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ARCHIVED - National Survey Of Chlorinated Disinfection By-Products In Canadian Drinking Water

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Environmental Health Directorate
Health Canada
1995
ISBN: 0-662-24295-5
Cat. No.: H46-2/95-197E

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Table of Contents

Appendices

Figures

  • Figure 1. Distribution of facilities based on TTHM levels
  • Figure 2. Distribution of facilities based on DCAA levels
  • Figure 3. Distribution of facilities based on TCAA levels
  • Figure 4. Distribution of facilities based on CH levels
  • Figure 5. DBP % Speciation in presence of bromide ion

Tables

  • Table 1 - Sampling Locations
  • Table 2 - DBPs Analysed in 1993 National Survey
  • Table 3 - DBPs (µg/L) in Canadian Drinking Water - 1993
  • Table 4 - % THM Distribution in Drinking Water
  • Table 5 - TOX [µg Cl-/L] in Drinking Water
  • Table 6 - DBP Speciation in Drinking Water
  • Table 7 - Recoveries (%) from fortified raw water (n=14)

Summary

The study was designed to determine the concentrations of halogenated disinfection by-products in Canadian drinking water supplies where chlorine was used at some stage in the treatment process. The effects of applied disinfectants (chlorine, chloramine and ozone), seasonal variation (winter and summer) and spatial variation (treatment plant and distribution system) were examined. Trihalomethanes and haloacetic acids were the major disinfection by-products found in all facilities for all treatment processes and haloacetic acid levels often equalled or exceeded trihalomethane concentrations. Haloacetonitriles, halopropanones, chloral hydrate and chloropicrin were usually detected in treated water samples but at lower concentrations. Mean and median trihalomethane levels were higher in the summer than the winter for all three treatment processes and increased in the distribution system except for chlorine-chloramine treatment. Mean and median trichloroacetic acid levels for chlorine-chlorine disinfection increased in the distribution system but winter and summer levels were similar. Mean and median trichloroacetic acid levels for chlorine-chloramine and ozone-chlor(am)ine treatment and mean and median dichloroacetic acid levels for all processes were slightly higher in summer compared to winter but levels were not higher in the distribution system. Additional research is required to delineate more clearly the spatial and temporal variations in disinfection by-product levels in drinking water at specific facilities. To obtain an accurate estimation of human exposure to disinfection by-products from drinking water, it would appear that samples should be collected at the consumer tap and not at the treatment plant. Further studies are in progress to define the most appropriate sampling strategy.

Acknowledgement

This survey report was prepared by David T. Williams, Guy L. LeBel and Frank M. Benoit. Thanks are extended to treatment plant personnel for assistance in sample collection and to R. O'Grady and S. Shah for technical assistance.

Introduction

The treatment of water supplies by disinfection has proven highly effective in destroying or inactivating human pathogenic microorganisms, particularly those responsible for typhoid fever and cholera (Ellis 1991). However, the lack of adequate disinfection can still lead to cholera epidemics (Glass et al., 1992). Consequently, in Canada, it is recognized that disinfection of all surface waters used for human consumption is crucial and that the health risks from pathogenic microorganisms far exceed those potential health risks associated with chemical disinfection by-products (DBPs) produced during potable water treatment. The challenge is, therefore, to minimize the potential risks from DBPs without compromising disinfection efficiency.

Chlorine is effective as both a primary and residual disinfectant and is also relatively easy to use. However, chlorine also reacts with biogenic organic matter, such as humic and fulvic acids, present in all natural surface water supplies. The resultant chlorinated organic contaminants have been widely reported in drinking water supplies but since the chemistry involved is extremely complex, it is not yet feasible to predict the concentrations of the various DBPs that will be formed in any given water sample. Following the first reports by Rook (1974) and Bellar et al. (1974), initial concerns focused on the health effects and levels of trihalomethanes (THMs) in drinking water. More recent surveys have also included haloacetic acids (HAAs), haloacetonitriles (HANs), chloropicrin (CPK), chloral hydrate (CH) and other DBPs. The World Health Organization has published drinking water guidelines (WHO 1993) for chloroform (TCM, 0.2 mg/L), bromodichlo-romethane (BDCM, 0.06 mg/L), dibromochloromethane (DBCM, 0.1 mg/L) and bromoform (TBM, 0.1 mg/L) and provisional guideline values for dichloroacetic acid (DCAA, 0.05 mg/L), trichloroacetic acid (TCAA, 0.1 mg/L), chloral hydrate (CH, 0.01 mg/L), dichloroacetonitrile (DCAN, 0.09 mg/L), dibromoacetonitrile (DBAN, 0.1 mg/L) and trichloroacetonitrile (TCAN, 0.001 mg/L). In addition to the guidelines for individual THMs, the World Health Organization suggests (WHO, 1993) that a guideline for the total THM (TTHM) be derived from the sum of the ratios (ratio not to exceed 1) of the measured values to the guideline values for each individual THM. It should be emphasized that WHO guidelines do not have any formal recognition in Canada, and they do not include consideration of achievability, which is a feature of Canadian guidelines. The current USEPA maximum contaminant level for TTHMs was set at 0.1 mg/L but a Disinfectants-Disinfection By-products Rule, expected to be promulgated by the USEPA in 1996 (USEPA 1991, AWWA 1994, Pontius 1995), will set new maximum contaminant levels for TTHMs (0.08 mg/L) and the sum of five haloacetic acids (HAA5, 0.06 mg/L). An interim maximum acceptable concentration (IMAC) for TTHMs (0.1 mg/L) has recently been assigned in the Guidelines for Canadian Drinking Water (Health Canada in press). No Canadian guidelines exist for other disinfection by-products although a guideline is under development for the haloacetic acids.

The formation of DBPs has been reported to be a function of precursor concentration, chlorine dose, chlorination pH, temperature, contact time and bromide ion concentration. Stevens et al. (1989) have discussed the formation and control of DBPs and have confirmed that the most important chemical variable in chlorination DBP formation was pH. THM formation was increased at high pH and decreased at low pH. TCAA formation was minimized at high pH and maximized at low pH whereas DCAA formation was essentially independent of the reaction pH. This implies that some measures used to decrease THM production might favour the formation of other DBPs. The occurrence of THMs, HANs, HAAs, CPK and other DBPs in drinking water has been reported for thirty-five US water treatment facilities (Krasner et al., 1989) and for thirty-five Utah water treatment facilities (Nieminski et al., 1993). The 1976 national survey of Canadian drinking water focused on THMs (Williams and Otson, 1978; Williams et al., 1980).

The current survey on the levels of DBPs in Canadian drinking water was intended to provide data which could be used in the preparation of future Canadian Drinking Water Guidelines. A total of 17 different chlorinated DBPs were determined as well as bromide ion, total organic carbon and total organic halides.

Sample Collection and Analytical Procedures

The 53 sites investigated (Table 1) were selected in consultation with provincial officials and represented most of the large population centres in nine provinces; Prince Edward Island was not included in the survey because of the limited use of chlorine in that province. The 53 sites were selected to represent the major populated geographical areas of the country and were distributed according to population as follows: <10,000 - 2 sites, 10,000 to 100,000 - 17 sites and > 100,000 - 34 sites. A questionnaire (Appendix 1) on water treatment processes and operating practices was prepared to record the plant operating conditions at the time of sampling and to record the location of each sampling point. The treatment plants drew raw water from the main types of Canadian sources: lakes, rivers and wells. Three main disinfection treatment processes were in use in the water treatment plants included in this survey. These were chlorine-chlorine, chlorine-chloramine and ozone-chlor(am)ine.

Samples were collected in 1993 during the winter season (February-March) and the summer season (August-September) when DBP levels were expected to be lowest and highest respectively. In order to minimize variations in sampling technique, the number of persons involved in sampling was kept to a minimum. Four technologists were involved in winter sample collection and one technologist was responsible for the summer sample collection. Replicate samples were collected of raw water, treatment plant water (after final disinfection but before distribution) and treated water from a well-flushed tap at a point in the distribution system (approximately the midpoint) some 5-10 kilometres from the treatment plant. Water samples for the analysis of HAAs were collected in amber bottles containing sodium thiosulphate; those for analysis of THMs, HANs, chloropropanones, chloral hydrate and chloropicrin were collected in amber bottles containing ammonium chloride and were adjusted to pH 4.5 at the time of collection. LeBel and Williams (1995) have shown that it is critical to adjust the water samples to pH 4.5 at the time of collection to prevent or minimize the production of additional THMs during transportation and storage. Samples also were collected in prewashed bottles for the analysis of total organic carbon, total organic halogen and bromide ion. The bottles were filled just to overflow with samples, sealed with Teflon-lined caps, returned to the laboratory in a cooler by the fastest available route and stored in a cold room until analyzed (usually within 1-4 days). Complete details of the sampling protocols are given in Appendix 2.

Table 1 - Sampling Locations
Province Location Water Source Disinfectant
Newfoundland St. John's(Windsor) Lake CL
St. John's(Bull Pond) Lake CL,O
Nova Scotia Dartmouth Lake CL
Halifax Lake CL
New Glasgow Lake CL
Truro Dam CL
New Brunswick Fredericton Well CL
Moncton River CL
Oromocto River CL
Saint John East Lake CL
Québec Drummondville River CL
Gatineau River CL
Granby River CL
Laval River CL, O
Lévis River CL
Montréal River CL
Pierrefonds River O,CA
Québec River CL,O
Repentigny River CL,O
St. Jean River CL,O
Trois-Rivières River CL
Ontario Barrie Well CL
Brantford River CL,CA
Grand Bend Lake CL
Guelph Well CL
Kingston Lake CL
Mississauga Lake CL,CA
North Bay Lake CL
Ottawa(Britannia) River CL,CA
Ottawa(Lemieux) River CL,CA
Peterborough River CL
St Catharines Lake CL
Sudbury River CL
Toronto Lake CL,CA
Manitoba Letellier River CL
Portage-La-Prairie River CL,O
Selkirk River CL
Winnipeg Lake CL
Whitemouth River CL
Saskatchewan Moose Jaw Lake CL
Prince Albert River CL
Saskatoon River CL,CA
Swift Current Lake CL
Alberta Calgary Lake CL
Edmonton River CL,CA
Lethbridge River CL,CA
Red Deer River CL,CA
British Columbia Chilliwack River CL
Kamloops Well, River CL
Nanaimo Lake CL
Penticton Lake CL
Vancouver Lake CL
Victoria Lake, River CL,CA
CL - chlorine
CA - chloramine
O - ozone

The water samples which had been adjusted to pH 4.5 in the field were extracted with methyl t-butyl ether (MTBE) and analyzed for THMs, HANs, chloropropanones, chloral hydrate and chloropicrin by gas chromatography using a Varian Vista 6000 GC equipped with an electron capture detector, an on-column injector and a J&W DB-5 capillary column. The HAA water samples were pH adjusted in the laboratory, extracted with diethyl ether and the HAAs converted to their methyl esters which were analyzed by gas chromatography-mass spectrometry (selected ion monitoring) using a Finnigan MAT 90 GC/MS fitted with DB-1701 capillary column. Bromide ion was determined by ion chromatography, total organic carbon was determined using a SKALAR SA5 segmented flow analyzer and total organic halogen was determined using a Mitsubishi TOX-10 analyzer. Instrumental parameters and full analytical details are provided in Appendix 2 and the minimum quantifiable limits for each parameter are listed in Table 2.

