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Assesment of drinking water quality using disinfection by-products in a distribution system following… Bush, Kelly Lynn 2008

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ASSESSMENT OF DRINKING WATER QUALITY USING DISINFECTION BY- PRODUCTS IN A DISTRIBUTION SYSTEM FOLLOWING A TREATMENT TECHNOLOGY UPGRADE by KELLY LYNN BUSH B.Sc., The University of Manitoba, 1999 B.A.Sc., The University of Waterloo, 2004 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE FACULTY OF GRADUATE STUDIES (Civil Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) April 2008 © Kelly Lynn Bush, 2008 Abstract Chlorine is the most widely used disinfectant for drinking water treatment. Chlorine can react with natural organic matter (NOM) in water sources resulting in the formation of potentially carcinogenic disinfection by-products (DBPs). The most common DBPs measured in chlorinated drinking water distribution systems are trihalomethanes (THMs) and haloacetic acids (HAAs). In 2005, the City of Kamloops, British Columbia upgraded the drinking water treatment system to ultrafiltration membrane treatment. The objective of this study was to determine the extent to which upgrades to a drinking water treatment system, specifically, implementation of an ultrafiltration treatment process, impacted DBP formation within a distribution system. This study used a two-phase research approach. Phase I of the study was a distribution system monitoring program that collected water samples and physical and chemical information using data loggers at five sampling sites within the distribution system. Phase II of the study used bench-scale simulations that modeled DBP formation using a flow- through reactor system, the material-specific simulated distribution system (MS-SDS), constructed of pipe material resurrected from the City of Kamloops distribution system. Phase I results suggested that implementation of the ultrafiltration treatment process and accompanying treatment system upgrade was not effective at reducing the concentration of DBPs delivered to consumers. Concentrations of THMs remained relatively constant at sampling sites, while concentrations of HAAs increased following implementation of the ultrafiltration treatment process. The increase in HAA formation was likely due to an increase in retention time of the water within the distribution system following implementation of the ultrafiltration treatment process, rather than due to the treatment process itself. The results of this study are consistent with previous work on South Thompson River water DBP precursors, which suggested that THM and HAA precursors of this source water are small and hydrophilic, and therefore cannot be removed by ultrafiltration processes. ll Phase II results showed that the MS-SDS was more representative of distribution system conditions than traditional glass bottles to estimate DBP formation. It is recommended that the MS-SDS be used in parallel with a simultaneous distribution system monitoring program to estimate distribution system retention times from THM and HAA concentrations. 111 Table of Contents Abstract ^ ii Table of Contents iv List of Tables^ vii List of Figures ix List of Abbreviations^ xi Acknowledgements xiii Chapter 1. Introduction^ 1 1.1 Report Structure 2 Chapter 2. Background^ 3 2.1 Membranes for Water Treatment^ 4 2.2 Disinfection By-Products 6 2.2.1 Chemistry of Chlorination 6 2.2.2 Types^ 7 2.2.3 Factors Affecting Disinfectant By-Product Formation^ 8 2.2.3.1 pH 10 2.2.3.2 Temperature^ 11 2.2.3.3 Chlorine Concentration^ 11 2.2.3.4 Bromide Concentration 12 2.2.3.5 Natural Organic Matter 12 2.2.3.6 Retention Time^ 14 2.2.4 Significance to Human Health^ 14 2.3 Characterizing Disinfectant By-Product Formation^ 17 2.3.1 Full-Scale Distribution System Studies 17 2.3.2 Bench-Scale Studies^ 18 2.3.2.1 Disinfectant By-Product Formation Potential Test^ 18 2.3.2.2 Simulated Distribution Systems^ 19 2.4 Policies for Disinfection By-Products in Drinking Water 20 2.5 Study Region^ 22 2.5.1 Drinking Water Treatment Process Overview^ 24 2.5.2 Previous Studies of South Thompson River Water and Disinfectant By-Product Formation^ 25 2.6 Research Opportunity^ 26 iv Chapter 3. Research Objectives and Scope^ 28 3.1 Research Objectives^ 28 3.2 Research Scope 28 Chapter 4. Analytical Methods^ 30 4.1 Glassware Preparation, Sample Collection, and Sample Storage^ 30 4.2 Analytical Methods to Characterize Disinfectant By-Product Formation^ 31 4.2.1 pH^ 32 4.2.2 Temperature^ 32 4.2.3 Free Chlorine 32 4.2.4 Total Organic Carbon^ 33 4.2.5 Ultraviolet Absorbance 33 4.2.6 Specific Ultraviolet Absorbance^ 33 4.2.7 Trihalomethanes^ 34 4.2.8 Haloacetic Acids 36 4.3 Quality Assurance / Quality Control^ 40 4.4 Assessment of Water Sample Storage Time 40 Chapter 5. Experimental Design and Methods^ 42 5.1 Phase I: Distribution System Monitoring 42 5.1.1 Overview of Phase I^ 42 5.1.2 Sampling Sites 43 5.1.3 Limitations of Phase I 44 5.1.4 Phase I Data Analysis^ 44 5.1.4.1 Pair-Wise Comparisons 45 5.2 Phase II: Bench-Scale Simulations 47 5.2.1 Overview of Phase II^ 47 5.2.2 Material-Specific Simulated Distribution System Test and Simulated Distribution System Tests 49 5.2.2.1 Material-Specific Simulated Distribution System Test^ 50 Chlorinated Raw Water Reactor Series^ 54 Chlorinated Membrane Treated Water Reactor Series 54 Control Reactor^ 55 5.2.2.2 Simulated Distribution System Tests^ 59 In-situ Simulated Distribution System Test 59 Standard Simulated Distribution System Test 64 5.2.3 Limitations of Phase II^ 65 5.2.4 Phase II Data Analysis 66 5.3 Timeline^ 66 Chapter 6. Results and Discussion^ 69 6.1 Phase I: Distribution System Monitoring^ 69 6.1.1 Water Quality^ 70 6.1.2 Disinfection By-Product Formation 71 6.1.2.1 Trihalomethanes 72 Details of Pair-Wise Comparisons^ 74 6.1.2.2 Haloacetic Acids^ 76 Details of Pair-Wise Comparisons 78 Haloacetic Acids Speciation^ 80 6.1.3 Assessment of Disinfection By-Product Formation in the Distribution System83 6.2 Phase II: Bench-Scale Simulations 85 6.2.1 Material-Specific Simulated Distribution System Test and In-situ Simulated Distribution System Test^ 85 6.2.1.1 Experimental Conditions^ 86 6.2.1.2 Disinfection By-Product Formation^ 90 Trihalomethanes^ 90 Haloacetic Acids 92 Summary 94 6.2.2 Standard Simulated Distribution System Test^ 96 6.2.2.1 Experimental Conditions^ 96 6.2.2.2 Disinfection By-Product Formation 96 Trihalomethanes^ 96 Haloacetic Acids 98 Summary 100 6.2.3 Factors Affecting Disinfectant By-Product Formation in the Material-Specific Simulated Distribution System Test^ 101 6.2.3.1 Chlorine Concentration 102 6.2.3.2 Biodegradation of Haloacetic Acids^ 103 6.3 Comparison of Disinfectant By-Product Formation in the Distribution System to Bench-Scale Simulations^ 106 Chapter 7. Conclusions 110 Chapter 8. Implications of Study Findings For Engineering, Public Health, and Policy Applications^ 112 Chapter 9. Recommendations^ 114 References ^ 117 Appendices  125 Appendix A ^ Sampling Events for Phase I: Distribution System Monitoring^ 125 Appendix B ^ Photographs^ 126 Appendix C ^ MS-SDS Test Reactor Tracer Study^ 128 Appendix D ^ Raw Data for Phase I: Distribution System Monitoring^ 131 Appendix E ^ Statistical Analyses for Phase I: Distribution System Monitoring^ 152 Appendix F. Raw Data for Phase II: Bench-Scale Simulations 155 Appendix G. Statement of Publication^ 163 vi List of Tables Table 2.1 Table 2.2 Table 2.3 Water treatment membrane processes and their general characteristics ^ 5 THM and HAA species^ 8 Summary of factors affecting DBP formation in the distribution system  ^10 Table 2.4^Relationship between SUVA values and NOM composition and removal using coagulation^ 13 Regulations and guidelines for THMs and HAAs in drinking water for select jurisdictions^ 21 South Thompson River raw water quality^ 23 GC parameters for chloroform analysis 35 GC parameters for HAA3 analysis^ 39 Quantification and confirmation ions and retention times to identify HAA3 compounds of interest^ 39 Table 2.5 Table 2.6 Table 4.1 Table 4.2 Table 4.3 Table 4.4 TOC, UV254 , THM, and HAA3 measurements for City of Kamloops drinking water sample storage study (values presented are mean ± standard deviation).41 Table 5.1^Water streams used in MS-SDS and SDS tests^ 49 Table 5.2^Pump flow rates for mean retention times in MS-SDS test reactors^56 Table 6.1^Summary of water quality characteristics for distribution system sampling sites before (Stage A) and after (Stage B) the distribution system upgrade (values presented are mean ± standard deviation)^ 70 Table 6.2^Pair-wise comparisons for DBP formation in the distribution system during Stage A and Stage B^ 72 Table 6.3^DCAA and TCAA concentrations during Stage A and Stage B (values presented are mean ± standard deviation)^ 82 Table 6.4^Distribution system conditions for Site 2 and Site 5 during Phase II (values presented for 1 sample collected in September 2006)^ 89 vu Table 6.5^DCAA and TCAA concentrations during the 12 hour and 36 hour experimental periods for the MS-SDS and in-situ SDS tests (values presented are mean ± standard deviation)^  105 viii List of Figures Figure 2.1 Schematic of membrane process^ 5 Figure 2.2 Location map for Kamloops, British Columbia^ 22 Figure 2.3 Overview of Kamloops Centre for Water Quality drinking water treatment process^ 25 Figure 2.4 Water treatment operation during a) Stage A and b) Stage B of the City of Kamloops distribution system upgrade^ 27 Figure 5.1 Phase I sampling site locations during a) Stage A and b) Stage B of the City of Kamloops drinking water distribution system upgrade^43 Sample of cast iron pipe section resurrected from City of Kamloops distribution system (before cleaning)^ 50 MS-SDS test reactor^ 52 MS-SDS test 53 MS-SDS test apparatus^ 55 Diagram of MS-SDS test configurations and sampling sites for a) 12 hour experimental period and b) 36 hour experimental period^58 In-situ SDS test^ 61 In-situ SDS test and MS-SDS test apparatus^ 61 Figure 5.2 Figure 5.3 Figure 5.4 Figure 5.5 Figure 5.6 Figure 5.7 Figure 5.8 Figure 5.9 Diagram of in-situ SDS test and standard SDS test bottle incubations for a) 12 hour experimental period and b) 36 hour experimental period^63 Figure 6.1 THM concentrations in the distribution system during a) Stage A and b) Stage B (values presented are mean ± standard deviation)^ 73 Figure 6.2 HAA3 concentrations in the distribution system during a) Stage A and b) Stage B (values presented are mean ± standard deviation)^ 77 Figure 6.3 DCAA / TCAA during Stage A and Stage B (values presented are mean ± standard deviation)^ 82 ix Figure 6.4 Free chlorine concentrations during the 12 hour and 36 hour experimental periods for the MS-SDS test (values presented are mean ± standard deviation). ^ 87 Figure 6.5 Free chlorine concentrations during the 12 hour and 36 hour experimental periods for the in-situ SDS test (values presented are mean ± standard deviation) ^ 87 Figure 6.6 THM concentrations during the 12 hour and 36 hour experimental periods for the MS-SDS test (values presented are mean ± standard deviation)^91 Figure 6.7 THM concentrations during the 12 hour and 36 hour experimental periods for the in-situ SDS test (values presented are mean ± standard deviation)^ 91 Figure 6.8 HAA3 concentrations during the 12 hour and 36 hour experimental periods for the MS-SDS test (values presented are mean ± standard deviation)^93 Figure 6.9 HAA3 concentrations during the 12 hour and 36 hour experimental periods for the in-situ SDS test (values presented are mean ± standard deviation) ^93 Figure 6.10 THM concentrations during the 12 hour and 36 hour experimental periods for the standard SDS test (values presented are mean ± standard deviation)^97 Figure 6.11 HAA3 concentrations during the 12 hour and 36 hour experimental periods for the standard SDS test (values presented are mean ± standard deviation) ...98 Figure 6.12 DCAA/TCAA during the MS-SDS test for the a) 12 hour experimental period and b) 36 hour experimental period (values presented are mean ± standard deviation) ^  104 Figure 6.13 DCAA/TCAA during the in-situ SDS test for the a) 12 hour experimental period and b) 36 hour experimental period (values presented are mean ± standard deviation)  105 List of Abbreviations BCAA^bromochloroacetic acid BDCAA^bromodichloroacetic acid BDCM^bromodichloromethane CCT^chlorine contact tank CGDWQ Canadian Guidelines for Drinking Water Quality CSTR^completely-stirred tank reactor DBAA^dibromoacetic acid DBCAA^dibromochloroacetic acid DBCM^dibromochloromethane DBP^disinfection by-product DBPFP^disinfectant by-product formation potential DCAA^dichloroacetic acid DOC^dissolved organic carbon HAA^haloacetic acid HAA3^sum of three haloacetic acids — monochloroacetic acid, dichloroacetic acid, and trichloroacetic acid HAA5^sum of five haloacetic acids — monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, dibromoacetic acid, and tribromoacetic acid concentrations HAA6 sum of six haloacetic acids — monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, dibromoacetic acid, and bromochloroacetic acid HAA9^sum of nine haloacetic acids — monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, dibromoacetic acid, tribromoacetic acid, bromochloroacetic acid, bromodichloroacetic acid, and dibromochloroacetic acid HAAFP^haloacetic acid formation potential KCWQ^Kamloops Centre for Water Quality MBAA^monobromoacetic acid MCAA^monochloroacetic acid MDL^method detection limit MS-SDS^material-specific simulated distribution system MTBE^methyl tertiary butyl ether nd^non detect NOM^natural organic matter SDS simulated distribution system SUVA^specific ultraviolet absorbance TBAA^tribromoacetic acid TCAA^trichloroacetic acid THM^trihalomethane THMFP^trihalomethane formation potential xi TTHM^total trihalomethanes; sum of four trihalomethanes^chloroform, bromodichloromethane, dibromochloromethane, bromoform TOC^total organic carbon UBC^University of British Columbia USEPA^United States Environmental Protection Agency UV254^ultraviolet absorbance measured at 254 nm WHO^World Health Organization xii Acknowledgements There are a many people that I am thankful to for their assistance throughout this project. My supervisor, Dr. Pierre Berube, for his guidance, knowledge, and for keeping me on track when I needed it. Mt. Jim Atwater for providing me with perspective on my work. The University of British Columbia Bridge Program for providing the funding that allowed me to complete this work. The Bridge Program Fellows and Mentors for fostering a unique interdisciplinary research environment that encouraged me to think "outside of the box". Ms. Susan Harper & Ms. Paula Parkinson for their wealth of expertise, knowledge, and on- going assistance to me with analytical (and many other) challenges in the laboratory. Mr. Wade Archambault for assisting me with field sampling and data acquisition. Dr. Sharon Brewer for providing her input and taking care of the logistical details throughout this project. Mr. Harald Schrempp and Mr. Bill Leung for their assistance with design and construction of the pipe reactors used in this study. The staff at KCWQ for providing data and for allowing me to occupy the lab for a few months. Most of all, thank you to my family and friends for their endless support through yet another degree — but I can make no promises that this is the end. Chapter 1. Introduction Significant improvements to public health have resulted from the design and implementation of water treatment systems that reduce levels of many waterborne pathogens in drinking water. These public health improvements are largely attributed to drinking water disinfection practices. However, chlorine, the most widely used disinfectant, can react with natural organic matter (NOM) present in drinking water sources. The reaction between chlorine and NOM results in the formation of potentially carcinogenic disinfection by-products (DBPs). The most common DBPs measured in chlorinated drinking water distribution systems are trihalomethanes (THMs) and haloacetic acids (HAAs). Emerging guidelines and regulations aimed at reducing public health risks from chronic exposure to DBPs, particularly THMs and HAAs, pose a significant challenge for public water utilities: to comply with policies that reduce DBP formation without compromising the microbiological quality of delivered drinking water to the public. Compliance with these policies often requires the modification of existing treatment processes and potentially, the implementation of new treatment technologies. As the need for improved water quality continues, new technologies coupled with conventional treatment processes are becoming more widely used. Membrane filtration systems are one example of a new drinking water treatment technology that is gaining popularity in use. It is known that membranes are effective at reducing overall concentrations of NOM and pathogens in water; on the other hand, less is known about how implementation of these treatment processes at the full-scale can affect the quality of delivered water within the distribution system, particularly DBP formation. Investigations of the formation and behaviour of THMs and HAAs at the treatment plant are only part of the solution. Since many consumers are often not located near water treatment facilities, complex networks of pipe systems deliver treated water, which results in a significant lag time from the time that water leaves the treatment plant to the time that water reaches the taps of consumers. 1 Therefore, studies that examine the formation (or degradation) of DBPs in drinking water within the distribution system are essential for developing effective solutions that mitigate potential public health risks from DBP exposure, while at the same time, ensure adequate health protection for tap water consumers. This study combined a unique approach to examine the impact of implementing a membrane treatment process, specifically, ultrafiltration, on DBP formation in delivered drinking water before and after implementation of membrane filtration. A two-phase research approach was used to examine DBP formation for raw water and membrane treated water within a full-scale distribution system (Phase I) and at the bench-scale (Phase II), which used a model distribution system constructed of pipe material resurrected from the distribution system of study. 1.1 Report Structure This report is structured to reflect the two-phase research approach used in the present study: distribution system monitoring and bench-scale simulations. Chapter 2 outlines relevant background information to the present study, including a description of the study region and the unique research opportunity available for this work. Chapter 3 outlines the research objectives and overall scope of the present study. The analytical methods are described in Chapter 4, while distribution system monitoring (Phase I) and bench-scale simulation (Phase II) experimental design and methods of both research phases are presented in detail in Chapter 5. The results of the distribution system monitoring and the bench-scale simulations are discussed in Chapter 6. Conclusions based on the results of this work are presented in Chapter 7 and the implications of the present study for engineering, health, and policy applications are outlined in Chapter 8. To conclude this report, recommendations for future work are made in Chapter 9. 2 Chapter 2. Background Safe drinking water is a universal human need. The occurrence of pathogens in drinking water is an issue that crosses boundaries of both developed and developing countries. Although advances in drinking water treatment technologies have led to significant reductions in waterborne pathogen outbreaks, outbreaks in developed countries still occur as demonstrated by the Cgptoiporidium outbreak in the municipal drinking water supply of Milwaukee, Wisconsin in 1993 and the Escherichia cob. 0157:H7 outbreak in Walkerton, Ontario in 2001 (Hrudey and Hrudey, 2004; Craun and Calderon, 2001; Craun and Murphy, 1999). In Canada and other developed countries, the occurrence of waterborne pathogens in treated drinking water has been reduced due largely in part to centralized water treatment processes and disinfection. However, chlorine (and some other disinfectants) can react with NOM present in drinking water sources. The reaction between chlorine and NOM results in the formation of DBPs. Epidemiological studies suggest that these DBPs pose potential public health risks over long-term (chronic) exposures (Singer, 2006; USEPA, 2006; Nieuwenhuijsen et al., 2000b; Morris et al., 1992). Improvements in drinking water treatment processes have virtually eliminated the presence of pathogens in finished drinking water and have prompted comparative evaluations of other emerging health risks, such as DBPs. An effective balance of acute disease risks associated with pathogens and chronic public health risks linked to DBPs from drinking water treatment must be maintained. Therefore, investigations into the factors that affect the formation and behaviour of DBPs in the distribution system can assist with developing effective mitigation strategies that reduce DBP exposure, while at the same time, maintain high quality drinking water for consumers. 3 2.1 Membranes for Water Treatment Advancements in drinking water treatment technologies have increased the capability of treatment systems to provide high quality drinking water for consumers. Filtration is the process of separating particles and colloidal material from liquids via physical and chemical processes. The filtration process is an effective treatment technology, particularly when coupled with coagulation and flocculation, for removal of NOM and pathogens from drinking water(Droste, 1997). The conventional filtration media most commonly used is sand; however, other granular media such as anthracite, magnetite, and garnet are also used. A recently developed filtration technology that is becoming more commonly used for water treatment applications is membrane filtration. Membrane filtration uses a selective barrier, such as a polymer, which retains constituents smaller than a specific size and allows the passage of other constituents through the membrane filter based on the size of the membrane pores. The influent water stream into the membrane is the feedstream, while the liquid that passes through the membrane pores is the permeate. The liquid containing constituents retained by the membrane filter pores is referred to as the concentrate or reject. Membrane filtration processes typically operate under an "inside-out" or "outside-in" movement of water through the membrane, which requires a pressure differential to occur. For example, GE-Zenon membrane technologies, such as ZeeWeed® ultrafiltration membranes, are hollow strands of porous polymer fibres that are immersed in water tanks These membrane fibres draw water through the membrane filter under slight suction using an "outside-in" approach (GE-Zenon, 2007). A schematic of the membrane filtration process is outlined in Figure 2.1. 4 Feedstream Permeate Concentrate Figure 2.1 Schematic of membrane process Classification of membrane filtration processes is based on pore size. Membrane filtration processes commonly used in drinking water treatment applications are microfiltration, ultrafiltration, nanofiltration, and reverse osmosis. A summary of common membrane processes used in water treatment is presented in Table 2.1. Table 2.1 Water treatment membrane processes and their general characteristics Membrane Process Microfiltration Ultrafiltration 0.005-0.2 urn Nanofiltration 0.001-0.01 um Reverse Osmosis 0.0001-0.001 urn Molecular Weight Cutoff [Daltons (Da)] 1000-500 000 Da (1-500 kDa) 200-1000 Da (0.2-1 kDa) <200 Da (<0.2 kDa) Permeate Water and dissolved solutes Water and small molecules Water and very small molecules, ionic solutes Water, very small molecules, ionic solutes Typical Constituents Removed Total suspended solids, turbidity, protozoan oocysts and cysts, some bacteria and viruses Macromolecules, colloids, most bacteria, some viruses, proteins Small molecules, some hardness, viruses Very small molecules, colour, hardness, sulphates, nitrate, sodium, other ions Operating Range illmi 0.08-2.0 lArn Adapted from Metcalf & Eddy, Inc. (2003) 5 Filtration processes can remove particles from 1.0 pm in size using conventional granular filtration processes to less than 0.001 lam in size using membrane filtration (GE-Zenon, 2007). The molecular size range of particles removed by membranes is highly variable; ultrafiltration, which is commonly used for pathogen and particle removal, has a molecular weight cutoff or removal for particles in the range of 1 to 500 kDa, while reverse osmosis, which is most often used for desalination treatment processes, can remove particles less than 0.2 kDa in size. As the size of particles to be removed from the source water is decreased, the pressure differential required to move water through the membrane filter is significantly increased (Metcalf & Eddy, Inc., 2003). Feedwater pre-treatment, such as coagulation and flocculation, is often used to increase the level of removal of constituents in water, such as TOC, colour, and DBP precursors, and to maintain the flow of water through the membrane by reducing membrane fouling (Jacangelo, 1999; Randtke, 1999). However, many utilities that coagulate surface water sources optimize these processes for turbidity removal rather than DBP precursor removal (Randtke, 1999). Appropriate selection of a technology for water treatment is based on a number of factors, such as economics and desired water quality outcomes. The choice of water treatment technology to be implemented should be optimized for the desired water quality outcomes to be achieved. 2.2 Disinfection By-Products 2.2.1^Chemistry of Chlorination Chlorine is the most widely used disinfectant for treatment of drinking water. Chlorine is economical, effective, and only chlorine-based disinfectants provide a long-lasting disinfectant residual within the distribution system to reduce the potential for microbiological re-growth and contamination in delivered drinking water. Chlorine is a strong oxidizer and is typically used in the form of free chlorine or hypochlorites, such as sodium hypochlorite (NaOC1). In chlorine reactions with water, chlorine (C12) combines with water to form hypochlorous acid (HOC1), hydrochloric acid (HC1), and hypochlorite ion (0C1), as shown in Equation 2.1 and Equation 2.2 (Sawyer et al., 1994). 6 C12 + H20 t-7 HOC1 + H + Cl-^ (2.1) HOC1 170 H+ + OC1 (2.2) Of note, free chlorine typically refers to the chlorine concentration as the sum of dissolved gas (C12), hypochlorous acid (HOC), and hypochlorite ion (0C1-). Sodium hypochlorite ionizes in water to yield hypochiorite ion, as shown in Equation 2.3. The hypochlorite ion then establishes an equilibrium with hydrogen ions (H+), as outlined in Equation 2.2. Na0C1 Na+ + 0C1- (2.3) The chlorine demand is largely affected by the presence of a number of compounds in water sources such as reducing agents; organic compounds, including humic substances; and other halogens found in water supplies (Sawyer et al., 1994). 2.2.2 Types DBPs are formed via a reaction with NOM and a disinfectant. As a result, many DBPs have been identified and measured in water following the disinfection process. The classes of DBPs identified from disinfection of water (using chlorination, chloramination, ozonation, and chlorine dioxide) include THMs, HAAs, haloacetonitriles, haloketones, cyanogen halides, oxyhalides, aldehydes, aldoketoacids, carboxylic acids, and maleic acids (Krasner, 1999). In disinfected drinking waters, the most common DBPs measured by weight are THMs and HAAs (Singer et al., 2002; Williams et al., 1995). Individual THM and HAA species found in disinfected drinking waters are presented in Table 2.2. 7 Table 2.2 THM and HAA species DBP Class^ Individual DBPs^Chemical Formula Trihalomethanes (THMs)^Chloroform^ CHC13 Bromodichloromethane* CHC12Br Dibromochloromethane*^CHC1Br2 Bromoform*^ CHBr3 Haloacetic Acids (HAAS)^Monochloroacetic acid (MCAA)^CH2C1COOH Dichloroacetic acid (DCAA) CHC12COOH Trichloroacetic acid (TCAA)^CC13COOH Bromochloroacetic acid (BCAA) CHBrC1COOH Bromodichloroacetic acid (BDCAA) *^CBrC12COOH Dibromochloroacetic acid (DBCAA)*^CBr2C1COOH Monobromoacetic acid (MBAA)*^CH2BrCOOH Dibromoacetic acid (DBAA)* CHBr2COOH Tribromoacetic acid (1:13AA)*^CBr3COOH *Brominated DBPs form when bromine is present in the water. Data from Krasner (1999) Recent investigations by Krasner et al. (2006) measured an additional 28 DBPs not previously identified in disinfected water. The measurement and characterization of DBPs in disinfected water will likely reveal additional DBPs as analytical laboratory methods are developed and improved. 2.2.3^Factors Affecting Disinfectant By-Product Formation DBP formation is complex. The formation of DBPs is governed by both the characteristics of the treated drinking water such as pH, water temperature, chlorine concentration, bromide concentrations, and NOM (Baribeau et al., 2006; Singer et al., 2002) as well as the characteristics of the distribution system, such as retention time prior to the point of use of the treated water and the presence of tuberculated materials on pipe walls (Baribeau et al., 2005; Tuovinen et al., 1984). Some of the factors influencing water quality within the distribution system include the following (Baribeau et al., 2006): ■ Treatment processes; ■ Type of disinfectant and disinfectant dose; 8 ■ Physical and chemical characteristics of the water, i.e., pH, temperature, nature and concentration of NOM; ■ Concentration and type of microorganisms, i.e., presence of a biofilm within the distribution system; ■ Type of pipe materials, including occurrence of pipe corrosion; ■ Sediments in distribution system pipes; ■ Hydraulics of the distribution system, including water velocity, pressure, and retention times within clearwells, pipes, reservoirs, and tanks; ■ Characteristics of the distribution system, i.e., size, age, and pipe configurations; and ■ Operation and maintenance of the distribution system. DBP concentrations in full-scale distribution systems can vary spatially and temporally (Rodriquez and Serodes, 2001). Temporal variability can be attributed to changes in raw water quality, temperature, flow rates, retention times within the distribution system, and the disinfectant doses in the treatment plant (Baribeau et al., 2006). Spatial variation is attributed to the continued formation of DBPs in distribution systems where free chlorine is used as a disinfectant; the nature of the distribution system, such as the presence/absence of storage tanks and water demand; and potential biodegradation of some DBPs (Baribeau et al., 2006). THMs and HAAs show differences in formation mechanisms, differences in precursors, and also differences in behaviour following formation (Xie, 2004; Singer et al., 2002). THM formation has been well studied and THMs are shown to be relatively stable in distribution systems, while HAA formation is less well studied. It has been suggested that HAAs appear to form at a faster rate than THMs (Singer et al., 2002). Some HAA species are thought to decompose at elevated pH levels with some HAA species subject to biodegradation in absence of chlorine concentration (Singer et al., 2002). Baribeau et al. (2006) conducted bench-scale biodegradation experiments with bacterial species isolates obtained from maximum retention time sampling sites of full-scale distribution systems. With respect to chlorinated HAAs, the study showed that Burkholderia sp. and Sphingomonas sp. degraded monochloroacetic acid (MCAA) and dichloroacetic acid (DCAA), 9 while none of the species were able to degrade trichloroacetic acid (TCAA). These bacterial species also appeared selective for dihalogenated acetic acids over monohalogenated acetic acids. A summary of the main factors that affect DBP formation in the distribution system and are outlined in Table 2.3. Table 2.3 Summary of factors affecting DBP formation in the distribution system Factor^ Effect on Disinfectant By-Product Formation pH ^ High pH levels tend to favour THM formation over HAA formation; trihalogenated acetic acid formation is favoured at lower pH. Temperature^Chemical reactions, including DBP formation, increase with increasing water temperature. Chlorine Concentration^Increased chlorine dose and chlorine concentration leads to increased formation of DBPs. It is suggested that in the absence of chlorine concentration, HAAs, particularly monohalogenated (MCAA, MBAA) and dihalogenated (DCAA, DBAA) acetic acids, may be biodegraded. Bromide Concentration^Occurrence of bromide ions in natural source waters results in the formation of brominated DBPs; in the absence of bromide ion, brominated DBPs will not be formed. Natural Organic Matter Increased concentrations of NOM in source waters leads to increased formation (NOM)^ of DBPs via more available precursors and higher chlorine demand (i.e., higher chlorine dose). HAA precursors are suggested to be more hydrophobic and aromatic in nature than THM precursors. Retention time^Increased retention time results in increased DBP formation and reduced chlorine concentration. At high retention times and low chlorine concentration, biodegradation of some HAA species may occur. 