.9  34.5  34.1  Plumbing coils/8 hr standing  01/10/92  48  15.0  37.3  56.8  40.3  51.7  39.4  40.3  02/10/92  49  15.0  35.9  48.8  39.6  54.9  42.8  42.7  05/10/92  52  14.5  37.7  52.0  40.7  51.3  42.3  39.6  06/10/92  53  14.4  36.8  51.0  44.4  55.9  46.7  44.0  07/10/92  54  14.2  35.8  54.6  45.2  54.9  50.0  44.1  196  Appendix R Conductivity Measurements Date  Days  Comments  Conductivity - u S / c m  From Start Loop Number:  1  2  3  4  5  6  7  08/10/92  55  15.1  39.1  54.6  43.3  54.9  44.6  45.7  09/10/92  56  14.9  44.1  53.0  42.3  53.3  41.3  43.2  13/10/92  60  14.6  36.9  44.5  43.4  53.8  43.9  41.5  15/10/92  62  14.4  36.2  56.2  50.9  68.1  38.2  44.9  16/10/92  63  15.4  40.5  57.8  51.4  62.7  41.1  46.1  19/10/92  66  15.0  37.2  52.1  50.7  55.9  42.5  40.4  20/10/92  67  14.5  36.9  51.3  45.9  56.9  38.2  51.3  21/10/92  68  14.2  35.5  56.8  43.9  57.7  44.9  40.3  14.6  33.2  39.2  41.3  50.8  35.7  29.8  Solder coils/8 hr standing  14.3  31.8  37.5  40.8  46.6  34.3  29.8  Faucets/8 hr standing  15.9  33.8  36.7  41.7  48.3  38.4  38.3  Plumbing coils/8 hr standing  22/10/92  69  14.8  36.7  49.0  41.8  55.5  43.8  43.9  23/10/92  70  13.1  32.6  44.1  38.9  49.5  36.1  39.1  26/10/92  73  12.8  34.0  57.9  38.8  57.6  43.7  44.6  27/10/92  74  12.4  33.6  53.8  39.0  54.3  42.9  42.5  28/10/92  75  12.4  33.0  42.0  35.7  50.5  41.2  42.3  29/10/92  76  12.5  34.5  49.8  38.8  51.8  40.3  43.7  30/10/92  77  12.1  31.7  48.9  35.4  50.4  37.7  41.1  03/11/92  81  -  -  -  -  -  -  -  meter  05/11/92  83  -  -  -  -  -  -  -  not working  06/11/92  84  11.6  32.8  70.1  37.2  48.0  36.8  37.1  09/11/92  87  14.2  44.5  54.2  45.9  62.3  50.6  49.0  10/11/92  88  14.8  43.7  63.2  45.6  61.8  46.5  51.2  197  Appendix R Conductivity Measurements Date  Days  Comments  Conductivity - u S / c m  From Start Loop N u m b e r :  1  2  3  4  5  6  7  12/11/92  90  14.6  40.9  59.1  50.3  67.8  56.9  51.1  13/11/92  91  14.7  41.6  61.0  46.9  63.7  52.9  48.6  16/11/92  94  14.4  42.9  63.3  50.4  65.0  45.7  52.3  17/11/92  95  14.3  41.2  59.1  49.5  62.0  51.2  45.5  18/11/92  96  14.1  41.9  58.9  48.9  62.4  52.3  48.5  14.8  38.9  48.3  47.7  54.2  41.7  35.0  Solder coils/8 hr standing  14.4  37.7  43.9  44.8  49.9  40.9  36.5  Faucets/8 hr standing  16.0  38.5  45.0  46.9  53.1  49.5  43.7  Plumbing coils/8 hr standing  19/11/92  97  14.1  42.7  61.9  51.2  63.8  52.8  48.3  20/11/92  98  13.9  40.9  67.1  49.1  63.4  46.5  48.1  23/11/92  101  14.5  42.0  49.8  52.0  66.5  48.7  49.3  24/11/92  102  14.3  40.9  66.0  49.3  65.0  49.1  50.3  25/11/92  103  14.5  39.7  59.4  48.2  63.8  46.3  41.0  14.2  37.1  47.4  49.0  59.3  39.8  35.2  Solder coils/8 hr standing  14.3  36.8  45.3  45.7  54.0  37.5  30.3  Faucets/8 hr standing  15.4  37.9  53.3  48.6  56.6  39.3  35.3  Plumbing coils/8 hr standing  26/11/92  104  14.1  39.5  55.4  51.0  67.5  47.4  57.0  27/11/92  105  14.4  38.8  75.3  49.9  67.1  50.2  51.9  30/11/92  108  14.1  45.6  58.3  51.1  61.3  46.6  46.6  02/12/92  110  14.0  40.4  49.2  41.5  61.6  37.8  40.2  03/12/92  111  13.8  41.7  59.9  46.1  65.8  47.3  48.3  04/12/92  112  14.0  39.7  55.7  45.5  56.5  47.0  47.1  07/12/92  115  13.7  36.1  56.1  43.9  58.2  44.6  46.0  198  Appendix R Conductivity