For quality control purposes all samples were collected at least in duplicate and control samples were included for all groups of target analytes (usually one field blank per two sites). All DBP analytical methods incorporated surrogate internal standards and quantification was based on response factors established by multi-level calibration with fortified samples analyzed under identical conditions. Additional fortified samples were analyzed at scheduled intervals. DBPs identified by GC-ECD were confirmed by GC-MS or by GC-ECD analysis on a second GC column (DB-17). Each week during the analytical period, duplicate 30 mL groundwater samples, known to be free of HAAs, were spiked with a HAA standard mixture of known concentration, stored in a refrigerator until the following week and, along with field samples, analyzed as described above.

Results And Discussion

Raw, treatment plant and distribution system water samples were collected from fifty-three drinking water treatment facilities on two occasions (winter and summer) in 1993 and were analyzed for the DBPs listed in Table 2. The analytes listed in Table 2 were selected based on the known occurrence of halogenated DBPs in drinking water treated with chlorine disinfectants and on the possibility that they may at some time be considered for inclusion in Canadian drinking water guidelines. One site was subsequently excluded from the statistical analyses when it was determined that chlorine was added at the raw water source some 160 km from the municipality and, consequently, no representative raw or treatment plant samples were obtained. Water samples (raw, plant and system waters) were collected from the three sampling locations on the same day and hence, the raw and plant waters present similar organic profiles. However, the system water sample is older and represents water that was processed within the plant at some undetermined time prior to the sampling date. Such a water sample could have a different burden of organic material and could also have been the subject of minor variations in the water treatment process. The exact age (from treatment to sampling) of a water sample taken within the distribution system is difficult to ascertain because of the wide variety of parameters that determine the time spent within the distribution system before discharge from the tap. Certainly, the age of the system water will vary between facilities because of different treatment plant sizes, capacities and water consumption.

Thirty-seven of the fifty-two treatment facilities used disinfection coupled with alum coagulation and filtration as the main treatment processes. The other fifteen facilities used only disinfection as the main process. Pre- and/or post-chlorination (chlorine-chlorine) was used at thirty-five facilities and pre-chlorination coupled with post-chloramination (chlorine-chloramine) was used at ten facilities. Ozone coupled with chlorine or chloramine (ozone-chlor(am)ine) was used at seven facilities. Some of these facilities used significant levels of pre-chlorination during the summer to control algal growth and to prevent filter media fouling. The raw water sources were rivers (28), lakes (18), wells (3), a dam (1) and a mixture of these sources (2). Appendix 3 contains an individual data sheet for each municipality which lists the raw water source and the general process used for water treatment. The data sheets also report the levels for the DBPs listed in Table 2 for raw, treated and distribution water samples collected in winter and summer.

Table 2 - DBPs analyzed in 1993 National Survey
Compound MQL*
Chloroform (CHCl3) [TCM] 0.2 µg/L
Bromodichloromethane (CHBrCl2)[BDCM] 0.1 µg/L
Chlorodibromomethane(CHBr2Cl)[CDBM] 0.1 µg/L
Bromoform(CHBr3)[TBM] 0.1 µg/L
Monochloroacetic acid (CH2ClCOOH) [MCAA] 0.01 µg/L
Dichloroacetic acid (CHCl2COOH) [DCAA] 0.01 µg/L
Trichloroacetic acid (CCl3COOH) [TCAA] 0.01 µg/L
Monobromoacetic acid (CH2BrCOOH) [MBAA] 0.01 µg/L
Dibromoacetic acid (CHBr2COOH) [DBAA] 0.01 µg/L
Dichloroacetonitrile (CHCl2CN) [DCAN] 0.1 µg/L
Trichloroacetonitrile (CCl3CN) [TCAN] 0.1 µg/L
Bromochloroacetonitrile (CHBrClCN) [BCAN] 0.1 µg/L
Dibromoacetonitrile (CHBr2CN) [DBAN] 0.1 µg/L
1,1-Dichloro-2-propanone (CHCl2COCH3) [DCP] 0.1 µg/L
1,1,1-Trichloro-2-propanone (CCl3COCH3) [TCP] 0.1 µg/L
Chloral hydrate (CCl3CH(OH)2) [CH] 0.1 µg/L
Chloropicrin (CCl3NO2) [CPK] 0.1 µg/L
Bromide ion (winter) 0.01 mg/L
Bromide ion (summer) 0.002 mg/L
Total organic carbon [TOC] 0.1 mg/L
Total organic halide [TOX] 5.0 µg/L
*MQL = minimum quantifiable limit

The individual results were sent to each of the respective municipalities and provinces who participated in the study, together with relevant excerpts from the Canadian and WHO Drinking Water Guidelines, with a description of the toxic effects attributed to each of the disinfection by-products (see Appendix 4). Although the DBP data can be compared with guideline values, it should be emphasized that the present study was not designed to evaluate compliance with guideline values. As can be seen in Appendix 4, it is recommended that, for compliance purposes, TTHM be measured at least quarterly in order to obtain an annual running average. This approach is particularly appropriate for carcinogens which usually require very long exposures before an effect is seen. It is not the approach taken with non-carcinogenic effects; hence for DCAA, TCAA and CH, shorter periods of exceedance are considered significant. However, even in these cases, short-term excursions over the guideline, if only occasional, may not be a reason for concern. As is clearly stated in the TTHM guideline (Appendix 4), the solution to any problems with high concentrations of disinfection by-products is not to reduce disinfection since this would pose an unacceptable health risk. The preferred approach is to reduce the organic precursors in the raw water that react with the disinfectant to produce the by-products. Fine tuning of the treatment system may also achieve a reduction in by-products without impairing disinfection.

Mean and median levels and concentration ranges for the major DBPs of each target group in summer and winter are reported in Table 3 for the three main disinfection processes for samples collected at the treatment plant just before distribution and for samples collected at the approximate mid-point of the distribution system. The target DBPs were either non-detectable or found at extremely low levels in the raw water samples. At most facilities, the dominant species found were chlorinated DBPs and, of these, TCM, DCAA and TCAA were the major components. The concentrations of the other target DBPs were usually an order of magnitude less.

TriHaloMethanes

The percentage distributions of THMs in winter and summer for treatment plant and distribution system samples are shown in Table 4. The percentage of chloroform was higher in summer than in winter for all three treatment processes and was slightly higher for chlorine-chlorine treatment compared to the other two processes. The bromine-containing THMs were relatively higher in the winter samples and for the chlorine-chloramine and ozone-chlor(am)ine treatment processes. Chloroform was the major THM detected except at three facilities where ground water sources (low TOC) were treated with minimal chlorination and, therefore, had low TTHM levels (<15 µg/L). At these three sites, chlorodibromomethane (2 sites) and bromoform (1 site) were the major THMs detected. For chlorine-chlorine treatment, mean TTHM levels (Table 3) were higher in summer than winter (e.g. 62.5 µg/L compared to 33.4 µg/L for distribution system samples) and were higher in the distribution system than at the treatment plant (e.g. 62.5 µg/L compared to 33.5 µg/L for summer samples). For chlorine-chloramine treatment, mean TTHM levels were higher in summer than winter (e.g. 32.8 µg/L compared to 13.7 µg/L for distribution system samples) but mean and median treatment plant TTHM levels were similar to those in the distribution system in both winter and summer. Those facilities which used ozone in their treatment process had mean TTHM levels which were low in winter but in the summer had mean and median levels similar to or higher than those at facilities using chlorine-chlorine treatment. A probable reason for this was that pre-chlorination was commonly used to supplement ozone disinfection during the warm water months at some facilities. This can be clearly seen (Table 5) by the significant increase in mean TOX concentrations in the summer sampl es compared to the winter samples for those facilities using ozone. The frequency distributions of facilities based on TTHM concentrations are illustrated in Figure 1 for the plant and distribution system samples for the three treatment processes. While the majority of treatment facilities had relatively low TTHM levels (<50 µg/L) for all three treatment processes during both winter and summer, a small number of facilities had relatively high TTHM values (>100 µg/L), particularly in the summer (except for chlorine-chloramine disinfection). This can also be seen in Table 3 where the median TTHM values are lower than the mean TTHM values except for ozone treatment.

The TTHM data from the present Canadian survey are consistent with data reported for USA facilities. A 1987 survey of 727 US facilities reported median TTHM values of 44 and 30 µg/L for the summer and winter seasons for water samples collected at the treatment plant after disinfection but before distribution (McGuire and Meadow, 1988). A 1988-89 survey of 35 US facilities also reported median values for TTHM of 44 and 30 µg/L for the summer and winter seasons for water samples collected at the treatment plant (Krasner et al., 1989). No breakdown of data by type of disinfectant was provided. In a 1990 survey of 35 Utah facilities which used chlorine as the only disinfectant, median (mean) summer values for TTHM of 22.4 (31.3) µg/L and 55.7 (60.0) µg/L for plant effluent and distribution system samples were reported; for a sub-set of 14 facilities, median (mean) values for TTHM of 21.6 (28.8) µg/L and 15.9 (20.9) µg/L for summer and winter plant effluent samples were reported (Nieminski et al., 1993).