2.2.3.1 pH High pH tends to favour the formation of THMs over HAAs (Baribeau et al., 2006; Xie, 2004). Liang and Singer (2003) showed that a pH increase from 6 to 8 favoured the formation of THMs, but decreased trihaloacetic acid formation. Singer et al. (2002) showed that HAA formation decreased with increasing pH, while total THM (TT'HM) concentrations increased with increasing pH. Among the HAAs, the trihalogenated acetic 1 0 acids decreased with an increase in pH, while dihalogenated acetic acid formation was independent of pH. 2.2.3.2 Temperature In general, the rate of chemical reactions, including DBP formation, increase with increasing temperature. As a result, reaction rates between disinfectants and NOM are faster in warmer water. At higher water temperatures, chlorine decay occurs more rapidly, which results in higher chlorine dose at the treatment plant to ensure that an adequate chlorine concentration is maintained within the distribution system. Full-scale distribution system monitoring studies have shown that TTHM and HAA concentrations, measured as HAAS (sum of MCAA, DCAA, TCAA, monobromoacetic acid (MBAA), dibromoacetic acid (DBAA), dibromoacetic acid (TBAA), bromochloroacetic acid (BCAA), bromodichloroacetic acid (BDCAA), and dibromochloroacetic acid (DBCAA)) concentrations are highest in the warmer months (Baribeau et al., 2006; Baribeau et al., 2004; Singer et al., 2002). It has been suggested that initial THM formation relies more on available concentrations of chlorine and DBP precursors than on water temperature (Rodriquez and Serodes, 2001). However, Rodriguez and Serodes (2001) used multivariate regression models to show that water temperature was a better predictor of THM seasonal variability than chlorine dose and free chlorine concentration, surrogates of NOM (total organic carbon (TOC) and ultraviolet absorbance at 254 nm (UV 254)), and pH. 2.2.3.3 Chlorine Concentration Increased chlorine dose leads to increased formation of DBPs (Xie, 2004) Similarly, the higher the concentration of disinfectant, the faster the rate of DBP formation (Baribeau et al., 2006). Baribeau et al. (2006) observed that chlorinated THMs accounted for approximately 80% to 98% of TTHM concentrations in free chlorinated distribution systems. The dominant HAA species measured in the same distribution systems were the dihalogenated and trihalogenated acetic acids. If a decrease in HAA concentration was observed, the decrease was associated with changes in concentrations of monohalogenated acetic acids and dihalogenated acetic acids; trihalogenated acetic acid concentrations within 11 the distribution system were relatively conserved with increased retention times, i.e., trihalogenated HAAs were shown to be a less biodegradable class of HAAs. In addition, chlorine decay in distribution system pipes, particularly cast iron pipes, is increased by the presence of corrosion products, tubercle buildup, and biofilm (Al-Jasser, 2007; Rossman, 2006; Frateur et al., 1999; Kiene et al., 1998). Rossman (2006) showed that changes to water chemistry (NOM, pH, alkalinity, and W254) following advanced treatment with conventional water treatment, ozonation, granular activated carbon, or reverse osmosis, affected the rate of disinfectant decay caused by pipe wall reactions in cast iron pipes. Further, chlorine decay in cast iron pipes was shown to be dominated by reactions with the pipe wall (Rossman, 2006). 2.2.3.4 Bromide Concentration Bromide may be present in natural source waters and with disinfection, may lead to the formation of brominated DBPs. However, bromide, the inorganic ion of bromine, does not react with NOM directly to form DBPs. Reaction with a disinfectant results in the oxidation of bromide to hypobromite or hypobromous acid that reacts with NOM to form brominated DBPs (Xie, 2004). Bromine is more reactive than chlorine, which results in the reduced formation of chlorinated DBPs, because bromine occupies reaction sites for chlorine substitution (Xie, 2004, Singer et al., 2002). In the absence of bromide ions, brominated DBPs will not be formed. 2.2.3.5 Natural Organic Matter NOM is a precursor for DBP formation in water sources. NOM can be separated into the following fractions: humic acids, fulvic acids, hydrophobic acids, hydrophobic neutrals, transphilic acids, transphilic neutrals, hydrophilic acids, and hydrophilic neutrals (Xie, 2004). In general, lower concentrations of DBPs are measured in ground waters compared to poor quality surface waters with higher organic carbon levels (Sirivedhin and Gray, 2005; Villanueva et al., 2003; Williams et al., 1995). High NOM concentrations increase DBP formation potential (DBPFP) because of the higher concentrations of DBP precursors available for reaction with the disinfectant and higher chlorine demand, which results in higher chlorine dose requirements to the source water (Xie, 2004). In addition, seasonality 12 • Mostly aquatic humics > 4 ^• High hydrophobicity High molecular weight • Good removals (>50% DOC removal using alum) impacts, particularly levels of precipitation and runoff affect the presence or absence of DBP precursors in water sources (Baribeau et al., 2006). DBP formation has been shown to be primarily related to humic species of NOM (Croue et al., 2000; Reckhow et al., 1990). Source waters with high hydrophobic organic carbon concentrations and high specific ultraviolet absorbance (SUVA) are more subject to HAA formation relative to THM formation (Singer et al., 2002). Note that SUVA is an indirect measure of the aromaticity of the NOM in water (Weishaar et al., 2003; Karanfil et al., 2002; Korshin et al., 2002; Kids et al., 2001). The results by Singer et al. (2002) suggested that HAA precursors were more aromatic in nature than THM precursors. Further, hydrophobic NOM fractions showed higher formation potentials for dihalogenated acetic acids, trihalogenated acetic acids, and TTHM than hydrophilic NOM fractions. SUVA values have been used to characterize NOM and the influence of coagulation on DOC removal. The relationship between SUVA values, NOM characteristics, and the effect of coagulation on NOM removal is summarized in Table 2.4. In the present study, coagulation and flocculation treatment of source water was used for pre-treatment of source water prior to membrane filtration. Table 2.4 Relationship between SUVA values and NOM composition and removal using coagulation SUVA [L/mg-m] NOM Composition Effect of Coagulation on NOM Removal • Mixture of aquatic hurnics and • Fair to good removals (25- other NOM 50°A DOC removal using Mixture•^of hydrophobic and^alum)2-4 ▪ Mixture of molecular weights • Mostly non-humics^• Poor removals (<25% DOC < 2^• Low hydrophobicity removal using alum) • Low molecular weight hydrophilic NOM Adapted from Edzwald and Tobiason (1999) 13 NOM, i.e., DBP precursors, removed from water via coagulation is typically higher in molecular weight, more hydrophobic in nature, and more highly coloured than non- removable NOM (Randtke, 1999). Singer et al. (2002) showed that for high SUVA waters, HAA9 precursors were more effectively removed via coagulation than TTHM precursors. 2.2.3.6 Retention Time Retention time is the amount of time treated water remains within the distribution system prior to the point of use. For DBPs, particularly THMs and HAAs, an increase in reaction time between the disinfectant and NOM increases overall DBP formation (Xie, 2004). An increased reaction time typically occurs with increased time within the distribution system. THM concentrations are typically highest in the distribution system locations with maximum retention times; however, HAA concentrations in the distribution system increase then decrease at extremities of the distribution system where low chlorine concentrations and long retention times occur (Speight and Singer, 2005; Rodriquez et al., 2005). Some species of HAAs are biodegradable (monohalogenated and dihalogenated species) and may be degraded in the absence of a sufficient chlorine residual (Baribeau et al., 2006; Baribeau et al., 2005; Rodriquez et al., 2005). Typically, significant variations in DBP concentrations are observed between the treatment plant and extremities in the distribution system (Rodriguez and Serodes, 2001). Baribeau et al. (2006) showed that increased retention times in the distribution system led to decreased free chlorine concentration, increased formation of TTHMs, and HAA9 concentrations that increased or remained constant. However, at distribution system sampling sites with high retention time (e.g., estimated retention time of 332 hours), concentrations of HAA9 decreased, with this decrease most prevalent during warmer water temperatures and low free chlorine concentrations, i.e., <0.5 mg/L. These results suggested that biodegradation occurred at the extremity sampling sites of the distribution system (Baribeau et al., 2006). 2.2.4 Significance to Human Health Concerns over the potential public health effects from exposure to DBPs in drinking water prompted toxicological and epidemiological studies of these compounds. Most health 14 studies completed to date have been conducted using THM exposure as a surrogate measure of overall DBP exposure (Arbuckle et al., 2002). Differences in the chemical properties of DBPs, such as volatility, and individual water use behaviours significantly affect the levels of DBPs that individuals may be exposed to. The adverse health effects of concern from DBP exposure are cancer and reproductive and developmental outcomes (USEPA, 2006). Cancers of the bladder, colon, and rectum are most frequently suggested to be associated with exposure to chlorinated water (Mills et al., 1998). Epidemiologic studies of cancer and chlorinated DBP exposure have been most consistent with a modest increased risk of bladder cancer (King et at, 2000; Morris et al., 1992), while conflicting results have been observed between THM exposure and colon and rectal cancers (Mills et al., 1998; Wigle, 1998; Morris et al., 1992). Some toxicological and epidemiological studies suggest an association between DBP exposure and adverse reproductive and fetal developmental effects. The main reproductive outcomes studied for DBP exposure include small for gestational age; low birth weight; pre- term births; birth defects, such as the central nervous system, cardiac defects, oral cleft, respiratory, and neural tube defects; and spontaneous abortions and fetal deaths (Savitz et al., 2006; Toledano et al., 2005; Bove et al., 2002; Nieuwenhuijsen et al., 2000b). Reviews of available epidemiological studies of adverse reproductive and developmental studies and DBP exposure have been conducted by Tardiff et al. (2006), Bove et al. (2002), and Nieuwenhuijsen et al. (2000b). Positive associations have been identified between THM exposure and fetal growth retardation, including low birth weight (often not statistically significant), small for gestational age, and small body length or head circumference (Nieuwenhuijsen et al., 2006b; Tardiff et al., 2006). There is some evidence that supports associations between small for gestational age, neural tube defects, and spontaneous abortions and THM exposure (Bove et al., 2002). Inconsistent to weak associations were found for congenital anomalies and birth defects, central nervous system anomalies, neural tube defects, and spontaneous abortions (Nieuwenhuijsen et al., 2006b; Tardiff et al., 2006). The weight of evidence for the increased risk of stillbirth is conflicting (Nieuwenhuijsen et al., 2000b). Toledano et al. (2005) showed significant associations between high THM exposure, i.e., >60 4g/L, and risk of stillbirth, while a robust cohort study conducted by Savtiz et al. (2006) found no association between 15 high THM exposure, i.e., >75 j.ig/L, and pregnancy loss and no increased risk of pregnancy loss in relation to THM or HAA9 concentrations (Howards and Hertz-Picciotto, 2006). No associations have been shown between THM exposure and pre-term delivery and neonatal death (Tardiff et al., 2006). A significant limitation identified in most DBP epidemiological studies conducted to date is misclassification of exposure (Savitz et al., 2006; Singer, 2006; Tardiff et al., 2006; King et al., 2004; Arbuckle et al., 2002; Bove et al.., 2002; Nieuwenhuijsen et al., 2000a, 2000b). This limitation is widely acknowledged by researchers, as it is difficult to accurately estimate individual DBP exposure and uptake. Variations in DBP concentrations within the distribution system and at different times of the year, i.e., influence of seasonal variations, and individual differences in behaviour at home and at work influence the overall level of DBP exposure (Symanski et al., 2004; Nieuwenhuijsen et al., 2000a). Tap water ingestion, showering and bathing, swimming, boiling water, and dishwashing are water use behaviours associated with the uptake of THMs and HAAs from chlorinated water (Whitaker et al., 2003; Batterrnan et al., 2000; Nieuwenhuijsen et al., 2000a; Weisel et al., 1999; Weisel and Jo, 1996). Ingestion, dermal absorption, and inhalation are the known routes of exposure to volatile DBPs, such as THMs, whereas ingestion is likely the main route of exposure to non-volatile DBPs, such as HAAs (Krasner and Wright, 2005; Nieuwenhuijsen, 2003; Xu and Weisel, 2003; Lin and Hoang, 2000). In addition to individual water use behaviours, exposure estimates can be further complicated by individual water handling activities, such as water storage, boiling, and in-home filtration (Levesque et al., 2006; Krasner and Wright, 2005; King et al., 2004). Consequently, inadequate or imprecise estimates of exposure may affect the use of these values in epidemiological or health-based risk assessments (Arbuckle et al., 2002). The identified health risks of carcinogenicity and adverse reproductive effects from DBP exposure appear to be low; however, these risks are of significant public health importance because of the ubiquitous nature of DBPs in public water supplies and the large populations potentially affected (Singer, 2006; Nieuwenhuijsen et al., 2000b; Morris et al., 1992). Understanding DBP formation within the distribution system will aid more accurate quantification of DBP concentrations at the tap. Use of this information in combination 16 with individual water-use behaviours could provide insight into estimating DBP exposures from chlorinated water and potential public health risks to aid policy development. 2.3 Characterizing Disinfectant By-Product Formation The most common approaches used to characterize DBP formation are full-scale distribution system studies and laboratory or bench-scale studies. 2.3.1 Full-Scale Distribution System Studies Full-scale distribution system studies allow assessment of spatial and temporal variability in DBP concentrations under actual distribution system conditions. A number of full-scale assessments of DBP formation within distribution systems have been conducted (Baribeau et al., 2006; Rodriguez and Serodes, 2005; Rodriguez and Serodes, 2001; Williams et al., 1995). Full-scale distribution studies are less standardized than laboratory methods as sampling procedures, such as frequency and duration of sampling, depend on the objectives of the study. Baribeau et al. (2006) conducted a full-scale distribution system monitoring study for 5 distribution systems in the United States. The distribution systems selected for study were based on treated drinking water characteristics; particularly DBP levels with TTHM greater than 40 ug/1_, and HAA9 greater than 20 pg/L. The distribution systems were also required to have a hydraulic model for determining water retention times at the sampling sites and maximum control over factors affecting water quality, for example, water utilities that mixed surface water and ground water sources were not used. This one year study sampled between 12 and 16 locations within each distribution system during 6 to 8 sampling periods. Rodriguez and Serodes (2005) used a comparison of laboratory-scale chlorination studies and full-scale distribution system monitoring to examine THM and HAA formation in two distribution systems in Quebec. The full-scale sampling program was conducted for approximately 1 year. Rodriguez and Serodes (2001) selected three distribution systems in Quebec that varied in surface water sources and physicochemical treatment processes to investigate THM formation within the distribution system. An intensive 25 week sampling program was conducted weekly during April to November. Further, Williams et al. (1995) 17 examined spatial and seasonal variations and effects of disinfectants on DBP formation within distribution systems using chlorine, chloramine, and ozone disinfectants for 53 sites across Canada. Sampling was conducted during winter months (February to March) and summer months (August to September) for one year. Sampling sites for the study included raw water, treatment plant point-of-entry to the distribution system, and well-flushed tap water located approximately mid-point within the distribution system. 2.3.2 Bench-Scale Studies Two bench-scale approaches commonly used for the assessment of DBP formation for a source water are the DBPFP test and simulated distribution system (SDS) test. The DBPFP test and the traditional SDS test are standardized tests with well-established laboratory procedures outlined in Standard Methods for the Examination of Water and Wastewater (APHA et al., 1998). However, the traditional SDS test has been modified by others to more closely estimate DBP formation in the distribution system (Rossman et al., 2001; Brereton, 1998). The DBPFP test and SDS test are discussed in the following sections. 2.3.2.1 Disinfectant By-Product Formation Potential Test The DBPFP test examines DBP precursors of source water (Xie, 2004). The raw water conditions of this laboratory-based test are standardized for pH (7.0±0.2), incubation temperature (25±2°C), reaction time (7 days), and free chlorine concentration (3 to 5 mg/L at the end of the reaction time) (Method 5710B; APHA et al., 1998). The difference in DBP concentrations between the final and the initial DBP value is the DBPFP of the source water. The DBPFP test generally produces higher DBP concentrations than concentrations that would be measured in treated drinking water and distribution systems because of excess chlorine concentrations and long reaction time (Xie, 2004). Due to the standardized conditions of the test, the DBPFP test cannot be used to predict DBP formation under actual chlorination conditions, following treatment processes, or distribution system conditions (Xie, 2004). 18 2.3.2.2 Simulated Distribution Systems Model distribution systems and reactors have been developed to study water quality under controlled operational conditions, such as flow rate, and controlled environmental conditions (Eisnor and Gagnon, 2003). The SDS test is used to estimate DBP formation in the full-scale distribution system under controlled laboratory conditions. The traditional SDS test developed by Koch et al. (1991) used glass bottles incubated under specific environmental conditions of chlorine dose and concentration, temperature, pH, and incubation times (APHA et al., 1998). In contrast to the DBPFP test, the environmental parameters of the SDS test are selected to represent conditions of the distribution system of interest. By comparing the DBP concentrations from the SDS test with the DBP concentrations from actual distribution system conditions, the SDS test is useful for distinguishing the effect of pipes in the distribution system (e.g. pipe material, pipe diameter, biofilm, and corrosion by-products) from detention time on disinfectant decay and DBP formation (Baribeau et al., 2004). The SDS experimental approach is particularly useful for studying DBP formation in the absence of full-scale distribution system information, such as distribution system retention times. To simulate full-scale distribution systems, model distribution systems have been developed that vary in design and study parameters. These model systems include bench-scale reactors constructed of pipe material obtained directly from the distribution system (Digiano and Zhang, 2005; Brereton, 1998), annular reactors (Baribeau et al., 2005; Chauret et al.., 2001), and large-scale flow-through pipe loop systems (Vasquez et al., 2006; Clark and Haught, 2005; Gibbs et al., 2003; Rossman et al., 2001). The work of Brereton (1998) and Rossman et al. (2001) highlight a comparison of the SDS test and distribution system pipe models. However, a significant difference in the approach used by both authors was the comparison of SDS bottle incubations to static pipe reactors (Brereton, 1998) and a large-scale flow-through pipe loop system (Rossman et al., 2001). Brereton (1998) developed a modified SDS test known as the material-specific distribution system test or MS-SDS test. This approach used the same environmental conditions of the SDS test; however, reactor vessels were constructed of resurrected cast-iron pipe material obtained directly from the distribution system. Brereton (1998) found that use of the MS- 19 SDS test reactors to examine THM formation more closely represented distribution system conditions than the SDS test. Chan et al. (2002) implemented the MS-SDS test developed by Brereton (1998) using reactors constructed of PVC pipe sections to examine THM formation at the bench-scale. A significant limitation of the approach of Brereton (1998) and Chan et al. (2002) was that these tests were both static in nature and did not adequately represent the dynamic nature of the distribution system pipe environment. Prior to the start of testing, the MS-SDS test reactors used by Brereton (1998) and Chan et al. (2002) were conditioned with source water using a flow-through approach. During testing, reactor vessels were removed from the flow- through water source and sealed as closed systems to ensure a headspace-free environment within the reactor. In contrast to bench-scale static vessels, large-scale flow-through pipe loops can more accurately represent the dynamic nature of the distribution system pipe environment. However, as Rossman et al. (2001) pointed out, these experimental set-ups require significant infrastructure demands, such as space and water storage systems for examination of a source water. Modification of the MS-SDS test developed by Brereton (1998) to include a flow-through loop system, such as the approach used in the present study, may provide a more practical approach to modeling distribution system conditions, particularly in the absence of known retention times. 2.4 Policies for Disinfection By-Products in Drinking Water Based on the potential health risks of exposure to concentrations of THMs and HAAs from treated drinking water, policies have been implemented for DBPs in the form of guidelines and regulations to protect public health. However, there are differences in how these policies are implemented. A guideline is a recommended value that should not be exceeded, but it is not a legally enforceable entity. In Canada, the Canadian Guidelines for Drinking Water Quality (CGDWQ) are developed at the federal level and are recommended values for the provinces to follow. It is at the discretion of each province to adhere to the CGDWQ, i.e., provincial guidelines cannot exceed the federal guidelines, but the guideline values are not legally enforceable. However, a water provider needs a permit to supply water and the requirements of this permit, which are based on the CGDWQ, are legally enforceable. In 20 contrast, a regulation is a law with potential legal consequences if there is a failure to comply with it. A summary of the regulation and guideline values for THMs and HAAs in drinking water for select jurisdictions is provided in Table 2.5. Table 2.5 Regulations and guidelines for THMs and HAAs in drinking water for select jurisdictions Jurisdiction Guideline orRegulation? Disinfection By-Product Level [µg/ L] Reference Canada Guideline TTHMa 100 Health Canada (2006) Guideline (Proposed in 2006) HAA5b 80 FPTCDW (2006) United States Regulation TTHMa 80 Regulation HAA5b 60 USEPA (2006) European Union Regulation TTHMa 100 Council of the European No guideline or regulation HAAs Union (1998) Australia Guideline TTHMa 250 NHMRC and NRMMC Guideline HAAs (2004) MCAA 150 DCAA 100 TCAA 100 World Health Guideline THMs World Health Organization Chloroform 300 Organization (2006) Bromoform 100 DBCM 100 BDCM 60 Guideline HAAs MCAA 20 DCAA 50 TCAA 200 Notes: TTHM is Total Trihalomethanes; the sum of chloroform, BDCM, DBCM, and bromoform species measured in drinking water b HAA5 is the sum of MCAA, DCAA, TCAA, MBAA, DBAA There is significant variation in the current guideline and regulation values for both THMs and HAAs. The CGDWQ for DBPs are among the lowest for the jurisdictions examined, second only to the United States. The CGDWQ values are generally on par with the United States, with United States regulation values lower by 20 pg/L for both TTHM and five HAAs (HAA5; sum of MCAA, DCAA, TCAA, DBAA, and TBAA). Of note, an HAA5 guideline of 80 tg/L was recently proposed in Canada; this guideline value is currently under going a nationwide review (FPTCDW, 2006). The World Health Organization (WHO) and 21 Australia use DBP guidelines based on individual DBP species rather than the sum of the mass of DBP species concentrations, i.e., TTHM and HAAS. It has been suggested that regulation of DBPs using individual species may be more reflective of the relative health effects of DBPs (Singer, 2006). Although the epidemiological evidence for DBP health impacts is weak compared to the weight of scientific evidence for health impacts from pathogen risks, many regulations and guidelines for DBPs are a precautionary measure to protect public health. This approach has resulted in a strategy to mitigate exposures from trace chemical contaminants, such as DBPs, in treated drinking water (Hrudey and Hrudey, 2004). As new toxicological and epidemiological evidence becomes available for DBPs, it is likely that guideline and regulation DBP concentrations will change and new DBP species may be added to existing DBP policies in the future. 2.5 Study Region Kamloops is a community with a population of approximately 80 000 in the southern interior of British Columbia Kamloops is located at the confluence of the North and South Thompson Rivers approximately 350 km northeast of Vancouver, as shown in Figure 2.2. Figure 2.2 Location map for Kamloops, British Columbia 22 The City of Kamloops drinking water distribution system is complex; the distribution system consists of 46 reservoirs, 51 booster stations, non-metered residential water use, and is characterized by very high per capita water demand at 2.1 m3 /d. This rate is approximately 3 to 4 times the provincial and national average per capita water consumption rates. The drinking water intake for the city is the South Thompson River. The water quality of the river is generally within the CGDWQ; however, it is impacted by turbidity events particularly during the spring snowmelt. A summary of historical raw water quality parameters of the South Thompson River is shown in Table 2.6. Table 2.6 South Thompson River raw water quality Parameter^Mean Canadian Guidelines for DrinkingWater Quality Turbidity [NTU]^ 3.1^ <1 Color^ 3.5 15 pH 7.8 6.5-8.5 Hardness [mg/L (as CaCO3)]^45^ <200 Alkalinity [mg/L (as CaCO3)] 40 No Guideline Total Organic Carbon [mg/L] 2 No Guideline Data from Fiorante (2006) and Health Canada (2006) Concerns over declining water quality of the river prompted an examination of alternatives to improve drinking water quality for the city (Comerford and LaPlante, 2004). In 2001, a decision was made by the City of Kamloops to install a membrane treatment system. Piloting of membrane technologies proved very encouraging for removal of turbidity and pathogens from South Thompson River water. In early 2005, the City of Kamloops brought online a new, state-of-the-art 160 ML/d membrane filtration, i.e., ultrafiltration, drinking water treatment system, the Kamloops Centre for Water Quality (KCWQ), with a potential for hydraulic capacity upgrade to 200 ML/d. Prior to the 2005 treatment upgrade, the original water treatment system for the city was 3 mm screening of raw South Thompson River water followed by chlorination with 23 chlorine gas. At the time of plant commissioning, the KCWQ membrane treatment facility was the largest plant of its kind in North America. 2.5.1 Drinking Water Treatment Process Overview Raw water is pumped from the South Thompson River and screened via a 3 mm aquatic screen at a low-lift pumping station. The KCWQ uses coagulation via aluminum chlorohydrate and single stage flocculation process to destabilize and agglomerate small particles. This process is followed by a two-stage Zenon ultrafiltration membrane treatment system (Zenon Environmental Inc., 2005). Stage 1 of the membrane treatment process has 12 trains of ZeeWeed® 500 membrane cassettes, with a nominal pore size of 0.04 pm. Membrane treated water from Stage 1 (primary permeate) is disinfected with on-site generated sodium hypochlorite prior to entering the distribution system. The filter reject (concentrate) from the Stage 1 membrane treatment process enters the Stage 2 membrane treatment process, which consists of six membrane treatment trains (approximately 12.5 ML/d). The membrane treated water from Stage 2 (secondary permeate) is returned to the beginning of the Stage 1 membrane treatment process. The remaining concentrate from Stage 2 is sent to a dissolved air flotation (DAF) unit for treatment. The treated water from the DAF is used to irrigate the KCWQ landscape, while the residual solids are dewatered for use as landfill cover (City of Kamloops, 2007). The two-stage membrane treatment system reduces loading to the sewer and the costs associated with pumping raw water (Zenon Environmental Inc., 2005). Photographs of the KCWQ drinking water treatment processes are shown in Figure 2.3. 24 lit, 1̂ . lii i i Flocculation Tanks Primary Membrane Train Secondary Membrane Train On-site Sodium Hypochlorite Generation Figure 2.3 Overview of Kamloops Centre for Water Quality drinking water treatment process 2.5.2^Previous Studies of South Thompson River Water and Disinfectant By- Product Formation Limited information is available on the formation and behaviour of DBPs for South Thompson River water. To date, studies have included investigations of THM formation potential (THMFP) and HAA formation potential (HAAFP) of raw and treated South Thompson River water and characterization of the NOM and DBP precursors of South Thompson River water. 25 Researchers at Thompson Rivers University have conducted studies of THMFP of raw and treated South Thompson River water. Study results suggested that changes in raw water quality, particularly related to turbidity events during the spring melt, resulted in significantly higher THMFP than at other times of the year (S. Brewer, Pers. Comm., March 5, 2007). Studies are underway using ion chromatography and capillary electrophoresis to characterize HAAFP of the South Thompson River water. Investigations into characterizing the NOM and DBP precursors in South Thompson River water were conducted by Chowdhury (2005). In the study, raw South Thompson River water NOM was fractionated based on molecular size and polar fraction, i.e., hydrophobic, transphilic, and hydrophilic. Results showed that approximately 95% of the NOM (measured as TOC) present in South Thompson River was less than 1 kDa and mainly hydrophilic in nature. DBPFP of the South Thompson River suggested that the majority of HAAFP and essentially all of the THMFP were attributed to NOM smaller than 1 kDa in size. No consistent trend was identified between DBP formation and the different polar fractions of the NOM present. Prior to the present study, an investigation of DBP formation for treated South Thompson River water in the full-scale distribution system or at bench-scale has not been conducted. 2.6 Research Opportunity Following the completion of Stage A of the treatment system upgrade, one section of the distribution system (southwest section) received drinking water treated using membrane filtration and sodium hypochlorite disinfection, while the other section of the distribution system (southeast section) received water that was treated using 3 mm screening (coarse screening) and disinfection using chlorine gas. Stage B of the treatment system upgrade included modifications to the distribution system. During Stage B of the treatment system upgrade, the southeast section of the distribution system was connected to the southwest section of the distribution system. Once Stage B of the upgrade was completed in early January 2006, the southeast section and southwest section of the distribution system received drinking water treated using membrane filtration and chlorine disinfection. The City of Kamloops two-stage treatment system and distribution system upgrade is presented in Figure 2.4. 