Measurements Date  Days  Comments  Conductivity - u S / c m  From Start Loop Number:  1  2  3  4  5  6  7  08/12/92  116  14.1  38.0  56.5  44.6  59.4  48.3  45.5  09/12/92  117  13.6  37.2  53.8  43.7  56.8  45.9  37.9  13.6  34.5  46.0  44.0  51.2  35.7  32.9  Solder coils/8 hr standing  14.0  34.2  45.0  42.3  48.0  35.9  29.4  Faucets/8 hr standing  14.9  34.9  45.8  42.3  49.7  35.3  30.7  Plumbing coils/8 hr standing  10/12/92  118  13.4  36.7  55.1  44.3  57.0  43.4  41.5  11/12/92  119  13.8  42.0  43.3  41.4  55.8  44.5  40.2  14/12/92  122  13.8  35.9  34.1  43.6  59.3  43.7  43.9  17/12/92  125  13.9  40.7  32.8  40.1  53.6  44.6  43.1  18/12/92  126  13.6  32.5  51.3  39.6  54.7  43.4  44.1  22/12/92  130  13.5  39.0  59.7  39.8  57.2  44.3  42.7  23/12/92  131  13.1  42.4  52.6  40.3  57.9  43.8  44.0  24/12/92  132  13.3  37.7  59.4  40.8  53.7  41.8  41.2  28/12/92 ,  136  13.4  35.7  45.3  38.0  55.0  38.1  40.9  30/12/92  138  13.4  30.1  57.6  39.7  53.1  39.3  42.0  31/12/92  139  14.1  38.8  62.6  40.6  55.7  46.5  48.0  04/01/93  143  14.2  42.8  51.1  37.1  53.8  39.3  44.7  05/01/93  144  14.1  34.1  53.3  35.5  51.5  39.9  44.6  06/01/93  T45  13.8  35.7  52.5  35.5  49.5  40.4  39.8  13.4  31.9  45.3  26.8  47.4  32.0  33.8  Solder coils/8 hr standing  13.5  30.1  45.0  26.4  45.5  30.3  30.5  Faucets/8 hr standing  14.0  30.4  45.2  26.5  46.3  32.4  31.6  Plumbing coils/8 hr standing  13.3  38.4  50.3  36.8  51.3  40.5  39.8  07/01/93  146  199  Appendix R Conductivity Measurements Date  Days  Comments  Conductivity - p S / c m  From Start Loop Number:  1  2  3  4  5  6  7  12/01/93  151  13.7  36.7  48.7  43.2  60.5  44.9  47.0  13/01/93  152  13.3  34.8  50.7  41.7  51.0  37.4  45.6  14/01/93  153  15.1  46.2  58.6  39.5  57.6  44.8  44.2  15/01/93  154  14.5  36.6  54.7  36.7  53.0  41.2  37.8  19/01/93  158  14.8  45.7  63.7  40.8  58.3  45.0  44.1  20/01/93  159  14.3  44.3  68.4  40.7  59.3  46.3  48.5  21/01/93  160  14.3  37.6  51.7  38.8  56.0  42.6  45.5  22/01/93  161  14.5  37.6  52.2  39.2  52.7  42.9  44.1  25/01/92  164  15.4  37.9  56.7  39.4  52.9  43.7  48.1  27/01/93  166  14.8  37.3  49.4  35.2  52.0  40.1  45.9  28/01/93  167  15.0  35.9  45.3  35.7  48.5  42.1  47.1  15.2  31.0  44.7  26.9  47.5  32.3  34.0  Solder coils/8 hr standing  14.3  30.2  44.0  26.6  47.7  29.9  30.1  Faucets/8 hr standing  16.4  31.2  45.5  28.3  50.0  33.1  33.2  Plumbing coils/8 hr standing  29/01/93  168  14.2  37.7  51.0  41.6  53.9  38.0  41.5  01/02/93  171  14.5  39.8  63.9  40.3  56.3  40.1  44.6  03/02/93  173  14.4  40.5  49.9  34.1  50.8  41.2  41.6  04/02/93  174  14.0  40.2  55.1  37.4  51.3  40.7  41.0  08/02/93  178  -  -  -  -  -  -  -  conductivity meter  05/03/93  203  -  -  -  -  -  -  not available  08/03/93  206  15.2  47.5  63.3  47.9  63.9  49.2  49.8  15.7  39.9  58.1  40.4  58.7  45.6  43.7  Solder coils/8 hr standing  16.3  38.5  55.7  36.7  62.0  45.8  48.1  Faucets/8 hr standing  18.6  40.4  60.2  38.8  51.2  49.9  46.7  Plumbing coils/8 hr standing  200  Appendix R Conductivity Measurements Date  Days  Comments  Conductivity - p S / c m  From Start Loop Number:  1  2  3  4  5  6  7  09/03/93  207  16.2  43.9  67.8  48.7  63.2  51.0  51.5  12/03/93  210  15.8  43.0  61.4  45.0  63.3  52.2  49.2  