Table 3 - DBPs (µg/L) in Canadian Drinking Water - 1993
Winter Summer
Compound Treatment Site Mean Median Range Mean Median Range
TTHM Chlorine - Plant 16.8 10.9 2.0-67.9 33.5 17.2 1.6-120.8
Chlorine - System 33.4 21.8 2.8-221.1 62.5 33.8 0.3-342.4
Chlorine - Plant 12.1 10.1 0.6-40.3 31.2 19.7 2.9-80.1
Chloramine- System 13.7 10.9 1.5-42.1 32.8 21.7 4.3-85.2
Ozone- Plant 6.8 5.7 1.7-12.3 44.0 57.4 2.5-74.9
Chlor(am)ine- System 9.9 11.0 2.4-15.4 66.7 90.9 4.9-107.8
DCAA Chlorine - Plant 13.2 9.0 0.3-45.4 21.1 12.5 0.6-163.3
Chlorine - System 15.6 11.8 0.2-63.6 19.0 10.4 0.3-120.1
Chlorine - Plant 9.8 7.7 1.2-23.3 12.5 10.5 5.3-27.6
Chloramine- System 10.0 9.9 1.2-22.6 11.4 10.8 4.2-23.8
Oz one- </ td> Plant 6.9 6.4 1.6-15.0 21.2 22.6 5.3-47.6
Chlor(am)ine- System 4.6 4.8 0.4-9.3 14.1 10.7 0.9-42.6
TCAA Chlorine - Plant 27.8 13.0 0.1-139.8 34.0 11.9 0.04-273.2
Chlorine - System 56.7 24.7 0.1-473.1 48.9 25.1 0.1-263.4
Chlorine - Plant 13.7 6.9 0.5-66.2 25.1 9.3 2.1-85.9
Chloramine- System 13.2 7.0 0.5-57.9 21.4 8.7 1.9-71.5
Ozone- Plant 5.8 1.5 0.7-16.9 24.6 21.6 1.3-66.1
Chlor(am)ine- System 4.1 2.0 0.9-12.8 28.3 13.3 0.7-77.3
CH Chlorine - Plant 2.2 1.4 <0.1-13.8 4.3 2.9 <0.1-14.7
Chlorine - System 3.8 2.5 <0.1-22.5 6.1 4.8 <0.1-18.9
Chlorine - Plant 1.2 0.8 <0.1-3.2 3.9 3.3 0.3-15.1
Chloramine- System 1.2 0.8 0.2-3.2 3.6 2.9 0.3-13.6
Ozone- Plant 1.5 1.0 0.2-2.9 8.1 10.4 0.7-14.5
Chlor(am)ine- System 2.2 1.9 0.2-5.8 8.4 5.6 0.2-20.1
DCAN Chlorine - Plant 2.1 1.0 0.1-12.6 2.7 1.7 <0.1-9.0
Chlorine - System 2.9 1.9 0.1-16.3 2.9 1.9 <0.1-9.5
Chlorine - Plant 1.5 1.0 <0.1-7.3 2.6 1.6 0.4-11.2
Chloramine- System 1.7 0.9 0.2-7.3 2.5 1.4 0.4-10.7
Ozone- Plant 0.8 0.6 0.2-1.3 2.5 3.1 0.3-4.1
Chlor(am)ine- System 0.8 0.7 <0.1-1.6 2.2 1.7 <0.1-5.0
DCP Chlorine - Plant 1.1 0.9 <0.1-3.7 0.9 0.8 <0.1-2.6
Chlorine - System 1.0 0.9 <0.1-3.3 0.8 0.6 <0.1-2.1
Chlorine - Plant 0.8 0.9 <0.1-1.5 1.3 1.4 0.3-2.4
Chloramine- System 1.0 1.2 0.3-1.6 1.3 1.4 0.3-2.1
Ozone- Plant 1.5 1.2 0.9-2.3 1.5 1.3 0.5-2.9
Chlor(am)ine- System 1.3 1.2 0.8-2.1 1.0 0.9 0.4-2.3
TCP Chlorine - Plant 1.7 1.4 <0.1-7.6 2.7 2.0 <0.1-9.1
Chlorine - System 2.7 2.2 <0.1-10.1 2.5 1.9 <0.1-7.8
Chlorine - Plant 1.0 0.9 <0.1-2.6 1.7 0.6 0.1-6.4
Chloramine- System 0.9 0.7 <0.1-2.6 1.3 0.6 <0.1-5.3
Ozone- Plant 1.3 0.9 0.2-3.1 4.4 4.1 0.5-9.2
Chlor(am)ine- System 1.6 1.3 0.3-3.3</ td> 2.5 1.5 0.4-10.4
CPK Chlorine - Plant 0.2 0.1 <0.1-1.2 0.3 0.2 <0.1-2.5
Chlorine - System 0.3 0.2 <0.1-1.6 0.3 0.2 <0.1-1.2
Chlorine - Plant 0.2 0.2 <0.1-0.9 0.2 0.2 <0.1-0.9
Chloramine- System 0.2 0.2 <0.1-0.9 0.3 0.3 <0.1-0.9
Ozone- Plant 0.2 0.1 <0.1-0.3 1.2 1.5 <0.1-2.2
Chlor(am)ine- System 0.3 0.3 <0.1-0.6 1.3 1.1 <0.1-2.3

Figure 1. Distribution of facilities based on TTHM levels

Figure 1. Distribution of facilities based on TTHM levels

Table 4 - % THM Distribution in Drinking Water
Treatment Site Winter % Summer %
TCM Chlorine - Plant 82.3 88.3
Chlorine System 88.3 91.4
Chlorine - Plant 77.2 86.2
Chloramine System 77.9 86.8
Ozone - Plant 78.6 85.2
Chlor(am)ine System 75.5 86.7
BDCM Chlorine - Plant 13.1 9.1
Chlorine System 9.4 7.1
Chlorine - Plant 16.9 10.6
Chloramine System 16.5 10.3
Ozone - Plant 15.5 11.0
Chlor(am)ine System 17.1 9.9
CDBM Chlorine - Plant 3.8 2.3
Chlorine System 1.9 1.2
Chlorine - Plant 4.7 2.4
Chloramine System 4.5 2.3
Ozone - Plant 5.0 3.2
Chlor(am)ine System 5.7 3.1
TBM Chlorine - Plant 0.8 0.4
Chlorine System 0.4 0.2
Chlorine - Plant 1.2 0.6
Chloramine System 1.2 0.6
Ozone - Plant 0.9 0.3
Chlor(am)ine System 1.6 0.3
Table 5 - TOX [µg Cl - /L] in Drinking Water
    Winter
Treatment Site Mean Median Range
Chlorine - Plant 95.0 81.5 6-396
Chlorine System 126.1 96.5 11-572
Chlorine - Plant 68.6 55.0 8-279
Chloramine System 71.7 51.0 7-286
Ozone - Plant 69.7 90.0 15-114
Chlor(am)ine System 55.6 56.0 20-85
    Summer
Treatement Site Mean Median Range
Chlorine - Plant 103.5 66.0 8-473
Chlorine System 141.3 106.0 <5-609
Chlorine - Plant 109.0 79.0 27-283
Chloramine System 92.2 71.0 20-218
Ozone - Plant 130.0 156.0 23-225
Chlor(am)ine System 124.0 87.0 17-229

HaloAcetic Acids

For all treatment processes, mean DCAA levels changed very little within the distribution system for either winter or summer samples (Table 3). For both chlorine-chlorine and chlorine-chloramine treatment, mean DCAA levels were only slightly higher in summer samples compared to winter samples. Those facilities which used ozone in their treatment process had mean DCAA levels which were low in winter (e.g. 4.6 µg/L, distribution system) but in the summer (e.g. 14.1 µg/L, distribution system) were similar to those for the other treatment processes. The frequency distributions of facilities based on DCAA concentration ranges are illustrated in Figure 2 for the plant and distribution system samples from the three treatment processes. While the majority of treatment facilities had relatively low DCAA levels (<50 µg/L) during winter and summer, there were a small number of facilities using chlorine-chlorine treatment which had relatively high DCAA values (>50 µg/L) in both summer and winter.

At facilities with chlorine-chlorine treatment, mean TCAA levels increased from the plant to the mid-point of the distribution system (from 27.8 to 56.7 µg/L and from 34.0 to 48.9 µg/L for winter and summer samples respectively) but the mean TCAA levels in winter (56.7 µg/L) and summer (48.9 µg/L) distribution system samples were similar (Table 3). For chlorine-chloramine treatment, mean TCAAlevels were higher in summer than winter (e.g. 21.4 µg/L compared to 13.2 µg/L for distribution system samples) but did not appear to increase within the distribution system in either winter or summer. Those facilities which used ozone in their treatment process had mean TCAA levels which were low in winter (e.g. 4.1 µg/L, distribution system) but in the summer (e.g. 28.3 µg/L, distribution system) were similar to those at facilities using chlorine-chloramine treatment. The frequency distributions of facilities based on TCAAconcentration ranges for the plant and distribution system samples are illustrated in Figure 3 for the three treatment processes. While the majority of treatment facilities had relatively low TCAA levels (<50 µg/L) during winter and summer, a few facilities had relatively high TCAA values (>100 µg/L) in both summer and winter for chlorine-chlorine disinfection. This can also be seen in Table 3 where the median TCAA values are lower than the mean TCAA values.

The other target HAAs - monochloroacetic acid (100% occurrence, range 0.3 to 9.7 µg/L), monobromoacetic acid (31% occurrence, range <0.01 to 9.2 µg/L) and dibromoacetic acid (62% occurrence, range <0.01 to 1.9 µg/L) - were present at lower levels than the DCAA and TCAA (Table 3). Tribro-moacetic acid is unstable in aqueous solution and consequently was not amenable to analysis; the mixed (Cl-Br) haloacetic acid standards were not available and, therefore, quantitative values are not presented here.

Figure 2. Distribution of facilities based on DCAA levels

Figure 2. Distribution of facilities based on DCAA levels

Figure 3. Distribution of facilities based on TCAA levels

Figure 3. Distribution of facilities based on TCAA levels

A 1988-89 survey (Krasner et al., 1989) of 35 US facilities gave median values for total haloacetic acids (THAA) of 20 and 13 µg/L for the summer and winter seasons for water samples collected at the treatment plant. No breakdown of data by type of disinfectant was provided. In a 1990 survey (Nieminski et al., 1993 ) of 35 Utah f acilitie s which used chlorine as the only disinfectant, median (mean) summer values for THAA of 13.2 (17.3) µg/L and 20.9 (29.6) µg/L for plant effluent and distribution system samples were reported. For a subset of 14 Utah facilities, median (mean) values for THAA of 11.4 (12.6) µg/L and 14.4 (11.9) µg/L for summer and winter plant effluent samples were reported.

Other Disinfection By-Products

Although the concentration of the other target DBPs were usually an order of magnitude lower, they were detected in most treated water samples and also exhibited spatial, seasonal and treatment types variations similar to those of the major DBPs. After the THMs and HAAs, CH (94% occurrence) was the most prominent DBP with concentrations ranging up to 22.5 µg/L for the winter samples and up to 20.1 µg/L for the summer samples. The frequency distributions of facilities based on CH concentration ranges for the plant and distribution system samples are illustrated in Figure 4 for the three treatment processes. In general, for all treatment types, the mean CH concentration (Table 3) was higher in the summer samples compared to the winter samples. Compared to TTHM the overall mean CH concentrations were 14% (plant) and 11% (distribution) of the overall mean TTHM concentration in both winter and summer samples. Based on treatment types, a significant variation was observed with ozone disinfection where the mean CH concentrations were 22% (plant) and 23% (distribution) of the mean TTHM concentration for the winter samples. For the summer samples, the mean CH concentrations were 18% (plant) and 13% (distribution) of the mean TTHM concentration, probably due to the added pre-chlorination used during the summer months.