26 / Membrane Plant Membrane Plant Dallas ^Screening intake ^ Chlorination I Screening Coagulation Flocculation Membrane Filtration Chlorination Screening Coagulation Flocculation Membrane Filtration Chlorination To Southwest ^ To Southeast ^ To Southwest^To Southeast Section of the City^Section of the City Section of the City^Section of the City a) Stage A^ b) Stage B February 2005 to December 2005^January 2006 to Present Figure 2.4 Water treatment operation during a) Stage A and b) Stage B of the City of Kamloops distribution system upgrade Drinking water is not re-chlorinated within the City of Kamloops distribution system. The lag time between Stage A and Stage B of the distribution system upgrades offered a unique opportunity to assess the impact of implementing advanced water treatment technologies on the formation of DBPs in the distribution system. Of particular interest in this study was the formation of DBPs in the distribution system, specifically THMs and HAAs. Previous studies of South Thompson River water showed that the DBP precursors of the raw water were predominantly small in size at less than 1 kDa and showed a relatively high formation potential for HAAs (Chowdhury, 2005). Ultrafiltration is effective at removing waterborne pathogens and many of the large precursors that affect formation of DBPs. However, the ability of ultrafiltration (with pre- coagulation and flocculation) to remove small DBP precursors (e.g. <1 kDa) and the formation of DBPs within the distribution system, via reactions between disinfectants and DBP precursors following treatment, needs to be assessed. 27 Chapter 3. Research Objectives and Scope 3.1 Research Objectives The aim of this study was to provide insight into the research question: What is the impact of implementing advanced water treatment technologies on DBP formation within an existing distribution system? To address this research question, the overall objective of the study was to determine the extent to which upgrades to a drinking water treatment system, specifically, implementation of an ultrafiltration treatment process, impacted DBP formation within a distribution system. The findings of the study are relevant to the identification of potential engineering, public health, and policy implications for municipal water purveyors. 3.2 Research Scope This study focused on the DBP formation for drinking water within the City of Kamloops drinking water distribution system in two distinct research phases. The specific tasks completed during the present study were the following: • Phase I: Distribution System Monitoring — To characterize the spatial variation of DBP formation, i.e., chlorinated THMs and HAAs, in the City of Kamloops distribution system at five locations before and after implementation of the membrane treatment system. Parameters fundamental to characterizing DBP formation were also monitored including pH, temperature, chlorine concentration, ultraviolet absorbance (UV254), and TOC; and • Phase II: Bench-Scale Simulations — To assess the DBP formation for raw and membrane treated water from the City of Kamloops under distribution system conditions using controlled laboratory experiments. This research approach compared the DBP formation results obtained from a flow-through loop system, constructed of 28 resurrected pipe material obtained directly from the City of Kamloops distribution system, to the DBP formation results obtained from traditional glass bottle incubations. The same parameters fundamental to characterizing DBP formation that were monitored during Phase I were also monitored during Phase II of the present study. 29 Chapter 4. Analytical Methods 4.1 Glassware Preparation, Sample Collection, and Sample Storage Due to the low concentrations of the parameters examined in the raw water and membrane treated water matrix, glassware was meticulously cleaned prior to use. All glassware, lids, and Teflon-lined septa were cleaned with laboratory grade detergent and rinsed three times with tap water followed by a final rinse with ultrapure water (Millipore Aqua-Q Ultra-pure Water System, Millipore). Non-volumetric glassware and sampling vials were fired at 400°C for at least 2 hours prior to use. During distribution system monitoring (Phase I), all water samples were collected headspace- free in 40 mL amber glass vials with Teflon-lined rubber septa. During bench-scale simulations (Phase II), all water samples collected directly from the online tap and glass bottle incubations were collected headspace-free in 40 mL amber glass vials with Teflon- lined rubber septa. Samples collected from the flow-through loop system for TOC, UV2543 and HAA3 analyses were collected in 40 mL amber glass vials with Teflon-lined rubber septa. Samples collected from the flow-through loop system for THM analysis were collected in 14 mL amber glass vials via a stainless steel sampling port that was inserted into a Teflon-lined septa and lid. This technique created an air-tight seal to minimize the potential for THM volatilization during the lengthy sample collection times. Water samples collected during distribution system monitoring (Phase I) were collected in duplicate and analyzed in singular for each sampling round. Water samples collected during bench-scale simulations (Phase II) were collected in triplicate and analyzed in duplicate for each sampling round. For each distribution system monitoring event and for each distribution sampling event, one sampling site was randomly selected for collection of extra samples. For these sites, samples were collected in triplicate (Phase I) or quadruplicate (Phase II). These extra samples were analyzed for quality assurance and quality control 30 (QA/QC) purposes, as described in Section 4.3, and were available for reanalysis when necessary. Water samples for each laboratory analysis were collected and preserved according to standard laboratory practices, as described in APHA et al. (1998), i.e., Method 5310C, Method 5910B, and Method 6232B, and USEPA (2003), i.e., Method 552.3. Samples collected from each sampling site were placed immediately on ice packs. Chemical and physical analyses of water samples were performed in Vancouver at the University of British Columbia (UBC) Environmental Engineering Laboratory. For distribution system monitoring (Phase I) sample collection, water samples were shipped from Kamloops in a styrofoam insulated container with ice packs and received at UBC no later than 24 hours after collection. Samples collected from bench-scale simulations (Phase II) were stored on- site in a refrigerator at the KCWQ Research Laboratory prior to transport and packed into coolers with ice packs for shipment to Vancouver. At UBC, samples collected from Phase I and Phase II were held in a refrigerator at 4°C prior to analysis. All samples were analyzed within 14 days of collection. 4.2 Analytical Methods to Characterize Disinfectant By-Product Formation Analytical methods used in this study were from Standard Methods for Examination of Water and Wastewater (APHA et al., 1998) and the United States Environmental Protection Agency (USEPA) (USEPA, 2003) Similar analytical methods were used for sample analyses in the distribution system monitoring (Phase I) and bench-scale simulation (Phase II) phases of the study. All solvents used for reagents and calibration standards were HPLC grade. Similarly, all chemicals used for preservatives and calibration standards were laboratory grade quality (certified ACS grade and/or greater than 97% purity ). pH, temperature, free chlorine concentration, TOC concentration, UV254 absorbance, and THM and HAA3 concentrations were measured in water during both phases of the study. During Phase I of the study, pH, temperature, and free chlorine concentration in the distribution system were monitored continuously at each sampling site using on-line data loggers. During Phase II of the study, pH, temperature, and free chlorine concentration in water samples were measured using grab samples. TOC concentration, UV254 absorbance, 31 and THM and HAA3 concentrations were analyzed using the same analytical methods during Phase I and Phase II of the study. The analytical methods used to measure pH, temperature, free chlorine concentration, TOC concentration, UV25 4 absorbance, and THM and HAA3 concentrations in the present study are described in the following sections. 4.2.1 pH During Phase I of the study, pH was monitored continuously at the KCWQ using the GLI International Model S3. pH was monitored continuously in the distribution system using the Endress + Hauser Liquisys M CPM253 and the ALLDOS CONEX® Multi logger. During Phase II of the study, pH measurements of grab samples conducted at the UBC Environmental Engineering Laboratory were taken with a Fisher Scientific Accumet pH Meter 50, while pH measurements conducted at the KCWQ were taken with a Horiba Ltd. D-13 Portable pH meter. Each pH meter was calibrated prior to use with three standard buffer solutions (pH 4.0, pH 7.0, and pH 10.0). 4.2.2 Temperature During Phase I of the study, temperature was monitored continuously at the KCWQ using the GLI International Model S3. Temperature was monitored continuously in the distribution system using the Endress + Hauser Liquisys M CPM253 and the ALLDOS CONEX® Multi logger. During Phase II of the study, temperature measurements of grab samples were conducted using a Checktemp digital thermometer. 4.2.3 Free Chlorine During Phase I of the study, free chlorine concentration was monitored continuously at the KCWQ using the Wallace and Tiernan Micro/2000. Free chlorine concentration was monitored continuously in the distribution system using the GLI International AccuChlor Chlorine Analyzer and the ALLDOS CONEX ® Multi logger. During Phase II of the study, chlorine concentrations of grab samples were measured as free chlorine using a portable Hach Free and Total Chlorine Test Kit, 0-3.5 mg/L (Hach Company, Model CN-66). The test kit used the DPD (N,N-diethyl-p-phenylenediamine) method to measure free chlorine concentrations. The method detection limit (MDL) for free chlorine concentration using this method was 0.1 mg/L (Pers. Comm. Hach Company, September 11, 2007). 32 4.2.4 Total Organic Carbon NOM in aquatic sources can be measured as TOG, which quantifies all organic material in the sample. TOC is composed of dissolved organic carbon (DOC) and particulate organic carbon (POC); DOC is typically defined as the organic carbon that passes through a 0.45 1.1.rn filter. For the source water used in this study (South Thompson River), essentially all (approximately 85%) of the TOG was present as DOC. TOG concentrations were measured using the Persulfate-Ultraviolet (UV) Oxidation Method 5310C (APHA et al., 1998) and the Dohrman Phoenix 8000 UV-Persulfate Analyzer. The MDL for TOG concentrations using this method was calculated to be 0.5 mg/L (Method 1030C, API-IA et al, 1998). Since concentrations of TOG in the water samples were expected to be low, samples were measured using the lowest analytical range of the instrument, 0.1 to 20 mg/L. Ultrapure water was used for preparation of TOG calibration standards and trip blanks, field blanks, and laboratory blanks. 4.2.5 Ultraviolet Absorbance UV absorbance measured at 254 nm (UV254) has been shown to correlate well with the aromaticity of the NOM molecules and DBP formation (Kids et al., 2001; Li et al., 2000; Najm et al., 1994). Most chlorine consumption of NOM has been shown to be the result of reactions with aromatic structures (Reckhow et al., 1990). It is also suggested that HAA precursors may have a higher aromatic content than THM precursors (Liang and Singer, 2003). The UV254 of water samples was measured using Ultraviolet Absorption Method 5910B (API-IA et al., 1998) and a LTV 300 LTV-Visible spectrometer (Spectronic Unicam) with a 1 cm pathlength quartz cuvette. Each sample was filtered with a 0.45 !Am Millipore membrane filter prior to analysis to remove any suspended particles that may have interfered with absorbance measurements. Ultrapure water was used for UV254 trip blanks, field blanks, and laboratory blanks. 4.2.6 Specific Ultraviolet Absorbance SUVA values provide an indication of the fraction of aromatic, hydrophobic nature of NOM (Croue et al., 2000). SUVA is the ratio of UV absorption per m at 254 nm to mg/L of DOC, 33 as shown in Equation 4.1. The SUVA value was multiplied by 100 since UV measurements were done with 1 cm UV cells for units of L/mg-m (Xie, 2004). SUVA -  UV x 100 [L/mg-m] DOC [4.1] For purposes of this study, TOC measurements were used to calculate SUVA values, since essentially all of the organic matter in the source water was present as DOC. 4.2.7 Trihalomethanes Bromine concentrations in Kamloops source water are very low; therefore, the only THM of concern was chloroform (Xie, 2004). Chloroform concentrations were measured using Liquid-Liquid Extraction Gas Chromatography Method 6232B (APHA et al., 1998). The MDL for chloroform concentration using this method was calculated to be 3 1.tg/L (Method 1030C, APHA et al., 1998). Samples for analysis were collected in 14 mL or 40 mL amber glass vials with Teflon-lined septa and caps and quenched with sodium thiosulphate prior to analysis. Any glassware or pipette tips used for THM analyses was heated at 105°C for at least one hour prior to use. Pentane was used as the extraction solvent. The extraction solvent was cleaned prior to use to ensure that it did not contain any chloroform. There is currently no standardized method to remove chloroform from pentane. Therefore, a pentane cleaning procedure was developed at the UBC Environmental Engineering Laboratory. Pentane cleaned using this method was analytically shown to be below the MDL for chloroform concentration. The following procedure was used to clean pentane: 1. A gas chromatograph (GC) column was packed with basic alumina and placed in a Hewlett-Packard 5880A Series GC and heated. Helium carrier gas was run through the column at 250°C for at least two hours to remove chloroform from the alumina. 2. The alumina-packed GC column was allowed to cool to 25°C and removed from the GC for use. 34 3. The clean alumina-packed GC column was fastened vertically in place using a buret clamp and stand. Pentane was poured into the column using a beaker via a funnel mounted to the top of the alumina-packed GC column. 4. Clean pentane was collected in an aluminum foil covered Erlenmeyer vacuum flask. The flask was placed in an ice water bath to reduce the potential for evaporation. A low- pressure vacuum was applied to the flask to permit more rapid solvent recovery from the alumina-packed GC column. 5. Clean pentane was measured into a volumetric flask and an appropriate volume of 1,2- dibromopropane (Fisher Scientific) was added as an internal standard to a concentration of 30 1,ig/L prior to use. Extracts were analyzed for chloroform using a Hewlett-Packard 6890 Series GC with a Ni" electron capture detector (ECD) and Hewlett-Packard 7672A autosampler. The carrier gas was pre-purified helium (purified via a Supelco Carrier Gas Purifier at the UBC Environmental Engineering Laboratory) transported through a 28 m x 530 tm x 3.0 lam capillary column (DB-624 Megabore, J&W Scientific). One !IL aliquots of extract were injected into the GC column using a 10 I.AL syringe. Chloroform and internal standard concentrations were measured using the GC temperature program outlined in Table 4.1. Table 4.1 GC parameters for chloroform analysis Parameter^Setting Injector Type^Splitless Temperature^90°C Detector Type^ECD Temperature^260°C Oven Initial temperature^30°C, hold for 2 minutes Ramp^6°C/min Final temperature^120°C Retention times of 6.7 min and 13.9 min were used to identify chloroform and 1,2- dibromopropane concentrations, respectively. 35 All chloroform trip, field, and laboratory blanks and calibration standards were made using bottled water. A commercially available brand of ozonated spring water (Safeway Select Refreshe, Canada Safeway Ltd.) was used to reduce the potential for contamination of blanks and standards with chloroform, which is commonly found in chlorinated water, such as the water used in the UBC Environmental Engineering Laboratory. The ozonated spring water was verified, using the above THM extraction method, to be consistently below the MDL for chloroform concentrations in all trip blanks, field blanks, and laboratory blanks. 4.2.8 Haloacetic Acids Due to the low concentrations of bromine in the raw water, the HAAs of interest were the following three chlorinated HAAs: MCAA, DCAA, and TCAA. The sum of MCAA, DCAA, and TCAA concentrations was used to determine total HAA (HAA3) concentration in the source water. HAA3 concentrations were measured using liquid-liquid microextraction based on USEPA Method 552.3 (USEPA, 2003). The MDL for each HAA compound using this method was calculated to be 4 ug/L for MCAA, 2 p.g/L for DCAA, and 1 .ig/L for TCAA (Method 1030C, APHA et al., 1998). However, the minimum concentration that could be reliably determined from the chromatograms using this method was 5 .ig/L for each HAA compound. Samples for analysis were collected in 40 mL amber glass vials with Teflon-lined septa and caps and quenched with ammonium chloride prior to analysis. Calibration standards were prepared from laboratory grade chemicals (approximately 99% purity) in methyl tertiary butyl ether (MTBE) as the solvent. Monobromoacetic acid (MBAA) was used as a surrogate analyte and 1,2-dibromopropane was used as an internal standard. The internal standard was incorporated into the MTBE extraction solvent prior to extraction. The HAA3 sample extraction procedure used was the following: 1. Samples were removed from storage and allowed to equilibrate to room temperature (approximately 2 hours). 2. 30 mL of water sample was poured into a pre-cleaned 40 mL amber glass vial with Teflon-lined screw cap using a clean, graduated cylinder for each sample. One graduated cylinder was used and rinsed thoroughly with ultrapure water between each sample. 36 3. 20 [IL of surrogate standard (20 1,tg/L of MBAA in M1BE) was added to the water sample using a pipette with disposal plastic tips. During addition of the surrogate standard, the tip of the pipette was placed below the surface of the water. After addition of the surrogate standard, the sample vial was capped and inverted a few times to mix the sample. 4. The pH of the water sample was reduced to less than or equal to 0.5 via the addition of 2 mL of concentrated sulphuric acid. Following sulphuric acid addition, the sample vial was capped and mixed. The pH of the sample was verified using narrow range pH paper. 5. Approximately 14 g of muffled sodium sulphate (muffled at 400°C in a shallow tray for up to four hours) was added to the sample immediately following the addition of sulphuric acid (the heat generated from the addition of the acid helped to dissolve the sodium sulphate). Following the addition of sodium sulphate, the sample was shaken by hand until almost all of the sodium sulphate was dissolved (approximately 1 minute). 6. Exactly 4 0 mL of MTBE with internal standard (1,2-dibromopropane) was added to each sample (using a pipette with disposable plastic tips) and shaken for 3 minutes. Shaking of the samples was accomplished for up to 12 samples at a time using a Burrell Wrist-Action Shaker (Burrell Scientific). 7. The samples were removed from the shaker and the phases were allowed to separate for approximately 5 minutes. 8. Using a Pasteur pipette, as much of the upper MTBE layer (no water phase) as possible was transferred to a COD vial with lid. 9. 3 mL of 10% sulphuric acid in methanol was added to each COD vial (containing the upper MTBE layer) using a pipette with plastic disposable tips. The samples were capped and inverted once to mix the sample. 10. Capped COD vials were placed in an uncovered water bath at 50°C for 2 hours. The depth of water in the bath was such that only half of the COD vial was covered. 37 11. The COD vials were removed from the water bath and allowed to cool completely before their caps were removed. 12. 7 mL of 150 g/L sodium sulphate solution was added to each COD vial. Each capped COD vial was vortexed for approximately 5 seconds to ensure full equilibration between the phases. The two phases were allowed to settle fully, but the samples were not allowed to sit more than a few minutes. (The addition of the sodium sulphate solution may cause some loss of HAA-esters over long periods of time.) 13. Using a disposable Pasteur pipette, the lower (acidic aqueous methanol) phase was removed and discarded from each COD vial. No more than approximately 0.3 mL of aqueous phase remained in the COD vial in order to ensure complete neutralization of the sample (see Step 14). 14. 1 mL of saturated sodium bicarbonate solution was added to the COD vial using a pipette. Each COD vial was vortexed for approximately five seconds, at least four times, in order to complete the neutralization reaction. After the first vortexing, the lid of the COD vial was loosened to allow the release of the CO 2 from the sample. 15. Approximately 1 mL of the upper ether layer was transferred to a GC autosampler vial. 16. The sample extracts were analyzed as soon as possible. However, if immediate analysis was not possible, extracts were stored in the freezer at s -10°C. Extracts were analyzed for MCAA, DCAA, and TCAA using a Hewlett-Packard 6890 Series GC with a Hewlett-Packard 5973 Mass Selective Detector and a Hewlett-Packard 6890 Series autosampler. The carrier gas was pre-purified helium (purified via a Supelco Carrier Gas Purifier at the UBC Environmental Engineering Laboratory) transported through a 30 m x 250 tm x 0.25 [Am capillary column (HP-5MS, 5% phenylmethyl siloxane, J&W Scientific). Two 1AL aliquots of extract were injected into the GC column using a 10 uL syringe. MCAA, DCAA, TCAA, surrogate standard (MBAA), and internal standard (1,2- dibromopropane) concentrations were measured using the GC temperature program outlined in Table 4.2. 38 Table 4.2 GC parameters for HAA3 analysis Parameter^Setting Injector Type^ Splitless Temperature^200°C Oven Initial temperature^30°C, hold for 8 minutes Ramp^5°C/min for 16 min Final temperature^110°C A primary quantification ion and a secondary confirmation ion were used to identify HAA3, MBAA, and 1,2-dibromopropane. The quantification and confirmation ions and retention times used to identify each compound are shown in Table 4.3. Table 4.3 Quantification and confirmation ions and retention times to identify HAA3 compounds of interest Compound QuantificationIon Confirmation Ion Retention Time [min] MCAA 77 64 6.9 DCAA 83 85 11.0 TCAA 117 141 14.5 MBAA 152 154 10.4 1,2-Dibromopropane 121 123 11.3 Due to the low concentrations of MCAA observed in the water samples, total ion current and retention time were used to identify the compound rather than quantification and confirmation ions. All HAA3 trip, field, and laboratory blanks and calibration standards were made using bottled water. A commercially available brand of ozonated spring water (Safeway Select Refreshe, Canada Safeway Ltd.) was used to reduce the potential for contamination of blanks and standards with HAA3, which is commonly found in chlorinated water, such as the water used in the UBC Environmental Engineering Laboratory. The ozonated spring water was verified, using the above HAA3 extraction method, to be consistently below the MDL for HAA3 concentrations in all trip blanks, field blanks, and laboratory blanks 39 4.3 Quality Assurance / Quality Control QA/QC measures were implemented to verify sample integrity during all stages of sample collection and analysis. Trip blanks, field blanks, and laboratory blanks were used to monitor for potential sources of sample contamination during bottle preparation and transport; sample collection, transport, and storage; and chemical analyses. Laboratory blanks were used every 10th sample or once for each batch of samples, whichever value was less, for each chemical analysis performed. 4.4 Assessment of Water Sample Storage Time To ensure that water samples were stable for the duration of the maximum recommended sample storage time between sample collection and analysis, a sample storage study was conducted. The maximum recommended sample storage time for the parameters of interest in the present study was 14 days (USEPA, 2003; APHA et al., 1998). The objective of the sample storage study was to examine the potential impacts of storage time on the City of Kamloops distribution system water matrix. In the sample storage study, all water samples were collected in quadruplicate from one distribution system sampling site (Site 2, Dallas Intake) and analyzed in triplicate at each time interval (discussed below) over the 14 day holding period. Site 2 was selected for study because of the consistently higher levels of DBPs observed at this site than at each of the other four sampling sites. TOG concentration, UV254 absorbance, and THM and HAA3 concentrations were measured and compared over 1 day, 4 days, 8 days, and 14 days sample storage periods. These time intervals were selected to minimize the number of samples required for analysis and to correspond with the four sampling intervals used by USEPA (2003) to assess sample storage times. In their assessment, USEPA (2003) used 0 day, 3 days, 7 days, and 14 days; however, for purposes of this study, 1 day, 4 days, 8 days, and 14 days sample storage time intervals were selected to account for the one day shipment period between sample collection in Kamloops and receipt at the UBC Environmental Engineering Laboratory. 40 Mean values were computed based on triplicate sample analyses for each parameter. The mean and standard deviation values for each parameter and sample storage time are presented in Table 4.4. Table 4.4 TOC, UV254 , THM, and HAA3 measurements for City of Kamloops drinking water sample storage study (values presented are mean ± standard deviation) Sample Storage Time [Days] TOC [mg/L] UV254 [cm-1] THM [ug/L] HAA3 [pg/L] 1 1.7+0.3 0.022±0.003 34+1 109±5 4 1.8+0.2 0.032±0.009 35±1 106+15 8 1.9+0.2 0.021±0.003 32±2 95+2 14 1.7+0.3 0.019±0.001 36±3 98±15 Note: Mean and standard deviation values calculated from triplicate measurements As shown in Table 4.4, no statistically significant change in TOC concentrations, UV254 absorbance, THM concentrations, or HAA3 concentrations was observed over the 14 day study period. Further, no apparent trend in TOC concentrations, UV254 absorbance values, THM concentrations, or HAA3 concentrations was observed during the 14 day study period. Due to the low concentrations of parameters of interest in the water samples, the observed differences in mean values and standard deviations were more likely due to inherent variability of the analytical methods rather than to due changes in sample quality over time. Based on the results obtained for the parameters of interest in this study, the City of Kamloops drinking water samples remained stable for at least 14 days during storage. 41 Chapter 5. Experimental Design and Methods This study was completed in two experimental phases. Phase I of the study consisted of full- scale monitoring of the City of Kamloops distribution system water quality, while Phase II of the study consisted of bench-scale simulations, which used a flow-through loop system constructed of pipe material resurrected from the distribution system and glass bottle incubations. 5.1 Phase I: Distribution System Monitoring 5.1.1^Overview of Phase I The aim of this phase of the study was to characterize the spatial variation of DBP formation in the distribution system before and after implementation of the membrane treatment system. Five sampling sites were selected; one raw water site and four sites located within the distribution system. Grab water samples were collected from each site in 10 sampling events from October 31, 2005 to March 27, 2006 at approximately bi-weekly intervals. Five sampling events were conducted before (Stage A) and after (Stage B) implementation of the membrane treatment system upgrade. Due to the extensive turnaround time required for preparation of sample bottles (2 to 4 days) and completion of sample analyses (7 to 10 days) for each sampling event, samples were collected at bi-weekly intervals to peimit adequate time for preparation between sampling events. At each sampling site, as described in Section 5.1.2., grab water samples were drawn from a sampling port. Prior to sample collection, each sampling port was flushed for at least five minutes. The grab water samples were collected and analyzed for TOC concentrations, UV254 absorbance, and THIVI and HAA3 concentrations. A summary of the dates and times when sampling events took place during Stage A and Stage B of the membrane treatment system upgrade is presented in Appendix A. 42 To Southwest Section of the City izh To Southeast Section of the City 5.1.2 Sampling Sites The following five sites were sampled in the southeast and southwest sections of the City of Kamloops drinking water distribution system: the raw water intake of the membrane treatment plant (Site 3); two sites located immediately after treatment and chlorination processes, which included the Dallas Intake (3 mm screening followed by chlorine gas) (Site 1) and membrane permeate site (Site 4); and two sites located downstream of treatment and chlorination processes, which included the Blackwell Booster Station (Site 2) and Thompson Rivers University (Site 5). Once treated water leaves the treatment plant, there is no further chlorination at any point in the City of Kamloops distribution system. Distribution system sampling sites used in this study during Stage A and Stage B of the distribution system upgrade are presented in Figure 5.1. Membrane Plant Treatment ^4 Plant Permeate Î Thompson^(5) Rivers University \--x To Sou hwest Section of the City Da las Intake (Y'' Dallas intake ((2) Blackwell 4.1 Booster Station To Southeast Section of the City a) Stage A ^ b) Stage B February 2005 to December 2005^January 2006 to Present Figure 5.1 Phase I sampling site locations during a) Stage A and b) Stage B of the City of Kamloops drinking water distribution system upgrade The same sites were sampled during Stage A and Stage B of the distribution system upgrade to permit a comparison of the physical and chemical characteristics of the water in the distribution system before and after implementation of the membrane treatment system upgrade. Photographs of each of the five sampling sites used in the distribution system monitoring study are presented in Appendix B. 43 As described in Section 4.2.1 to Section 4.2.3, pH, temperature, and free chlorine data were continuously monitored at each sampling site for the duration of the study. Distribution system monitoring data for Site 1, Site 3, and Site 4 were obtained from the City of Kamloops via the City of Kamloops on-line SCADA system. Distribution system monitoring data for Site 2 and Site 5 were downloaded at periodic intervals directly from the data loggers. Photographs of the City of Kamloops on-line data logger system (Site 1 and Site 4) and the data loggers installed for the present study (Site 2 and Site 5) are shown in Appendix B. 5.1.3 Limitations of Phase I The City of Kamloops drinking water distribution system is hydraulically complex with numerous reservoirs and booster stations and a non-metered residential water supply. These factors make it difficult to obtain accurate measurements of residence times associated with the distribution system sampling sites and sampling events. Therefore, this phase of this study could only verify whether there was an overall effect of implementing advanced water treatment technologies, i.e., ultrafiltration, on DBP formation within the distribution system. It was difficult to estimate potential causes of the changes in water quality without further exploration and testing. A bench-scale investigation of DBP formation for water in the City of Kamloops distribution system was implemented in Phase II of this study to supplement the information on full-scale distribution system DBP formation obtained during this phase. 5.1.4 Phase I Data Analysis The focus of this study was to determine the impact of membrane treatment processes on DBP formation within the distribution system. Statistical differences in DBP concentrations during Stage A and Stage B of the distribution system upgrade were confirmed using pair- wise comparisons (paired t-tests) conducted at a 95% confidence level. Pair-wise comparisons were performed for each sampling event during Stage A and each sampling event during Stage B. Pair-wise comparisons were also conducted for each of the additional water quality parameters monitored during the study, i.e., pH, temperature, chlorine concentration, TOC concentration, UV254 absorbance, and SUVA, to establish if there was a difference in applying membrane treatment processes on delivered water quality in the distribution system. 