1 5/03/93  213  16.1  50.1  63.1  49.0  68.5  51.7  53.1  17/03/92-  215  15.7  45.1  62.0  48.5  65.1  49.3  52.7  18/03/93  216  15.8  46.2  64.0  46.9  65.1  54.2  50.0  19/03/93  217  17.1  48.4  70.0  42.1  62.9  52.3  45.7  Solder coil/16 hr standing  17.2  45.8  67.0  39.3  62.7  53.2  48.6  Faucets/16 hr standing  21.8  50.0  68.5  39.6  57.3  49.7  46.9  Plumbing coils/16 hr standing  23/03/93  221  14.4  47.5  74.4  47.5  55.0  57.3  52.5  24/03/93  222  14.2  49.6  64.5  44.2  61.8  53.2  48.7  25/03/93  223  -  -  -  -  -  -  -  conductivity meter  19/04/93  248  -  -  -  -  -  -  -  not available  22/04/93  251  12.1  46.4  66.0  48.5  62.1  65.9  48.2  new meter  27/04/93  256  12.6  43.6  59.8  48.3  65.5  42.7  51.2  29/04/93  258  11.8  43.8  61.5  42.9  64.8  36.5  48.9  03/05/93  262  11.0  48.3  65.1  44.6  66.3  52.4  50.5  05/05/93  264  13.0  49.1  74.2  49.2  64.3  54.3  58.8  06/05/93  265  11.1  44.4  60.2  47.1  62.4  40.0  49.4  07/05/93  266  11.1  36.5  48.9  34.0  55.3  40.8  47.9  Solder coil/16 hr standing  -  36.6  48.2  33.0  55.2  40.9  51.1  Faucets/16 hr standing  13.4  37.6  51.1  35.0  56.6  41.9  48.8  Plumbing coils/16 hr standing  11/05/93  270  11.1  42.8  60.1  45.7  65.6  54.3  50.6  12/05/93  271  11.3  42.0  63.2  46.1  65.9  45.2  50.1  14/05/93  273  11.8  45.5  63.9  49.6  63.7  48.6  54.9  201  Appendix R Conductivity Measurements Date  Days  Comments  Conductivity - u S / c m  From Start Loop Number:  1  2  3  4  5  6  7  12.1  35.4  52.4  36.6  62.0  42.7  50.3  Solder coils/8 hr standing  11.9  33.8  50.1  30.7  49.6  48.8  55.1  Faucets/8 hr standing  12.9  36.3  54.0  33.8  58.4  41.3  53.0  Plumbing coils/8 hr standing  18/05/93  277  11.8  44.1  65.5  49.6  67.8  46.7  52.0  20/05/93  279  12.0  43.9  55.9  46.3  66.2  43.3  51.8  21/05/93  280  11.1  46.9  65.4  51.6  67.7  46.6  50.1  27/05/93  286  11.0  43.6  67.6  47.7  67.9  44.7  50.1  28/05/93  287  10.7  43.8  61.7  46.8  72.0  53.1  47.9  03/06/93  293  11.0  -  -  -  -  -  -  04/06/93  294  13.0  45.6  64.2  47.7  69.9  47.1  51.9  08/06/93  298  13.1  51.7  59.2  46.7  67.8  42.2  54.9  09/06/93  299  14.5  59.7  71.6  45.5  67.0  46.7  39.9  10/06/93  300  13.5  39.7  63.3  50.4  65.4  51.1  53.8  11/06/93  301  14.3  29.1  52.7  32.1  62.4  45.5  44.2  Solder coil/16 hr standing  14.1  28.2  52.5  33.1  63.0  45.8  48.3  Faucets/16 hr standing  16.3  30.8  54.8  33.3  63.5  46.6  45.8  Plumbing coils/1 6 hr standing  1 5/06/93  305  13.6  47.5  64.1  47.2  68.4  49.1  46.5  1 6/06/93  306  14.1  47.7  68.3  52.5  69.8  55.8  48.8  1 7/06/93  307  13.9  49.4  65.1  48.1  74.6  47.8  55.9  18/06/93  308  14.3  41.2  62.5  47.9  68.4  52.5  59.5  22/06/93  312  14.1  51.1  65.5  46.8  68.0  48.9  53.6  23/06/93  313  14.1  44.7  68.0  49.9  65.7  50.3  55.1  24/06/93  314  14.8  45.1  67.1  49.5  68.7  51.7  52.0  202  Appendix R Conductivity Measurements Date  Days  Comments  Conductivity - p S / c m  From Start Loop N u m b e r :  1  2  3  4  5  6  7  25/06/93  315  14.9  42.1  71.4  48.9  71.7  47.1  57.4  29/06/93  319  14.8  47.6  66.4  48.5  59.0  46.5  54.4  30/06/93  320  14.8  28.6  56.7  26.5  52.6  40.2  40.1  14.9  27.9  55.4  28.2  54.4  40.6  43.2  Faucets/16 hr standing  15.4  30.8  58.0  28.9  54.8  42.3  42.7  Plumbing