The other target DBPs had mean concentrations less than 5 µg/L and occurred with the following frequencies - DCAN 97%, TCAN 9 %, BCAN 92%, DBAN 57%, DCP 93%, TCP 91%, CPK 73%. Very little spatial variation was seen for DCAN, TCP, DCP and CPK with the chlorine-chloramine treatment. For the chlorine-chlorine treatment for both seasons DCAN concentrations increased in the distribution system whereas DCP and CPK remained relatively unchanged. TCP increased only for the winter samples and was relatively unchanged in the summer samples. For the ozone treatment, mean concentrations of DCAN, DCP and TCP in distribution water compared to treated water were similar in winter but decreased in summer; the CPK mean concentration did not exhibit marked spatial variation but was considerably higher for the summer samples than for the winter samples (e.g. 1.2 µg/L compared to 0.3 µg/L). These data for CH, HAN, DCP, TCP and CPK are consistent with those reported in other surveys (Uden and Miller 1983; Krasner et al., 1989; IARC 1991; Nieminski et al.,1993).

Correlation of DBPs with Other Parameters

The effect of bromide ion on DBP formation has been shown to be dependent on the bromide ion concentration, the chlorine dose and residual, the pH and the concentration and nature of the organic precursors (Pourmoghaddas et al., 1993; Summers et al., 1993; Symons et al., 1993). The percentage of brominated and mixed halogenated DBPs increases both as the molar ratio of bromide ion to chlorine increases and as the TOC concentration decreases. Some countries have reported that brominated DBPs are significant components of their drinking waters (Peters et al., 1991; Fayad 1993). In this study only four sites in winter and eight sites in summer had raw water bromide ion levels >0.01 mg/L (maximum 0.5 mg/L) and at these sites the relative percentage of brominated and mixed halogenated DBPs increased. The changes in speciation for THMs, HAAs and HANs in winter, treatment plant samples are shown in Table 6, expressed as µg/L concentrations, and in Figure 5, expressed as % speciation, for three sites with very low (Site A, <0.01 mg/L), low (Site B, 0.06 mg/L) and moderate (Site C, 0.5 mg/L) bromide ion concentrations. As the bromide ion concentration increases the relative percentage of brominated and mixed halogenated DBPs increases for all three groups. This is consistent with data reported in laboratory and field studies (Krasner et al., 1989; Fayad 1993; Pourmoghaddas et al., 1993; Summers et al., 1993).

A comparison of total DBP as a function of raw water source for chlorine-chlorine treated waters suggested that the DBP burden was least with groundwater, higher with lake water and highest with river water in both summer and winter periods. This trend may be a reflection of the TOC content of the various water sources, however, only weak correlations (r2=0.2-0.4) were found between TOC and DBP burden. Correlations of individual DBP levels with TOX were weak but the correlation of total DBP (µmoles/L) with TOX (µg/L) was significantly stronger (r2=0.71-0.87) for all chlorine-chlorine treated water samples. No significant correlations were observed between DBP levels and any other parameters. Because of the wide variety of parameters and the treatment variations at each facility, the database obtained in the present study was not large enough and was too heterogeneous to permit meaningful multivariate analysis.

Figure 4. Distribution of facilities based on CH levels

Figure 4. Distribution of facilities based on CH levels

Figure 5. DBP% Speciation in presence of bromide ion

Figure 5. DBP% Speciation in presence of bromide ion

Table 6 - DBP Speciation in Drinking Water
Compound Site A Site B Site C
TOC (mg/L) 1.3 0.9 1.2
Br- (mg/L) <0.01 0.06 0.5
THM (µg/L)
TCM 15.4 3.1 0.5
BDCM 0.5 3.9 0.7
CDBM <0.1 2.9 1.5
TBM <0.1 0.8 3.3
HAA (µg/L)
AMCA 2.1 1.2 0.6
ADCA 20.6 3.8 0.3
ATCA 43.4 3.8 0.1
AMBA 0.1 0.1 <0.01
ADBA <0.01 0.9 0.8
HAN (µg/L)
TCAN <0.1 <0.1 <0.1
DCAN 0.9 0.9 0.1
BCAN <0.1 0.9 0.6
DBAN <0.1 0.6 1.2

Conclusions

TTHMs and HAAs were the major DBPs found in all facilities for all treatment processes and HAA levels often equalled or exceeded TTHM concentrations. Mean and median TTHM levels were higher in the summer than the winter for all three treatment processes and increased in the distribution system except for chlorine-chloramine treatment.

Mean and median TCAA levels for chlorine-chlorine disinfection increased in the distribution system but winter and summer levels were similar. Mean and median TCAA levels for chlorine-chloramine and ozone-chlor(am)ine treatment and mean and median DCAA levels for all processes were slightly higher in summer compared to winter but levels were not higher in the distribution system. Further studies are required to delineate more clearly the spatial and temporal variations in DBP levels in drinking water at specific facilities. To obtain an accurate estimation of human exposure to DBPs from drinking water, it would appear that samples should be collected at the consumer tap and not at the treatment plant. Further studies are in progress to define the most appropriate sampling strategy.

References

  • AWWA Mainstream (1994) D-DBP Rule, ESWTR issued by USEPA. 38(7) (July).
  • Bellar, T.A.; Lichtenberg, J.J.; Kroner, R.C. (1974) The Occurrence of Organohalides in Chlorinated Drinking Water. Jour. AWWA, 66(12), 703-706.
  • Ellis, K.V. (1991) Water Disinfection: A review with some consideration of the requirements of the Third World. Crit. Rev. Environ. Control 20, 341-407.
  • Fayad, N. M. (1993) Seasonal Variations of THMs in Saudi Arabian Drinking Water. J. AWWA, 85(1), 46-50.
  • Glass, R.I., Libel, M., Brandling-Bennet, A.D. (1992) Epidemic cholera in the Americas. Science 256, 1524-1525.
  • Health Canada. Guidelines for Canadian Drinking Water, 6th edition, (in press).
  • IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. (1991) Volume 52. Chlorinated Drinking Water; Chlorination By-products; Some Other Halogenated Compounds; Cobalt and Cobalt Compounds. World Health Organization 1991.
  • Krasner, S.W., McGuire, M.J., Jacangelo, J.G., Patania, N.L., Reagan, K.M., Aieta, E.M. (1989) The Occurrence of Disinfection By-products in US Drinking Water. J.AWWA81(8), 41-53.
  • LeBel, G.L., Williams, D.T. (1995) Differences in Chloroform Levels in Drinking Water Samples analyzed Using Various Sampling and Analytical Techniques. Int. J. Environ. Anal. Chem. 60, 213-220.
  • McGuire, M.J., Meadow, R.G. (1988) AWWARF Trihalomethane Survey. Jour. AWWA, 80(1), 61-68.
  • Nieminski, E.C., Chaudhuri, S., Lamoreaux, T. (1993) The Occurrence of DBPs in Utah Drinking Waters. J. AWWA, 85(9), 98-105.
  • Peters, R.J.B., Erkelens, C., De Leer, E.W.B., De Galan, L. (1991) The Analysis of Halogenated Acetic Acids in Dutch Drinking Water. Water Res., 25(4), 473-477.
  • Pontius, F.W. (1995) An Update of the Federal Drinking Water Regs. J. AWWA, 85(2), 48-58.
  • Pourmoghaddas, H., Stevens, A.A., Kinman, R.N., Dressman, R.C., Moore, L.A., Ireland, J.C. (1993). Effect of Bromide Ion on Formation of HAAs During Chlorination. J. AWWA, 85(1), 82-87.
  • Rook, J.J. (1974) Formation of Haloforms During Chlorination of Natural Waters. Proc. Soc. Water Treatment Exam. 23, 234-243.
  • Stevens, A.A., Moore, L.A., Miltner, R.J. (1989) Formation and Control of Non-Trihalomethane Disinfection By-products. J. AWWA, 81(8), 54-60.
  • Summers, R.S., Benz, M.A., Shukairy, H.M., Cummings, L. (1993) Effect of Separation Processes on the Formation of Brominated THMs. J. AWWA, 85(1), 88-95.
  • Symons, J.M., Krasner, S.W., Simms, L.A. Sclimenti, M. (1993) Measurement of THM and Precursor Concentrations Revisited: The Effect of Bromide Ion. J. AWWA, 85(1), 51-62.
  • Uden, P.C., Miller, J.W. (1983) Chlorinated Acids and Chloral in Drinking Water. J. AWWA, 75(10), 524-527.
  • US Environmental Protection Agency. (1991) Status Report on the Development of the Disinfectants-Disinfection By-products Rule. Proceedings AWWA Ann. Conf., Philadelphia, Pa.
  • WHO (1993) Guidelines for Drinking-Water Quality 2nd Edition Volume 1 Recommendations, World Health Organization, Geneva 1993.
  • Williams, D.T., Otson, R. (1978) Trihalomethane Levels in Canadian Drinking Water. Environmental Health Review, 22(1), 9-10.
  • Williams, D.T., Otson, R.O., Bothwell, P.D., Murphy, K.L. Robertson, J.L. (1980) Trihalomethane Levels in Canadian Drinking Water in "Hydrocarbons and Halogenated Hydrocarbons in the Aquatic Environment", Afghan, B.K., Mackay, D., Eds., Plenum Publishing Corporation, New York, pp 503-512.

Appendix 1 - Questionnaire

National Study on Disinfection By-Products in Water

  • 1. Treatment Plant Address:_______________________

  • 2. Plant Telephone No.:_______________________

  • 3. Questionnaire completed by: _______________________

  • 4. Title_______________________

  • 5. Telephone No.: _______________________

  • 6. Population served by Plant:_______________________

    Date completed: _______________________

  • 7. Water Source_______________________
    Lake ____________________________________________
    River ____________________________________________
    Well ____________________________________________
    Other ___________________________________________
    Name ___________________________________________
    Name ___________________________________________
    No _____________________________________________

  • 8. Raw Water Quality_______________________
    pH ____________________________________________
    TOC ___________________________________________ppm
    Turbidity ________________________________________JTU
    Colour __________________________________________Hazen
    Temperature Range _______________________________
    °C (winter) _______________________________________
    °C (summer) _____________________________________

  • 9. Type of treatment: listed below are several typical unit operations. Number the operations in the sequence at the plant.
_________________
_________________
_________________
_________________
_________________
_________________
_________________
_________________
Pre-chlorination
Screening
Flocculation (Lime)
Flocculation (Alum)
Flocculation (Iron)
Flocculation (_____)
Sedimentation
Post-chlorination
_________________
_________________
_________________
_________________
_________________
_________________
_________________
_________________
Filtration (Multi Media)
Filtration (Sand)
Aeration
Carbon Adsorption
Ozone
Fluoridation
Chloramine
Other

For example, a plant with pre-chlorination, sedimentation, sand-filtration and post-chlorination would insert 1,2,3,4 beside the above operation in the sequence they are found in the plant.