44 DBP concentrations are presented using mean and standard deviation to describe the magnitude and variability in measurement values. The mean and standard deviation values for each water quality parameter were calculated from the five sampling events during Stage A and the five sampling events during Stage B. 5.1.4.1 Pair-Wise Comparisons Pair-wise comparisons were performed for sampling sites within the southwest section, i.e., Site 4 and Site 5, and sampling sites within the southeast section, i.e., Site 1 and Site 2, of the distribution system during Stage A and Stage B. Pair-wise comparisons were also performed for each paired sampling site between the southwest section and southeast section of the distribution system, i.e., Site 4 and Site 1 and Site 5 and Site 2, respectively, during Stage A and Stage B. One sampling site (Site 3) was used to monitor raw water quality during Stage A and Stage B. Four questions of interest were examined with pair-wise comparisons, which included the following: a) Was the source water similar during Stage A and Stage B? Pair-wise comparisons were conducted within the southwest section of the distribution system, i.e., between Site 3 and Site 4 and between Site 4 and Site 5, during Stage A and Stage B. During both Stage A and Stage B, the southwest section of the distribution system received water from the membrane treatment system. A pair-wise comparison of the southwest section of the distribution system was used to confirm whether the source water was similar during Stage A and Stage B. b) Did water quality change within each section of the distribution system? Pair-wise comparisons were conducted within the southwest section of the distribution system, i.e., between Site 3 and Site 4 and between Site 4 and Site 5, and within the southeast section of the distribution system, i.e., between Site 3 and Site 1 and between Site 1 and Site 2, during Stage A and Stage B. During Stage A, the southwest section of the distribution system received water from the membrane treatment system, while the southeast section of the distribution system received water treated by coarse screening and chlorination with chlorine gas. During Stage B, both the southwest and southeast sections of the distribution system received water from the membrane treatment system. A pair-wise comparison within the southwest section of the distribution system and 45 within the southeast section of the distribution system was used to confirm whether water quality changed between the raw water and the distribution system sampling sites during Stage A and Stage B. c) Was water quality similar between each section of the distribution system? Pair- wise comparisons were conducted between the southwest section and the southeast section of the distribution system immediately following treatment and chlorination processes, i.e., between Site 4 and Site 1, during Stage A and Stage B. Pair-wise comparisons were also conducted between the southwest section and the southeast section of the distribution system at extremity sampling sites within the distribution system, i.e., between Site 5 and Site 2, during Stage A and Stage B. During Stage A, the southwest section of the distribution system received water from the membrane treatment system, while the southeast section of the distribution system received water treated by coarse screening and chlorination with chlorine gas. Site 4 and Site 1 were located immediately following treatment and chlorination processes. During Stage B, both the southwest and southeast sections of the distribution system received water from the membrane treatment system. Site 1 and Site 2 were now located a significant distance downstream of treatment and chlorination processes, i.e., the membrane treatment plant. A pair-wise comparison between sampling sites in the southwest section of the distribution system and the sampling sites in the southeast section of the distribution system during Stage A and Stage B was used to confirm whether changes in water quality occurred in the southeast section of the distribution system following the implementation of the membrane treatment system. d) Was water quality similar in the southeast section of the distribution system during Stage A and Stage B? Pair-wise comparisons were conducted within the southeast section of the distribution system, i.e., between Site 1 and Site 2, during Stage A and Stage B. During Stage A, the southeast section of the distribution system received water treated by coarse screening and chlorination with chlorine gas and Site 1 was located immediately following treatment and chlorination processes. During Stage B, the southeast section of the distribution system received water from the membrane treatment system and Site 1 was now located a significant distance downstream of 46 treatment and chlorination processes, i.e., the membrane treatment plant. A pair-wise comparison within the southeast section of the distribution system during Stage A and Stage B was used to confirm whether changes in water quality occurred between Site 1 and the extremity sampling site (Site 2), following the implementation of the membrane treatment system. Pair-wise comparisons were conducted for five sampling events during Stage A and five sampling events during Stage B, which is a relatively small sample size. Due to this small sample size, the results of the pair-wise comparisons should be interpreted with caution. 5.2 Phase II: Bench-Scale Simulations 5.2.1 Overview of Phase II The hydraulic complexities of the City of Kamloops distribution system make it difficult to obtain system retention times via modeling. The aim of this phase of the study was to investigate DBP formation in the City of Kamloops distribution system at bench-scale using a modified SDS test, i.e., the MS-SDS test, constructed of pipe material resurrected from the distribution system. DBP formation results using the MS-SDS test were then compared to DBP formation results using traditional glass bottle incubations. The bench-scale approach allowed control of retention times to monitor changes in THM and HAA3 formation over time. The MS-SDS test was developed as an experimental technique to more closely represent actual distribution system conditions (Chan et al., 2002; Brereton, 1998). Using controlled retention times under actual distribution system conditions, i.e., pH, temperature, and chlorine concentration, an assessment of DBP formation was performed. This phase was conducted between July 12, 2006 and September 20, 2006. DBP formation results using the MS-SDS test were compared to the DBP formation results using the following two SDS tests: an in-situ SDS test was performed in parallel with the MS-SDS test under the same environmental conditions (Method 5710C, APHA et al., 1998) and a standard SDS test was performed at standard reaction conditions (Method 5710, APHA et al., 1998). For purposes of comparison, both SDS tests were performed using the same retention times as the retention times used in the MS-SDS test. The in-situ SDS test was conducted in parallel with the MS-SDS test to determine the effect of the pipe environment 47 on THM and HAA3 formation of South Thompson River water. The standard SDS test was conducted under controlled laboratory conditions to determine THM and HAA3 formation of South Thompson River water under standardized environmental conditions of pH, temperature, and chlorine concentration. The MS-SDS test, in-situ SDS test, and standard SDS test were each performed in triplicate. Due to the extensive turnaround time required for preparation of sample bottles (2 to 4 days), laboratory sample collections (7 to 10 days), and completion of sample analyses (7 to 14 days) for each experimental period, samples were collected from only three sampling events for each experimental period to permit adequate preparation time between experimental periods. For the MS-SDS test, in-situ SDS test, and standard SDS test, DBP formation for South Thompson River water was examined at the following four time intervals: 0 hour, 3 hours, 12 hours, and 36 hours. Two experimental periods were used, including a 12 hour experimental period and a 36 hour experimental period. Each experimental period was comprised of three retention time intervals. The 12 hour experimental period was comprised of 0 hour, 3 hours, and 12 hours retention times. The 36 hour experimental period was comprised of 0 hour, 12 hours, and 36 hours retention times. Since the retention times for Phase I distribution system sampling sites were not known, the experimental periods used for this phase were selected to investigate the impact of relatively long retention times (such as those retention times that might occur at the extremities of the distribution system) on DBP formation for South Thompson River water. DBP formation was examined for two water streams (raw water and membrane treated water, obtained via on-line taps from the water treatment plant) as well as for an experimental control. A summary of the water streams used in the MS-SDS test, in -situ SDS test, and standard SDS test are presented in Table 5.1. 48 Table 5.1 Water streams used in MS-SDS and SDS tests Water Stream Test Type MS-SDS SDS Standard SDS Chlorinated Raw Waters ^ ^ ^ Chlorinated Membrane Treated Water 2 ^ ^ Unchlorinated Membrane Treated Water 3 ^ Control (Unchlorinated Spring Water) 4 ^ ^ ^ Notes: Raw South Thompson River water was collected from an on-line tap. Sodium hypochlorite was added to the raw water to achieve a concentration of 1.0 to 1.1 mg/L free chlorine, following a 20 minute chlorine contact time. The chlorine dose for raw water was selected to achieve a free chlorine concentration equivalent to that of the membrane treated water prior to entry into the distribution system. 2 Chlorinated membrane treated water (from the clearwell) was collected from an on-line tap prior to entry into the distribution system. The minimum contact time in the clearwell was 20 minutes. 3 Unchlorinated membrane treated water was collected from a sampling port prior to entry into the clearwell. Sodium hypochlorite was added to the unchlorinated membrane treated water to achieve a chlorine concentration of 3 to 5 mg/L free chlorine at the end of the incubation period. 4 Control water was a commercial brand of ozonated spring water (Safeway Select Refreshe, Canada Safeway Ltd.). The control water was analytically shown to contain no free chlorine and THMs and HAA3 concentrations were below the MDL. The control water was not chlorinated during the MS-SDS test, in-situ SDS test, or standard SDS test. 5.2.2 Material-Specific Simulated Distribution System Test and Simulated Distribution System Tests The MS-SDS test developed by Brereton (1998) and the SDS test bench-scale methods (Method 5710C and 5710D; APHA et al., 1998) provide an estimate of DBP formation in a distribution system following chlorination. The MS-SDS test, in-situ SDS test, and standard SDS test methods were used to investigate the impact of retention times on THM and HAA3 formation within the distribution system. DBP concentrations measured in the City of Kamloops distribution system during distribution system monitoring (Phase I) were compared to the DBP concentrations measured during the bench-scale simulations. pH, temperature, and free chlorine concentration were measured for each grab sample at the time of sample collection and prior to analyses for TOC, UV254 absorbance, THM, and HAA3. 49 150 mm (inside diameter) The experimental designs and methods for the MS-SDS test, in-situ SDS test, and standard SDS tests are discussed in the following sections. 5.2.2.1^Material-Specific Simulated Distribution System Test The reactors used for the MS-SDS test were constructed of resurrected 170 mm (150 mm inside diameter) cast iron pipe material obtained directly from the City of Kamloops distribution system. Before the MS-SDS test reactors were constructed, each pipe section was cleaned with distilled water and gently tapped to remove loose sediment and loose tuberculated material. A sample pipe section used to construct the MS-SDS test reactors is presented in Figure 5.2. Figure 5.2 Sample of cast iron pipe section resurrected from City of Kamloops distribution system (before cleaning) 50 For purposes of this study, a modified version of the MS-SDS test reactor developed by Brereton (1998) was used. Pipe sections were cut from the same original pipe piece to 60 mm lengths. Five MS-SDS test reactors were constructed; four experimental reactors and one control reactor. The final working volume of each MS-SDS test reactor was approximately 1025 m.L. The MS-SDS test reactors were constructed using the following materials: ■ section of resurrected cast-iron pipe obtained directly from the distribution system; ■ 2 x Teflon gaskets [205 mm x 205 mm x 2 mm]; ■ 2 x aluminum plates [210 mm x 210 mm x 12 mm]; ■ 8 x bolts [105 mm length, 1/4" diameter], washers, and nuts at evenly spaced intervals around the outside circumference of the pipe section; and ■ 2 x Swagelok NPT male connector fittings [1/8" diameter] for inlet and outlet ports in each reactor. For measurement of THM and HAA3 formation, it was critical that the reactors were free of introduced chemical contaminants during construction and be air-tight and water-tight. Each cast iron pipe section was cut without the use of cutting fluid to avoid potential contamination of the inside pipe material. After cutting, both edges of the pipe sections were lathed smooth to ensure a flush seal against the Teflon gasket. An inlet (side of reactor) port and outlet (top of reactor) port (Swagelok NPT male connector fittings) were installed at 90° angles to each other to allow air bubbles to migrate to the top of the reactor, to facilitate connection of two reactors in series, and to permit complete mixing within the reactor. Each reactor was assumed to be a completely stirred tank reactor (CSTR). The CSTR assumption for each reactor was verified via a continuous tracer study. The results of the tracer study are presented in Appendix C. Photographs of the reactors used for the MS-SDS test are presented in Figure 5.3. 51 4------ Teflon Gasket NPT Thread Swagelok Male Connector Fitting TOP = Outlet Port SIDE = Inlet Port 11 4-- Aluminum Plate Bolt (with nut and washer) Cast Iron Pipe Section (Resurrected from City of Kamloops distribution system) St Iron P (Resurre City of K distributio pe Secti ted from mloops system) Aluminum Plate Front View Bolts (with nuts and washers) NPT Thread Swagelok Male Connector Fitting TOP = Outlet Port, SI E = Inlet Port Teflon Gasket Side View Figure 5.3 MS-SDS test reactor 52 R Water S, Ply onti tap)CONTROL IREACTOR Chl Treated 1Neter Supply ta ritact r Raw ater CHLORINAT RAW WAT REACTO -AlitEMBRANE TREATED WATER REACTOR SERIES As shown in Figure 5.3, the cast iron pipe section used to build the MS-SDS test reactors was much cleaner than the original cast iron pipe section shown in Figure 5.2. Due to the fragile nature of the sediments and tuberculated material, most of the material that remained after the pipe was cleaned fell off during the lathing process. The lathing process was a crucial step in the construction process to ensure a smooth, secure fit between the pipe section and the Teflon gaskets. The bench-scale MS-SDS test was set-up at the KCWQ in Kamloops. In order to examine DBP formation in the raw water and membrane treated water streams as well as an experimental control, the MS-SDS test used the following reactor configurations: chlorinated raw water reactor series, chlorinated membrane treated water series, and control reactor. The raw water reactor series and the membrane treated water reactor series each consisted of two MS-SDS test reactors connected in series, as described in the following sections. Each of the MS-SDS test reactors were submersed in a water bath through which raw water and chlorinated membrane treated water flowed. This enabled the MS-SDS test reactors to be maintained at a temperature equivalent to that of the influent raw water and chlorinated membrane treated water. A photograph of the MS-SDS test is presented in Figure 5.4. Figure 5.4 MS-SDS test 53 The set-up of each reactor series is discussed in the following sections. Chlorinated Raw Water Reactor Series For the chlorinated raw water reactor series, two MS-SDS test reactors were connected in series i.e., connected from the outlet port of the first reactor to the inlet port of the second reactor, using 1/8" diameter (outside diameter) Teflon tubing and two Swagelok NPT male connector fittings. Raw South Thompson River water was obtained via on-line taps, as shown in Appendix B, and chlorinated using the procedure described below. Raw water was pumped into a completely mixed chlorine contact tank (CCT), which consisted of a 2 L Erlenmeyer vacuum flask, via a peristaltic pump. The CCT was rapidly mixed with a stir plate and stir bar to simulate flash mixing. A chlorine solution (700 mg/L sodium hypochlorite) was dosed to the CCT (approximately 0.5 mL/min) using a diaphragm dosing pump (ALLDOS Primus 208). Sodium hypochlorite solution was added to the raw water in the CCT to achieve a dose of 1.0 to 1.1 mg/L free chlorine, following a 20 minute chlorine contact time. The chlorine dose for raw water was selected to achieve a free chlorine concentration equivalent to that of the membrane treated water prior to entry into the distribution system. The 20 minute chlorine contact time in the CCT simulated the minimum chlorine contact time in the KCWQ clearwell during peak daily demand for the full-scale treatment system. The CCT was insulated to maintain the chlorinated raw water in the chamber at the same temperature as the influent raw water from the on-line tap. Chlorinated raw water was pumped from the CCT directly into the MS-SDS test reactors using a low-flow peristaltic pump (Lachat Instruments Model 2200-000). Chlorinated Membrane Treated Water Reactor Series For the chlorinated membrane treated water reactor series, two MS-SDS test reactors were connected in series, i.e., connected from the outlet port of the first reactor to the inlet port of the second reactor, using 1/8" diameter (outside diameter) Teflon tubing and two Swagelok NPT male connector fittings. Chlorinated membrane treated water was obtained from the clearwell via on-line taps, as shown in Appendix B. Chlorinated membrane treated water was pumped directly into the MS-SDS test reactors using a low-flow peristaltic pump (Lachat Instruments Model 2200-000). 54 ChlorinesiBritact :: 4.010R7 1;14`iiiikfirell^ater "". -^44!' APer,^!tic, Control Water Supply,, , Pump   liiir4 ^(  . Reservoir --- w, - -AI 4^, , 3 It 1T ' 4 Chlorinated Membrane Treated Water Supply (via on-line tap) Sodium Hypochiorite Solution Control Reactor For the control reactor, only one MS-SDS test reactor was used. Bottled ozonated spring water (Safeway Select Refreshe, Canada Safeway Ltd.) was used for the experimental control. The water used for the experimental control was not chlorinated for the duration of the MS- SDS test. The ozonated spring water was added to a reservoir, which consisted of a 2 L Erlenmeyer flask. The ozonated spring water was pumped directly from the reservoir into the MS-SDS test control reactor using a low-flow peristaltic pump (Lachat Instruments Model 2200-000). A photograph of the MS-SDS test apparatus is presented in Figure 5.5. Figure 5.5 MS-SDS test apparatus A limited number of pipe reactors were available; therefore, two separate experimental periods were used to investigate the effect of retention times on DBP formation. The 12 hour experimental period examined DBP formation using 0 hour, 3 hours, and 9 hours 55 retention times within the MS-SDS test reactors. The configuration of the MS-SDS test reactors in series resulted in a maximum mean retention time of 12 hours. The 36 hour experimental period examined DBP formation using 0 hour, 12 hours, and 24 hours retention times within the MS-SDS test reactors. The configuration of the MS-SDS test reactors in series resulted in a maximum mean retention time of 36 hours. As a result, DBP formation was examined using the following four mean retention time intervals: 0 hour (samples collected prior to entry into the MS-SDS test reactors), 3 hours, 12 hours, and 36 hours. Controlled mean retention times of the MS-SDS test were achieved by control of inlet and outlet flow rates through the MS-SDS test reactors using a low-flow peristaltic pump. MS- SDS test inlet and outlet flow rates of the MS-SDS test reactors were monitored during the operation of the system and were within approximately 15% of the required flow rate. The peristaltic pump flow rates used to achieve the mean retention times in the MS-SDS test are summarized in Table 5.2. Table 5.2 Pump flow rates for mean retention times in MS-SDS test reactors Retention time* [hours] Flow Rate [mL/min] 12 hour Experimental Period 3 5.7 9 1.9 12 1.4 36 hour Experimental Period 12 1.4 24 0.7 36 0.5 *All retention times were based on a reactor working volume of 1025 mL. The MS-SDS test was conducted from July 12, 2006 to September 20, 2006 at the KCWQ. The 12 hour experimental period for the MS-SDS test was conducted between August 9, 2006 and August 12, 2006. The 36 hour experimental period for the MS-SDS test was conducted between September 15 and September 20, 2006. Prior to the start of sample collection for the 12 hour experimental period and the 36 hour experimental period, the MS- 56 SDS test reactors were conditioned with a continuous flow of chlorinated membrane treated water for approximately 4 weeks. All reactors were conditioned in the same manner to provide a baseline for comparison of DBP formation between all MS-SDS test reactors. Following the 4 week conditioning period for the MS-SDS test reactors and prior to the start of the 12 hour and 36 hour experimental periods, the raw water reactors and the control reactor were disconnected from the continuous flow of membrane treated water. Chlorinated raw water, which was chlorinated via the CCT, was pumped through the chlorinated raw water reactors for approximately 1.3 retention times prior to sampling. Ozonated spring water was pumped through the control reactor for at least one retention time prior to sampling. A total of eight locations were sampled in the MS-SDS test. Chlorinated raw water 0 hour samples were collected from the outlet of the CCT, prior to entering the MS-SDS test reactors. Chlorinated membrane treated water 0 hour samples were collected directly from the on-line tap at KCWQ. Control water 0 hour samples were collected directly from the control reservoir. All 3 hours, 12 hours, and 36 hours water samples were collected directly from the outlets of the MS-SDS test reactors. Water samples were collected in sample bottles from the outlets of the MS-SDS test reactors using Teflon tubing. A schematic diagram of the 12 hour experimental period, the 36 hour experimental period, and sampling sites for the MS-SDS test are presented in Figure 5.6. 57 T = 12 hr T = 12 hr --0-- T = 9 hr _ T = 3 hr T = 3 hr CHLORINATED RAW WATER T = 0 hr1÷O—CD1— Chlorine Dose (as Sodium Hypochlorite) CONTROL (unchlorinated water)^T=Ohr T = 12 hrT = 3 hr CHLORINATED MEMBRANE TREATED T = 0 hr —1•0-0— WATER —0--- T = 9 hr a) 12 hour Experimental Period Maximum retention time, T = 12 hours T = 12 hr CHLORINATED RAW WATER T = 0 hr Chlorine Dose (as Sodium Hypochlorite) CONTROL (unchlorinated water)^T = 0 hr T = 12 hr CHLORINATED MEMBRANE TREATED T = 0 hr WATER T = 36 hr T = 36 hr  1■0 t = 36 hr T = 36 hr -0- T = 24 hr ....____...." b) 36 hour Experimental Period Maximum retention time, T = 36 hours (g) = Sampling sites Figure 5.6 Diagram of MS-SDS test configurations and sampling sites for a) 12 hour experimental period and b) 36 hour experimental period 58 5.2.2.2 Simulated Distribution System Tests Koch et al. (1991) developed the SDS test as a standardized tool to estimate DBP formation within the distribution system under controlled laboratory conditions. Parameters of the method, including chlorine dose, temperature, and retention times were selected to replicate the conditions of the distribution system under study. Typically, the test is performed using glass bottles. In this study, the SDS test was conducted using the following two experimental conditions: ■ In-situ SDS test — In-situ SDS test bottle incubations were conducted in parallel with the MS-SDS test under similar environmental conditions of pH, temperature, and free chlorine concentration for raw water and chlorinated membrane treated water (prior to entry to the distribution system) at the KCWQ. In-situ SDS test bottles were incubated using the same time periods as the retention times used in the MS-SDS test 12 hour experimental period and 36 hour experimental period. ■ Standard SDS test — Standard SDS test bottle incubations were conducted under controlled laboratory conditions using standard reaction conditions of pH (7.0±0.2), temperature (25±2°C), and free chlorine concentration (3 to 5 mg/L at end of incubation period) (Method 5710A, APHA et al., 1998) for raw water and unchlorinated membrane treated water at the UBC Environmental Engineering Laboratory. Standard SDS test bottles were incubated for the same time periods as the retention times used in the MS-SDS test 12 hour experimental period and 36 hour experimental period and the in-situ SDS test. In-situ SDS tests and standard SDS tests used 250 mL and 500 mL amber glass bottles and lids with Teflon-lined septa for incubations. Bottles were incubated headspace-free. In-situ Simulated Distribution System Test The in-situ SDS test was conducted in parallel with the MS-SDS test at KCWQ. The in-situ SDS test was conducted from July 12, 2006 to September 20, 2006 at the KCWQ. The 12 hour experimental period for the in-situ SDS test was conducted between August 9, 2006 59 and August 12, 2006. The 36 hour experimental period for the in-situ SDS test was conducted between September 15 and September 20, 2006. The glass bottles used for the in-situ SDS tests were filled with the same raw water and chlorinated membrane treated water as water used for the MS-SDS test. As a result, the only difference between the MS-SDS test and the in-situ SDS test was the physical environment, i.e., resurrected pipe material versus glass bottles. A control bottle was incubated with ozonated spring water, which was the same water used in the MS-SDS test control reactor, as discussed in Section 5.2.1. In-situ SDS test bottles were prepared using the procedure described below. Raw water samples were collected from the on-line tap in clean 250 mL amber glass bottles. The raw water samples were dosed with a concentrated sodium hypochlorite solution (350 mg/L) to achieve a free chorine concentration in the raw water that was similar to that of the chlorinated membrane treated water prior to entry to the distribution system, i.e., 1.0 to 1.1 mg/L. Chlorinated membrane treated water samples were collected from the on-line tap in clean 250 mL amber glass bottles. Control samples were prepared by filling clean 250 mL amber glass bottles with ozonated spring water. The chlorinated raw water, chlorinated membrane treated water, and control water samples for the in-situ SDS test were incubated in parallel with the MS-SDS test. The incubation times used for the in-situ SDS test were the same as the retention times used for the MS-SDS test. The in-situ SDS test was conducted in two batches, with each in-situ SDS test replicated three times, to correspond with the 12 hour experimental period and the 36 hour experimental period used in the MS-SDS test. Incubation times for the in-situ SDS test for the 12 hour experimental period were 0 hour, 3 hours, and 12 hours. Incubation times for the in-situ SDS test for the 36 hour experimental period were 0 hour, 12 hours, and 36 hours. In-situ SDS test bottles were incubated at the same temperature as the MS-SDS test reactors using a water bath of drain water from the MS-SDS test, as shown in Figure 5.7 and Figure 5.8. 60 Figure 5.7 In-situ SDS test Figure 5.8 In-situ SDS test and MS-SDS test apparatus 61 0 hour chlorinated raw water samples were collected within 5 minutes of chlorination. 0 hour chlorinated membrane treated water samples were collected directly from the on-line tap at KCWQ. All 3 hours, 12 hours, and 36 hours water samples were collected at the end of the desired incubation period. A diagram of the in-situ SDS test incubations is presented in Figure 5.9. 62 = 12 hr= 3 hr CHLORINATED RAW WATER CHLORINATED RAW WATER = 12 hr = 36 hr CHLORINATED MEMBRANE TREATED WATER t = 0 hr t = 3 hr T = 12 hr CHLORINATED MEMBRANE TREATED WATER CONTROL (unchlorinated water) = 0 hr = 3 hr = 12 hr CONTROL (unchlorinated water) = 0 hr = 12 hr = 36 hr a) 12 hour Experimental Period^b) 36 hour Experimental Period In-situ SDS Test and Standard SDS In-situ SDS Test and Standard SDS Test Incubations^ Test Incubations Figure 5.9 Diagram of in-situ SDS test and standard SDS test bottle incubations for a) 12 hour experimental period and b) 36 hour experimental period 63 Standard Simulated Distribution System Test The standard SDS test was conducted at the UBC Environmental Engineering Laboratory rather than at KCWQ because of the requirements for precise control of incubation temperature. Unchlorinated water samples were collected from the KCWQ; raw water was collected via an on-line tap, as shown in Appendix B, and unchlorinated membrane treated water was collected from a sampling port prior to entry to the clearwell. Raw water and unchlorinated membrane treated water were collected in clean 4 litre amber glass bottles and transported on ice packs to UBC for standard SDS testing. The 12 hour experimental period for the standard SDS test was conducted on raw and unchlorinated membrane treated water that was collected from KCWQ on August 29, 2006. The 36 hour experimental period for the standard SDS test was conducted on raw and unchlorinated membrane treated water that was collected from KCWQ on September 20, 2006 and September 21, 2006. Similar to the in-situ SDS test, the standard SDS test incubations were performed in glass bottles. However, in contrast to the in-situ SDS test, incubation conditions for the standard SDS test were based on the standard reaction conditions outlined in Method 5710A (APHA et al., 1998). The standard SDS test permitted a comparison of DBP formation in glass bottle incubations under standardized conditions to the in-situ SDS test, which examined DBP formation in glass bottle incubations under operating conditions similar to KCWQ. For the standard SDS test, the chlorine dose of raw water and unchlorinated membrane treated water was high enough to ensure a 3 to 5 mg/L free chlorine concentration at the end of the incubation period. A concentrated sodium hypochlorite solution (350 mg/L) was used to dose raw water and unchlorinated membrane treated water samples. The dosing volume of sodium hypochlorite solution required to obtain the desired free chlorine concentration at the end of the incubation period was dependent on water type and the length of the incubation period. Samples were incubated at 25±2°C in an incubator shaker (Innova 4230, New Brunswick Scientific). Water sample pH was controlled to pH 7.0±0.2 by addition of a phosphate buffer solution, prepared according to Method 5710C (APHA et al., 1998). The incubation times used in the standard SDS test were the same as the retention times used in the MS-SDS test and the in-situ SDS test. Standard SDS tests were performed in two 64 separate batches to correspond with the completion of the MS-SDS test and in-situ SDS test, i.e., in late-August 2006 and late-September 2006. Incubation times for the first standard SDS test were 0 hour, 3 hours, and 12 hours to correspond with the 12 hour experimental period. Incubation times for the second standard SDS test were 0 hour, 12 hours, and 36 hours to correspond with the 36 hour experimental period. Chlorinated raw water and chlorinated membrane treated water 0 hour samples were collected within five minutes of chlorination. All 3 hours, 12 hours, and 36 hours water samples were collected at the end of the desired incubation period. It should be noted that the temperature of the raw water and unchlorinated membrane treated water was not equilibrated to 25°C prior to the start of the standard SDS test. Therefore, the temperature of the chlorinated raw water and chlorinated membrane treated water following the start of the SDS tests was slightly lower than 25°C, for a short period of time, as the water equilibrated to 25°C. A schematic diagram of the standard SDS test incubations is presented in Figure 5.9. 