coils/16 hr standing  01/07/93  321  14.8  49.1  62.0  48.0  66.0  52.4  51.8  05/07/93  325  14.8  49.6  64.1  49.7  73.1  48.4  55.1  06/07/93  326  15.6  45.0  64.3  49.2  69.9  47.4  50.1  07/07/93  327  15.2  49.1  67.2  45.2  76.9  53.0  47.9  09/07/93  329  15.8  47.4  68.6  48.4  71.5  46.3  65.3  1 2/07/93  332  15.8  51.4  67.5  51.1  66.2  53.5  51.3  13/07/93  333  16.2  47.7  62.7  34.5  65.6  52.5  44.2  14/07/93  334  15.2  46.7  63.8  53.5  71.4  51.9  47.2  16.2  29.5  56.1  31.0  55.5  42.9  41.3  16.0  26.6  54.9  30.8  52.9  40.4  47.4  17.6  28.8  55.1  30.9  53.9  42.5  32.4  1 5/07/93  335  16.1  52.6  67.6  54.4  69.1  48.8  50.7  19/07/93  339  16.2  49.5  69.8  52.1  69.3  47.7  51.4  20/07/93  340  16.5  47.9  65.8  44.1  67.1  50.1  50.6  21/07/93  341  16.4  29.8  56.4  30.4  53.4  46.1  43.9  17.5  28.9  55.7  32.2  56.6  46.8  47.5  17.7  31.0  58.1  32.1  55.8  47.9  45.1  Solder coil/16 hr standing  Solder clils/8 hr standing Faucets/8 hr standing Plumbing coils/8 hr standing  Solder coil/16 hr standing Faucets/16 hr standing Plumbing coils/16 hr standing  203  Appendix R Conductivity Measurements Date  Days From Start  Loop Number:  Comments  Conductivity - uS/cm  1  2  3  4  5  6  7  22/07/93  342  16.6  48.9  63.2  49.8  65.1  62.2  58.3  23/07/93  343  16.7  41.7  69.7  50.3  67.6  47.8  48.4  27/07/93  347  16.4  49.4  70.1  46.0  76.2  46.8  48.2  28/07/93  348  16.9  51.9  69.4  52.7  68.1  58.7  55.7  29/07/93  349  18.3  48.1  70.4  40.8  74.8  52.2  52.5  30/07/93  350  17.0  48.7  68.4  58.3  73.3  54.0  50.0  03/08/93  354  17.1  60.1  67.5  39.7  71.2  64.3  51.0  04/08/93  355  17.3  46.1  74.6  59.0  69.7  51.7  53.2  05/08/93  356  17.4  50.4  67.1  55.9  66.4  51.1  53.2  06/08/93  357  16.2  46.4  58.7  53.0  68.2  50.0  54.7  17.0  26.2  50.1  30.1  50.4  37.8  36.0  Solder coils/8 hr standing  16.5  26.5  50.6  30.4  51.5  35.3  29.3  Faucets/8 hr standing  17.3  22.9  48.4  28.0  46.5  34.6  29.0  Plumbing coils/8 hr standing  09/08/93  360  14.8  44.4  53.1  46.9  49.6  39.6  46.4  10/08/93  361  14.3  25.3  46.2  28.0  46.2  33.0  31.8  Solder coil/16 hr standing  13.1  23.7  43.9  28.3  49.7  31.8  33.4  Faucets/16 hr standing  12.4  25.1  44.1  28.3  46.2  32.8  32.4  Plumbing coils/1 6 hr standing  204  Appendix S Quality Control Samples  UBC Environmental Laboratory Results Relative to GVRD Laboratory Results Copper Measurements Sample  Date Collected  UBC Measure  GVRD Measure  UBC/GVRD  Copper concentration mg/L Blank  14/07/93  0.04  0.05  0.80  30/09/92  0.46  0.58  0.79  21/10/92  0.24  0.27  0.89  25/08/92  1.24  1.27  0.98  01/09/92  0.22  0.24  0.92  Faucet/ Loop 2  30/06/93  0.10  0.16  0.63  Faucet/ Loop 2  06/08/93  0.14  0.16  0.88  Faucet/ Loop 3  16/09/92  0.04  0.08  0.50  Faucet/ Loop 2  19/03/93  0.09  0.12  0.75  Faucet/ Loop 4  07/05/93  0.02  0.04  0.50  Faucet/ Loop 5  10/08/93  0.10  0.14  0.71  Faucet/ Loop 5  06/01/93  0.20  0.23  0.87  Faucet/ Loop 6  30/09/92  0.16  0.19  0.84  Faucet/ Loop 6  21/10/92  0.21  0.22  0.95  Faucet/ Loop 7  19/02/93  0.10  0.17  0.59  16/09/92  0.96  0.99  0.97  Plumbing coil/Loop 1  26/08/92  1.08  1.12  0.96  Plumbing coil/Loop 2  10/10/92  3.89  3.97  0.98  Plumbing coil/Loop 4  16/09/92  0.17  0.22  0.77  Plumbing coil/Loop 4  14/07/92  1.26  1.32  0.95  Plumbing coil/Loop 4  14/07/92  1.27  . 