  • 10.
Chemical Added Average conc.
Added (ppm)
Residual Conc. in treated water
Pre Chlorine (as Cl2)
Post Chlorine (as Cl2)
Ozone (as O3)
Fluoride (as F)
Alum (as ___)
Lime (as CaO)
Iron (as ___)
Other (as ___)
Other (as ___)
Carbon
  • 11. Explain variation in treatment process, if any, between summer (Aug.-Sep.'93) and winter sampling (Feb.-Mar.'93)

  • 12. Treated water Quality
    TOC ______________________________ ppm
    pH _______________________________
    Temperature Range _________________°C (winter)
    Temperature Range _________________°C (summer)

  • 13. Residence time in system ____________

  • 14. Sampling location (required for same location sampling for winter and summer '93)
    Raw water (prior to any treatment) __________________
    Treated water (plant effluent) ______________________
    Distribution water (5-10 km from plant) ______________

Please return completed questionnaire with sampling kit or send to:

Monitoring and Criteria Division
Envir onmental Health Directorate
Health Canada
EHC Room B-19 Tunney's Pasture
OTTAWA, Ont.
K1A 0L2

Appendix 2- Sampling Protocol And Analytical Methodology

Experimental

Reagents

Silica gel (chromatography grade, 100-200 mesh) was washed with diethyl ether (DEE) and dried at 110°C; sodium sulphate was heated at 400°C for 4 hours, washed with DEE and dried at 110°C and glass wool was acidified with sulphuric acid, washed with DEE and oven dried at 110°C. Diazomethane was prepared as required according to the Aldrich Diazald method. Groundwater, free of DBPs, obtained from a local well was used for blanks and the preparation of fortified standards.

Sample Collection and Extraction

During two periods, February-March 1993 and August-September 1993, replicate water samples were collected at fifty-three water treatment plants across Canada. Samples requested were raw water, treatment plant water (after final disinfection but before distribution) and treated water from a well-flushed tap at a point near the middle of the distribution system.

Water samples for the analysis of THMs, HANs, chloro-propanones, chloral hydrate and chloropicrin were collected in 62 mL amber bottles containing ammonium chloride (62 mg per bottle). The water sample was adjusted to pH 4.5 at the time of collection; the volume of acid (0.1N HCl) needed to adjust the pH was determined using a 62 mL water sample which was then discarded. The determined amount of acid was added to each sampling bottle and, using a gentle stream of water, the bottles were filled just to overflow to prevent any headspace and dilution of the added preservatives. The bottles were capped with Teflon-lined seals, returned to the laboratory in a cooler and stored in a cold room until analyzed (usually within 1-4 days). For the analyses, a 12 mL aliquot was withdrawn and discarded, 16 g NaCl was added to the remaining sample (ca 50 mL; the accurate volume of the sample bottle was determined later using a volumetric cylinder), and the solution was shaken for 3 minutes with 3 mL of methyl t-butyl ether (MTBE) containing dibromomethane (IS-1) and 1,2-dibromopropane (IS-2) (50 and 250 pg/µL respectively) as internal standards. After transfer to a precalibrated (3.0 mL) vial, any residual water was removed with a pasteur pipet and the volume adjusted to 3 mL. Sodium sulphate was then added to the extract and the MTBE solution fortified with 1,3-dibromopropane (IS-3) (15 µL of 50 ng/µL in MTBE) and analyzed by GC-ECD. Quantification was based on response factors relative to IS-2 (IS-1 was added in case there were interferences with IS-2, however this did not occur). IS-3 was used to determine the percent recovery of IS-2 (95 ± 4%). Data from the first replicate sample was evaluated before analysis of other replicates and if the chloroform concentration in the sample exceeded the ECD linear range (0.2-50 µg/L), only an aliquot of the other replicate samples was used for analysis.

For the HAAs, the sampling vials used for water collection, field blanks and fortified samples were prepared by adding sodium thiosulphate solution (100 µL of 125 µg/µL) to each vial, which was then oven dried at 110°C for 2 hours. The vials were filled just to overflow with samples, sealed with Teflon-lined caps, returned to the laboratory in a cooler and stored in a cold room until analyzed (usually within 1-4 days). For analysis of HAAs the 30 mL water sample was transferred to a 60 mL separatory funnel containing NaCl (8 g) and the recovery standard (5.0 µl of 100 ng/µL 2-bromo-n-butyric acid (MBBA) in acetone) was added. The accurate volume of the sample vial was then determined using a volumetric cylinder. The solution was made basic (pH = 11.5) by adding 1 N sodium hydroxide (100 µL or as determined on representative replicates), shaken and left to stand for 5 minutes. The sample vial was rinsed with 6 mL DEE, the rinsing transferred to the separatory funnel and the sample extracted. After phase separation (ca 5 minutes) the aqueous layer was transferred from the separatory funnel into a 50 mL disposable centrifuge tube. The organic phase was discarded and, after washing the separatory funnel with a small amount of DEE (also discarded), the aqueous phase was returned to the separatory funnel. The solution was acidified to pH 0.5 by adding sulphuric acid (1.2 mL, 1:1) and left to stand for 5 minutes. The 50 mL tube was washed with 6 mL of DEE which was transferred to the separatory funnel and used to extract the aqueous solution. This process was repeated with a second 6 mL of DEE; the separatory funnel was washed with 2 mL DEE after each extraction and the combined DEE extracts were passed through a drying tube containing 2.8 grams of sodium sulphate (washed with 20 mL DEE prior to use). The eluent was collected in disposable centrifuge tubes (15 mL; pre-calibrated at the 2 mL mark) and the volume reduced to 1.8 mL using a nitrogen gas evaporator. The GC/MS quantification standard (5.0 µL of 200 ng/µLpara bromochlorobenzene in DEE), methanol (10 µL, dried), diazomethane (60 µL) were added and the volume adjusted to 2 mL with DEE. After 30 minutes with minimal exposure to light, silica gel (50 mg) was added and the samples allowed to stand for at least 30 minutes before they were analyzed by GC/MS.

Water samples were collected for the analysis of total organic carbon (300 mL samples collected in prewashed poly-carbonate bottles containing 1 mL of 10% H2SO4) and total organic halogen (500 mL samples collected in prewashed amber glass bottles containing sodium thiosulfate). Water samples (60 mL in prewashed polypropylene bottles) were collected for the determination of bromide ion.

Gas chromatography

GC/ECD analysis was conducted using a Varian Vista 6000 GC with an on-column injector and a J&W DB-5 30 m × 0.32 mm id (1 µ film) column. The GC was interfaced to a Vista 402 chromatography data system. The operating parameters were: oven temperature program; 50°C (3 min), 1.5°C/min to 65°C (1 min), 5°C/min to 120°C, 20°C/min to 180°C (10 min); on-column injector program: 100°C, 140°C/min to 240°C (15 min); detector 290°C. The helium carrier gas was set at 1 mL/min (ambient) with nitrogen make-up gas set at 25 mL/min.

The confirmation analyses were conducted on a DB-17 column (J&W DB-17 30 m × 0.32 mm id (0.25 µ film). The oven temperature program was: 35°C (3 min), 0.5°C/min to 40°C (1 min), 6°C/min to 100°C (1 min), 15°C/min to 160°C (1 min). All other GC/ECD settings remained unchanged.

Response factors, obtained by analyses of multi-level fortified water samples, were used to calculate DBP concentrations in the samples.

Gas chromatography - mass spectrometry

GC/MS analysis for HAAs was carried out by selected ion monitoring using a Finnigan MAT 90 GC/MS fitted with a DB-1701 30m × 0.32 mmid (0.25 µ film) column by injection of 3 µL aliquots (Varian SPI injector). The GC operating parameters were: injector - 100°C increased to 240°C at 100°/min, hold 24 min; oven - 40°C held for 3 min, increased to 140°C at 3.3°/min, then to 180°C at 23°/min. The ions monitored (mass resolution 1000) for each target HAA were: monochloroacetic acid - 49,77,79; dichloroacetic acid - 83,85; trichloroacetic acid - 117,119,121; monobromoacetic acid - 93,95; dibro-moacetic acid - 171,173,175; tribromoacetic acid - 251,253; bromochloroacetic acid - 127,129; bromodichloroacetic acid - 141,161,163; chlorodibromoacetic acid - 207,209. DBP quantification was carried out by using rela ti ve response factors derived from the analysis of fortified water samples.

Auxiliary parameters

Auxiliary chemical parameters were determined by NOVAMANN (Ontario) Inc. Bromide ion concentration was determined by chromatography using a DIONEX 2000i ion chromatograph; for the summer samples, the detection limit was improved by a 10:1 preconcentration.

Total organic carbon (TOC) was determined using a SKALAR SK 12 organic carbon analyzer. After sparging with nitrogen to remove inorganic carbon or volatile organics, the organic carbon of the sample was converted to CO2 by UV/per-sulfate oxidation followed by catalytic conversion (H2; Ni/ 400°C) to methane. The methane was then detected by flame ionization detector (FID) and quantified by reference to a standards calibration curve.

The total organic halogen (TOX) was determined using a Mitsubishi TOX-10 analyzer using coulometric/activated charcoal techniques. The samples were passed through TOX adsorbing activated charcoal (AC) tubes and washed with a nitrate solution to remove any adsorbed inorganic halide ions. The TOX adsorbing AC tube was then transferred to a combustion chamber where the TOX was converted (O2 / (800-900°C) to halogenated hydrogen. The generated halogenated hydrogen was then titrated automatically with silver ions generated coulometrically.

Quality Control

All samples were collected at least in duplicate and control samples were included for all groups of target analytes (usually one field blank per two sites). All DBP analytical methods incorporated surrogate internal standards and quantification was based on response factors established by multi-level calibration with fortified samples analyzed under identical conditions.

For the THMs, HANs, chloropropanones, chloral hydrate and chloropicrin analyses, the response factors were initially set by triplicate analyses of DBP-free groundwater fortified at 0, 0.2, 1, 2, 5 and 10 µg/L [chloroform = 5×]. Additional fortified samples were also analyzed at scheduled intervals. A total of 12 replicates (four sets of triplicate samples spiked at each fortification levels) were analyzed during each season. The response factors were not changed if variation was less than 10%. In addition, several raw water samples (unused raw replicates from all regions) from different water sources (matrix spikes; n=14) were analyzed at a fortification level of 5 µg/L (chloroform = 25 µg/L). The overall percent recovery was 99.4% (range 87.4 - 107.2) with standard deviation of 3.5. The results are shown in Table 7.