5.2.3 Limitations of Phase II During the reactor construction process, specifically the lathing process, much of the remaining loose sediment and loose tuberculated material on the inside of the distribution system pipe section was removed. It should be noted that the loss of this material may impact the DBP formation observed within the MS-SDS test. Since each MS-SDS test reactor was prepared in exactly the same manner, the DBP formation within each MS-SDS reactor was assumed to be the same. A comparison of DBP formation between each of the reactors was not conducted during the MS-SDS test. Recall that prior to the start of the MS-SDS test for the 12 hour experimental period and the 36 hour experimental period, the reactors were conditioned by running chlorinated membrane treated water through each of the reactors for approximately four weeks. Prior to the start of sampling for each experimental period, chlorinated raw water was run through the chlorinated raw water reactor series and ozonated spring water was run through the control reactor to permit flushing of the membrane treated water out of the reactors. Based on CSTR theory, to achieve 99% flushing of the reactors in series, approximately six retention times were required, i.e., for the 12 hour and 36 hour experimental periods, 65 72 hours (3 days) and 216 hours (9 days) were required, respectively. Since the number of retention times between the reactor conditioning period and the start of the sampling period were less than the theoretical retention times required to flush the reactors, some chlorinated membrane treated water likely remained within the chlorinated raw water reactors and the control reactor. In the chlorinated raw water reactors, DBP concentrations may be slightly lower due to dilution by the remaining chlorinated membrane treated water in the reactor. In the control reactor, DBP concentrations may be slightly higher due to the remaining chlorinated membrane treated water in the reactor. Phase I and this phase of the study were conducted during different time periods. Due to the intensive nature of the sampling program during this phase of the study, distribution system monitoring was not conducted at the same time. The difference in time periods between the two study phases must be considered when comparing results between Phase I and this phase of the study. 5.2.4 Phase II Data Analysis The results are presented graphically and in tabular format for each water stream and experimental control using the mean and standard deviation of water quality parameters (chlorine concentrations, THM concentrations, and HAA3 concentrations) for the MS-SDS test, in-situ SDS test, and the standard SDS test. Statistical differences in water quality parameters between the water streams (chlorinated raw water, chlorinated membrane treated water, and the experimental control) for each test method i.e., MS-SDS test, in-situ SDS test, and standard SDS test, were assessed using a comparison of mean and standard deviation values. For discussion purposes, the chlorinated water streams herein, i.e., chlorinated raw water and chlorinated membrane treated water, are referred to as "raw water" and "membrane treated water". Similarly, the experimental control stream is referred to as the "control". 5.3 Timeline The study period extended from October 2005, which was the start of the distribution system monitoring study (Phase I), to November 2006, which was the completion of the laboratory analysis for samples from the bench-scale simulations (Phase II). The length of 66 this study period was due largely in part to the nature of trace organic chemical analysis, such as DBPs, i.e., THMs and HAA3, the high number of samples collected per sampling event, and the number of water quality parameters of interest. Each of the steps required for bottle preparation; sample collection, particularly during Phase II; laboratory analyses; and data extraction were completed by one analyst for the duration of the study period. As outlined in Section 4.2.7 and 4.2.8, there were a number of steps involved with each round of THM and HAA3 analysis, including meticulous washing, cleaning, and preparation of sample bottles; multi-step laboratory analysis, particularly extraction of the THM and HAA3 from the water sample matrix; and manual data extraction from the GC and GC/MS. In addition, all collected samples, particularly THM samples, had to be analyzed within 14 days of collection. Therefore, the number of steps required for THM and HAA3 analysis for each sampling event in Phase I and Phase II resulted in a labour-intensive and time- consuming sampling program. During Phase I, sampling events were limited to bi-weekly intervals between October 2005 and March 2006 to allow for a sufficient amount of time for sample bottle preparation, laboratory analyses, and data extraction between each sampling event. During Phase II, the bench-scale experiments were limited to three sampling events per 12 hour experimental period and three sampling events per 36 hour experimental period because of the high number of samples required for each sampling event. For each MS-SDS test and in-situ SDS test experimental period, more than 200 water samples were collected at the KCWQ. In addition to the MS-SDS test and in-situ SDS test, the standard SDS test was performed at the UBC Environmental Laboratory. However, the standard SDS test could only be performed when there were an adequate number of sample bottles available, i.e., following completion of MS-SDS test and in-situ SDS test laboratory analyses. For each experimental period in Phase II, a total of more than 300 samples were collected and analyzed; therefore, laboratory analyses for each 12 hour and 36 hour experimental period took approximately one month to complete from the start of sample bottle preparation to the end of data extraction from the GC and GC/MS. Although the DBP analyses were the most labour-intensive and time-consuming parameters examined in the present study, other water quality parameters were also monitored, i.e., pH, 67 temperature, free chlorine concentration, TOG, and UV254. Each water quality parameter assessed in the study added more time and more resources needed to complete the study. In summary, the complex nature of trace organic chemical analyses, i.e., THM and HAA3; the high number of samples collected and analyzed; the number of water quality parameters monitored; and only one analyst available for this work resulted in a labour-intensive study and lengthy timeline for completion of this work. 68 Chapter 6. Results and Discussion The objective of this study was to determine the extent to which upgrades to a drinking water treatment system, specifically implementation of an ultrafiltration treatment process, impacted DBP formation within a distribution system. DBP formation was investigated using both full-scale distribution system monitoring (Phase I) and bench-scale simulations (Phase II). 6.1 Phase I: Distribution System Monitoring Distribution system monitoring (Phase I) was conducted between October 2005 and March 2006. The distribution system was characterized before (Stage A) and after (Stage B) implementation of the membrane treatment system upgrade (Figure 5.1). The characterization was performed at five sampling sites within the distribution system using in- situ data loggers and laboratory analyses of water samples collected from these sites. Data loggers collected real-time data on the physical and chemical characteristics (pH, temperature, and free chlorine concentrations) of the raw water and treated water in the distribution system. TOC concentrations and UV254 absorbance were monitored to characterize the nature of the NOM in raw and treated water, since these parameters can significantly influence the formation potential of DBPs within distribution systems. Chemical analyses of water samples were performed to determine the concentrations of DBPs, specifically THMs and HAA3, at each sampling site within the distribution system. The raw data for each water quality parameter monitored during the study are presented in Appendix D. The results of the pair-wise analyses for DBP formation within the distribution system are discussed in detail in the sections below, while the results of the pair-wise analyses for other water quality parameters monitored in the distribution system during the study are presented in Appendix E. 69 6.1.1^Water Quality The water quality characteristics for each of the five sampling sites during Stage A and Stage B of the distribution system upgrade are summarized in Table 6.1. The values presented for pH, temperature, and free chlorine concentrations are the mean of the daily values for each sampling event. Table 6.1 Summary of water quality characteristics for distribution system sampling sites before (Stage A) and after (Stage B) the distribution system upgrade (values presented are mean ± standard deviation) Site pH Temperature [°C] Free Chlorine [mg/L] TOC [m /L] UVA [cm-1] SUVA [L/mg-m] STAGE A Raw Water 7.9±0.1 5.9±2.9 1.6+0.7 0.035±0.005 2.4+0.7 (Site 3) Dallas Intake 7.6±0.1 7.1 ±3.4 1.2±0.2 1.7+1.0 0.026±0.003 2.0±1.0 (Site 1) Blackwell Booster 7.3 12.1±2.5 0.2±0.1 1.9+0.9 0.028±0.003 1.8+0.8 (Site 2) Membrane 8.0±0.1 6.1±3.4 1.3±0.1 1.3+0.5 0.015±0.003 1.3±0.5 Permeate (Site 4) TRU (Site 5) 7.6±0.1 13.1±2.8 0.8±0.2 1.3+0.5 0.021 ±0.004 1.9+0.9 STAGE B Raw Water 8.0 3.8±1.1 1.7±0.1 0.036±0.005 2.1+0.2 (Site 3) Dallas Intake No Data 6.2±0.8 0.8±0.1 1.4+0.2 0.020±0.003 1.6±0.2 (Site 1) Blackwell Booster 8.0±0.1 8.2±0.4 0.5±0.1 1.4+0.2 0.022±0.002 1.6±0.3 (Site 2) Membrane 8.0 3.5±1.3 1.2±0.1 1.6±0.3 0.018±0.006 1.2+0.5 Permeate (Site 4) TRU (Site 5) 7.7±0.2 9.5±0.6 0.5±0.2 1.4±0.1 0.024±0.006 1.7±0.5 The environmental conditions of the distribution system, particularly pH, temperature, and free chlorine concentration, affect the formation (and degradation) of DBPs. Changes in water temperature and free chlorine concentrations at distribution sampling sites likely had a more significant impact on DBP formation than pH for the duration of Stage A and Stage B, since the pH of the water did not change significantly between sample sites for the duration of Stage A and Stage B. The increase in water temperature between the raw water and the extremity sampling sites was statistically significant. This temperature increase may have favoured increased DBP formation at the extremity sampling sites (Singer et al., 2002). The 70 decreases in free chlorine concentrations between the sampling sites immediately following chlorination processes and the sampling sites at the extremities of the distribution system during Stage A and Stage B were also statistically significant. These decreases were expected, since chlorine is consumed in the distribution system over time, i.e., via reactions with NOM and pipe material (Mutoti et al., 2007; Baribeau et al., 2006; Gang et al., 2002). From these results, it also appears that chlorine concentrations at the extremity sampling site in the southeast section of the distribution system increased following the implementation of membrane treatment. These changes in chlorine concentrations likely affected DBP formation (and potential degradation) in the distribution system (Gang et al., 2002; Singer et al., 2002; Montgomery Watson, 1993; Amy et al., 1987). Changes in NOM before and after implementation of membrane filtration processes were characterized using TOC, UV254, and SUVA. Although the differences between TOC, UV254, and SUVA values for raw water and TOC, UV254, and SUVA values for membrane treated water were not consistently significantly different, it appears that membrane treatment was effective at removing some NOM, i.e., DBP precursors. However, the lack of statistically significant differences in NOM and NOM surrogates between the sampling sites were not surprising, since other studies have indicated that the majority of TOC in the source water has a molecular weight of <1 kDa (Chowdhury, 2005) and ultrafiltration processes are typically not effective at removing organic material this small 6.1.2 Disinfection By-Product Formation DBP formation in the distribution system was characterized using concentrations of THMs and HAAs (measured as HAA3), the most common DBPs found in chlorinated drinking water. Pair-wise comparisons of THM and HAA3 concentrations of samples collected on similar sampling dates were performed to determine if there was a statistically significant difference in DBP formation between sampling sites during Stage A and Stage B of the distribution system upgrade. The results of the pair-wise comparisons for THM and HAA3 concentrations are summarized in Table 6.2 and discussed in the following sections. 71 Table 6.2 Pair-wise comparisons for DBP formation in the distribution system during Stage A and Stage B Pair-Wise Comparison* Statistically Significant Difference? THM HAA3 Stage A Stage B Stage A Stage B SW Site 3 vs. Site 4 L L L L Site 4 vs. Site 5 L L L L SW Site 3 vs. Site 4 L L L L Site 4 vs. Site 5 L L L L SE Site 3 vs. Site 1 L L L L Site 1 vs. Site 2 L L N L SW &SE Site 4 vs. Site 1 Site 5 vs. Site 2 Question of Interest a) Was the DBP formation potential of the source water similar during Stage A and Stage B? b) Did DBP formation change within each section of the distribution system? c) Was DBP formation similar between each section of the distribution system? d) Was DBP formation in^SE the southeast section of the^Site 1 vs. Site 2 distribution system similar during Stage A and Stage B? *Pair-wise comparisons were performed at 95% confidence level SW = Southwest section of the distribution system (Site 4 and Site 5); SE = Southeast section of the distribution system (Site 1 and Site 2); L = parameter value is statistically significantly lower at 95% confidence level; H = parameter value is statistically significantly higher at 95% confidence level; N = parameter value is not statistically significantly different at 95°/0 confidence level 6.1.2.1^Trihalomethanes The mean THM concentrations for each sampling site before (Stage A) and after (Stage B) connection of the southeast section of the distribution system to the southwest section of the distribution system are presented in Figure 6.1. 72 Membrane Plant Da las Intake 25±4 120_13±4 tg/L nd Membrane Plant To Southwest ^ To Southeast Section of the City ^ Section of the City Stage A Monitored October 2005 -. December 2005 28±5 tig/L^ 36±8 To Southwest ^ To Southeast Section of the City ^ Section of the City Stage B Monitored January 2006 --0 March 2006 Figure 6.1 THM concentrations in the distribution system during a) Stage A and b) Stage B (values presented are mean ± standard deviation) 73 Details of Pair-Wise Comparisons a) Was the THM formation potential of the source water similar during Stage A and Stage B? THM formation potential of the source water was similar during Stage A and Stage B. ■ The THM concentrations observed in the southwest section of the distribution system were similar during Stage A and Stage B. ■ Pair-wise comparisons confirmed that the THM concentrations observed at Site 4 were consistently statistically significantly lower than THM concentrations observed at Site 5 during Stage A and Stage B. b) Did THM concentrations change within each section of the distribution system? THM concentrations increased between the sampling sites located immediately downstream of chlorination and the sampling sites located at the extremities of the southwest and southeast sections of the distribution system during Stage A and Stage B. ■ During Stage A and Stage B, THM concentrations observed immediately downstream of the membrane plant and chlorination (Site 4) and Site 1 were statistically significantly lower than THM concentrations observed immediately downstream of chlorination at the extremity sampling sites of the southwest section (Site 5) and southeast section (Site 2) of the distribution system c) Were THM concentrations similar between each section of the distribution system? Compared to the original treatment process (coarse screening followed by chlorination), the membrane treatment process reduced THM concentrations immediately downstream of chlorination. However, THM concentrations were not significantly reduced at the extremity sampling sites in the southeast section of the distribution system following implementation of membrane treatment processes. 74 • During Stage A, THM concentrations observed immediately downstream of chlorination following membrane treatment (Site 4) were statistically significantly lower than the THM concentrations observed immediately downstream of chlorination following coarse screening (Site 1). • THM concentrations at the extremity sampling site of the southwest section (Site 5) of the distribution system were not statistically significantly different from the extremity sampling site of the southeast section (Site 2) of the distribution system. • During Stage B, THM concentrations immediately following chlorination (Site 4) were statistically significantly lower than THM concentrations at extremity sampling sites. • In contrast to Stage A, THM concentrations at the extremity sampling site of the southwest section (Site 5) of the distribution system were statistically significantly lower than THM concentrations at the extremity sampling site of the southeast section (Site 2) of the distribution system following the Stage B upgrade. • This finding is likely due to the fact that for Stage B, Site 1 and Site 2 were located a further distance downstream of chlorination. d) Were THM concentrations similar in the southeast section of the distribution system during Stage A and Stage B? After implementation of membrane treatment (Stage A), THM concentrations in the southeast section of the distribution system were similar to the THM concentrations observed during the original treatment processes (Stage B). • During Stage A and Stage B, THM concentrations observed in the southeast section of the distribution system at Site 1 (immediately following chlorination during Stage A and further downstream of membrane treatment processes and chlorination in Stage B) were statistically significantly lower than THM 75 concentrations observed at the extremity sampling site of the southeast section (Site 2) of the distribution system. 6.1.2.2^Halo acetic Acids The mean HAA3 concentrations for each sampling site before (Stage A) and after (Stage B) connection of the southeast section of the distribution system to the southwest section of the distribution system are presented in Figure 6.2. 76 Da las Intake 24±8 72±12 tg/L To Southwest Section of the City 47±20 tig/L 89±19 lig/L To Southeast Section of the City Stage A Monitored October 2005 December 2005 To Southwest ^ To Southeast Section of the City ^ Section of the City Stage B Monitored January 2006 —> March 2006 Figure 6.2 HAAS concentrations in the distribution system during a) Stage A and b) Stage B (values presented are mean ± standard deviation) 77 Details of Pair-Wise Comparisons a) Was the HAA3 formation potential of the source water similar during Stage A and Stage B? HAA3 formation potential of the source water was similar during Stage A and Stage B. ■ The HAA3 concentrations observed in the southwest section of the distribution system were similar during Stage A and Stage B. ■ Pair-wise comparisons confirmed that the HAA3 concentrations observed at Site 4 were consistently statistically significantly lower than HAA3 concentrations observed at Site 5 during Stage A and Stage B. b) Did HAA3 concentrations change within each section of the distribution system? HAA3 concentrations increased between the sampling sites located immediately downstream of chlorination and the sampling sites located at the extremities of the southwest and southeast sections of the distribution system during Stage A and Stage B. ■ During Stage A, HAA3 concentrations observed immediately downstream of chlorination at the membrane treatment plant (Site 4) were statistically significantly lower than HAA3 concentrations observed at the extremities of the southwest section (Site 5) of the distribution system. ■ HAA3 concentrations observed immediately downstream of chlorination following coarse screening (Site 1) and the extremity sampling site in the southeast section (Site 2) of the distribution system were not significantly statistically significant. ■ During Stage B, a statistically significant increase in HAA3 concentrations was observed between the sampling site immediately downstream of the membrane plant (Site 4) and Site 1 and towards the extremities of the southwest section (Site 5) and the southeast section (Site 2) of the distribution system. 78 c) Were HAA3 concentrations similar between each section of the distribution system? Compared to the original treatment process (coarse screening followed by chlorination), the membrane treatment process reduced HAA3 concentrations immediately downstream of chlorination. However, HAA3 concentrations were not significantly reduced at the extremity sampling sites in the southeast section of the distribution system following implementation of membrane treatment processes. ■ During Stage A, HAA3 concentrations observed immediately downstream of chlorination following membrane treatment (Site 4) were statistically significantly lower than the HAA3 concentrations observed immediately downstream of chlorination following coarse screening (Site 1). ■ HAA3 concentrations at the extremity sampling site of the southwest section (Site 5) of the distribution system were not different from the extremity sampling site of the southeast section (Site 2) of the distribution system. ■ During Stage B, HAA3 concentrations immediately following chlorination were statistically significantly lower than HAA3 concentrations at extremity sampling sites. ■ In contrast to Stage A, HAA3 concentrations at the extremity sampling site of the southwest section (Site 5) of the distribution system were statistically significantly lower than the HAA3 concentrations at the extremity sampling site of the southeast section (Site 2) of the distribution system. ■ This is likely due to the fact that for Stage B, Site 1 and Site 2 were located a further distance downstream of chlorination. 79 d) Were HAA3 concentrations similar in the southeast section of the distribution system during Stage A and Stage B? After implementation of membrane treatment (Stage A), HAA3 concentrations in the southeast section of the distribution system were higher than the HAA3 concentrations observed during the original treatment processes (Stage B). ■ During Stage A, HAA3 concentrations observed in the southeast section of the distribution system at Site 1 (immediately following chlorination during Stage A and downstream of treatment processes and chlorination in Stage B) were not statistically significantly different than the HAA3 concentrations observed at the extremity location of the southeast section (Site 2) of the distribution system. ■ During Stage B, HAA3 concentrations in the southeast section of the distribution system downstream of the membrane plant (Site 1) were statistically significantly lower than the HAA3 concentrations observed at the extremity location of the southeast section (Site 2) of the distribution system. The observed increase in HAA3 concentrations in the southeast section of the distribution system was likely due to the increased retention time in the distribution system, i.e., between the point of chlorination and the extremity sampling sites, following the connection of the southeast section of the distribution system to the southwest section of the distribution system (Stage B), rather than due to implementation of the membrane treatment process itself. Further analysis to confirm this hypothesis is presented in the following section. Haloacetic Acids Speciation In the absence of known retention times at distribution system sampling sites, this study can only verify the formation (or degradation) of DBPs in the distribution system. One approach to investigate the cause of the higher HAA3 concentrations in the southeast section of the distribution system, following the implementation of membrane treatment processes, is to examine relative concentrations of HAA3 species measured within the distribution system. Changes in the relative concentrations of HAA3 species can provide insight into the rates of formation (or degradation) of these compounds within the distribution system and the 80 availability of precursors. Since the HAA3 concentrations measured in the distribution system were significantly lower than the HAA3 formation potential of the raw water source (Section 6.2.2), it is likely that the availability of precursors did not affect the formation of DCAA and TCAA. However, unlike THMs, some HAA species are biodegradable in the distribution system at low chlorine residual concentrations, i.e., <0.5 mg/L (Baribeau et al., 2006). DCAA has been shown to be more biodegradable than MCAA and MCAA has been shown to be more biodegradable than TCAA (Baribeau et al., 2006; Singer et al., 2002). During the present study, MCAA concentrations were consistently below the MDL. Therefore, a change in the ratio of DCAA to TCAA (DCAA/TCAA) was used as an indicator of possible biodegradation of HAA3 within the distribution system. The DCAA/TCAA for each sampling site during Stage A and Stage B were compared. Recall that for Stage A, Site 1 and Site 4 were located immediately downstream of chlorination, while Site 2 and Site 5 were located near the extremities of the distribution system. During Stage B, Site 1 and Site 2 were located a further distance downstream of membrane treatment processes and chlorination. DCAA/TCCA for each sampling site is presented in Figure 6.3 and a summary of measured DCAA and TCAA concentrations is presented in Table 6.3. 81 2.5 -- Stage A Stage B 3.0 2.0 0 1. a 1.0 0.5 0.0 ki Site 2 (Blackwell Booster) Sampling Site Site 3 (Raw) Site 1 Dal as Intake) Site 4 (Permeate) Site 5 (TRU) Figure 6.3 DCAA / TCAA during Stage A and Stage B (values presented are mean ± standard deviation) Table 6.3 DCAA and TCAA concentrations during Stage A and Stage B (values presented are mean ± standard deviation) Stage A Stage B Location DCAA TCAA DCAA TCAA [pg/L] [1.1g/L] [1.1g/L] [1.tg/L] Site 3 (Raw Water) nd nd nd nd Site 1 (Dallas Intake) 30±12 17±8 29±3 36±6 Site 2 (Blackwell Booster) 18±10 70±10 45±4 60±7 Site 4 (Permeate) 16±5 8±3 16±3 11±4 Site 5 (Thompson Rivers University) 42±8 32±7 35±10 39±7 During Stage A, the large decrease in DCAA/TCAA and DCAA concentration between Site 1 and Site 2 suggests possible biodegradation. This finding is consistent with the low 82 chlorine residual observed at Site 2, i.e., 0.2 mg/L, during this stage. Less of a decrease in DCAA/TCAA and no decrease in DCAA concentrations between Site 4 and Site 5 indicate limited or no biodegradation. This finding is consistent with the high chlorine residual observed at Site 5, i.e., 0.7 mg/L, during this stage. Therefore, these results indicate some possible biodegradation of HAA3 in the southeast section of the distribution system and limited or no biodegradation of HAA3 in the southwest section of the distribution system during Stage A. During Stage B, less or no statistically significant decrease in DCAA/TCAA and no decrease in DCAA concentration were observed between Site 1 and Site 2 and Site 4 and Site 5. These findings are consistent with the relatively high chlorine residuals observed at Site 2, i.e., approximately 0.7 mg/L, and Site 5, i.e., 0.6 mg/L, during this stage. Therefore, these results indicate limited or no biodegradation of HAA3 in the southeast and southwest sections of the distribution system during Stage B. In summary, it is likely that the increased residual chlorine concentration and increased retention time in the distribution system following the implementation of membrane treatment processes (Stage B) resulted in the statistically significant increase in HAA3 concentrations in the southeast section of the distribution system. 6.1.3 Assessment of Disinfection By-Product Formation in the Distribution System DBP concentrations were not significantly reduced in the distribution system following the implementation of membrane treatment processes. The concentrations of DBPs observed in the southwest section (membrane treated water) of the distribution system were similar during Stage A and Stage B. These results suggested that the DBP formation potential of the raw water was similar during Stage A and Stage B. To further support this finding, pH, temperature, UV254, and SUVA values for the raw water (Site 3) were relatively similar between Stage A and Stage B (Appendix D, Appendix E). Therefore, the higher concentration of DBPs observed in the southeast section of the distribution system during Stage B was not likely due to differences in the raw water characteristics between Stage A and Stage B. 83 Even though TOC concentrations were not significantly reduced following the implementation of membrane treatment, membrane filtration was effective to remove some of the organic precursors required for DBP formation. This hypothesis is supported by the fact that UV254 values, a surrogate for aromatic NOM, decreased in the southeast section of the distribution system following the implementation of advanced treatment (Appendix E). During Stage A and Stage B, the concentrations of DBPs were highest at the extremities of the southwest and southeast sections of the distribution system. This is simply because the formation of DBPs in the distribution system increases with time. Similarly, the higher concentrations of DBPs, particularly HAA3, in the southeast section of the distribution system during Stage B, i.e., following implementation of membrane treatment, was likely due to an increase in the retention time at Site 1 and Site 2. During Stage A, Site 1 was located immediately downstream of chlorination (Dallas Intake). During Stage B, Site 1 was located a considerable distance (approximately 10 kilometers) downstream of chlorination at the membrane treatment plant. In addition, the higher chlorine concentrations observed in the southeast section of the distribution system during Stage B likely contributed to increasing the concentrations of DBPs. The higher chlorine concentrations in this section also likely inhibited the biodegradation of DCAA, resulting in higher HAA3 concentrations. The observed concentrations of THMs were consistently below the CGDWQ of 100 lig/L (Health Canada, 2006), even at the furthest extremity site of the distribution system that was monitored (Site 2 during Stage B). Although there is currently no CGDWQ for HAAs, a guideline value for HAA5 has been proposed by the Federal-Provincial-Territorial Committee on Drinking water at 80 !let, (FPTCDW, 2006). Therefore, some sections of the City of Kamloops distribution system may exceed the proposed HAA5 guidelines during the fall and winter months. Fortunately, the City of Kamloops has been proactive at addressing this potential shortcoming by developing a comprehensive distribution system maintenance program and collaborating with UBC and Thompson Rivers University on research aimed at optimizing the quality of the drinking water delivered to consumers. The specific cause of the increase in HAA3 concentrations in the southeast section of the distribution system during Stage B was not conclusively confirmed in this phase of the study; however, one conclusion that can be drawn is that the implementation of membrane 84 treatment was not effective at substantially reducing the concentration of DBPs in the drinking water delivered to consumers. These results are consistent with those from a previous study, which showed that the DBP precursors in the raw water from the South Thompson River are predominantly small and hydrophilic (Chowdhury, 2005). Typically, ultrafiltration membranes are not effective at removing small and hydrophilic NOM. 6.2 Phase II: Bench-Scale Simulations Phase I results showed that implementation of membrane treatment was not effective at significantly reducing the concentration of DBPs in the distribution system. As discussed previously, the absence of known retention times for distribution system sampling sites was a significant limitation of Phase I of this study. Therefore, bench-scale simulations were implemented to further investigate DBP formation in raw and membrane treated water using controled retention times. A bench-scale approach, i.e., the MS-SDS test, was developed to improve estimates of DBP formation under distribution system conditions over traditional glass bottle incubations, i.e., in-situ SDS test and standard SDS. The DBP formation in the MS-SDS test and in-situ SDS test under distribution system conditions were compared to DBP formation in the standard SDS test under standardized environmental conditions for DBP formation. Bench-scale simulations were conducted between July 2006 and September 2006. The MS- SDS test and the in-situ SDS test were performed at the KCWQ, while the standard SDS tests were performed at the UBC Environmental Engineering Laboratory. The results of the bench-scale simulations are presented the sections below. A summary of the raw data is presented in Appendix F. 6.2.1 Material-Specific Simulated Distribution System Test and In-situ Simulated Distribution System Test Although the MS-SDS test used a flow-through loop constructed of actual pipe material resurrected from the distribution system, it is acknowledged that the MS-SDS test is not a complete representation of the distribution system; however, this was not the intent of the MS-SDS test. The intent of the MS-SDS test was to develop a bench-scale tool to improve 85 DBP formation estimates under distribution system conditions over traditional SDS tests, i.e., the in-situ SDS test. The results presented in Section 6.2.1 refer to the MS-SDS test and the in-situ SDS test. 6.2.1.1 Experimental Conditions The experimental conditions used in both the MS-SDS test and the in-situ SDS test were designed to represent the reaction conditions of the distribution system. In addition to the controlled retention times, the experimental conditions that were controlled for the MS-SDS test and in-situ SDS test were pH, temperature, and free chlorine concentration. The pH of raw water and membrane treated water following chlorination was relatively constant at pH 7.8 for the 12 hour and 36 hour experimental periods. The temperature of raw and membrane treated water was relatively similar between the MS- SDS test and the in-situ SDS test during the 12 hour and 36 hour experimental periods. However, a slightly higher source water temperature was observed during the 12 hour experimental period (21°C) than the source water temperature observed during the 36 hour experimental period (18°C). The difference in water temperature between the 12 hour experimental period and the 36 hour experimental period was attributed to the difference in the temperature of the raw water source. The 12 hour experimental period ranged from mid- July to mid-August 2006, while the 36 hour experimental period ranged from mid-August to mid-September 2006, when South Thompson River water temperatures are lower. Chlorine was consumed more rapidly in the MS-SDS test than in the in-situ SDS test for raw and membrane treated water. Free chlorine concentrations measured during the MS-SDS test and in-situ SDS test are shown in Figure 6.4 and Figure 6.5, respectively. Chlorine was not detected in the control MS-SDS reactor and the control in-situ SDS test bottles. 