1.34  0.95  Plumbing coil/Loop 5  18/11/92  7.58  7.72  0.98  Plumbing coil/Loop 6  14/07/92  1.19  1.30  0.92  Plumbing coil/Loop 7  16/09/92  0.73  0.80  0.91  Faucet/ Loop 1 Faucet/ Loop 1 Faucet/ Loop 1 Faucet/ Loop 1  Plumbing coil/Loop 1  205  Appendix S Quality Control Samples Copper Measurements Sample  Date Collected  UBC  Measure  G V R D Measure  UBC/GVRD  Copper concentration m g / L Plumbing coil/Loop 7  26/08/92  0.42  0.46  0.91  Plumbing coil/Loop 7  16/09/92  1.62  1.64  0.99  Plumbing coil/Loop 7  14/07/92  1.05  1.11  0.95  Plumbing coil/Loop 1  14/07/93  1.23  1.40  0.88  Plumbing coil/Loop 3  28/01/93  0.57  0.78  0.73  Plumbing coil/Loop 3  18/06/93  2.81  2.97  0.95  Plumbing coil/Loop 4  30/06/93  1.74  1.82  0.96  Plumbing coil/Loop 4  10/08/93  1.58  1.70  0.93  Plumbing coil/Loop 5  28/01/93  4.60  4.66  0.99  Plumbing coil/Loop 5  18/06/93  1.86  2.10  0.89  Plumbing coil/Loop 6  06/08/93  0.33  0.39  0.85  Plumbing coil/Loop 7  08/04/93  0.23  0.31  0.74  Plumbing coil/Loop 7  04/06/93  1.83  1.97  0.93  Plumbing coil/Loop 4  28/01/93  2.30  2.37  0.97  Plumbing coil/Loop 2  08/04/93  5.48  5.33  1.03  Plumbing coil/Loop 3  28/01/93  2.98  3.08  0.97  Plumbing coil/Loop 3  02/04/93  2.25  2.30  0.98  Plumbing coil/Loop 3  07/05/93  2.10  2.13  0.99  Plumbing coil/Loop 3  04/06/93  6.00  5.82  1.03  Plumbing coil/Loop 4  08/04/93  0.83  0.97  0.86  Plumbing coil/Loop 4  21/07/93  1.94  1.95  0.99  Plumbing coil/Loop 6  18/04/93  . 4.32  4.13  1.05  Plumbing coil/Loop 6  14/07/93  0.36  0.43  0.84  Plumbing coil/Loop 7  08/03/93  0.73  0.85  0.86  Plumbing coil/Loop 7  18/04/93  1.14  1.21  0.94  Plumbing coil/Loop 7  21/07/93  3.25  3.21  1.01  206  Appendix S Quality Control S a m p l e s  Copper Measurements Sample  Date Collected  UBC Measure  GVRD Measure  UBC/GVRD  Copper concentration mg/L Plumbing coil/Loop 7  06/08/93  0.18  0.24  0.75  Solder coil/Loop 1  21/10/92  0.16  0.17  0.94  Solder coil/Loop 1  02/04/93  0.14  0.20  0.70  Solder coil/Loop 1  18/06/93  0.21  0.39  0.54  Solder coil/Loop 2  16/09/92  0.09  0.09  1.00  Solder coii/Loop 2  21/10/92  0.00  0.10  0.00  Solder coil/Loop 2  08/03/93  0.09  0.13  0.69  Solder coil/Loop 2  21/07/93  0.10  0.13  0.77  Solder coil/Loop 3  30/09/92  0.16  0.19  0.84  Solder coil/Loop 3  21/10/92  0.17  0.20  0.85  Solder coil/Loop 3  28/0193  0.05  0.09  0.56  Solder coil/Loop 3  08/04/93  0.42  0.54  0.78  Solder coil/Loop 3  07/05/93  0.04  0.08  0.50  Solder coil/Loop 3  18/06/93  0.05  0.17  0.29  Solder coil/Loop 4  21/10/92  0.05  0.06  0.83  Solder coil/Loop 4  21/01/93  0.03  0.05  0.60  Solder coil/Loop 4  14/05/93  0.01  0.04  0.25  Solder coil/Loop 4  30/06/93  0.01  0.04  0.25  Solder coil/Loop 4  10/08/93  0.04  0.06  0.67  Solder coil/Loop 5  30/09/92  0.28  0.32  0.88  Solder coil/Loop 5  21/10/92  0.07  0.09  0.78  Solder coil/Loop 5  21/01/93  0.03  0.05  0.60  Solder coil/Loop 5  04/06/93  0.03  0.05  0.60  Solder coil/Loop 6  28/01/93  0.04  1.23  0.03  Solder coil/Loop 6  09/12/92  0.02  0.05  0.40  Solder coil/Loop 7  09/12/92  0.01  0.04  0.25  207  Appendix S Quality Control Samples Lead Measurements Sample  Date  Collected  UBC  Measure  G V R D Measure  UBC/GVRD  Lead concentration