The accuracies of the analytical methods were estimated (TTHMs ± 5%, HAAs ± 20%) from the periodic analysis, throughout the study, of water samples fortified with known levels of target analytes. The mean recovery of HAAs was typically 96% as estimated from the recovery of the added MBBA internal standard.

Samples with a chloroform concentration exceeding the ECD linear range (0.2-50 µg/L) were reanalyzed using an aliquot from a replicate sample. DBPs identified by GC-ECD were confirmed by GC-MS or by GC-ECD analysis on a second GC column (DB-17). Each week during the analytical period, duplicate 30 mL groundwater samples were spiked with a HAA standard mixture of known concentration (6 µL of 80 ng/µL), stored in a refrigerator until the following week and analyzed as described above.

Table 7 - Recoveries (%) from fortified raw water (n=14)
Compounds Spking Level (µg/L) RT RF Mean % Recovery SD
Chloroform 25 5.80 0.73 98.4 3.1
Bromodichloromethane 5 8.97 4.82 99.9 1.8
Chlorodibromomethane 5 14.20 4.16 100.1 1.8
Bromoform 5 19.77 1.53 92.3 2.3
Trichloroacetonitrile 5 7.71 8.63 104.7 3.1
Dichloroacetonitrile 5 9.13 4.74 96.5 1.9
Bromochloroacetonitrile 5 15.05 3.88 102.7 1.7
Dibromoacetonitrile 5 20.83 3.10 107.0 2.3
1,1-dichloro-2-propanone 5 10.24 2.78 92.3 1.9
1,1,1-trichloro-2-propanone 5 17.27 4.09 107.2 1.9
Chloral Hydrate 5 9.30 4.88 104.5 4.1
Chloropicrin 5 13.20 9.20 87.4 16.4
  • RT - retention time in minutes
  • RF - response factor based on IS-2
  • SD - standard deviation

Appendix 3 - Sampling Site Datasheets (Continued)

Water Treatment Facility Information and Data Sheet

The information on the water treatment facilities and on the treatment processes was provided by plant personnel at the time of the survey (see Appendix 1 questionnaire). The treatment process for each treatment plant is summarized as a general sequence of operations; there will be some variation in the treatment process throughout the year in response to changes in raw water quality.