86 —40— Raw Water - 12 hr Membrane Treated - 12 hr -^- Control - 12 hr —o— Raw Water - 36 hr --0-- Membrane Treated - 36 hr - -a- - Control - 36 hr -8) E 0.8 .c O 5 0.6 O u. 0.4 0.2 0.0 1.2 1.4 - Raw Water - 12 hr —+— Membrane Treated - 12 hr - -A- - Control - 12 hr —0— Raw Water - 36 hr Membrane Treated - 36 hr - Br • Control - 36 hr 0.0 n^ 1.2 0 ^ 6^12^18^24 ^ 30 ^ 36 Retention Time - MS-SDS Test [hours] Figure 6.4 Free chlorine concentrations during the 12 hour and 36 hour experimental periods for the MS-SDS test (values presented are mean ± standard deviation) 0 6^12^18^24 ^ 30 ^ 36 Retention Time - In-situ SDS Test [hours] Figure 6.5 Free chlorine concentrations during the 12 hour and 36 hour experimental periods for the in-situ SDS test (values presented are mean ± standard deviation) 87 For the MS-SDS test, there was essentially no chlorine residual at the end of the 12 hour and 36 hour experimental periods. However, during the 36 hour experimental period, chlorine was measured after a 12 hour retention time within the MS-SDS test reactors for raw and membrane treated water. The observed initial chlorine concentrations were approximately 0.9 mg/L for the 12 hour experimental period for raw and membrane treated water, compared to approximately 1.2 mg/L for raw water and membrane treated water during the 36 hour experimental period. As shown in Figure 6.4, raw water and the membrane treated water exerted a similar chlorine demand. Since the MS-SDS test reactors were constructed of cast iron pipe, it is likely that the pipe material pipe also exerted a chlorine demand (Mutoti et al., 2007; Al-Jasser, 2007; Frateur, 1999; Tuovinen et al., 1984). For the in-situ SDS test, there was a chlorine residual for both raw water and membrane treated water at the end of the 12 hour and 36 hour experimental periods. Similar to the results observed for the MS-SDS test during the 36 hour experimental period, chlorine was measured after a 12 hour retention time within the in-situ SDS test for raw and membrane treated water. This result was likely due to the higher initial chlorine concentration observed during this period. However, unlike the MS-SDS test, the membrane treated water showed a lower chlorine demand than the taw water for the 12 hour and 36 hour experimental periods during the in-situ SDS test. These results suggest that membrane treatment was effective to remove some of the chlorine consuming material from the source water. The difference in chlorine demand for raw and membrane treated water during the MS-SDS test and the in-situ SDS test under similar reaction conditions, i.e., pH, temperature, chlorine concentration, and retention times, further suggests that the pipe environment of the MS-SDS test exerted a more significant chlorine demand than the glass bottles of the in-situ SDS test. The above results suggest that more chlorine consumption occurred during the MS-SDS test than during the in-situ SDS test for raw and membrane treated water. However, the low chlorine concentrations measured during the MS-SDS tests for raw and membrane treated water were somewhat unexpected, since during Phase I of the study, chlorine concentrations between 0.2 mg/L and 0.8 mg/L were observed at distribution system sites located furthest from the point of chlorination (Appendix D). Unfortunately, the chlorine concentration at these sites was not monitored during this phase of the study. To gain, additional insight on the distribution system conditions during this phase of the study, one grab sample was 88 collected from each of the extremity sampling sites located furthest from the point of chlorination on September 18, 2006 (Site 2) and September 19, 2006 (Site 5). A summary of the distribution system conditions at the time of grab sample collection is presented in Table 6.4. Table 6.4 Distribution system conditions for Site 2 and Site 5 during Phase II (values presented for 1 sample collected in September 2006) Sampling site pH Temperature[°C1 Chlorine Concentration [mg/LI Site 2 (Blackwell Booster Station) September 18, 2006 8.0 19 0.1 Site 5 (Thompson Rivers University) September 19, 2006 8.0 19 0.3 The low chlorine concentrations measured in the MS-SDS test could be the result of higher water temperatures observed during the summer months and potentially longer retention times in the MS-SDS test compared to the distribution system sampling sites during Phase I. The pH observed at Site 2 and Site 5 during Phase II was relatively similar to the pH observed during Phase I (Appendix D). However, the water temperatures observed at Site 2 and Site 5 during this phase were significantly higher than the water temperatures observed during Phase I (Appendix D). This difference in water temperature between Phase II and Phase I can be attributed to differences in the temperature of the raw water source during the study periods. On the other hand, the chlorine concentrations observed at Site 2 and Site 5 during Phase II were significantly lower than the chlorine concentrations observed during Phase I (Stage B, Appendix D). Therefore, it is likely that the difference between the chlorine concentrations observed at the distribution system sampling sites during Phase II and the chlorine concentrations observed during Phase I may be attributed to the higher water temperatures (Mutoti et al., 2007). Recall that the pipe material used in the MS-SDS test was the same as the pipe material used in the distribution system; however, the retention times at each of the distribution system sampling sites were not known. As discussed above, the difference in chlorine 89 concentrations observed during the MS-SDS test and the distribution system monitoring (Phase I) were likely due to the higher water temperatures observed during the summer months, which led to increased chlorine consumption. The summer months were also the period of highest water demand for the City of Kamloops; it is possible that the retention times used in the MS-SDS test were longer than the actual retention times in the distribution system at the time of sample collection, i.e., at Site 2 and Site 5, which resulted in more time for chlorine consuming reactions to occur. However, without actual hydraulic retention times for the distribution system sampling sites, the accuracy of the retention times used in this study to assess DBP formation cannot be verified based on chlorine demand alone. Based on these findings for chlorine demand, the following question is posed: did the higher chlorine consumption observed in the MS-SDS test result in greater DBP formation than in the in-situ SDS test? 6.2.1.2 Disinfection By-Product Formation Trihalomethanes THM formation results for 12 hour and 36 hour experimental periods for the MS-SDS test and the in-situ SDS test, respectively, are presented in Figure 6.6 and Figure 6.7. THM concentrations were below the MDL for the control MS-SDS test reactor and in -situ SDS test bottles. 90 o 30 c.) 2 X1- 20 --el— Raw Water - 12 hr —0— Membrane Treated - 12 hr - -Ir - Control - 12 hr —0— Raw Water - 36 hr —0-- Membrane Treated - 36 hr - Cr - Control - 36 70 I 0 ^ 6^12^18^24 ^ 30 ^ 36 Retention Time - MS-SDS Test [hours] Figure 6.6 THM concentrations during the 12 hour and 36 hour experimental periods for the MS-SDS test (values presented are mean ± standard deviation) 80 70  ,7j.. 60 c 500wet; 40  30 1- 20 Raw Water - 12 hr^—c— Raw Water - 36 hr 10^—0— Membrane Treated - 12 hr^—0—Membrane Treated - 36 hr - -Ar - Control - 12 hr^- -A- - Control - 36 hr 0 - - -A 0 ^ 6^12^18^24^30 ^ 36 Retention Time - In-situ SDS Test [hours] Figure 6.7 THM concentrations during the 12 hour and 36 hour experimental periods for the in- situ SDS test (values presented are mean ± standard deviation) 91 For the MS-SDS test, there was no statistically significant difference in THM formation between the raw water and membrane treated water. For the in-situ SDS test, the difference in THM concentrations between the raw water and membrane treated water was not consistently significantly different. Nonetheless, the concentration of THMs in the raw water was typically higher than the concentration of THMs in membrane treated water after 12 hour retention time. These results suggest that the membrane treatment process may have removed some of the organic precursors that favour formation of THMs. The majority of THM formation occurred within 3 hours in the MS-SDS test and in-situ SDS test. In general, THM formation in the in-situ SDS test was slightly higher than THM formation in the MS-SDS test for both experimental periods. Based on the above results, it appears that the greater chlorine consumption observed in the MS-SDS test than in the in-situ SDS test (Section 6.2.1.1) did not lead to greater THM formation within the MS-SDS test. However, the higher chlorine concentration observed in the in-situ SDS test than in the MS-SDS test resulted in slightly greater THM formation. Halo acetic Acids HAA3 formation results for 12 hour and 36 hour experimental periods for the MS-SDS test and the in-situ SDS test, respectively, are presented in Figure 6.8 and Figure 6.9. HAA3 concentrations were below the MDL for the control MS-SDS test reactor and in-situ SDS test bottles. 92 —41— Raw Water - 12 hr —4-- Membrane Treated - 12 hr -^' Control  - 12 hr —0—Raw Water - 36 hr —0—Membrane Treated - 36 hr - r - Control - In-situ SDS .7 300 a.) oc 250 'E 200a) U O • 150 • 100 50 400 350 400 350 300 cn=- g 250 7.- ns .5 200 c.) 0 150 100 —A—Raw Water - 12 hr - Membrane Treated - 12 hr - -A- - Control - 12 hr —o— Raw Water - 36 hr —0— Membrane Treated - 36 hr - k - Control - 36 hr  50 0^6^12^18^24^30^36 Retention Time - MS-SOS Test [hours] Figure 6.8 HAM concentrations during the 12 hour and 36 hour experimental periods for the MS-SDS test (values presented are mean ± standard deviation) ^ 0 • r.^A 0^6^12^18^24^30 ^ 36 Retention Time - In-situ SDS Test [hours] Figure 6.9 HAAS concentrations during the 12 hour and 36 hour experimental periods for the in- situ SDS test (values presented are mean ± standard deviation) 93 For the MS-SDS test, there was no statistically significant difference in HAA3 formation between the raw water and membrane treated water. HAA3 formation during the 36 hour experimental period was statistically significantly lower than HAA3 formation during the 12 hour experimental period for both raw water and membrane treated water. Unfortunately, based on the data collected, it was not possible to determine why HAA3 formation after 12 hours was significantly lower for the 36 hour experimental period than the for 12 hour experimental period. For the in-situ SDS test, the difference in HAA3 concentrations between the raw water and membrane treated water was not consistently significantly different. Nonetheless, the concentration of HAA3 in the raw water was typically higher than the concentration of HAA3 in membrane treated water after 12 hour retention time. These results suggest that the membrane treatment process may have removed some of the organic precursors that favour formation of HAA3. Similar to the findings for THM formation, the majority of HAA3 formation occurred within 3 hours in the MS-SDS test and in-situ SDS test. However, for the 36 hour experimental period, HAA3 formation appeared to decrease after 12 hours in the MS-SDS test. Although the cause of the decrease in HAA3 formation is not clear, one hypothesis is that DCAA was possibly biodegraded in the absence of chlorine residual in the MS-SDS test reactors (Section 6.1.2.2). In general, HAA3 formation in the in-situ SDS test was higher than the HAA3 formation in the MS-SDS test. Based on the above results, it appears that the greater chlorine consumption observed in the MS-SDS test than in the in-situ SDS test (Section 6.2.1.1) did not lead to greater HAA3 formation within the MS-SDS test. In fact, it appears that HAA3 concentrations decreased after 12 hours in the MS-SDS test. However, the higher chlorine concentration observed in the in-situ SDS test than in the MS-SDS test resulted in greater HAA3 formation. Summary In summary, the MS-SDS test and in-situ SDS test were performed to investigate DBP formation under distribution system conditions. The MS-SDS test was specifically developed as a tool to improve estimates of DBP formation within the distribution system, using a 94 flow-through pipe loop constructed of material resurrected from the distribution system, over the traditional in-situ SDS test that used glass bottle incubations. During the MS-SDS test and the in-situ SDS test, greater chlorine demand was observed in the MS-SDS test than in the in-situ SDS test. However, the greater chlorine demand did not lead to greater DBP formation in the MS-SDS test. Generally, THM and HAA3 formation were lower in the MS-SDS test than THM and HAA3 formation in the in-situ SDS test. It was also observed that under distribution system conditions, the majority of THMs and HAA3 were formed within 3 hours, with THM and HAA3 formation essentially leveling off after 12 hours. This finding is consistent with others (Sohn et al., 2004; Chang et al., 2002; Gang et al., 2002) that describe THM and HAA3 formation using a two-step kinetic model, i.e., a fast reaction and a slow reaction. These kinetic models suggested that DBP formation occurs more rapidly in the short-term (hours) than in the long-term (days) (Sohn et al., 2004). The results observed in the present study also showed that HAA3 were reduced, i.e., possibly biodegraded, in the MS-SDS test after 12 hours for both raw water and membrane treated water. Overall, the findings from the in-situ SDS test showed that the concentrations of THMs and HAA3 in raw water were typically higher than the concentrations of THMs and HAA3 in membrane treated water. These results suggest that the membrane treatment process may have removed some of the organic precursors that favour formation of THMs and HAA3 for the source water. However, more HAA3 formation was observed than THM formation for both raw and membrane treated water over similar experimental periods. These results are consistent with previous findings, which suggested that the organic DBP precursors in this source water significantly favour HAA3 formation (Chowdhury, 2005). These findings confirm that although membrane filtration, i.e., ultrafiltration, can remove some of the DBP precursors in this source water, the DBP formation results suggest that DBP precursors in this particular source water cannot effectively be removed by membrane filtration processes. 95 6.2.2^Standard Simulated Distribution System Test 6.2.2.1 Experimental Conditions The standard SDS test was performed to compare DBP formation for raw water and membrane treated water under standardized environmental conditions to DBP formation for raw and membrane treated water under distribution system conditions i.e., the MS-SDS test and in-situ SDS test. During the standard SDS test, water samples were tested under controlled conditions of pH, incubation temperature, and high chlorine dose. pH values during the standard SDS test (approximately pH 7.0) were lower than pH values during the MS-SDS test and in-situ SDS test (approximately pH 7.8). Water temperatures during the standard SDS test were higher (25±2°C) than the MS-SDS test (21°C) and in-situ SDS test (18°C). Chlorine concentrations during the standard SDS test (3 mg/L to 5 mg/L at the end of 12 hour or 36 hour experimental period) were significantly higher than the chlorine concentrations during the MS-SDS test and in-situ SDS test (0 mg/L to 1.2 mg/L). 6.2.2.2 Disinfection By-Product Formation Trihalomethanes THM formation results for the 12 hour and 36 hour experimental periods for the standard SDS test are presented in Figure 6.10. TH_M concentrations were below the MDL for the control standard SDS test bottles. 96 360^6^12 18^24^30 80 70 60 a) c 500 t' 40 0° 30 2 1– 20 --0— Raw Water - 12 hr^—0—Raw Water - 36 hr 10^Membrane Treated - 12 hr —0—Membrane Treated 36 hr - -A- - Control - 12 hr^- tr - Control - 36 hr Retention Time - Standard SDS Test [hours] Figure 6.10 THM concentrations during the 12 hour and 36 hour experimental periods for the standard SDS test (values presented are mean ± standard deviation) For the 12 hour experimental period, the difference in THM concentrations between the raw water and membrane treated water was not consistently significantly different. Nonetheless, the concentrations of THMs in the raw water were typically higher than the concentrations of THMs in membrane treated water. For the 36 hour experimental period, the difference in THM concentrations between the raw water and membrane treated water were statistically significant; THM concentrations for raw water were consistently higher than the THM concentrations for membrane treated water. Overall, THM formation during the 36 hour experimental period was slightly lower than THM formation during the 12 hour experimental period for both raw water and membrane treated water. Similar to the findings for the MS-SDS test and in-situ SDS test for the 12 hour experimental period, the majority of THM formation occurred within 3 hours in the standard SDS test. 97 400 —0— Raw Water - 12 hr^0^ Raw Water - 36 hr 350^Membrane Treated - 12 hr^—0—Membrane Treated - 36 hr - -Jr - Control -12 hr^- fr - Control -36 hr :1" 300 0, g 250 tr. t 200a 0 150 100 50 However, for the 36 hour experimental period, it appears that THM formation continued until at least 36 hours for the standard SDS test. Overall, THM formation in the standard SDS test was higher than THM formation in the MS-SDS test and in-situ SDS test. Based on the above results, it appears that higher chlorine concentrations in the standard SDS test lead to significantly greater THM formation than in the MS-SDS test and in-situ SDS test (Section 6.2.1.2). Nonetheless, the THM formation results for the standard SDS test are consistent with the findings for the MS-SDS test and the in-situ SDS test, which suggested that the membrane treatment process may have removed some of the organic precursors that favour formation of THMs. Haloacetic Acids HAA3 formation results for the 12 hour and 36 hour experimental periods for the standard SDS test are presented in Figure 6.11. HAA3 concentrations were below the MDL for the control standard SDS test bottles. 0 ^ 6^12^18^24^30 ^ 36 Retention Time - Standard SDS Test [hours] Figure 6.11 HAA3 concentrations during the 12 hour and 36 hour experimental periods for the standard SDS test (values presented are mean ± standard deviation) 98 For the 12 hour experimental period, the difference in HAA3 concentrations between the raw water and membrane treated water was significantly different. The concentrations of HAA3 in the raw water were higher than the concentrations of HAA3 in membrane treated water. For the 36 hour experimental period, the difference in HAA3 concentrations between the raw water and membrane treated water were also statistically significant; HAA3 concentrations for raw water were consistently higher than the HAA3 concentrations for membrane treated water. Overall, HAA3 formation during the 36 hour experimental period was relatively similar to the HAA3 formation during the 12 hour experimental period for both raw water and membrane treated water. This finding is different from the HAA3 formation results for the MS-SDS test and in-situ SDS test, which showed that HAA3 concentrations during the 36 hour experimental period were lower than THM concentrations observed during the 12 hour experimental period. Similar to the findings for the MS-SDS test and in-situ SDS test for the 12 hour experimental period, the majority of HAA3 formation in the standard SDS test occurred within 3 hours. However, for the 36 hour experimental period, it appears that HAA3 formation continued until at least 36 hours. Overall, HAA3 formation in the standard SDS test was significantly higher than HAA3 formation in the MS-SDS test and in-situ SDS test. The HAA3 formation results also suggest that more HAA3 were formed than THMs over similar experimental periods for the source water. Based on the above results, it appears that higher chlorine concentrations in the standard SDS test lead to significantly greater HAA3 formation than in the MS-SDS test and in-situ SDS test (Section 6.2.1.2). Nonetheless, the lower HAA3 formation observed in the membrane treated water than in the raw water for the standard SDS test is consistent with the findings for the MS-SDS test and the in-situ SDS test, which suggested that the membrane treatment process may have removed some of the organic precursors that favour formation of HAA3. 99 Summary In summary, the standard SDS test was performed to investigate DBP formation under standardized environmental conditions. Although the standard SDS test is not representative of distribution conditions for DBP formation, the standard SDS test allows investigation of the DBP formation potential of a particular source water with respect to the occurrence of DBP precursors. DBP formation during the standard SDS test for raw and member treated water was significantly greater than DBP formation during the MS-SDS test and the in-situ SDS test. These results confirm that DBP formation is sensitive to changes in environmental conditions. During the standard SDS test, greater chlorine residual lead to greater DBP formation. It was also observed that the majority of THMs and HAA3 were formed within 3 hours, which was consistent with the fmdings of the MS-SDS test and the in-situ SDS test. A significant difference between THM and HAA3 formation in the standard SDS test and THM and HAA3 formation in the MS-SDS test and in-situ SDS test was that DBP formation appeared to continue until at least 36 hours for both raw water and membrane treated water. This continued DBP formation is likely due to the standardized conditions of pH, temperature, and high chlorine residual, which favour DBP formation (Montgomery Watson, 1993; Amy et al, 1987). Overall, the findings from the standard SDS test showed that the concentrations of THMs and HAA3 in raw water were typically higher than the concentrations of THMs and HAA3 in membrane treated water. These results are consistent with the findings from the MS-SDS test and in-situ SDS test, which suggested that the membrane treatment process may have removed some of the organic precursors that favour formation of THMs and HAA3 for the source water. Generally, for the standard SDS test, HAA3 formation was significantly higher than THM formation for both raw and membrane treated water, which confirm that the organic DBP precursors in the source water favour HAA3 formation (Chowdhury, 2005). These fmdings confirm that although membrane filtration, i.e., ultrafiltration, can remove some of the DBP precursors in this source water, the DBP formation results suggest that DBP precursors in this particular source water cannot effectively be removed by membrane filtration processes. 100 6.2.3^Factors Affecting Disinfectant By-Product Formation in the Material- Specific Simulated Distribution System Test Chlorine consumption in the MS-SDS test was greater than the chlorine consumption observed in the in-situ SDS test; however, the greater chlorine consumption in the MS-SDS test did not lead to greater DBP formation than the in-situ SDS test. THM formation observed during the MS-SDS test was relatively similar to the THM formation observed during the in-situ SDS test, but HAA3 formation observed during the MS-SDS test was significantly lower than HAA3 formation observed during the in-situ SDS test. The THM formation results for the MS-SDS test and the in-situ SDS test observed in the present study differ from the findings of others. Rossman et al. (2001) showed that total THM (TTHM; sum of chloroform, bromodichloromethane, dibromochloromethane, and bromoform) formation in a flow-through cast-iron pipe loop was higher than TTHM formation in the in-situ SDS test. This higher TTHM formation was suggested to be the result of TTHM precursors in scale, tubercules, and biofilm on the pipe wall. The HAA3 formation results were consistent with the findings of Brereton (1998), while Rossman et al. (2001) showed that HAA6 (sum of MCAA, DCAA, TCAA, MBAA, DBAA, and BCAA) formation in a flow-through cast-iron pipe loop was the same as HAA6 formation in the in-situ SDS test. Of note, Rossman et al. (2001) used an initial free chlorine dose of 7 mg/L and a 2 hour retention time prior to entering pipe loop. This chlorine concentration and initial chlorine contact time were significantly higher than the values used in this study, which likely explains some of the observed differences in DBP formation between the findings of Rossman et al. (2001) and this work. Brereton (1998) suggested that the lower HAA3 formation in the cast iron pipe reactors were the result of sorption of HAA3 to the cast-iron wall matrix or the removal of HAA precursors by cast iron corrosion products within the pipe reactors. Recall that during this study, each of the MS-SDS test reactors were conditioned with chlorinated membrane treated water prior to the start of the test. As a result, it can be argued that potential oxidation sites within the MS-SDS test reactors may have been exhausted prior to the start of the test. Therefore, significant concentrations of HAA3 were not likely adsorbed to the pipe wall of the MS-SDS test reactors. 101 The following two hypotheses were proposed to further explain the low HAA3 formation in the MS-SDS test compared to HAA3 formation in the in-situ SDS test: ■ The higher chlorine consumption in the MS-SDS test, than in the in-situ SDS test, limited HAA3 formation in the MS-SDS test. ■ The low chlorine concentrations in the MS-SDS test resulted in conditions that favoured possible biodegradation of HAA3. These hypotheses are examined in the following sections. 6.2.3.1^Chlorine Concentration The aim of this analysis was to determine whether the high chlorine consumption observed in the MS-SDS test limited the formation of HAA3. The chlorine demand for the MS-SDS test was higher than the chlorine demand for the in-situ SDS test during 12 hour and 36 hour experimental periods for raw and membrane treated water. The high chlorine demand observed for the MS-SDS test is consistent with the findings of others (Brereton and Mavinic, 2002; Chan et al., 2002; Rossman et al., 2001; Brereton, 1998), which compared the chlorine demand of pipe environments to the chlorine demand of glass bottle incubations. Empirical models by Montgomery Watson (1993) were used to assess the impact of chlorine concentration on HAA3 formation. These models were selected because of the significance of these works in the published literature; Montgomery Watson (1993) developed one of the first empirical HAA3 formation models (Sadiq and Rodriguez, 2004). The main limitation of this model is that it was developed based on data from raw water chlorination. The model was also developed from database values with boundary conditions for each of the model parameters. Model results for HAA3 formation of treated water and for parameters outside of the model boundary conditions should be interpreted with caution (Chowdhury and Amy, 1999). Based on the empirical models, HAA3 formation is proportional to the chlorine dose raised to the power of 0.509 for MCAA, 0.480 for DCAA, and 0.881 for TCAA (Montgomery and Watson, 1993). These values suggest that chlorine concentration is expected to have a greater effect on the formation of TCAA than on the formation of MCAA or DCAA. Using 102 these models for essentially no chlorine residual, as was observed in the 12 hour and 36 hour MS-SDS test reactors, there was no HAA3 formation. However, using a chlorine residual of 0.2 mg/L and 0.5 mg/L, as was observed at the end of the 12 hour and 36 hour in-situ SDS test, HAA3 formation of approximately 8 1..ig/L to 10 pg/L HAA3, respectively, was estimated. The above results suggest that the higher chlorine consumption, and as a result, the lower residual chlorine concentrations, observed in the MS-SDS test than in the in-situ SDS test likely limited the formation of HAA3 in the MS-SDS test. Since it was shown that the majority of HAA3 for this source water were formed within 12 hours, low chlorine residual, such as that observed in the MS-SDS test for retention times greater than 12 hours, did not result in additional HAA3 formation. These findings support the hypothesis that low chlorine concentrations in the MS-SDS test likely limited further HAA3 formation and may have resulted in the significantly lower HAA3 formation observed in the MS-SDS test than in the in-situ SDS test. 6.2.3.2 Biodegradation of Haloacetic Acids The aim of this analysis was to examine whether the low chlorine concentrations observed in the MS-SDS test resulted in conditions that may have favoured possible biodegradation of some HAA3 species. Recall that unlike THMs, some HAA species are biodegradable in distribution systems conditions with low chlorine residual, i.e., <0.5 mg/L (Baribeau et al., 2006). During Phase II, DBP formation was assessed in cast iron pipe sections using the MS-SDS test, while DBP formation was assessed in glass bottles using the in-situ SDS and standard SDS tests. Since the MS-SDS test and in-situ SDS test were performed under similar environmental conditions, differences in DBP formation, particularly reduction of HAA3, might be attributed to differences in the reactor vessel material. With respect to the possible biodegradation of HAA3, more biodegradation would be expected in the MS-SDS test than in the in-situ SDS test because the MS-SDS test reactors i.e., pipe reactors, were not sterili7ed before the tests. On the other hand, for the in-situ SDS test, the reactor vessels i.e., glass 103 Raw Water Membrane Treated b) 3.0 2.5 1 .0 0.5 0.0 a) 3.0 2.5 12.0 01.0 0.5 0 Raw Water Membrane Treated 0.0 bottles, were sterilized before the test. For the standard SDS test, the reactor vessels i.e., glass bottles, were also sterilized before the test. Similar to the analysis performed for Phase I, DCAA/TCAA and concentrations of individual HAA3 species were used as an indicator of possible biodegradation of HAA3. Since biodegradation effects would not be expected in the standard SDS test due to the very high chlorine residual, only the DCAA/TCAA for raw and membrane treated waters for the MS-SDS test and in-situ SDS test were compared. DCAA/TCAA for the 12 hour and 36 hour experimental periods for the MS-SDS test are shown in Figure 6.12. DCAA/TCAA for the 12 hour and 36 hour experimental periods for the in-situ SDS test are shown in Figure 6.13. DCAA and TCAA concentrations measured during the MS-SDS test and in-situ SDS test for 12 hour and 36 hour experimental periods are presented in Table 6.5. 