m g / L Blank  14/07/93  <0.001  0.002  <0.50  Faucet/ Loop 1  30/09/92  0.049  0.110  0.45  Faucet/ Loop 1  21/10/92  0.006  0.014  0.43  Faucet/ Loop 1  25/08/92  0.144  0.260  0.55  Faucet/ Loop 1  01/09/92  <0.001  0.015  <0.07  Faucet/ Loop 2  30/06/93  <0.001  0.008  <0.13  Faucet/ Loop 2  06/08/93  0.006  0.009  0.67  Faucet/ Loop 3  16/09/92  <0.001  0.009  <0.11  Faucet/ Loop 2  19/03/93  0.003  0.006  0.50  Faucet/ Loop 4  07/05/93  0.004  0.003  1.33  Faucet/ Loop 5  10/08/93  0.006  0.012  0.50  Faucet/ Loop 5  06/01/93  <0.001  0.007  <0.14  Faucet/ Loop 6  30/09/92  <0.001  0.005  <0.20  Faucet/ Loop 6  21/10/92  <0.001  0.005  <0.20  Faucet/ Loop 7  19/02/93  <0.001  0.004  <0.25  Plumbing coil/Loop 1  16/09/92  <0.001  0.006  <0.17  Plumbing coil/Loop 1  26/08/92  <0.001  0.005  <0.20  Plumbing coil/Loop 2  10/10/92  <0.001  0.021  <0.05  Plumbing coil/Loop 4  16/09/92  <0.001  0.005  <0.20  Plumbing coil/Loop 4  14/07/92  <0.001  0.006  <0.17  Plumbing coil/Loop 4  14/07/92  <0.001  0.006  <0.17  Plumbing coil/Loop 5  18/11/92  <0.001  0.130  <0.01  Plumbing coil/Loop 6  14/07/92  <0.001  0.005  <0.20  Plumbing coil/Loop 7  16/09/92  <0.001  0.010  <0.10  208  Appendix S Quality Control Samples Lead Measurements Sample  Date  Collected  U B C Measure  G V R D Measure  UBC/GVRD  Lead concentration m g / L Plumbing coil/Loop 7  26/08/92  <0.001  0.003  <0.33  Plumbing coil/Loop 7  16/09/92  0.010  0.015  0.67  Plumbing coil/Loop 7  14/07/92  <0.001  0.006  <0.17  Plumbing coil/Loop 1  14/07/93  <0.001  0.004  <0.25  Plumbing coil/Loop 3  28/01/93  <0.001  0.004  <0.25  Plumbing coil/Loop 3  18/06/93  0.009  0.018  0.50  Plumbing coil/Loop 4  30/06/93  0.006  0.018  0.33  Plumbing coil/Loop 4  10/08/93  0.018  0.036  0.50  Plumbing coil/Loop 5  28/01/93  0.046  0.068  0.68  Plumbing coil/Loop 5  1 8/06/93  0.019  0.030  0.63  Plumbing coil/Loop 6  06/08/93  <0.001  0.002  <0.50  Plumbing coil/Loop 7  08/04/93  0.013  0.014  0.93  Plumbing coil/Loop 7  04/06/93  0.014  0.014  1.00  Plumbing coil/Loop 4  28/01/93  0.013  0.019  0.68  Plumbing coil/Loop 2  08/04/93  0.020  0.026  0.77  Plumbing coil/Loop 3  28/01/93  0.010  0.021  0.48  Plumbing coil/Loop 3  02/04/93  0.012  0.013  0.92  Plumbing coil/Loop 3  07/05/93  0.010  0.018  0.56  Plumbing coil/Loop 3  04/06/93  0.059  0.062  0.95  Plumbing coil/Loop 4  08/04/93  0.009  0.009  1.00  Plumbing coil/Loop 4  21/07/93  <0.001  0.019  <0.05  Plumbing coil/Loop 6  18/04/93  0.020  0.029  0.69  Plumbing coil/Loop 6  14/07/93  0.006  0.002  3.00  209  Appendix S Quality Control Samples Lead Measurements Sample  Date  Collected  U B C Measure  G V R D Measure  UBC/GVRD  Lead concentration m g / L Plumbing coil/Loop 7  08/03/93  0.008  0.007  1.14  Plumbing coil/Loop 7  18/04/93  0.008  0.010  0.80  Plumbing coil/Loop 7  21/07/93  <0.001  0.029  <0.03  Plumbing coil/Loop 7  06/08/93  <0.001  0.002  <0.50  Solder coil/Loop 1  21/10/92  1.110  1.220  0.91  Solder coil/Loop 1  02/04/93  0.660  0.800  0.83  Solder coil/Loop 1  18/06/93  0.850  1.070  0.79  Solder coil/Loop 2  16/09/92  1.360  1.530  0.89  Solder coil/Loop 2  21/10/92  2.660  2.660  1.00  Solder coil/Loop 2  08/03/93  2.990  3.130  0.96  Solder coil/Loop 2  21/07/93  1.760  1.800  0.98  Solder coil/Loop 3  30/09/92  6.620  6.760  