  • Municipality: Whitemouth, MB
  • Raw Water Source: Winnipeg (river)
  • Water Treatment Process: sedimentation - chlorine
  Winter (Mar 10 '93) Summer (Sep 1 '93)
Water Type: Raw Treated System Raw Treated System
Chloroform (µg/L) 2.1 64.0 216.2 0.4 114.1 335.9
Bromodichloromethane (µg/L) 0.1 3.4 5.0 <0.1 3.6 6.5
Chlorodibromomethane (µg/L) <0.1 0.6 <0.1 <0.1 0.1 <0.1
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 2.1 67.9 221.1 0.4 117.8 342.4
Monochloroacetic acid (µg/L) 3.07 7.54 5.33 1.18 6.51 4.50
Dichloroacetic acid (µg/L) 5.11 45.35 19.60 0.73 163.34 98.01
Trichloroacetic acid (µg/L) 13.74 131.67 473.06 0.16 273.16 146.17
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 0.12
Dibromoacetic acid (µg/L) 0.01 <0.01 <0.01 0.02 0.02 0.02
Trichloroacetonitrile (µg/L) <0.1 0.3 0.2 <0.1 0.2 <0.1
Dichloroacetonitrile (µg/L) <0.1 6.8 10.4 <0.1 9.0 0.5
Bromochloroacetonitrile (µg/L) <0.1 1.5 <0.1 <0.1 0.6 <0.1
Dibromoacetonitrile (µg/L) <0.1 0.9 <0.1 <0.1 0.5 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 2.6 2.2 <0.1 2.1 2.1
1,1,1-Trichloro-2-propanone (µg/L) <0.1 7.6 10.1 <0.1 9.1 4.0
Chloral Hydrate (µg/L) <0.1 8.5 9.4 <0.1 11.7 1.7
Chloropicrin (µg/L) <0.1 0.6 0.1 <0.1 0.4 <0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 9.3 9.2 8.9 NA 8.1 9.5
Total Organic Halides (µg/L) 69 396 572 NA 473 609
NA = Not Analyzed
  • Municipality: Winnipeg, MB
  • Water Source: Shoal (lake)
  • Water Treatment Process: screening - fluoridation - chlorine - chlorine
  Winter (Mar 15 '93) Summer (Sep 2 '93)
Water Type: System 1 System 2 System 3 System 1 System 2 System 3
Chloroform (µg/L) 48.1 50.2 61.4 127.5 131.3 143.4
Bromodichloromethane (µg/L) 4.6 4.9 5.5 6.9 7.2 8.0
Chlorodibromomethane (µg/L) 0.1 0.3 0.2 0.2 0.4 0.4
Bromoform (µg/L) <0.1 0.1 <0.1 <0.1 0.1 <0.1
Total Trihalomethanes (µg/L) 52.8 55.5 67.1 134.7 139.0 151.7
Monochloroacetic acid (µg/L) 1.39 1.86 3.04 4.27 1.11 1.79
Dichloroacetic acid (µg/L) 10.23 12.45 11.92 49.05 11.51 15.32
Trichloroacetic acid (µg/L) 66.20 72.57 92.39 296.06 186.29 128.55
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 0.21 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 <0.01 <0.01 0.04 0.03 0.03
Trichloroacetonitrile (µg/L) 0.1 0.1 0.2 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) 5.4 5.8 7.4 15.0 12.5 12.6
Bromochloroacetonitrile (µg/L) 0.3 0.6 0.4 0.6 0.7 0.5
Dibromoacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 0.2 <0.1
1,1-Dichloro-2-propanone (µg/L) 2.1 1.8 1.7 0.7 1.7 0.9
1,1,1-Trichloro-2-propanone (µg/L) 3.6 4.1 4.7 9.3 4.1 5.3
Chloral Hydrate (µg/L) 2.9 3.8 5.2 28.3 4.9 8.2
Chloropicrin (µg/L) 0.1 0.1 0.2 0.3 0.3 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 7.7 7.5 7.4 NA 7.1 7.6
Total Organic Halides (µg/L) 233 190 225 NA 276 395
NA = Not Analyzed
  • Municipality: Fredericton, NB
  • Raw Water Source: (well)
  • Water Treatment Process: chlorine - pH adjustment - sulphur dioxide - pressure filtration (multi-media)
  Winter (Feb 23 '93) Summer (Sep 20 '93)
Water Type: Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 5.7 17.4 0.3 9.6 57.6
Bromodichloromethane (µg/L) <0.1 1.4 3.8 <0.1 2.1 5.8
Chlorodibromomethane (µg/L) <0.1 0.3 0.6 <0.1 0.4 0.5
Bromoform (µg/L) <0.1 0.1 <0.1 <0.1 0.2 <0.1
Total Trihalomethanes (µg/L) 0.3 7.5 21.8 0.3 12.3 63.9
Monochloroacetic acid (µg/L) 0.96 1.80 1.92 1.83 1.22 6.51
Dichloroacetic acid (µg/L) 0.27 4.34 8.55 0.71 7.03 25.88
Trichloroacetic acid µg/L) 0.04 3.16 12.93 <0.01 6.40 29.65
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.01 0.04 0.09 <0.01 0.03 0.06
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.8 1.9 <0.1 1.2 2.9
Bromochloroacetonitrile (µg/L) <0.1 0.3 0.4 <0.1 0.5 0.7
Dibromoacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 0.1 0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 0.5 0.4 <0.1 0.5 0.3
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.4 1.4 <0.1 0.8 1.6
Chloral Hydrate (µg/L) <0.1 0.4 1.4 <0.1 0.9 6.1
Chloropicrin (µg/L) <0.1 0.1 0.2 <0.1 0.2 0.5
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 0.003 <0.002
Total Organic Carbon (mg/L) 1.8 1.7 1.6 NA <1.8 2.0
Total Organic Halides (µg/L) 6 30 61 NA NA NA
NA = Not Analyzed
  • Municipality: Moncton, NB
  • Raw Water Source: Turtle Creek (reservoir)
  • Water Treatment Process: chlorine - fluoridation
  Winter (Feb 24 '93) Summer (Sep 15 '93)
Water Type: Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 3.3 21.4 0.4 5.7 59.1
Bromodichloromethane (µg/L) <0.1 0.7 3.2 <0.1 1.0 5.1
Chlorodibromomethane (µg/L) <0.1 0.1 0.2 <0.1 0.1 0.5
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.4 4.1 24.9 0.4 6.8 64.7
Monochloroacetic acid (µg/L) 0.95 1.77 3.66 0.34 1 .55 7.60
Dichloroacetic acid (µg/L) 0.38 8.13 37.56 0.34 11.70 120.11
Trichloroacetic acid (µg/L) 0.10 7.67 87.14 0.07 10.51 263.35
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 0.16
Dibromoacetic acid (µg/L) 0.02 0.03 0.04 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.7 2.7 <0.1 0.7 6.7
Bromochloroacetonitrile (µg/L) <0.1 0.3 0.3 <0.1 0.2 0.5
Dibromoacetonitrile (µg/L) <0.1 0.3 0.3 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.7 1.1 <0.1 1.7 1.5
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.7 2.9 <0.1 1.6 7.5
Chloral Hydrate (µg/L) <0.1 0.7 3.1 <0.1 1.0 13.3
Chloropicrin (µg/L) <0.1 0.2 0.7 <0.1 0.2 0.8
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 0.010 0.010
Total Organic Carbon (mg/L) 1.1 1.1 1.3 3.1 3.2 2.5
Total Organic Halides (µg/L) <5 31 108 12 96 258
NA = Not Analyzed
  • Municipality: Oromocto, NB
  • Raw Water Source: Saint John (river)
  • Water Treatment Process: screening - chlorine - flocculation (alum) - sedimentation - filtration (sand) - fluoridation
  Winter (Feb 22 '93) Summer (Sep 20 '93)
Water Type: Raw Treated System Raw Treated System
Chloroform (µg/L) 0.6 31.7 44.6 0.5 116.2 126.0
Bromodichloromethane (µg/L) <0.1 2.2 2.4 <0.1 4.4 4.7
Chlorodibromomethane (µg/L) <0.1 0.3 <0.1 <0.1 0.3 0.2
Bromoform (µg/L) <0.1 0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.6 34.3 46.9 0.5 120.8 130.8
Monochloroacetic acid (µg/L) 0.31 3.27 2.30 1.06 4.28 1.47
Dichloroacetic acid (µg/L) 0.24 34.78 28.25 0.52 69.69 9.58
Trichloroacetic acid (µg/L) 0.97 80.54 66.81 0.23 121.83 59.57
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 0.08 <0.01
Dibromoacetic acid (µg/L) 0.01 0.03 0.02 <0.01 0.02 0.01
Trichloroacetonitrile (µg/L) <0.1 0.1 <0.1 <0.1 0.1 0.1
Dichloroacetonitrile (µg/L) <0.1 3.8 4.8 <0.1 6.4 6.6
Bromochloroacetonitrile (µg/L) <0.1 0.3 0.2 <0.1 0.3 0.3
Dibromoacetonitrile (µg/L) <0.1 0.3 <0.1 <0.1 0.1 0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.3 1.3 <0.1 0.8 0.9
1,1,1-Trichloro-2-propanone (µg/L) <0.1 3.2 4.5 <0.1 7.3 7.8
Chloral Hydrate (µg/L) <0.1 4.4 5.5 <0.1 11.3 11.5
Chloropicrin (µg/L) <0.1 0.7 0.7 <0.1 1.0 1.0
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 4.4 2.6 2.5 NA 2.9 2.9
Total Organic Halides (µg/L) 38 122 156 NA NA NA
NA = Not Analyzed
  • Municipality: Saint John, NB
  • Raw Water Source: Latimer (lake)
  • Water Treatment Process: screening - chlorine - fluoridation
  Winter (Feb 23 '93) Summer (Sep 16 '93)
Water Type: Raw Treated System Raw Treated System
Chloroform (µg/L) 0.5 5.4 15.6 0.3 6.0 20.1
Bromodichloromethane (µg/L) <0.1 0.8 1.8 <0.1 2.0 2.5
Chlorodibromomethane (µg/L) <0.1 <0.1 0.1 <0.1 1.7 0.1
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 1.6 <0.1
Total Trihalomethanes (µg/L) 0.5 6.2 17.5 0.3 11.3 22.7
Monochloroacetic acid (µg/L) 0.34 2.69 2.88 0.69 1.90 3.15
Dichloroacetic acid (µg/L) 0.28 14.85 29.81 0.50 15.51 25.80
Trichloroacetic acid (µg/L) 0.08 11.59 32.86 0.19 11.39 28.02
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.01 0.03 0.02 <0.01 0.02 0.05
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 5.4 1.2 <0.1 0.8 1.3
Bromochloroacetonitrile (µg/L) <0.1 0.8 <0.1 <0.1 0.6 0.1
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 0.6 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 2.1 1.7 <0.1 1.9 1.6
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.3 3.1 <0.1 2.0 3.9
Chloral Hydrate (µg/L) <0.1 0.6 1.3 <0.1 0.8 3.6
Chloropicrin (µg/L) <0.1 0.2 0.4 <0.1 0.1 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 0.005 0.002
Total Organic Carbon (mg/L) 4.0 4.1 3.9 3.5 3.2 3.1
Total Organic Halides (µg/L) 9 102 104 15 105 136
NA = Not Analyzed
  • Municipality: St. John's, NF
  • Raw Water Source: Windsor (lake)
  • Water Treatment Process: chlorine - screening - lime
  Winter (Feb 15 '93) Summer (Sep 15 '93)
Water Type: Raw Treated System Raw Treated System
Chloroform (µg/L) 0.6 12.5 7.5 0.6 9.2 13.3
Bromodichloromethane (µg/L) <0.1 5.9 3.8 0.2 4.4 5.8
Chlorodibromomethane (µg/L) <0.1 1.2 <1.0 <0.1 1.4 1.4
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 0.3 <0.1
Total Trihalomethanes (µg/L) 0.6 19.7 12.3 0.7 15.3 20.5
Monochloroacetic acid (µg/L) 1.43 2.52 2.50 0.21 1.02 0.61
Dichloroacetic acid (µg/L) 1.17 17.95 15.99 1.04 16.14 9.34
Trichloroacetic acid (µg/L) 0.66 25.06 21.63 0.95 21.96 15.76
Monobromoacetic acid (µg/L) <0.01 0.17 0.22 <0.01 0.13 <0.01
Dibromoacetic acid (µg/L) 0.03 0.27 0.32 0.02 0.27 0.29
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 1.3 0.9 <0.1 1.0 1.4
Bromochloroacetonitrile (µg/L) <0.1 0.3 0.5 <0.1 0.4 0.3
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.0 1.0 0.1 <1.0 1.1
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.7 1.7 <0.1 2.5 2.6
Chloral Hydrate (µg/L) <0.1 1.8 1.3 <0.1 2.9 2.9
Chloropicrin (µg/L) <0.1 0.2 0.1 <0.1 0.1 0.2
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA 0.002 0.003
Total Organic Carbon (mg/L) 1.6 1.7 1.5 1.9 1.4 1.4
Total Organic Halides (µg/L) 16 170 168 NA 100 112
NA = Not Analyzed
  • Municipality: St. John's, NF
  • Raw Water Source: Bay Bulls Big Pond (lake)
  • Water Treatment Process: filtration (multi-media) - ozone - chloramine
  Winter (Feb 15 '93) Summer (Sep 15 '93)
Water Type: Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 1.4 2.0 <0.2 2.2 3.7
Bromodichloromethane (µg/L) <0.1 0.3 0.4 <0.1 0.3 0.9
Chlorodibromomethane (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 0.1
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.4 1.7 2.4 2.5 4.8
Monochloroacetic acid (µg/L) 0.97 2.89 2.35 0.25 0.53 0.73
Dichloroacetic acid (µg/L) 0.68 7.37 4.86 0.39 5.30 2.73
Trichloroacetic acid (µg/L) 0.13 1.47 1.00 <0.01 1.26 0.73
Monobromoacetic acid (µg/L) <0.01 0.10 0.11 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 0.04 0.03 <0.01 <0.01 0.02
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.2 <0.1 <0.1 0.3 <0.1
Bromochloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 >0.2 <0.1
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 2.2 1.1 <0.1 2.4 0.8
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.6 0.5 <0.1 0.5 0.4
Chloral Hydrate (µg/L) <0.1 0.4 0.2 <0.1 0.7 0.2
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA <0.002 <0.002
Total Organic Carbon (mg/L) 3.4 3.4 3.1 3.1 2.7 2.3