0^3^12 ^ 0^12^36 ^ Retention Time - MS-SOS Test [hours] Retention Time - MS-SOS Test [hours] Figure 6.12 DCAA/TCAA during the MS-SDS test for the a) 12 hour experimental period and b) 36 hour experimental period (values presented are mean ± standard deviation) 104 a) 3.0 2.5 1 2.0 1.5 0 1 - 0 0.5 0 .0 Raw Water Membrane Treated  b) 3.0 Raw Water 2.5^Membrane Treated / 2.0 1.5 0 1.0 0.5 0.0 0^3^12^ 0^12^36 Retention Time - In-Situ SDS Test Retention Time -^SDS Test Figure 6.13 DCAA/TCAA during the in-situ SDS test for the a) 12 hour experimental period and b) 36 hour experimental period (values presented are mean ± standard deviation) Table 6.5 DCAA and TCAA concentrations during the 12 hour and 36 hour experimental periods for the MS-SDS and in -situ SDS tests (values presented are mean ± standard deviation) Experimental Period MS-SDS Test In-situ SDS Test Raw Water Membrane Treated Raw Water Membrane Treated DCAA [µg/L] TCAA [µg/I.,] DCAA [ptg/L] TCAA [iig/1..] DCAA [tig/L] TCAA [Ng/L] DCAA [iig/L] TCAA [iig/L] 12 hours 0 hour 31±3 1912 26±5 21±6 26±3 16±4 28±5 22±5 3 hours 39±6 25±5 35±2 29±5 47±1 41±4 40±4 38±5 12 hours 27±3 36±5 24±2 35±3 60±4 54±9 52±12 44±7 36 hours 0 hour 27±2 15±2 23±1 16±2 24±2 11±3 27±5 18±6 12 hours 7±2 24±4 7±4 20±5 54±3 44±5 44±2 35±2 36 hours nd 13±2 nd 23±3 63±2 42±3 56±5 39±5 Note: nd indicates "non detect"; for calculation purposes, values reported as half the MDL for DCAA (1 fig/L These results indicate that DCAA concentrations were reduced after 12 hours in the MS- SDS test. However, for the in-situ SDS test, both DCAA and TCAA concentrations 105 continued to increase over time. Possible biodegradation would not be expected to occur in the in -situ SDS test, since the bottles used in the in-situ SDS test were sterilized before the start of the test, whereas the MS-SDS test reactors were not sterilized before the start of the test. Based on the above results, possible biodegradation of HAA3 within the MS-SDS test reactors might explain the lower HAA3 concentrations observed in the MS-SDS test than in the in-situ SDS test. It appears that the relatively low chlorine concentrations, relatively warm water, and the pipe environment, i.e., non-sterilized environment, of the MS-SDS test were possibly favorable conditions for biodegradation of HAA3 species (Baribeau et al., 2006; Baribeau et al., 2005; Speight and Singer, 2005). The above results are consistent with the findings from Phase I, which suggested that biodegradation of HAA3 may have been possible at distribution system sampling sites with high retention times and low chlorine concentration. 6.3 Comparison of Disinfectant By-Product Formation in the Distribution System to Bench-Scale Simulations This work examined DBP formation, particularly THM and HAA3 formation, within a full- scale distribution system (Phase I) and under bench-scale simulations (Phase II). The hydraulic complexities of the distribution system made it difficult to assess the formation of DBPs over time at full-scale. Therefore, Phase II of the study was implemented to assess DBP formation over time using controlled retention times. In Phase II, an MS-SDS flow- through reactor system was designed and built using pipe material obtained directly from the City of Kamloops distribution system. The results of the MS-SDS test were compared to traditional glass bottle incubations using the in-situ SDS test, which was performed in parallel with the MS-SDS test and the standard SDS test. A significant limitation of this work was the difference in time periods over which Phase I and Phase II of the study were conducted. Phase I was performed during the fall and winter months, from October 2005 to March 2006, while Phase II was conducted during the summer months from July though September 2006. During the summer months, the water temperatures of the South Thompson River and the distribution system were higher. This 106 difference in water temperature between Phase I and Phase II made it difficult to comprehensively compare the results for Phase I and Phase II of the study. Seasonality may have also affected the nature of the NOM in South Thompson River water during the study periods (Goslan et al., 2002); however, the impact of seasonality on the nature of NOM in the source water was beyond the scope of this study. Similar THM formation was observed during Phase I and the MS-SDS test and in-situ SDS test (Phase II). THM concentrations immediately following membrane treatment (7- 17 Kg/L) were similar to THM concentrations in the MS-SDS test (15-21 iug/L) and in-situ SDS test (15-23 pg/L) at 0 hour for membrane treated water. THM concentrations immediately following chlorination (9-23 iug/L) were also similar to THM concentrations in the MS-SDS test (15-19 pi,g/L) and in-situ SDS test (11-23 jug/L) at 0 hour for raw water. At a longer distribution system retention time, Phase I THM concentrations at the extremities of the distribution system for membrane treated water (23-52 jug/L) were similar to THM concentrations for the MS-SDS test (33-37 jug/L) and in-situ SDS test (43-47 jug/L) for membrane treated water following the 36 hour experimental period. Phase I THM concentrations at the extremities of the distribution system for raw water (33-51 jug/L) were similar to THM concentrations for the MS-SDS test (33-37 iug/L) and in-situ SDS test (39- 57 lug/L) for raw water following the 36 hour experimental period. These results were not surprising, since THMs are relatively stable within the distribution system (Singer et al., 2002). THM formation measured during Phase II, i.e., MS-SDS test, in-situ SDS test, and standard SDS test, showed that the majority of the THMs were formed within 3 hours in raw water and membrane treated water. Therefore, it is difficult to estimate the retention times of the Phase I distribution system sampling sites from the Phase II THM formation results. Nevertheless, despite the difference in water temperatures between Phase I and Phase II, the above THM formation results suggest that the MS-SDS test and the in-situ SDS test were representative of distribution system conditions for THM formation. Unlike THM formation, significant differences in HAA3 formation were observed between Phase I and the MS-SDS test and in-situ SDS test (Phase II). HAA3 concentrations immediately following membrane treatment (16-324g/L) were lower than HAA3 107 concentrations in the MS-SDS test (36-57 lag/L) and in-situ SDS test (34-62 ug/L) at 0 hour for membrane treated water. However, HAA3 concentrations immediately following chlorination (27-67 ug/L) were relatively similar to HAA3 concentrations in the MS-SDS test (39-5611g/L) and the in-situ SDS test (20-52 ug/L) at 0 hour for raw water. At a longer distribution system retention time, Phase I HAA3 concentrations at the extremities of the distribution system for membrane treated water (60-115 pg/L) were significantly higher than HAA3 concentrations for the MS-SDS test (22-28 ug/L), but relatively similar to the HAA3 concentrations for the in-situ SDS test (86-110 ug/L) for membrane treated water following the 36 hour experimental period. Phase I HAA3 concentrations at the extremities of the distribution system for raw water (70-10811g/L) were significantly higher than HAA3 concentrations for the MS-SDS test (13-17 ug/L), but relatively similar to the HAA3 concentrations for the in-situ SDS test (104-112R/L) for raw water following the 36 hour experimental period. The findings of the MS-SDS tests performed in the summer and the findings of distribution system monitoring performed in the fall and winter suggested that HAA3 formation may be lower in the summer months. This result is somewhat counter-intuitive to what might be expected, as DBP formation is typically highest during the summer months when water temperatures are higher. However, in warmer water temperatures and an absence of adequate chlorine residual, biodegradation may have possibly reduced HAA3 concentrations in the MS-SDS test. This hypothesis was supported by the fact that the chlorine concentrations at the extremity sampling sites of the distribution system were relatively low and that DCAA/TCAA decreased during Phase I. HAA3 formation measured during Phase II, i.e., the MS-SDS test, in-situ SDS test, and standard SDS test, showed that most of the HAA3 were formed within 3 hours in raw and membrane treated water. Therefore, it is difficult to estimate the retention times of the Phase I distribution system sampling sites from the Phase II HAA3 results. However, despite the significant difference in water temperatures between Phase I and Phase II, the above HAA3 formation results suggest that the MS-SDS test was likely more representative of distribution system conditions than the in-situ SDS test. 108 In summary, the results from Phase I and Phase II investigations of THM and HAA3 formation showed that although distribution system retention times could not be estimated from the bench-scale simulations, bench-scale approaches could be used to estimate DBP formation under distribution system conditions for raw and membrane treated water. For estimates of the formation of THMs, which are relatively stable within the distribution system, the MS-SDS test and in-situ SDS test closely estimated THM formation. On the other hand, for estimates of the formation of HAA3, which are subject to biodegradation, the MS-SDS test was likely more representative of distribution system conditions than the in- situ SDS test. Although the standard SDS test was not intended to replicate the environmental conditions of the distribution system, the results showed that membrane treatment processes may have removed some of the THM and HAA3 precursors from the source water. 109 Chapter 7. Conclusions Based on the results of this study, the following conclusions are made: ■ Distribution system monitoring (Phase I) showed that concentrations of DBPs (measured as THM and HAA3) were not significantly reduced in the distribution system following the implementation of membrane treatment, i.e., ultrafiltration. ■ Distribution system monitoring (Phase I) showed that concentrations of HAA3 increased at some sampling sites following the implementation of the membrane treatment process. However, the increase in HAA3 concentrations was likely due to an increase in the retention time in the distribution system following the distribution system upgrade, rather than due to implementation of the membrane treatment process itself. ■ Bench-scale simulations (Phase II) showed that DBP formation was generally higher in raw water than DBP formation in membrane treated water. These results suggested that the membrane treatment process was effective to remove some of the DBP precursors from the source water. ■ THM and HAA3 formation measured during bench-scale simulations (Phase II) suggested that most of the THMs and HAA3 were formed within 3 hours in raw water and membrane treated water. ■ In the presence of low chlorine residual, possible biodegradation of HAA3, specifically DCAA, may have occurred at the extremities of the distribution system (Phase I) and in the MS-SDS test reactors with long retention times (Phase II), i.e., 12 hours and 36 hours. ■ Despite the difference in water temperature between Phase I and Phase II, the THM and HAA3 formation results suggested that the MS-SDS test was more representative of 110 distribution system conditions than the in-situ SDS test and standard SDS test. The MS- SDS test was able to simulate DBP formation and DBP degradation, particularly degradation of HAA3, which was observed in the distribution system. • Although membrane filtration, i.e., ultrafiltration, can remove some of the DBP precursors in this source water, the DBP formation results for the full-scale distribution system monitoring (Phase I) and bench-scale simulations (Phase II) suggested that DBP precursors in this source water cannot effectively be removed by membrane filtration processes. 111 Chapter 8. Implications of Study Findings For Engineering, Public Health, and Policy Applications The objective of this study was to determine the extent to which upgrades to a drinking water treatment system, specifically, implementation of an ultrafiltration treatment process, impacted DBP formation within a distribution system. In early 2005, the City of Kamloops brought on-line a new, state-of-the-art membrane filtration, i.e., ultrafiltration, drinking water treatment system. Prior to the 2005 treatment upgrade, the original drinking water treatment process was coarse screening followed by chlorination. The membrane treatment process was effective at reducing turbidity and pathogens in South Thompson River water, thus improving the overall drinking water quality from the original drinking water treatment process. Results from distribution system monitoring (Phase I) of the present study suggested that implementation of the membrane treatment process did not significantly reduce DBP formation within the distribution system. Results from bench-scale simulations (Phase II) of the present study showed that the MS-SDS test developed during this study was more representative of actual distribution system conditions compared to traditional glass bottle incubations (in-situ SDS test and standard SDS test) commonly used to estimate DBP formation. CGDWQ have been implemented for THMs at 100 pg/L (Health Canada, 2006). In 2006, a guideline value of 80 1..tg/L was proposed for HAAS (FPTCDW, 2006). The results of the present study showed that although THM concentrations were consistently below the CGDWQ, concentrations of HAA3, particularly at the extremity locations of the City of Kamloops distribution system, may exceed the proposed HAA5 guideline value. Distribution system monitoring (Phase I) showed that HAA3 concentrations in the fall and 112 winter months frequently exceeded 80 1.ig/L at the extremity sampling sites. However, bench-scale simulations (Phase II) showed that HAA3 concentrations in the summer months were lower than the HAA3 concentrations observed during distribution system monitoring (Phase I). These findings suggest that an annual mean HAA3 concentration based on an average of a minimum of quarterly samples taken in the distribution system (Health Canada, 2006) would result in an annual mean HAA3 concentration that may nonetheless meet the proposed CGDWQ for HAA5. Distribution system monitoring (Phase I) of the present study showed that DBP (THM and HAA3) concentrations were highest at the extremity sampling sites of the distribution system. Similarly, bench-scale simulations (Phase II) of the present study showed that DBP (THM and HAA3) concentrations were highest in the MS-SDS test reactors with the longest retention times i.e., 12 hours and 36 hours. The results of the present study confirm that DBP distribution system sampling programs that do not include representative sampling sites, such as following chlorination processes, mid-points within the distribution system, and at extremity locations within the distribution system i.e., sites with long retention times, may not accurately estimate mean DBP concentrations in the distribution system and DBP exposure for tap water consumers. Scientific assessment tools, such as the MS-SDS test used in the present study, are needed to aid policy makers with development of drinking water policies that protect public health, while at the same time, efficiently use capital funds to implement drinking water treatment infrastructure improvements. Based on the findings of this study, water quality and health professionals could use the MS-SDS test approach as an alternative method to the standard SDS test to estimate DBP formation in the full-scale distribution system, particularly in the absence of known retention times. 113 Chapter 9. Recommendations Based on the findings of this study, the following recommendations for future work are made: 1. In the present study, distribution system monitoring (Phase I) was conducted during fall and winter; DBP formation within the full-scale distribution system during spring and summer was not investigated. A one year (minimum) study of DBP formation within the City of Kamloops distribution system should be performed. The study could assess the effects of seasonality and changes in raw water quality on DBP formation within the full- scale distribution system. As shown by the significant difference in DBP formation at sampling sites used in the present study, sampling sites should be representative of the distribution system i.e., following chlorination processes, mid-distribution system, and extremity locations of the distribution system. The study should also include monitoring of factors that affect DBP formation within the distribution system, including pH, temperature, and free chlorine concentrations; concentration and characterization of organic material by TOC, UV254, and SUVA; and DBP concentrations (THM and HAA3). 2. The results of the distribution system monitoring (Phase I) and bench-scale simulations (Phase II) of the present study suggested that DBP concentrations were not significantly reduced following the implementation of membrane treatment. These findings suggested that DBP precursors were not removed during the membrane treatment process. Additional characterization of DBP precursors in South Thompson River water could provide further insight into the size (size fractionation) and nature (polar fractionation) of the NOM, particularly the impact of seasonality on the size and nature of DBP precursors. The characterization of DBP precursors in South Thompson River water should be performed simultaneously with a monitoring study that examines the effects 114 of seasonality and changes in raw water quality on DBP formation within the full-scale distribution system (see Recommendation 1). 3. The City of Kamloops distribution system is hydraulically complex with a number of reservoirs and booster stations throughout the distribution system. In distribution system monitoring (Phase I) of the present study, retention times of sampling sites were not known. Retention times are an important factor in determining DBP formation within the distribution system, such as the rates of DBP formation. Studies should be performed that estimate retention times within the City of Kamloops distribution system, particularly at the extremity locations within the distribution system (e.g. physical tracer studies). Estimates of retention times, coupled with water quality information obtained from the distribution system (see Recommendation 1), could be used to more accurately estimate DBP formation within the distribution system. 4. In the present study, distribution system monitoring (Phase I) was conducted during the fall and winter, while bench-scale simulations (Phase II) were conducted during the summer. The MS-SDS test should be performed simultaneously with a full-scale distribution system sampling program, as outlined in Recommendation 1. The study could provide an estimate of retention times at distribution system sampling sites based on DBP formation within the distribution system and DBP formation within the MS- SDS test under controlled retention times. 5. In distribution system monitoring (Phase I) of the present study, the effect of sediment and tuberculated material on DBP formation is not known. The City of Kamloops is currently cleaning the distribution system pipes using uni-directional water main flushing. An assessment of distribution system pipe flushing and the effect of pipe cleaning on DBP formation within the distribution system should be performed. Sampling sites within sections of the City of Kamloops distribution system should be sampled before and after implementation of the uni-directional water main flushing. The study could examine the impact of sediment and tuberculated material on DBP formation within a full-scale distribution system. Further, the full-scale distribution system study could be performed simultaneously with the MS-SDS test and in-situ SDS test (see Recommendation 6). 115 6. In bench-scale simulations (Phase II) of the present study, the effect of sediment and tuberculated material on DBP formation is not known. During construction of the MS- SDS test reactors, the sediment and tuberculated material on the inside of distribution system pipe sections was removed during the lathing process. It is recommended that MS-SDS tests and in-situ SDS tests be performed with the loose sediment and tuberculated material collected from the distribution system pipe sections. 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Sampling Events for Phase I: Distribution System Monitoring Table A.1 Distribution system monitoring (Phase I) sampling events of the Kamloops distribution system Time of Sample Collection Sampling Date Event SITE 1 Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' Stage A 1^31-Oct-05 10:15 am 10:50 am 11:20 am 11:30 am 12:20 pm 2 9-Nov-05 11:59 am 11:40 am 12:15 pm 12:27 pm 9:45 am 3^23-Nov-05 11:15 am 10:45 am 11:40 am 11:45 am 9:58 am 4 5-Dec-05 11:01 am 10:45 am 11:20 am 11:35 am 9:53 am 5^14-Dec-05 10:20am 10:00 am 10:40 am 10:45 am 9:23 am Stage B 6^24-Jan-06 11:30 am 11:05 am 10:13 am 10:16 am 11:55 am 7 7-Feb-06 12:25 pm 12:15 pm 12:40 pm 12:45 pm 11:35 am 8^28-Feb-06 3:00 pm 2:15 pm 1:50 pm 1:45 pm 3:45 pm 9 15-Mar-06 12:35 pm 12:00 pm 10:30 am 10:45 am 11:15 am 10^27-Mar-06 12:00 pm 11:45 am 11:05 am 11:10 am 8:15 am Notes: 'Science Building Room 5237 125 Sampling Port Appendix B. Photographs Site 1 — Dallas Intake Site 2 — Blackwell Booster Station Site 3 (Centre Port) — Raw Water ^ Site 5 — Thompson Rivers University Site 4 (Right Port) — Membrane Permeate Water Figure B.1 Photographs of distribution system monitoring (Phase I) sampling sites and on-site data loggers for the City of Kamloops distribution system 126 pH and Temperature Data Logger System at Free Chlorine Analyzer Data Logger System KCWQ for Site 4 ^ at KCWQ for Site 4 (Similar data logger system installed for Site 3) Figure B.1 (continued) Photographs of distribution system monitoring (Phase I) sampling sites and on-site data loggers for the City of Kamloops distribution system 127 Appendix C. MS-SDS Test Reactor Tracer Study Introduction The objective of the continuous tracer study was to verify that the MS-SDS test reactors used in Phase II of the present study behaved as completely-mixed stirred tank reactors (CSTRs). The continuous tracer study was conducted for an individual MS-SDS test reactor and for two MS-SDS test reactors in series using the same retention times as those used in Phase II, i.e., 12 hour retention time and 36 hour retention time. The extent to which mixing occurred within the MS-SDS test reactors was investigated via periodic measurements of the fraction of tracer present within the reactors over several retention times. The tracer concentrations observed in the MS-SDS test reactors during the tracer study were compared to the theoretical tracer concentrations expected for ideal CSTRs using mathematical equations. Experimental Methods Prior to the start of the tracer study, each MS-SDS test reactor was rinsed, flushed, and filled with distilled water. The tracer used during this study was rhodamine WT. A tracer solution was prepared using 1 drop of rhodamine WT dye per 1025 mL of distilled water. The tracer solution was pumped continuously through the MS-SDS test reactors using the same flow rates, as outlined in Table 5.2, for several reactor retention times. The fraction of tracer present within each MS-SDS test reactor at each sampling interval was determined using UV absorbance measurements. Water samples were collected from each MS-SDS test reactor using clean, glass 14 mL COD vials. The UV absorbance of each water sample was measured at 543 nm (Method 4500-NO 3-E, APHA et al., 1998) using a Hach DR 2800 Portable Spectrophotometer (Hach Company). A calibration curve was prepared for each batch of rhodamine WT solution used in the tracer study by measuring the UV absorbance of different fractions or dilutions of the original tracer solution, i.e., 0%, 20%, 40%, 60%, 80%, and 100% dilution of the original tracer solution. 128 The actual tracer concentrations observed during the tracer study for the individual MS-SDS test reactors were compared to the theoretical tracer concentrations for an ideal CSTR (Metcalf and Eddy, 2003) Similarly, actual tracer concentrations observed during the tracer study for two MS-SDS test reactors in series were compared to the theoretical tracer concentrations for two ideal CSTRs in series (Grady et al., 1999). Results and Discussion The results of the tracer study for 12 hour retention time and 36 hour retention time are presented in Figure C.1 and Figure C.2, respectively. a) 3 hour retention time^ b) 9 hour retention time 1.0 ti^ ":311 1 0.8 14, 0.8re cc c c tr, 0.6 d0.6 o oO .,..o 1.0 i 0.2 t^ c f) 0.2 - 3 hr MS-SOS Test Reactor 0.0 0.0 E.'u_ - - - - 3 hr Ideal CSTR^u_ 0.0^2.0^4.0^6.0^8.0^10.0^0 0 th c) 12 hour retention time (3 hour and 9 hour MS-SDS test reactors in series) 1.0 - 9 hr MS-SDS Test Reactor ---- 9 hr Ideal CSTR 2.0^4.0^6.0^8.0^10.0 tit 0.8 t • 0.6 • 0.4 0 0 ▪ 0.2 0.0 - 12 hr MS-SDS Test Reactor (Series) ---- 12 hr Ideal CSTR (Series) 0.0^2.0^4.0^6.0^8.0^10.0 tit Figure C.1 Tracer study results for MS-SDS test reactors and ideal CSTRs for 12 hour retention time it 0.4 I- 0.4 129 0 f, 0.2 0 . 0 I 24 hr MS-SDS Test Reactor --- 24 hr Ideal CSTR `6 0.8 •S r, 0.6 ea 0.4 I; 0.2 / I 0.0 1 1.0 — 12 hr MS-SDS Test Reactor 12 hr Ideal CSTR a) 12 hour retention time b) 24 hour retention time 1.0 0.6^.1 0.4 0^2^4^6^8^10 tit 0^2^4^6^8^10 tit c) 36 hour retention time (12 hour and 24 hour MS-SDS test reactors in series) 1.0 0.4 0.2 ; 1 ii I 1 — 36 hr MS-SDS Test Reactor (Series) 36 hr Ideal CSTR (Series) 0^2^4^6^8^10 tit Figure C.2 Tracer study results for MS-SDS test reactors and ideal CSTRs for 36 hour retention time As shown in Figure C.1 and Figure C.2, the individual reactors, i.e, 3 hour, 9 hour, 12 hour, and 24 hour MS-SDS test reactors and the 12 hour and 36 hour MS-SDS test reactors in series essentially behave as CSTRs. Since the tracer curves for the MS-SDS test reactors generally follow the theoretical curves for ideal CSTRs, these results suggest that the MS- SDS test reactors essentially behave as CSTRs. Conclusion Based on the findings of the continuous tracer study, the MS-SDS test reactors used in the present study essentially behave as CSTRs. Therefore, the assumption of complete-mixing for the individual MS-SDS test reactors and for two MS-SDS test reactors in series is valid. 130 Appendix D. Raw Data for Phase I: Distribution System Monitoring In-situ Data Logger Monitoring Data for Distribution System Sampling Sites There were limitations with the use of the in-situ data loggers for monitoring physical and chemical characteristics (pH, temperature, and free chlorine concentration) of the raw and treated water in the distribution system during the distribution system monitoring (Phase I) portion of the study. Technical difficulties with the in-situ data loggers resulted in data gaps during the distribution system monitoring (Phase I) period. For Site 1, pH data were not available for Stage B due to a data logger malfunction after the connection of the southeast section of the distribution system to the southwest section of the distribution system. For Site 2, the data logger appeared to calibrate low during operation in Stage A and Stage B. During Stage B, the Site 2 data logger battery failed to maintain a full charge during the monitoring period. This battery failure resulted in large gaps in the physical and chemical monitoring data at Site 2 from January 2006 to March 2006. The Site 5 sampling site was missing data from February 10, 2006 to February 28, 2006 and March 15, 2006 to March 31, 2006. At Site 5, deposits of iron and manganese were also observed on the probe that measured free chlorine concentration, which resulted in variable free chlorine readings throughout the Phase I monitoring period. The physical and chemical (mean daily pH, temperature, and free chlorine concentrations) monitoring data for City of Kamloops distribution system monitoring sites are presented in Table D.1 to Table D.3. 131 Table D.1 Mean daily pH for distribution system sampling sites Date SITE 1Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' 20-Oct-05 7.5 7.4 7.7 8.0 7.6 21-Oct-05 7.5 7.4 7.8 8.0 7.6 22-Oct-05 7.5 7.4 7.8 8.0 7.5 23-Oct-05 7.5 7.4 7.8 8.1 7.6 24-Oct-05 7.5 7.4 7.8 8.0 7.6 25-Oct-05 7.5 7.4 7.8 8.1 7.7 26-Oct-05 7.5 7.4 7.8 8.1 7.6 27-Oct-05 7.5 7.4 7.8 8.1 7.5 28-Oct-05 7.5 7.4 7.8 8.1 7.6 29-Oct-05 7.5 7.4 7.8 8.1 7.6 30-Oct-05 7.5 7.4 7.8 8.1 7.4 31-Oct-05 7.5 7.3 7.8 8.1 7.4 1-Nov-05 7.5 7.3 7.8 8.1 7.5 2-Nov-05 7.5 7.3 7.7 8.0 7.7 3-Nov-05 7.6 7.3 7.8 8.0 7.8 4-Nov-05 7.6 7.3 7.8 8.0 7.7 5-Nov-05 7.6 7.3 7.8 7.9 7.6 6-Nov-05 7.6 7.3 7.8 8.1 7.4 7-Nov-05 7.6 7.3 7.8 8.1 7.4 8-Nov-05 7.6 7.3 7.8 8.0 7.5 9-Nov-05 7.6 7.3 7.8 8.0 7.5 10-Nov-05 7.6 7.8 8.0 7.5 11-Nov-05 7.6 7.8 8.1 7.4 12-Nov-05 7.6 7.8 8.1 7.5 13-Nov-05 7.6 7.8 8.1 7.5 14-Nov-05 7.6 7.8 8.1 7.6 15-Nov-05 7.6 7.8 8.0 7.6 16-Nov-05 7.6 7.8 8.0 7.4 17-Nov-05 7.6 7.8 8.0 7.6 18-Nov-05 7.6 7.8 8.0 7.6 19-Nov-05 7.6 7.8 8.0 7.6 20-Nov-05 7.6 7.8 8.0 7.7 21-Nov-05 7.6 7.7 7.9 7.6 22-Nov-05 7.6 7.3 7.7 8.0 7.6 23-Nov-05 7.7 7.3 7.7 8.0 7.6 24-Nov-05 7.7 7.3 7.8 8.0 7.6 25-Nov-05 7.7 7.3 7.8 8.0 7.8 26-Nov-05 7.7 7.3 7.8 8.0 7.6 27-Nov-05 7.7 7.3 7.9 8.0 7.7 28-Nov-05 7.7 7.3 7.9 8.0 7.6 29-Nov-05 7.7 7.3 7.9 7.8 7.6 30-Nov-05 7.7 7.3 7.9 7.9 7.4 132 Table D.1 (continued) Mean daily pH for distribution system sampling sites Date SITE 1Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' 1-Dec-05 7.7 7.3 7.9 8.0 7.4 2-Dec-05 7.7 7.3 7.9 7.9 7.4 3-Dec-05 7.7 7.3 7.9 8.0 7.5 4-Dec-05 7.7 7.3 7.9 7.9 7.5 5-Dec-05 7.7 7.3 7.9 7.9 7.6 6-Dec-05 7.7 7.3 7.9 7.9 7.7 7-Dec-05 7.7 7.3 7.8 8.0 7.4 8-Dec-05 7.7 7.3 7.9 8.0 7.4 9-Dec-05 7.7 7.3 7.9 8.0 7.6 10-Dec-05 7.7 7.3 7.9 7.9 7.4 11-Dec-05 7.7 7.4 7.9 8.0 7.4 12-Dec-05 7.4 7.9 8.0 7.4 13-Dec-05 7.3 7.9 8.0 7.5 14-Dec-05 7.3 7.9 8.0 7.4 15-Dec-05 7.3 7.9 8.0 7.4 16-Dec-05 7.3 8.0 8.0 7.4 17-Dec-05 7.3 8.0 8.0 7.4 18-Dec-05 7.3 7.9 8.0 7.3 19-Dec-05 7.3 8.0 8.0 7.5 20-Dec-05 7.4 8.0 8.0 7.4 21-Dec-05 7.3 8.0 8.0 7.4 22-Dec-05 7.3 8.0 8.0 7.6 23-Dec-05 7.4 8.0 8.0 7.5 24-Dec-05 8.0 8.0 7.7 25-Dec-05 8.0 8.0 7.6 26-Dec-05 8.0 8.0 7.8 27-Dec-05 8.0 8.0 7.8 28-Dec-05 7.9 8.0 7.8 29-Dec-05 7.9 8.0 7.7 30-Dec-05 8.0 8.0 7.6 31-Dec-05 8.0 8.0 7.8 1-Jan-06 7.9 8.0 7.7 2-Jan-06 7.9 8.0 7.6 3-Jan-06 7.9 7.9 7.8 4-Jan-06 7.9 8.0 7.7 5-Jan-06 7.9 8.0 7.6 6-Jan-06 7.9 8.0 7.7 7-Jan-06 7.8 8.0 7.4 8-Jan-06 7.9 8.1 7.8 9-Jan-06 7.9 8.0 7.8 10-Jan-06 7.9 8.0 7.8 11-Jan-06 7.9 8.0 7.7 133 Table D.1 (continued) Mean daily pH for distribution system sampling sites SITE 1Date Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' 12-Jan-06 7.9 8.0 7.7 13-Jan-06 7.9 8.0 7.6 14-Jan-06 7.9 8.0 7.9 15-Jan-06 7.9 8.0 7.7 16-Jan-06 8.0 8.0 7.8 17-Jan-06 8.0 8.0 7.8 18-Jan-06 7.9 8.0 7.7 19-Jan-06 8.0 8.0 7.7 20-Jan-06 8.0 8.0 7.5 21-Jan-06 8.0 8.0 7.7 22-Jan-06^- 8.0 7.9 7.5 23-Jan-06 8.0 8.0 7.7 24-Jan-06 8.0 8.0 7.8 25-Jan-06 ---- 8.0 8.0 7.6 26-Jan-06 7.9 8.0 8.1 7.5 27-Jan-06 7.9 8.0 8.0 7.7 28-Jan-06 7.9 8.1 7.7 29-Jan-06 7.9 8.1 7.7 30-Jan-06 8.0 8.0 7.7 31-Jan-06 8.0 8.0 7.8 1-Feb-06 8.0 8.0 7.7 2-Feb-06 8.0 8.1 7.6 3-Feb-06 8.0 8.0 7.8 4-Feb-06 8.0 8.0 7.7 5-Feb-06 8.0 8.0 7.9 6-Feb-06 8.0 8.0 7.7 7-Feb-06 ---- 7.9 8.0 7.8 8-Feb-06 8.0 7.9 8.0 7.9 9-Feb-06 8.0 8.0 8.0 7.8 10-Feb-06 8.0 7.9 8.0 7.8 11-Feb-06 8.1 8.0 8.0 12-Feb-06 8.1 8.0 8.0 13-Feb-06 8.0 8.0 14-Feb-06 7.9 8.0 15-Feb-06 8.0 7.9 16-Feb-06 8.0 7.9 17-Feb-06 7.9 8.0 18-Feb-06 7.9 8.0 19-Feb-06 - 7.9 8.0 20-Feb-06 7.9 8.0 21-Feb-06 7.9 8.0 22-Feb-06 8.0 8.0 134 Table D.1 (continued) Mean daily pH for distribution system sampling sites SITE 1 Date Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' 23-Feb-06 8.0 8.0 24-Feb-06 7.9 8.0 25-Feb-06 7.9 8.0 26-Feb-06 8.0 8.0 27-Feb-06 8.0 8.0 28-Feb-06 8.1 8.0 8.0 7.6 1-Mar-06 8.1 7.9 8.0 7.6 2-Mar-06 7.9 8.0 7.4 3-Mar-06 7.9 8.0 7.6 4-Mar-06 7.9 8.0 7.3 5-Mar-06 8.0 8.0 7.6 6-Mar-06 8.0 8.0 7.1 7-Mar-06 8.0 8.0 7.6 8-Mar-06 7.9 8.0 7.6 9-Mar-06 7.9 8.0 7.7 10-Mar-06 7.9 8.0 7.6 11-Mar-06 7.9 8.0 7.5 12-Mar-06 7.9 8.0 7.6 13-Mar-06 7.9 8.0 7.7 14-Mar-06 8.0 8.0 7.8 15-Mar-06 7.9 8.0 7.8 16-Mar-06 8.0 8.0 17-Mar-06 7.9 8.0 18-Mar-06 7.9 8.0 19-Mar-06 7.9 8.0 20-Mar-06 7.9 8.0 21-Mar-06 7.9 8.0 22-Mar-06 7.9 7.9 23-Mar-06 7.9 8.1 24-Mar-06 7.9 8.0 25-Mar-06 8.0 8.0 26-Mar-06 8.0 8.1 27-Mar-06 8.0 8.0 28-Mar-06 8.0 8.0 29-Mar-06 7.9 8.0 30-Mar-06 7.9 8.1 31-Mar-06 7.9 8.1 Notes: 'Science Building Room S237 Bold value indicates mean calculated based on values from partial day ---- indicates no data available due to data logger malfunction Stage B of distribution system upgrade begins January 12, 2006 Daily mean pH values based on average of 5 minute values 135 Table D.2 Summary of mean daily pH during sampling events (values presented are mean ± standard deviation) Daily Mean pH Sampling^ SITE 1^SITE 2^SITE 3^SITE 4^SITE 5 Event Date^Dallas^Blackwell^Raw Water Membrane^ThompsonIntake^Booster Permeate Rivers University' STAGE A 1^31-Oct-05^7.5^7.3 2^9-Nov-05 7.6 7.3 3 23-Nov-05^7.7^7.3 4^5-Dec-05 7.7 7.3 5 14-Dec-05^no data^7.3 7.8 8.1 7.4 7.8 8.0 7.5 7.7 8.0 7.6 7.9 7.9 7.6 7.9 8.0 7.4 8.0±0.1 7.5±0.1 8.0 7.8 8.0 7.8 8.0 7.6 8.0 7.8 8.0 no data 8.0 7.7±0.1 Mean^7.6±0.1 7.3^7.8±0.1 STAGE B 6^24-Jan-06^no data^no data^8.0 7 06-Feb-06 no data^no data 7.9 8^28-Feb-06^no data 8.1^8.0 9^06-Mar-15 no data^no data 7.9 10^27-Mar-06^no data^no data^8.0 Mean^---- ---- 8.0 Notes: 1 Science Building Room S237 Daily mean pH values based on average of 5 minute values "No data" indicates data was not available due to data logger malfunction 136 Table D.3 Mean daily water temperature (°C) for distribution system sampling sites Date SITE 1 Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' 20-Oct-05 13.3 15.9 11.2 12.2 16.9 21-Oct-05 13.1 15.7 11.1 12.2 17.1 22-Oct-05 12.8 15.7 10.7 11.6 17.0 23-Oct-05 13.0 15.8 10.9 