0.98  Solder coil/Loop 3  21/10/92  5.030  5.260  0.96  Solder coil/Loop 3  28/01/93  4.690  4.900  0.96  Solder coil/Loop 3  08/04/93  3.690  3.870  0.95  Solder coil/Loop 3  07/05/93  1.320  1.400  0.94  Solder coil/Loop 3  18/06/93  2.130  2.340  0.91  Solder coil/Loop 4  21/10/92  4.550  4.680  0.97  Solder coil/Loop 4  21/01/93  6.500  6.490  1.00  Solder coil/Loop 4  14/05/93  3.860  4.040  0.96  Solder coil/Loop 4  30/06/93  0.970  1.070  0.91  Solder coil/Loop 4  10/08/93  1.010  1.110  0.91  Solder coil/Loop 5  30/09/92  3.530  3.580  0.99  Solder coil/Loop 5  21/10/92  4.520  4.600  0.98  Solder coil/Loop 5  21/01/93  2.430  2.530  0.96  210  Appendix S Quality Control Samples Lead Measurements Sample  Date  Collected  U B C Measure  G V R D Measure  UBC/GVRD  Lead concentration m g / L Solder coil/Loop 5  04/06/93  2.770  3.070  0.90  Solder coil/Loop 6  28/01/93  0.930  1.080  0.86  Solder coil/Loop 6  09/12/92  0.740  0.850  0.87  Solder coil/Loop 7  09/12/92  0.160  0.110  1.46  G V R D Measure  UBC/GVRD  line Measurements Sample  Date Collected  U B C Measure  Zinc concentration m g / L Blank  14/07/93  0.03  0.03  1.00  Faucet/ Loop 1  30/09/92  0.10  0.13  0.77  Faucet/ Loop 1  21/10/92  0.12  0.14  0.86  Faucet/ Loop 1  25/08/92  0.24  0.25  0.96  Faucet/ Loop 1  01/09/92  0.10  0.11  0.91  Faucet/ Loop 2  30/06/93  0.07  0.08  0.88  Faucet/ Loop 2  06/08/93  0.04  0.06  0.67  Faucet/ Loop 3  16/09/92  0.05  0.04  1.25  Faucet/ Loop 2  19/03/93  0.02  0.05  0.40  Faucet/ Loop 4  07/05/93  <0.01  0.02  <0.50  Faucet/ Loop 5  10/08/93  0.07  0.08  0.88  Faucet/ Loop 5  06/01/93  0.12  0.17  0.71  Faucet/ Loop 6  30/09/92  0.53  0.59  0.90  Faucet/ Loop 6  21/10/92  0.65  0.71  0.92  Faucet/ Loop 7  19/02/93  1.02  1.61  0.63  2 1 1  Appendix S Quality Control Samples Zinc Measurements Sample  Date Collected  U B C Measure  G V R D Measure  UBC/GVRD  Zinc concentration m g / L Plumbing coil/Loop 1  16/09/92  0.01  0.02  0.50  Plumbing coil/Loop 1  26/08/92  0.01  0.02  0.50  Plumbing coil/Loop 2  10/10/92  0.02  0.02  1.00  Plumbing coil/Loop 4  1 6/09/92  0.01  0.01  1.00  Plumbing coil/Loop 4  14/07/92  0.03  0.02  1.50  Plumbing coil/Loop 4  14/07/92  0.01  0.02  0.50  Plumbing coil/Loop 5  18/11/92  0.13  0.15  0.87  Plumbing coil/Loop 6  14/07/92  0.02  0.05  0.40  Plumbing coil/Loop 7  16/09/92  1.42  1.50  0.95  Plumbing coil/Loop 7  26/08/92  1.04  1.12  0.93  Plumbing coil/Loop 7  16/09/92  1.98  1.99  0.99  Plumbing coil/Loop 7  14/07/92  0.02  0.04  0.50  Plumbing coil/Loop 1  14/07/93  0.01  <0.01  1.00  Plumbing coil/Loop 3  28/01/93  <0.01  0.02  <0.50  Plumbing coil/Loop 3  18/06/93  <0.01  <0.01  <1.00  Plumbing coil/Loop 4  30/06/93  0.03  0.03  1.00  Plumbing coil/Loop 4  10/08/93  0.02  0.03  0.67  Plumbing coil/Loop 5  28/01/93  0.07  0.09  0.78  Plumbing coil/Loop 5  1 8/06/93  0.01  0.04  0.25  Plumbing coil/Loop 6  06/08/93  0.40  0.48  0.83  Plumbing coil/Loop 7  08/04/93  1.10  1.30  0.85  Plumbing coil/Loop 7  04/06/93  3.67  3.96  0.93  Plumbing coil/Loop 4  28/01/93  0.03  0.07  0.43  212  Appendix S Quality Control Samples Zinc Measurements Sample  Date Collected  U B C Measure  G V R D Measure  UBC/GVRD  Zinc concentration m g / L Plumbing coil/Loop 2  08/04/93  0.02  0.02  1.00  Plumbing coil/Loop 3  28/01/93  0.02  0.04  0.50  Plumbing coil/Loop 3  02/04/93  <0.01  0.02  <0.50  Plumbing coil/Loop 3  07/05/93  0.01  0.02  0.50  Plumbing coil/Loop 3  04/06/93  0.01  0.02  0.50  Plumbing coil/Loop 4  08/04/93  0.02  0.02  1.00  Plumbing coil/Loop 4  21/07/93  0.04  0.04  1.00  Plumbing coil/Loop 6  18/04/93  1.51  1.51  1.00  Plumbing coil/Loop 6  14/07/93  0.53  0.64  0.83  Plumbing coil/Loop 7  08/03/93  4.61  4.86  0.95  Plumbing coil/Loop 7  1 8/04/93  3.30  3.43  0.96  Plumbing coil/Loop 7  21/07/93  2.42  2.60  0.93  Plumbing coil/Loop 7  06/08/93  0.46  0.58  0.79  Solder coil/Loop 1  21/10/92  0.03  0.03  1.00  Solder coil/Loop 1  02/04/93  0.01  0.02  0.50  Solder coil/Loop 1  18/06/93  0.01  0.04  0.25  Solder coil/Loop 2  16/09/92  0.02  0.03  0.67  Solder coil/Loop 2  21/10/92  0.01  0.02  0.50  Solder coil/Loop 2  08/03/93  <0.01  0.03  <0.33  Solder coil/Loop 2  21/07/93  <0.01  0.02  <0.05  Solder coil/Loop 3  30/09/92  <0.01  0.02  <0.05  Solder coil/Loop 3  21/10/92  0.02  0.02  1.00  Solder coil/Loop 3  28/0193  0.02  0.02  1.00  Solder coil/Loop 3  08/04/93  0.02  0.03  0.67  213  Appendix S Quality Control Samples Zinc Measurements Sample  Date Collected  U B C Measure  G V R D Measure  UBC/GVRD  Zinc concentration mg/L Solder coil/Loop 3  07/05/93  <0.01  . 0.02  <0.05  Solder coil/Loop 3  1 8/06/93  <0.01  0.02  0.05  Solder coil/Loop 4  21/10/92  0.01  0.02  0.50  Solder coil/Loop 4  21/01/93  0.02  0.02  1.00  Solder coil/Loop 4  14/05/93  0.01  0.04  0.25  Solder coil/Loop 4  30/06/93  0.02  0.02  1.00  Solder coil/Loop 4  10/08/93  0.01  0.02  0.50  Solder coil/Loop 5  30/09/92  0.01  0.03  0.33  Solder coil/Loop 5  21/10/92  0.01  0.02  0.50  Solder coil/Loop 5  21/01/93  0.03  0.02  1.50  Solder coil/Loop 5  04/06/93  0.03  0.03  1.00  Solder coil/Loop 6  28/01/93  0.36  .0.58  0.62  Solder coil/Loop 6  09/12/92  0.36  0.48  0.75  Solder coil/Loop 7  09/12/92  1.14  1.32  0.86  214  Appendix T Unplanned Incidents The following are incidents which occurred during the course of the study which may have influenced outcomes. Date  Event  30/11/92  Pilot plant shut down for two days so maintenance crew could do work. New injection port installed on loop two to make it easier to control pH and alkalinity.  21/12/92  Circuit breaker shut down on weekend so pilot plant may have not been running for up to two days.  09/01/93  Unable to get to pilot plant because road to dam closed due to overturned tanker truck.  10/01/93  Road conditions to dam very hazardous, unable to do check on pilot plant.  11/01/93  Bicarbonate vat found to have run dry, likely for not more than one day.  07/02/93  Automatic timer that starts pipe-loop operation had been off for two days, due to electrical problems.  12/02/93  Electrical work being done at the dam so power shut off and pipeloop system not running for a number of hours.  03/06/93  Bicarbonate pumps shut down for one day due to electrical problem.  07/06/93  Six day supply of chemicals infused over a two day period, possibly because timer had been incorrectly set. Pumps infused the appropriate dose, but for a total of 18 hours a day instead of 6 hours per day.  09/08/93  Bicarbonate pumps shut down for one day due to electrical problem.  215  

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