11.8 17.1 24-Oct-05 13.3 15.8 11.1 12.1 17.2 25-Oct-05 13.6 15.8 11.4 12.5 16.8 26-Oct-05 13.3 15.8 11.1 12.1 16.7 27-Oct-05 12.7 15.2 10.5 11.6 16.6 28-Oct-05 12.1 15.1 10.1 11.0 16.2 29-Oct-05 12.1 15.1 10.1 11.1 16.3 30-Oct-05 11.8 14.8 10.0 11.0 16.6 31-Oct-05 11.7 14.7 9.8 10.7 16.4 1-Nov-05 11.7 14.6 9.9 10.7 16.8 2-Nov-05 11.3 14.3 9.6 10.5 18.7 3-Nov-05 11.2 14.3 9.5 10.3 19.2 4-Nov-05 10.9 14.2 9.3 10.1 19.5 5-Nov-05 10.7 14.1 9.1 9.9 17.8 6-Nov-05 10.8 14.1 9.1 9.9 15.8 7-Nov-05 10.4 13.8 8.8 9.8 15.7 8-Nov-05 9.9 13.7 8.5 9.2 15.4 9-Nov-05 9.9 13.6 8.3 9.2 15.1 10-Nov-05 9.9 8.4 9.1 15.0 11-Nov-05 10.0 8.3 9.1 15.4 12-Nov-05 9.7 8.1 8.8 15.7 13-Nov-05 9.6 8.2 8.8 15.6 14-Nov-05 9.0 -^- 7.7 8.4 15.3 15-Nov-05 8.2 7.3 7.8 14.8 16-Nov-05 8.0 7.3 7.9 14.7 17-Nov-05 8.4 7.5 8.0 14.1 18-Nov-05 8.4 7.3 7.9 14.0 19-Nov-05 8.6 7.4 8.1 14.3 20-Nov-05 8.5 7.3 7.9 14.5 21-Nov-05 8.5 ---- 7.2 7.7 14.3 22-Nov-05 8.2 12.3 7.0 7.6 13.8 23-Nov-05 7.9 12.3 6.8 7.3 13.7 24-Nov-05 7.6 12.1 6.5 7.0 13.3 25-Nov-05 6.7 11.9 6.1 6.5 13.3 26-Nov-05 6.6 11.8 6.1 6.2 13.5 27-Nov-05 6.0 11.6 5.7 5.9 13.5 28-Nov-05 5.5 11.5 5.4 5.4 13.1 29-Nov-05 5.4 11.4 5.3 5.4 12.7 30-Nov-05 5.0 11.2 4.9 4.9 12.4 137 Table D.3 (continued) Mean daily water temperature (°C) for distribution system sampling sites Date SITE 1Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers Universityl 1-Dec-05 4.8 11.0 4.5 4.5 12.1 2-Dec-05 4.9 10.8 4.4 4.3 12.0 3-D ec-05 4.3 10.6 3.7 3.6 12.1 4-Dec-05 3.7 10.5 3.0 2.9 12.2 5-Dec-05 3.6 10.3 3.0 2.8 12.2 6-Dec-05 3.4 10.3 2.9 2.7 11.6 7-Dec-05 2.9 10.3 2.7 2.5 11.5 8-Dec-05 3.2 10.0 2.6 2.3 11.4 9-Dec-05 3.4 10.0 2.7 2.4 11.1 10-D ec-05 5.0 10.1 3.0 2.6 10.9 11-D ec-05 4.8 9.9 2.8 2.6 11.0 12-D ec-05 3.5 9.9 2.7 2.4 11.2 13-D ec-05 3.6 9.6 2.7 2.5 10.8 14-Dec-05 3.3 9.6 2.5 2.4 10.5 15-D ec-05 3.1 9.4 2.5 2.1 10.4 16-Dec-05 3.7 9.3 2.7 2.3 10.6 17-Dec-05 3.5 9.1 2.5 2.3 10.3 18-D ec-05 3.1 9.0 2.3 2.2 10.5 19-D ec-05 2.5 8.9 2.2 2.1 10.6 20-D ec-05 2.4 8.7 2.0 1.7 10.4 21-Dec-05 2.9 8.8 2.6 2.0 10.4 22-D ec-05 3.7 8.9 3.1 2.7 10.4 23-D ec-05 4.0 8.9 3.4 3.2 10.5 24-D ec-05 4.2 3.6 3.3 10.3 25-Dec-05 4.7 4.0 3.7 10.6 26-Dec-05 4.6 4.0 3.9 10.8 27-D ec-05 4.4 3.6 3.5 10.6 28-D ec-05 4.2 3.5 3.4 10.6 29-Dec-05 4.0 3.5 3.3 10.5 30-D ec-05 4.2 3.5 3.3 10.5 31-D ec-05 4.4 3.7 3.5 10.4 1-Jan-06 4.4 3.7 3.6 10.3 2-Jan-06 4.5 3.7 3.6 10.1 3-Jan-06 4.7 3.7 3.6 10.2 4-Jan-06 5.4 3.8 3.5 10.0 5-Jan-06 6.3 3.9 3.6 9.8 6-Jan-06 6.0 4.0 3.8 9.8 7-Jan-06 5.9 4.2 3.9 9.8 8-Jan-06 6.0 4.1 4.0 9.9 9-Jan-06 5.9 4.0 4.0 10.0 10-Jan-06 5.7 4.0 3.9 9.5 11-Jan-06 5.7 3.9 3.8 9.2 138 Table D.3 (continued) Mean daily water temperature (°C) for distribution system sampling sites Date SITE 1Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' 12-Jan-06 5.5 4.0 3.8 9.1 13-Jan-06 5.7 4.1 3.8 9.3 14-Jan-06 5.8 4.1 4.0 10.1 15-Jan-06 5.7 3.9 3.8 10.7 16-Jan-06 5.6 3.4 3.3 10.7 17-Jan-06 5.2 3.3 3.1 10.2 18-Jan-06 3.6 3.3 10.1 19-Jan-06 ---- 3.4 3.2 9.9 20-Jan-06 3.3 3.1 9.6 21-Jan-06 3.3 3.0 9.8 22-Jan-06 3.2 2.9 10.2 23-Jan-06 3.2 2.9 10.5 24-Jan-06 3.5 3.2 10.1 25-Jan-06 ---- ---- 3.6 3.3 9.9 26-Jan-06 7.0 8.5 3.7 3.6 8.9 27-Jan-06 6.3 8.4 3.6 3.4 9.0 28-Jan-06 7.3 3.7 3.4 9.0 29-Jan-06 3.4 3.2 9.5 30-Jan-06 3.5 3.2 10.1 31-Jan-06 ---- 3.5 3.3 10.1 1-Feb-06 6.3 3.7 3.4 9.2 2-Feb-06 6.5 3.9 3.7 9.0 3-Feb-06 4.0 3.8 8.8 4-Feb-06 6.7 4.1 4.0 8.6 5-Feb-06 6.6 4.1 4.0 9.0 6-Feb-06 6.7 4.0 3.9 9.6 7-Feb-06 6.6 ---- 3.7 3.6 9.7 8-Feb-06 6.7 8.5 3.6 3.4 9.1 9-Feb-06 6.7 8.4 3.5 3.3 9.1 10-Feb-06 6.4 8.2 3.1 2.8 9.1 11 -Feb-06 6.5 8.2 3.1 2.8 12-Feb-06 6.1 8.5 3.2 2.9 13-Feb-06 5.8 3.3 3.1 14-Feb-06 5.9 3.2 2.9 15-Feb-06 5.8 ---- 2.9 2.6 16-Feb-06 5.8 2.5 2.2 17-Feb-06 5.5 2.1 1.7 18-Feb-06 5.4 1.7 1.3 19-Feb-06 5.0 1.7 1.3 20-Feb-06 4.9 2.1 1.5 21-Feb-06 4.9 2.4 1.9 22-Feb-06 5.0 2.6 2.2 139 Table D.3 (continued) Mean daily water temperature (°C) for distribution system sampling sites Date SITE 1Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' 23-Feb-06 5.0 2.6 2.2 24-Feb-06 5.1 2.3 1.9 - 25-Feb-06 5.1 2.0 1.6 - 26-Feb-06 5.0 2.3 1.7 27-Feb-06 5.2 ---- 2.9 2.3 ---- 28-Feb-06 5.4 7.7 3.3 3.1 8.6 1-Mar-06 5.7 7.6 3.3 2.9 8.7 2-Mar-06 5.9 3.3 3.0 8.5 3-Mar-06 5.9 3.1 2.9 9.1 4-Mar-06 5.9 3.4 3.0 10.2 5-Mar-06 5.8 3.6 3.4 9.6 6-Mar-06 5.9 3.4 3.2 9.3 7-Mar-06 6.1 3.6 3.3 9.0 8-Mar-06 5.9 3.5 3.4 8.9 9-Mar-06 6.0 3.5 3.2 9.1 10-Mar-06 6.1 3.6 3.3 9.3 11-Mar-06 6.1 3.7 3.6 10.6 12-Mar-06 6.0 3.7 3.5 10.2 13-Mar-06 6.1 3.7 3.5 10.0 14-Mar-06 6.0 4.0 3.8 15-Mar-06 6.2 4.1 3.9 16-Mar-06 6.3 4.3 4.1 17-Mar-06 6.4 4.7 4.5 18-Mar-06 6.5 4.9 4.8 19-Mar-06 6.7 4.9 4.8 20-Mar-06 6.8 4.7 4.7 21-Mar-06 6.9 5.1 4.9 22-Mar-06 6.9 ---- 5.4 5.2 23-Mar-06 7.2 5.8 5.7 24-Mar-06 7.5 6.2 6.3 25-Mar-06 7.5 5.8 5.9 26-Mar-06 7.9 5.7 5.8 27-Mar-06 7.8 6.0 6.0 28-Mar-06 7.8 5.8 5.9 29-Mar-06 8.0 ---- 6.3 6.3 30-Mar-06 7.5 6.8 6.9 31-Mar-06 7.5 6.9 7.2 Notes: 1 Science Building Room S237 Bold value indicates mean calculated based on values from partial day ---- indicates no data available due to data logger malfunction Stage B of distribution system upgrade begins January 12, 2006 Daily mean temperature values based on average of 5 minute values 140 Table D.4 Summary of mean daily water temperature (°C) during sampling events (mean values presented are mean ± standard deviation) Daily Mean Temperature [°C] Sampling Event Date SITE 1 Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' STAGE A 1 31-Oct-05 11.7 14.7 9.8 10.7 16.4 2 9-Nov-05 9.9 13.6 8.3 9.2 15.1 3 23-Nov-05 7.9 12.3 6.8 7.3 13.7 4 5-Dec-05 3.6 10.3 3.0 2.8 12.2 5 14-Dec-05 3.3 9.6 2.5 2.4 10.5 Mean 7.3±3.7 12.1±2.2 6.1±3.2 6.5±3.8 13.6±2.3 STAGE B 6 24-Jan-06 no data no data 3.5 3.2 10.1 7 06-Feb-06 6.6 no data 3.7 3.6 9.7 8 28-Feb-06 5.4 7.7 3.3 3.1 8.6 9 06-Mar-15 6.2 no data 4.1 3.9 no data 10 27-Mar-06 7.8 no data 6.0 6.0 no data Mean 6.5±1.0 7.7 4.1±1.1 4.0±1.2 9.4±0.8 Notes: 1 Science Building Room S237 Daily mean temperature values based on average of 5 minute values "No data" indicates data were not available due to data logger malfunction 141 Table D.5 Mean daily free chlorine concentrations (mg/L) for distribution system sampling sites Date SITE 1Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' 20-Oct-05 1.0 0.0 n/a 1.3 0.4 21-Oct-05 1.2 0.1 n/a 1.5 0.5 22-Oct-05 1.3 0.0 n/a 1.5 0.6 23-Oct-05 1.3 0.0 n/a 1.4 0.5 24-Oct-05 1.2 0.0 n/a 1.3 0.5 25-Oct-05 1.2 0.1 n/a 1.3 0.8 26-Oct-05 1.3 0.1 n/a 1.3 0.7 27-Oct-05 1.3 0.1 n/a 1.3 0.9 28-Oct-05 1.3 0.1 n/a 1.3 1.0 29-Oct-05 1.4 0.1 n/a 1.4 0.8 30-Oct-05 1.4 0.1 n/a 1.3 0.6 31-Oct-05 1.4 0.1 n/a 1.3 0.6 1-Nov-05 1.2 0.1 n/a 1.4 0.7 2-Nov-05 1.1 0.1 n/a 1.3 0.9 3-Nov-05 1.2 0.1 n/a 1.4 0.6 4-Nov-05 1.3 0.1 n/a 1.5 0.8 5-Nov-05 1.5 0.1 n/a 1.4 0.8 6-Nov-05 1.5 0.1 n/a 1.4 0.5 7-Nov-05 1.4 0.2 n/a 1.4 0.5 8-Nov-05 1.5 0.2 n/a 1.5 0.7 9-Nov-05 1.3 0.2 n/a 1.5 0.6 10-Nov-05 1.4 n/a 1.5 0.7 11-Nov-05 1.3 n/a 1.4 0.6 12-Nov-05 1.2 n/a 1.4 0.6 13-Nov-05 1.2 n/a 1.4 0.6 14-Nov-05 1.2 n/a 1.4 0.6 15-Nov-05 1.2 n/a 1.3 0.7 16-Nov-05 1.2 n/a 1.5 0.7 17-Nov-05 1.2 n/a 1.4 0.9 18-Nov-05 0.9 n/a 1.4 0.9 19-Nov-05 0.8 n/a 1.3 0.8 20-Nov-05 0.9 n/a 1.3 0.7 21-Nov-05 0.9 n/a 1.2 0.6 22-Nov-05 0.9 0.3 n/a 1.3 0.8 23-Nov-05 0.9 0.3 n/a 1.2 0.7 24-Nov-05 0.9 0.2 n/a 1.3 0.5 25-Nov-05 1.2 0.2 n/a 1.3 0.6 26-Nov-05 1.3 0.2 n/a 1.3 0.7 27-Nov-05 1.2 0.2 n/a 1.3 0.6 28-Nov-05 1.2 0.2 n/a 1.4 0.8 29-Nov-05 1.1 0.2 n/a 1.3 0.9 142 Table D.5 (continued) Mean daily free chlorine concentrations (mg/L) for distribution system sampling sites Date SITE 1 Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' 30-Nov-05 1.1 0.2 n/a 1.3 0.7 1-Dec-05 1.1 0.2 n/a 1.2 0.8 2-Dec-05 1.2 0.2 n/a 1.2 0.7 3-Dec-05 1.3 0.2 n/a 1.4 0.7 4-Dec-05 1.2 0.2 n/a 1.2 0.6 5-Dec-05 1.2 0.2 n/a 1.3 0.7 6-Dec-05 1.2 0.2 n/a 1.3 1.0 7-Dec-05 1.2 0.3 n/a 1.2 0.6 8-Dec-05 1.2 0.3 n/a 1.3 0.9 9-Dec-05 1.3 0.3 n/a 1.4 1.0 10-Dec-05 1.4 0.3 n/a 1.4 0.7 11-Dec-05 1.3 0.3 n/a 1.4 0.7 12-Dec-05 1.3 0.3 n/a 1.4 0.7 13-Dec-05 1.3 0.3 n/a 1.5 0.9 14-Dec-05 1.3 0.3 n/a 1.6 1.0 15-Dec-05 1.3 0.3 n/a 1.5 1.1 16-Dec-05 1.3 0.3 n/a 1.6 0.9 17-Dec-05 1.3 0.3 n/a 1.4 0.9 18-Dec-05 1.3 0.3 n/a 1.3 0.9 19-Dec-05 1.3 0.4 n/a 1.2 1.0 20-Dec-05 1.3 0.4 n/a 1.4 1.0 21-Dec-05 1.2 0.4 n/a 1.3 0.9 22-Dec-05 1.2 0.4 n/a 1.3 1.1 23-Dec-05 1.3 0.4 n/a 1.2 1.0 24-Dec-05 1.3 n/a 1.2 1.3 25-Dec-05 1.3 n/a 1.0 1.1 26-Dec-05 1.3 n/a 1.3 1.2 27-Dec-05 1.3 n/a 1.1 1.1 28-Dec-05 1.3 n/a 1.2 1.1 29-Dec-05 1.3 n/a 1.2 1.0 30-Dec-05 1.3 n/a 1.3 0.9 31-Dec-05 1.3 n/a 1.2 1.1 1-Jan-06 1.3 n/a 1.2 0.9 2-Jan-06 1.3 n/a 1.2 0.8 3-Jan-06 1.3 n/a 1.2 0.9 4-Jan-06 1.5 n/a 1.2 0.9 5-Jan-06 1.2 n/a 1.2 0.9 6-Jan-06 1.0 n/a 1.1 1.1 7-Jan-06 0.8 n/a 1.1 0.9 8-Jan-06 0.8 n/a 1.1 1.0 9-Jan-06 0.8 n/a 1.2 1.0 143 Table D.5 (continued) Mean daily free chlorine concentrations (mg/L) for distribution system sampling sites Date SITE 1Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' 10-Jan-06 0.7 n/a 1.2 1.0 11-Jan-06 0.7 n/a 1.2 0.9 12-Jan-06 0.8 n/a 1.2 1.0 13-Jan-06 0.8 n/a 1.2 0.8 14-Jan-06 0.8 n/a 1.1 0.6 15-Jan-06 0.8 n/a 1.1 0.5 16-Jan-06 0.8 n/a 1.1 0.5 17-Jan-06 0.8 n/a 1.1 0.6 18-Jan-06 0.8 n/a 1.1 0.6 19-Jan-06 0.8 n/a 1.2 0.7 20-Jan-06 0.8 n/a 1.1 0.5 21-Jan-06 0.8 n/a 1.1 0.7 22-Jan-06 0.8 n/a 1.2 0.5 23-Jan-06 0.8 n/a 1.3 0.5 24-Jan-06 0.9 n/a 1.2 0.6 25-Jan-06 0.8 n/a 1.2 0.5 26-Jan-06 0.9 0.4 n/a 1.2 0.6 27-Jan-06 0.9 0.4 n/a 1.2 0.6 28-Jan-06 0.9 n/a 1.2 0.7 29-Jan-06 0.8 n/a 1.2 0.6 30-Jan-06 0.9 n/a 1.3 0.5 31-Jan-06 0.9 n/a 1.2 0.5 1-Feb-06 0.8 n/a 1.2 0.6 2-Feb-06 0.9 n/a 1.2 0.5 3-Feb-06 0.9 n/a 1.2 0.7 4-Feb-06 0.9 n/a 1.1 0.6 5-Feb-06 0.8 n/a 1.0 0.8 6-Feb-06 0.8 n/a 1.1 0.6 7-Feb-06 0.8 ---- n/a 1.1 0.6 8-Feb-06 0.8 0.5 n/a 1.1 0.7 9-Feb-06 0.8 0.5 n/a 1.0 0.7 10-Feb-06 0.8 0.5 n/a 1.0 0.6 11-Feb-06 0.8 0.5 n/a 1.1 12-Feb-06 0.8 0.5 n/a 1.0 13-Feb-06 0.7 n/a 1.0 14-Feb-06 0.8 n/a 1.0 15-Feb-06 0.7 n/a 1.1 16-Feb-06 0.7 n/a 1.1 17-Feb-06 0.8 n/a 1.1 18-Feb-06 0.8 n/a 1.1 19-Feb-06 0.8 n/a 1.1 144 Table D.5 (continued) Mean daily free chlorine concentrations (mg/L) for distribution system sampling sites Date SITE 1Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' 20-Feb-06 0.8 n/a 1.1 21-Feb-06 0.8 n/a 1.1 22-Feb-06 0.8 n/a 1.1 23-Feb-06 0.8 n/a 1.4 24-Feb-06 0.9 n/a 1.4 25-Feb-06 0.9 n/a 1.3 26-Feb-06 0.9 n/a 1.4 27-Feb-06 0.9 n/a 1.4 28-Feb-06 1.0 0.7 n/a 1.2 0.5 1-Mar-06 0.9 0.7 n/a 1.1 0.4 2-Mar-06 0.9 n/a 1.2 0.4 3-Mar-06 0.8 n/a 1.2 0.5 4-Mar-06 0.9 n/a 1.2 0.3 5-Mar-06 0.8 n/a 1.1 0.3 6-Mar-06 0.8 n/a 1.2 0.3 7-Mar-06 0.9 n/a 1.2 0.3 8-Mar-06 0.8 n/a 1.1 0.4 9-Mar-06 0.8 n/a 1.1 0.7 10-Mar-06 0.8 n/a 1.1 0.3 11-Mar-06 0.8 n/a 1.1 0.5 12-Mar-06 0.8 n/a 1.1 0.3 13-Mar-06 0.8 n/a 1.0 0.3 14-Mar-06 0.7 n/a 1.1 15-Mar-06 0.8 n/a 1.1 16-Mar-06 0.8 n/a 1.1 17-Mar-06 0.8 n/a 1.1 18-Mar-06 0.8 n/a 1.1 19-Mar-06 0.8 n/a 1.1 20-Mar-06 0.8 n/a 1.1 21-Mar-06 0.8 n/a 1.1 22-Mar-06 0.8 n/a 1.2 23-Mar-06 0.8 n/a 1.1 24-Mar-06 0.7 n/a 1.3 25-Mar-06 0.8 n/a 1.3 26-Mar-06 0.9 n/a 1.2 27-Mar-06 0.9 n/a 1.2 28-Mar-06 0.8 n/a 1.2 29-Mar-06 0.9 n/a 1.2 30-Mar-06 0.9 n/a 1.2 31-Mar-06 0.9 n/a 1.2 145 Notes: 'Science Building Room S237 Bold value indicates mean calculated based on values from partial day ---- indicates no data available due to data logger malfunction Stage B of distribution system upgrade begins January 12, 2006 "n/a" indicates measurement "not applicable" to sampling site Daily mean chlorine concentration values based on average of 5 minute values Table D.6 Summary of mean daily chlorine concentrations (mg/L) during sampling events (mean values presented are mean ± standard deviation) Sampling Event Daily Mean Chlorine Concentration [mg/L] Date SITE 1 Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' STAGE A 1 31-Oct-05 1.4 0.1 n/a 1.3 0.6 2 9-Nov-05 1.3 0.2 n/a 1.5 0.6 3 23-Nov-05 0.9 0.3 n/a 1.2 0.7 4 5-Dec-05 1.2 0.2 n/a 1.3 0.7 5 14-Dec-05 1.3 0.3 n/a 1.6 1.0 Mean 1.2±0.2 0.2±0.1 1.4±0.1 0.7±0.2 STAGE B 6 24-Jan-06 0.9 no data n/a 1.2 0.6 7 06-Feb-06 0.8 no data n/a 1.1 0.6 8 28-Feb-06 1.0 0.7 n/a 1.2 0.5 9 06-Mar-15 0.8 no data n/a 1.1 no data 10 27-Mar-06 0.9 no data n/a 1.2 no data Mean 0.9±0.1 ---- 1.2±0.1 0.6±0.1 Notes: 1Science Building Room S237 Daily mean temperature values based on average of 5 minute values "No data" indicates data were not available due to data logger malfunction "n/a" indicates measurement "not applicable" to sampling site 146 Table D.7 TOC concentrations for distribution system sampling sites TOC Concentration [mg/L] Sampling^ SITE 5Date^ SITE 2^ SITE 4Event SITE 1^ SITE 3^ ThompsonBlackwell MembraneDallas Intake Booster PermeateRaw Water Rivers University' STAGE A 1 31-Oct-05 3.2 2.4 2.3 1.9 1.9 2 9-Nov-05 2.4 3.1 2.4 1.7 1.8 3 23-Nov-05 1.2 1.1 1.1 1.0 0.8 4 5-Dec-05 0.9 1.0 1.1 0.8 0.9 5 14-Dec-05 0.9 1.8 1.2 1.0 1.0 Mean 1.7±1.0 1.9±0.9 1.6±0.7 1.3±0.5 1.3±0.5 STAGE B 6 24-Jan-06 ---- 1.5 1.8 1.4 1.4 7 7-Feb-06 1.3 1.4 1.6 1.4 1.6 8 28-Feb-06 1.7 1.7 1.7 2.0 1.5 9 15-Mar-06 1.3 1.3 1.8 1.8 1.3 10 27-Mar-06 1.2 1.3 1.6 1.3 1.2 Mean 1.4±0.2 1.4±0.2 1.7±0.1 1.6±0.3 1.4±0.1 Notes: 1 Science Building Room S237 ---- indicates no data available 147 Table D.8 UV254 absorbance values for distribution system sampling sites UV254 Absorbance [cm - '] Sampling Event Date SITE 1Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' STAGE A 1 31-Oct-05 0.028 0.033 0.043 0.020 0.019 2 9-Nov-05 0.021 0.026 0.034 0.011 0.018 3 23-Nov-05 0.027 0.025 0.034 0.014 0.020 4 5-Dec-05 0.027 0.028 0.034 0.017 0.027 5 14-Dec-05 0.029 0.028 0.029 0.014 0.019 Mean 0.026±0.003 0.028±0.003 0.035±0.005 0.015±0.003 0.021±0.004 STAGE B 6 24-Jan-06 0.018 0.021 0.037 0.018 0.020 7 7-Feb-06 0.018 0.030 0.018 0.028 8 28-Feb-06 0.024 0.023 0.034 0.008 0.014 9 15-Mar-06 0.024 0.025 0.042 0.021 0.030 10 27-Mar-06 0.018 0.020 0.039 0.023 0.026 Mean 0.020±0.003 0.022±0.007 0.036±0.005 0.018±0.006 0.024±0.006 Notes: 1 Science Building Room S237 ---- indicates no data available Table D.9 SUVA values for distribution system sampling sites SUVA [L/mg-m] Sampling^ SITE 5Date^SITE 1^SITE 2^ SITE 4Event SITE 3^ThompsonDallas^Blackwell MembraneRaw Water RiversIntake Booster Permeate University' STAGE A 1 31-Oct-05 0.9 1.4 1.8 1.0 1.0 2 9-Nov-05 0.9 0.8 1.4 0.6 1.0 3 23-Nov-05 2.3 2.4 3.0 1.4 2.4 4 5-Dec-05 2.9 2.8 3.2 2.1 3.0 5 14-Dec-05 3.0 1.6 2.4 1.4 2.0 Mean 2.0±1.0 1.8±0.8 2.4±0.7 1.3±0.5 1.9±0.9 STAGE B 6 24-Jan-06 ---- 1.4 2.0 1.3 1.4 7 7-Feb-06 1.4 ---- 1.8 1.3 1.8 8 28-Feb-06 1.4 1.3 2.0 0.4 1.0 9 15-Mar-06 1.9 1.9 2.4 1.2 2.2 10 27-Mar-06 1.5 1.6 2.4 1.7 2.1 Mean 1.6±0.2 1.6±0.3 2.1±0.2 1.2±0.5 1.7±0.5 Notes: 1 Science Building Room S237 ---- indicates no data available 148 Table D.10 THM (measured as chloroform) concentrations for distribution system sampling sites Sampling Event THM Concentration (µg/L] Date SITE 1 Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water SITE 4 Membrane Permeate SITE 5 Thompson Rivers University' STAGE A 1 31-Oct-05 18 37 nd 10 30 2 9-Nov-05 23 49 nd 13 55 3 23-Nov-05 17 50 nd 12 35 4 5-Dec-05 17 46 nd 11 47 5 14-Dec-05 5 28 nd 5 21 Mean 16±7 42+9 nd 10±3 38±14 STAGE B 6 24-Jan-06 20 28 nd 9 22 7 7-Feb-06 28 40 nd 16 31 8 28-Feb-06 22 34 nd 10 26 9 15-Mar-06 25 30 nd 11 28 10 27-Mar-06 30 47 nd 17 35 Mean 25±4 36±8 nd 13±4 28±5 Notes: 'Science Building Room S237 "nd" indicates non detect, values were below the MDL; MDL (chloroform) = 3 l_tg/L 149 Table D.11 HAA3 concentrations (ig/L) for distribution system sampling sites Sampling Event Date SITE 1 Dallas Intake SITE 2 Blackwell Booster SITE 3 Raw Water MCAA DCAA TCAA HAA3 MCAA DCAA TCAA HAA3 MCAA DCAA TCAA HAA3 Stage A 1 31-Oct- nd 48 29 77 nd 14 79 93 nd nd nd nd 05 2 9-Nov- nd 23 12 35 nd 10 53 64 nd nd nd nd 05 3 23- nd 31 16 46 nd 14 73 87 nd nd nd nd Nov-05 4 5-Dec- nd 33 20 53 nd 68 nd nd nd nd 05 5 14- nd 17 8 25 nd 33 78 111 nd nd nd nd Dec-05 Mean nd 30+12 17+8 47+20 nd 18±10 70±10 89+19 nd nd nd nd Stage B 6 24-Jan- nd 30 28 58 nd 49 59 107 nd nd nd nd 06 7 7-Feb- nd 32 37 69 nd 48 67 115 nd nd nd nd 06 8 28-Feb- nd 26 35 62 nd 38 50 88 nd nd nd nd 06 9 15- nd 32 45 76 nd 45 64 109 nd nd nd nd Mar-06 10 27- nd 27 32 59 nd 44 62 106 nd nd nd nd Mar-06 Mean nd 29+3 36+6 65+8 nd 45+4 60+7 105+10 nd nd nd nd Table D.11 (continued) HAM concentrations (lga) for distribution system sampling sites Sampling Event Date SITE 4 Membrane Permeate Water SITE 5 Thompson Rivers University) MCAA DCAA TCAA HAA3 MCAA DCAA TCAA HAA3 Stage A 1 31-Oct- nd 24 11 35 nd 41 40 81 05 2 9-Nov- nd 17 10 28 nd 46 26 72 05 3 23- nd 14 6 20 nd 49 31 80 Nov-05 4 5-Dec- nd 15 7 23 nd 38 05 5 14-Dec- nd 10 5 15 nd 31 24 55 05 Mean nd 16+5 8+3 24+8 nd 42+8 32+7 72+12 Stage B ---- 5 3 8 ---- 8 7 12 6 24-Jan- nd 17 8 25 nd 34 34 68 06 7 7-Feb- nd 20 14 34 nd 37 38 75 06 8 28-Feb- nd 13 7 20 nd 27 30 57 06 9 15-Mar- nd 15 11 26 nd 27 46 74 06 10 27-Mar- nd 16 nd 50 46 96 06 Mean nd 16+3 11+4 26+6 nd 35±10 39±7 74+14 Notes: 1 Science Building Room S237 "nd" indicates non detect, values below the MDL; MDL (MCAA) = 4 t.i,g/L, MDL (DCAA) = 2 pg/L, MDL (TCAA) = 1 pg/L; however, HAA peak areas could not be determined reliably from chromatograms for concentrations less than 5 tg/L Appendix E. Statistical Analyses for Phase I: Distribution System Monitoring The statistical analyses for each parameter are based on a pair-wise comparison (95% confidence level) of data obtained from continuous monitoring during five sampling events before (Stage A) and five sampling events after (Stage B) connection of the southeast section of the distribution system to southwest section of the distribution system. Distribution System Conditions Distribution system conditions were characterized using pH, temperature, and free chlorine concentrations. As discussed in Section 2.2.3, pH, temperature, and chlorine concentrations affect DBP formation in distribution systems (Baribeau et al., 2006; Xie, 2004; Singer et al., 2002). A summary of the pair-wise comparisons for pH, temperature, and free chlorine concentrations are presented in Table E.1. 152 Table E.1 Pair-wise comparisons for distribution system conditions during Stage A and Stage B Pair-Wise Comparison* Statistically Significant Difference? pH Temperature Chlorine Conc. Stage A Stage B Stage A Stage B Stage A Stage B SW Site 3 vs. Site 4 L L N N L L Site 4 vs. Site 5 H H L L H H SW Site 3 vs. Site 4 L L N N L L Site 4 vs. Site 5 H H L L H H SE Site 3 vs. Site 1 N NA L L L L Site 1 vs. Site 2 H NA L NA H NA SW & SE Site 4 vs. Site 1 H NA L L N H Site 5 vs. Site 2 H NA H NA H NA SE Site 1 vs. Site 2 H NA L NA H NA Question of Interest a) Was the source water similar during Stage A and Stage B? b) Did water quality change within each section of the distribution system? c) Was water quality similar between each section of the distribution system? d) Was water quality similar in the southeast section of the distribution system during Stage A and Stage B? *Pair-wise comparisons were performed at 95% confidence level SW = Southwest section of the distribution system (Site 4 and Site 5); SE = Southeast section of the distribution system (Site 1 and Site 2); L = parameter value is statistically significantly lower at 95% confidence level; H = parameter value is statistically significantly higher at 95% confidence level; N = parameter value is not statistically significantly different at 95% confidence level; NA = no analysis, data not available due to malfunction of data logger. Concentration and Characteristics of Organic Material in South Thompson River Water The nature of the NOM in the South Thompson River source water was characterized using TOC concentrations, UV254 and SUVA values. Organic material in raw water is the precursor to the formation of DBPs and the aromaticity of organic material is considered to be an indicator of the tendency for organic material to form DBPs (Kids et al., 2001; Li et al., 2000; Najm et al., 1994). TOC measurements were used to determine the concentration of organic material in the water, while UV254 measurements and SUVA were used to determine 153 the aromaticity of the organic material in the water (Croue et al., 2000). A summary of the pair-wise comparisons for TOC concentrations, UV254, and SUVA values are presented in Table E.2. Table E.2 Pair-wise comparisons for concentration and characteristics of NOM in South Thompson River water during Stage A and Stage B Statistically Significant Difference? Question of Interest a) Was the source water similar during Stage A and Stage B? b) Did water quality change within each section of the distribution system? c) Was water quality similar between each section of the distribution system? Pair-Wise Comparison* TOC UV254 SUVA Stage A Stage B Stage A Stage B Stage A Stage B SW Site 3 to Site 4 H N H H H H Site 4 to Site 5 N N L L L L SW Site 3 vs. Site 4 H N H H H H Site 4 vs. Site 5 N N L L L L SE Site 3 vs. Site 1 N N H H N H Site 1 vs. Site 2 N N N N N N SW & SE Site 4 vs. Site 1 N N L N N N Site 5 vs. Site 2 L N L N N N d) Was water^SE quality similar in^Site 1 vs. Site 2 the southeast section of the distribution system during Stage A and Stage B? *Pair-wise comparisons were performed at 95% confidence level SW = Southwest section of the distribution system (Site 4 and Site 5); SE = Southeast section of the distribution system (Site 1 and Site 2); L = parameter value is statistically significantly lower at 95% confidence level; H = parameter value is statistically significantly higher at 95% confidence level; N = parameter value is not statistically significantly different at 95% confidence level 154 Appendix F. Raw Data for Phase II: Bench-Scale Simulations Table F.1 pH, temperature, and free chlorine concentrations for 12 hour experimental period for MS-SDS test and in-situ SDS tests (values presented are mean ± standard deviation) MS-SDS Test^ SDS Test Water Stream Temperature^Free^ Temperature*^Free ^ pHChlone pH*^ Chlorine*[° CI^ Chlorine r CI[mg/LI [mg/LI Raw Water 0 hours 7.8±0.3 22±1 0.9±0.1 7.8±0.3 20±2 0.9±0.1 3 hours 7.8±0.3 23±1 0.4±0.1 7.9±0.2 20±1 0.4±0.2 12 hours 7.9±0.2 21±1 0 7.9±0.2 20±1 0.2±0.1 Mean 7.8 22±1 7.9± 0.1 20 Membrane Treated Water 0 hours 7.8±0.1 20±1 0.9 7.9±0.1 20±1 1.0 3 hours 7.8±0.1 23±1 0.4±0.1 7.9±0.1 20±1 0.6±0.1 12 hours 7.7±0.4 21±1 0.0±0.1 7.9±0.1 20±1 0.5 Mean 7.8± 0.1 21±1 ---- 7.9 20 ---- Control (Non-chlorinated Water) 0 hours 7.9±0.2 23±2 0 8.0±0.1 22±2 0 3 hours 7.9±0.2 20±1 0 12 hours 7.6±0.3 21±1 0 7.9±0.1 20±1 0 Mean 7.8± 0.2 22±1 7.9 21±1 Note: Mean and standard deviation based on three sampling rounds, except where noted (*mean and standard deviation based on 4 sampling rounds) 155 Table F.2 pH, temperature, and free chlorine concentrations for 36 hour experimental period for MS-SDS test and in-situ SDS tests (values presented are mean ± standard deviation) Water Stream MS-SDS Test In-situ SDS Test TemperaturepH [° C] Free Chlorine [mg/L] pH Temperature[0 C] Free Chlorine [mg/L] Raw Water 0 hours 7.9 18 1.2 7.9 17±1 1.1 12 hours 7.9 20 0.2±0.1 7.9 17 0.4 36 hours 7.9 19 0 7.9 17 0.2±0.1 Mean 7.9 19±1 7.9 17 ---- Membrane Treated Water 0 hours 7.9 18 1.1 7.9 17 1.1±0.1 12 hours 7.9 20 0.3 7.9 17±1 0.7±0.1 36 hours 7.9±0.1 19 0 7.8±0.1 17 0.5±0.1 Mean 7.9 19±1 7.9 17 Control (Non-chlorinated Water) 0 hours 8.5±0.1 21 0 8.4±0.1 20±1 0 12 hours 8.2±0.3 17 0 36 hours 8.6 19 0 8.2±0.2 17 0 Mean 8.5±0.1 20±1 8.2 18±2 Note: Mean and standard deviation based on three sampling rounds Table F.3 TOC concentration and UV2, and SUVA values for 12 hour experimental period for MS-SDS and in-situ SDS tests (values presented are mean ± standard deviation) Water Stream TOC[mg/L] UV254 [cm-1] SUVA [L/mg-m] Raw Water (MS-SDS) 0 hours 2.0 0.033±0.001 1.7±0.1 3 hours 2.0±0.1 0.058±0.002 2.9 12 hours 1.9±0.2 0.118±0.007 6.3±0.6 Raw Water (in -situ SDS) 0 hours 2.3 0.037±0.003 1.6±0.1 Membrane Treated Water 0 hours 1.6±0.1 0.023±0.003 1.4±0.2 3 hours 1.6 0.052±0.004 3.2±0.2 12 hours 1.6±0.2 0.105±0.007 6.5±0.6 Control (Non-chlorinated Water) 0 hours 0.3±0.1 0.002±0.003 1.0±1.2 12 hours 0.4±0.1 0.005±0.002 1.3±0.7 Note: Mean and standard deviation based on three sampling rounds 156 Table F.4 TOC concentration and UV2m and SUVA values for 36 hour experimental period for MS-SDS and^SDS tests (values presented are mean ± standard deviation) Water Stream TOC[mg/L] UV254 SUVA [L/mg-m] Raw Water (MS-SDS) 0 hours 1.9±0.1 0.030±0.001 1.6±0.1 12 hours 1.8 0.087±0.009 4.7±0.5 36 hours 1.6±0.1 0.098±0.020 5.9±1.3 Raw Water (in -situ SDS) 0 hours 2.0±0.2 0.036±0.008 1.9±0.5 Membrane Treated Water 0 hours 1.6±0.1 0.022 1.4±0.1 12 hours 1.5±0.1 0.080±0.012 5.3±0.9 36 hours 1.4±0.1 0.079±0.020 5.5±1.4 Control (Non-chlorinated Water) 0 hours 0.2 0.004±0.003 2.0±1.4 36 hours 0.4±0.1 0.010±0.005 2.5±1.1 Note: Mean and standard deviation based on three sampling rounds Table F.5 THM concentrations for 12 hour experimental period for MS-SDS test and in-situ SDS tests (values presented are mean ± standard deviation) MS-SDS Test In-situ SDS Test Water Stream THM [Aga] THM [gg/L] Raw Water 0 hours 3 hours 12 hours 16±1 28±5 39+5 17+5 27±4 46±15 Membrane Treated Water 0 hours 18+3 19+4 3 hours 30±7 34±10 12 hours 34±5 33±6 Control (Non -chlorinated Water) 0 hours nd nd 3 hours nd 12 hours nd nd Note: Mean and standard deviation based on 4 sampling rounds "nd" indicates non detect, values below the MDL; MDL = 3 .tg/L 157 Table F.6 THM concentrations for 36 hour experimental period for MS-SDS test and in-situ SDS tests (values presented are mean ± standard deviation) MS-SDS Test SDS Test Water Stream THM [gg/1..] THM [Aga] Raw Water 0 hours 17+2 15+6 12 hours 34+3 47+12 36 hours 35±2 48+9 Membrane Treated Water 0 hours 19+2 20±3 12 hours 36±2 39+4 36 hours 35+2 45+2 Control (Non-chlorinated Water) 0 hours nd nd 12 hours nd 36 hours nd nd Note: Mean and standard deviation based on three sampling rounds "nd" indicates non detect, values below the MDL; MDL = 3 pg/L Table F.7 HAA concentrations for 12 hour experimental period for MS-SDS test and in-situ SDS tests (values presented are mean ± standard deviation) Water Stream MS-SDS Test SDS Test MCAA [Ag/L] DCAA [tg/L] TCAA Dig/L] HAA3 [ig/L] MCAA lug/Li DCAA [ttg/L] TCAA [gg/1..] HAA3 bag/LI Raw Water 0 hours nd 31±3 19±2 51±5 nd 26±3 16±4 42+7 3 hours nd 39±6 25±5 65±10 nd 47±1 41±4 90±6 12 hours nd 27±3 36±5 64+9 nd 60±4 54±9 117+12 Membrane Treated Water 0 hours nd 26±5 21±6 47±10 nd 28±5 22±5 51+11 3 hours nd 35±2 29±5 64+6 nd 40±4 38±5 80±10 12 hours nd 24±2 35±3 58±4 nd 52±12 44±7 99+23 Control (Non-chlorinated Water) 0 hours nd nd nd nd nd nd nd nd 3 hours ---- ---- nd nd nd ---- 12 hours nd nd nd nd nd nd nd nd Note: Mean and standard deviation based on 4 sampling rounds "nd" indicates non detect, values below the MDL; MDL (MCAA) = 4 ug/L, MDL (DCAA) = 2^MDL (TCAA) = 1 i.tg/L; however, HAA peak areas could not be determined reliably from chromatograms for concentrations less than 5 i.ig/L 158 Table F.8 HAA concentrations for 36 hour experimental period for MS-SDS test and in-situ SDS tests (values presented are mean ± standard deviation) MS-SDS Test In-situ SDS Test Water MCAAStream [ug/1.1 DCAA [ug/L] TCAA [ug/L1 HAA3 [ug/LI MCAA Rig/L1 DCAA [pig/LI TCAA [gg/L] HAA3 [ug/L] Raw Water 0 hours^rid 27±2 15±2 43+4 rid 24±2 11±3 36+5 12 hours^rid 7±2 24±4 32±6 rid 54±3 44±5 100±8 36 hours^nd nd 13±2 15±2 nd 63±2 42±3 108±4 Membrane Treated Water 0 hours^nd 23±1 16±2 39±3 nd 27±5 18±6 44+10 12 hours^nd 7±4 20±5 27+7 nd 44±2 35±2 80±5 36 hours^nd rid 23±3 25+3 nd 56±5 39±5 98±12 Control (Non-chlorinated Water) 0 hours^rid nd nd nd rid rid rid nd 12 hours^---- ---- ---- ---- rid rid rid rid 36 hours^rid rid nd rid rid rid rid rid Note: Mean and standard deviation based on three sampling rounds "rid" indicates non detect, values below the MDL; MDL (MCAA) = 4 pg/L, MDL (DCAA) = 2 tg/L, MDL (TCAA) = 11.1,g/L; however, HAA peak areas could not be determined reliably from chromatograms for concentrations less than 5 tg/L Table F.9 pH, temperature, and free chlorine concentration at end of 12 hour experimental period for standard SDS test (values presented are mean ± standard deviation) Water Stream pH Temperature [° C] Free Chlorine [mg/LI Raw Water 0 hours 7.1 15±2 4.7±0.5 3 hours 7.2 25 4.4±0.4 12 hours 7.1 25 4.1±0.6 Mean 7.1 21±6 4.4± 0.3 Membrane Treated Water 0 hours 7.2 15±3 5.0±0.2 3 hours 7.1 25 4.6±0.3 12 hours 7.1±0.1 24±1 4.3±0.4 Mean 7.1 21±6 4.6± 0.4 Control (Non-chlorinated Water) 0 hours 7.1±0.1 21 0 3 hours 7.2 25 0 12 hours 7.2 25 0 Mean 7.1 23± 2 0 Note: Mean and standard deviation based on three sampling rounds; 0 hours samples not incubated to 25°C 159 Table F.10 pH, temperature, and free chlorine concentration at end of 36 hour experimental period for standard SDS test (values presented are mean ± standard deviation) Water Stream pH Temperature [°C] Free Chlorine [mg/L] Raw Water 0 hours 7.2 19±2 5.5 12 hours 7.2 25 4.5 36 hours 7.2 25 3.9±0.1 Mean 7.2 23±4 4.6±0.8 Membrane Treated Water 0 hours 7.2 19±2 5.0 12 hours 7.2 25 4.1±0.1 36 hours 7.2 25 3.7±0.3 Mean 7.2 23±4 4.3±0.7 Control (Non-chlorinated Water) 0 hours 7.3 23±1 0 12 hours 7.3±0.1 25 0 36 hours 7.3 25 0 Mean 7.3 24±1 0 Note: Mean and standard deviation based on three sampling rounds; 0 hours samples not incubated to 25°C Table F.11 TOC concentration and UV254 and SUVA values for 12 hour experimental period for standard SDS test (values presented are mean ± standard deviation) Water Stream TOC[mg/L] UV254 [cm-1] SUVA [L/mg-m] Raw Water 1.8±0.1 0.037±0.008 2.1±0.4 Membrane Treated 1.4±0.1 0.023±0.001 1.6±0.1 Control (Non- chlorinated water) 0.2 0.004±0.003 2.1±1.7 Note: Mean and standard deviation based on three sampling rounds; Values presented are for 0 hour samples only. Water quality assumed to remain same for duration of the standard SDS test. 160 Table F.12 TOC concentration and UV254 and SUVA values for 36 hour experimental period for standard SDS test (values presented are mean ± standard deviation) Water Stream TOC [mg/L] UV254 [cm-'] SUVA [L/mg-m] Raw Water 1.9±0.1 0.034±0.002 1.8±0.2 Membrane Treated 1.5 0.030±0.004 2.0±0.3 Control (Non- chlorinated water) 0.2 0.002±0.003 1.5±2.2 Note: Mean and standard deviation based on three sampling rounds; Values presented are for 0 hour samples only. Water quality assumed to remain same for duration of the standard SDS test. Table F.13 THM and HAA concentrations for 12 hour experimental period for standard SDS tests (values presented are mean ± standard deviation) Water Stream THM [pig/L] HAA [p.tg/L] MCAA DCAA TCAA HAA3 Raw Water 0 hours 3 hours 12 hours 14+3 38±4 62+6 14+1 12+2 12±2 34+1 54±3 73±7 27±3 113±12 154±18 75+5 180±13 240±22 Membrane Treated Water 0 hours 16±11 14+2 33+11 23±6 67±18 3 hours 33+4 15±2 50+17 70±11 135±10 12 hours 47±6 10+1 55+3 118±20 191±11 Control (Non -chlorinated Water) 0 hours nd nd nd nd nd 3 hours nd nd nd nd nd 12 hours nd nd nd nd nd Note: Mean and standard deviation based on three sampling rounds "nd" indicates non detect, values below the MDL; MDL (chloroform)= 3 µg/L; MDL (MCAA) = 4µg/L, MDL (DCAA) = 2 1.ig/L, MDL (TCAA) = 1 .1.g/L; however, HAA peak areas could not be determined reliably from chromatograms for concentrations less than 5 p.g/L 161 Table F.14 THM and HAA concentrations for 36 hour experimental period for standard SDS tests (values presented are mean ± standard deviation) Water Stream THM[ng/1..] HAA [ng/L] MCAA DCAA TCAA HAA3 Raw Water 0 hours 13+2 12+4 33±12 31+3 74±20 12 hours 42+5 12+1 79+2 163±7 254±9 36 hours 58+5 13+1 115±6 218±12 346±17 Membrane Treated Water 0 hours 12+2 9+3 28±10 25+3 62+15 12 hours 31+6 11+1 61+1 107+6 179+6 36 hours 46+4 10+1 83±3 137±5 230±4 Control (Non-chlorinated Water) 0 hours nd nd nd nd nd 12 hours nd nd nd nd nd 36 hours nd nd nd nd nd Note: Mean and standard deviation based on three sampling rounds "nd" indicates non detect, values below the MDL; MDL (chloroform)= 3 ug/L; MDL (MCAA) = 4 ug/L, MDL (DCAA) = 2 ug/L, MDL (TCAA) = 1 ug/L; however, HAA peak areas could not be determined reliably from chromatograms for concentrations less than 5 ug/L 162 Appendix G. Statement of Publication The research, data analysis, and manuscript preparation for this work was performed by the author. The co-authors of this work, Dr. Pierre Berube, Dr. Sharon Brewer, and Mr. Wade Archambault, provided assistance with the design of the research program, critiques of manuscripts submitted for publication, and review of the work presented herein. In addition to the co-authors, Mr. Jim Atwater and Ms. Margaret Parsotan reviewed the work presented herein; however, the final work presented was the responsibility of the author. Portions of Chapter 2, Chapter 5, and Chapter 6 have been published in the following: Bush, K. L., Berube, P. R., Archambault, W. R., Brewer, S. E. 2007. Assessment of drinking water quality in Kamloops, British Columbia following a treatment technology upgrade. Proceedings of the Canadian Water and Wastewater Association 12 th Canadian National Conference and 3 rd Policy Forum, St. John, NB, April 1-4, 2006. Bush, K. L., Berube, P. R., Archambault, W. R., Brewer, S. E. 2006. Investigation of disinfection by-product formation kinetics using a material-specific flow-through reactor system. Proceedings of the American Water Works Association Water Quality Technology Conference & Exposition, Denver, CO, November 5-9, 2006. Copyright © 2006, American Water Works Association. All rights reserved. 163

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