Total Organic Halides (µg/L) 25 92 48 NA 23 17
NA = Not Analyzed
  • Municipality: Dartmouth, NS
  • Raw Water Source: Lamont (lake) and Major (lake)
  • Water Treatment Process: screening - fluoridation - pH adjustment - chlorine - pgp corrosion inhibitor
  Winter (Feb 18 '93) Summer (Sep 13 '93)
Water Type: Raw Treated System Raw Treated System
Chloroform (µg/L) 0.5 6.8 85.3 0.4 16.2 130.6
Bromodichloromethane (µg/L) <0.1 1.1 5.7 <0.1 6.7 9.9
Chlorodibromomethane (µg/L) <0.1 0.2 0.2 <0.1 5.0 0.6
Bromoform (µg/L) <0.1 0.1 <0.1 <0.1 4.2 <0.1
Total Trihalomethanes (µg/L) 0.5 8.3 91.2 0.4 32.2 141.0
Monochloroacetic acid (µg/L) 1.58 4.30 4.45 0.77 0.95 1.46
Dichloroacetic acid (µg/L) 1.35 21.90 61.91 1.05 16.00 10.78
Trichloroacetic acid (µg/L) 0.21 29.88 195.61 0.26 24.62 59.97
Monobromoacetic acid (µg/L) <0.01 0.12 0.13 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.02 0.04 0.04 <0.01 0.05 0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 0.1
Dichloroacetonitrile (µg/L) <0.1 0.7 3.7 <0.1 1.1 3.1
Bromochloroacetonitrile (µg/L) <0.1 0.2 <0.1 <0.1 0.9 0.3
Dibromoacetonitrile (µg/L) <0.1 0.2 <0.1 <0.1 0.1 0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 3.0 1.8 <0.1 2.6 0.8
1,1,1-Trichloro-2-propanone (µg/L) <0.1 3.4 9.2 <0.1 4.0 1.0
Chloral Hydrate (µg/L) <0.1 1.5 10.8 <0.1 2.3 16.9
Chloropicrin (µg/L) <0.1 0.1 0.3 <0.1 0.2 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA <0.002 <0.002
Total Organic Carbon (mg/L) 2.9 2.9 2.6 NA 2.9 2.9
Total Organic Halides (µg/L) 19 104 230 NA 83 212
NA = Not Analyzed
  • Municipality: Halifax, NS
  • Raw Water Source: Pockwock (lake)
  • Water Treatment Process: screening - potassium permanganate - pH adjustment - flocculation (alum) - chlorine - filtration (multi media) - fluoridation - pH adjustment - chlorine
  Winter (Feb 26 '93) Summer (Sep 13 '93)
Water Type: Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 7.2 20.7 0.3 33.5 71.3
Bromodichloromethane (µg/L) <0.1 2.0 4.0 <0.1 6.1 8.8
Chlorodibromomethane (µg/L) <0.1 0.4 0.6 <0.1 1.6 1.0
Bromoform (µg/L) <0.1 0.1 <0.1 <0.1 0.3 <0.1
Total Trihalomethanes (µg/L) 0.3 9.7 25.3 0.3 41.4 81.2
Monochloroacetic acid (µg/L) 1.14 1.09 1.94 1.13 1.42 1.54
Dichloroacetic acid (µg/L) 0.56 9.00 15.13 0.46 6.63 3.58
Trichloroacetic acid (µg/L) 0.09 5.98 14.11 0.13 20.52 25.10
Monobromoacetic acid (µg/L) <0.01 <0.01 0.11 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.02 0.06 0.10 <0.01 0.03 0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.7 1.2 <0.1 2.1 1.4
Bromochloroacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 0.4 0.3
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 0.1 <0.1
1,1-Dichloro- 2-propanone (µg/L) <0.1 1.8 0.5 <0.1 1.0 0.6
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.9 3.9 <0.1 5.7 0.4
Chloral Hydrate (µg/L) <0.1 1.2 2.8 <0.1 5.5 7.5
Chloropicrin (µg/L) <0.1 0.1 0.2 <0.1 0.2 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 0.032 <0.002
Total Organic Carbon (mg/L) 2.3 1.5 1.6 <1.9 1.7 1.7
Total Organic Halides (µg/L) 7 92 92 9 66 106
NA = Not Analyzed
  • Municipality: New Glasgow, NS
  • Raw Water Source: Forbes (lake)
  • Water Treatment Process: chlorine - screening - aggressiveness control - fluoridation -corrosion control
  Winter (Feb 25 '93) Summer (Sep 14 '93)
Water Type: Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 18.9 67.8 0.4 43.7 210.7
Bromodichloromethane (µg/L) <0.1 3.2 7.3 <0.1 5.0 13.2
Chlorodibromomethane (µg/L) <0.1 0.3 0.4 <0.1 1.7 0.6
Bromoform (µg/L) <0.1 0.3 0.5 <0.1 1.2 <0.1
Total Trihalomethanes (µg/L) 0.4 22.8 76.0 0.4 51.6 224.5
Monochloroacetic acid (µg/L) 1.25 4.52 4.81 1.15 1.57 2.74
Dichloroacetic acid (µg/L) 0.41 24.93 63.55 0.66 29.53 25.15
Trichloroacetic acid (µg/L) 0.18 28.62 147.43 0.17 45.53 146.28
Monobromoacetic acid (µg/L) <0.01 <0.01 0.08 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.04 0.10 0.11 <0.01 0.04 0.02
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 0.1
Dichloroacetonitrile (µg/L) <0.1 1.8 5.7 <0.1 3.2 5.2
Bromochloroacetonitrile (µg/L) <0.1 0.3 0.2 <0.1 0.7 0.4
Dibromoacetonitrile (µg/L) <0.1 0.3 <0.1 <0.1 0.2 0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.3 0.9 <0.1</ td> 1.6 1.4
1,1,1-Trichloro-2-propanone (µg/L) <0.1 2.0 5.3 <0.1 3.8 0.7
Chloral Hydrate (µg/L) <0.1 2.3 9.6 <0.1 5.5 18.9
Chloropicrin (µg/L) <0.1 0.5 1.1 <0.1 0.4 0.9
Bromide ion (mg/L) <0.01 <0.01 <0.01 0.006 <0.002 NA
Total Organic Carbon (mg/L) 2.4 3.1 3.4 NA 3.4 3.5
Total Organic Halides (µg/L) <5 96 220 NA NA NA
NA = Not Analyzed
  • Municipality: Truro, NS
  • Raw Water Source: Lepper Brook (dam)
  • Water Treatment Process: screening - chlorine - flocculation (lime) - flocculation (alum) -sedimentation - filtration (multi-media) - chlorine
  Winter (Feb 25 '93) Summer (Sep 14 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 6.9 34.5 24.3 1.8 110.0 112.2
Bromodichloromethane (µg/L) 0.3 4.4 3.6 <0.1 8.4 9.8
Chlorodibromomethane (µg/L) <0.1 0.4 0.4 <0.1 0.5 0.6
Bromoform (µg/L) <0.1 0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 7.2 39.4 28.2 1.8 118.9 122.6
Monochloroacetic acid (µg/L) 2.58 3.71 2.49 1.68 4.12 3.81
Dichloroacetic acid (µg/L) 4.07 24.32 17.82 7.04 56.53 36.90
Trichloroacetic acid (µg/L) 24.96 55.17 43.33 11.61 104.25 89.15
Monobromoacetic acid (µg/L) <0.01 <0.01 0.10 <0.01 0.09 <0.01
Dibromoacetic acid (µg/L) 0.05 0.11 0.12 <0.01 0.06 0.04
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) 0.4 2.1 1.9 <0.1 8.5 8.3
Bromochloroacetonitrile (µg/L) <0.1 0.2 0.1 <0.1 0.4 0.4
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) 0.4 1.1 1.1 <0.1 1.8 1.8
1,1,1-Trichloro-2-propanone (µg/L) 0.7 2.9 2.5 <0.1 3.5 3.2
Chloral Hydrate (µg/L) <0.1 2.0 2.3 <0.1 14.7 15.5
Chloropicrin (µg/L) <0.1 0.7 0.6 <0.1 1.1 1.0
Bromide ion (mg/L) <0.01 <0.01 <0.01 0.012 0.007 0.009
Total Organic Carbon (mg/L) 7.0 3.3 3.0 7.1 2.90 3.00
To tal Organi c Halides (µg/L) 48 107 93 NA NA NA
NA = Not Analyzed
  • Municipality: Barrie, ON
  • Raw Water Source: (well)
  • Water Treatment Process: flocculation silicate - chlorine
  Winter (Mar11 '93) Summer (Aug5 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 0.8 2.2 0.3 0.5 2.3
Bromodichloromethane (µg/L) <0.1 0.8 3.5 <0.1 0.7 3.2
Chlorodibromomethane (µg/L) <0.1 0.8 4.9 <0.1 1.0 4.2
Bromoform (µg/L) <0.1 0.5 2.4 <0.1 1.2 1.9
Total Trihalomethanes (µg/L) 0.3 3.0 12.9 0.3 3.4 11.7
Monochloroacetic acid (µg/L) 1.71 0.95 2.02 1.57 0.70 0.98
Dichloroacetic acid (µg/L) 0.23 0.40 0.94 1.20 1.57 2.10
Trichloroacetic acid (µg/L) 0.05 0.25 1.11 0.16 1.12 1.33
Monobromoacetic acid (µg/L) <0.01 <0.01 2.11 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 0.12 1.34 <0.01 0.03 0.65
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.1 0.4 <0.1 0.1 0.4
Bromochloroacetonitrile (µg/L) <0.1 0.3 0.8 <0.1 0.5 0.8
Dibromoacetonitrile (µg/L) <0.1 0.6 1.3 <0.1 0.4 0.6
1,1-Dichloro-2-propanone (µg/L) <0.1 <0.1 0.1 <0.1 <0.1 0.1
1,1,1-Trichloro-2-propanone (µg/L) <0.1 <0.1 0.2 <0.1 <0.1 0.2
Chloral Hydrate (µg/L) <0.1 <0.1 0.3 <0.1 <0.1 0.2
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA <0.002 0.018
Total Organic Carbon (mg/L) 0.2 0.2 0.2 0.5 0.9 0.8
Total Organic Halides (µg/L) <5 6 12 NA 12 22
NA = Not Analyzed
  • Municipality: Brantford, ON
  • Raw Water Source: Grand (river)
  • Water Treatment Process: screening - aeration (winter) - chlorine - sedimentation - flocculation (silica) - ammonia - flocculation (alum) - settling - filtration (multi-media) - fluoridation - chlorine
  Winter (Feb 1 '93) Summer (Sep 28 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 30.2 31.3 0.5 63.4 67.7
Bromodichloromethane (µg/L) <0.1 8.3 8.6 <0.1 15.2 15.8
Chlorodibromomethane (µg/L) <0.1 1.2 1.2 <0.1 1.5 1.7
Bromoform (µg/L) <0.1 0.5 1.0 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.3 40.3 42.1 0.5 80.1 85.2
Monochloroacetic acid (µg/L) 1.04 3.46 3.25 0.27 2.01 1.73
Dichloroacetic acid (µg/L) 0.43 23.29 22.60 0.25 27.62 23.76
Trichloroacetic acid (µg/L) 0.82 66.22 57.87 1.36 85.72 67.76
Monobromoacetic acid (µg/L) <0.01 0.09 <0.01 <0.01 0.26 0.05
Dibromoacetic acid (µg/L) <0.01 0.23 0.15 <0.01 0.07 0.12
Trichloroacetonitrile (µg/L) <0.1 0.1 0.2 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 7.3 7.3 <0.1 11.2 10.7
Bromochloroacetonitrile (µg/L) <0.1 1.5 1.6 <0.1 1.8 2.0
Dibromoacetonitrile (µg/L) <0.1 0.5 0.6 <0.1 0.2 0.2
1,1-Dichloro-2-propanone (µg/L) <0.1 <1.5 <1.6 <0.1 <1.8 1.9
1,1,1-Trichloro-2-propanone (µg/L) <0.1 2.6 2.6 <0.1 6.4 5.3
Chloral Hydrate (µg/L) <0.1 3.0 3.2 <0.1 15.1 13.6
Chloropicrin (µg/L) <0.1 0.9 0.9 <0.1 0.9 0.9
Bromide ion (mg/L) <0.01 <0.01 0.06 NA NA NA
Total Organic Carbon (mg/L) 1.4 1.4 1.5 3.0 4.6 4.2
Total Organic Halides (µg/L) 12 279 286 NA 283 218
NA = Not Analyzed
  • Municipality: Guelph, ON
  • Raw Water Source: Eramosa (river) and #22 (well)
  • Water Treatment Process: chlorine - aeration - flocculation (poly phosphates)
  Winter (Feb 1 '93) Summer (Sep 21 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.2 0.5 0.6 0.3 1.0 1.2
Bromodichloromethane (µg/L) <0.1 0.5 0.6 <0.1 1.6 2.0
Chlorodibromomethane (µg/L) <0.1 0.6 0.9 <0.1 2.3 2.9
Bromoform (µg/L) <0.1 0.4 0.7 <0.1 1.0 1.1
Total Trihalomethanes (µg/L) 0.2 2.0 2.8 0.3 5.9 7.3
Monochloroacetic acid (µg/L) 0.23 0.36 0.61 1.31 0.40 0.51
Dichloroacetic acid (µg/L) 0.18 0.45 0.39 0.63 0.57 0.69
Trichloroacetic acid (µg/L) <0.01 0.11 0.10 0.04 0.18 0.20
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.06 0.40 0.30 0.01 0.45 0.43
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.1 0.1 <0.1 0.1 0.2
Bromochloroacetonitrile (µg/L) <0.1 0.1 0.1 <0.1 0.4 0.4
Dibromoacetonitrile (µg/L) <0.1 0.2 0.3 <0.1 0.3 0.3
1,1-Dichloro-2-propanone (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
1,1,1-Trichloro-2-propanone (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Chloral Hydrate (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 0.006 0.005
Total Organic Carbon (mg/L) 2.6 3.8 2.4 1.3 1.0 1.1
Total Organic Halides (µg/L) 22 10 12 53 21 42
NA = Not Analyzed
  • Municipality: Kingston, ON
  • Raw Water Source: Ontario (lake)
  • Water Treatment Process: chlorine screening - flocculation (alum) - sedimentation - filtration (multi-media) - sulphur dioxide
  Winter (Mar 10 '93) Summer (Sep 27 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 3.8 14.4 0.4 7.1 11.5
Bromodichloromethane (µg/L) <0.1 4.2 8.7 <0.1 7.3 9.6
Chlorodibromomethane (µg/L) <0.1 2.6 2.5 <0.1 4.4 5.3
Bromoform (µg/L) <0.1 0.3 <0.1 <0.1 0.6 0.7
Total Trihalomethanes (µg/L) 0.3 10.9 25.6 0.4 19.4 27.2
Monochloroacetic acid (µg/L) 0.17 0.69 2.26 0.26 0.42 1.57
Dichloroacetic acid (µg/L) 0.15 2.84 8.34 0.21 1.68 1.64
Trichloroacetic acid (µg/L) 0.09 4.39 20.36 0.11 2.62 5.16
Monobromoacetic acid (µg/L) 0.02 <0.01 0.06 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.01 0.49 0.49 <0.01 0.26 0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 1.0 2.6 <0.1 1.7 1.9
Bromochloroacetonitrile (µg/L) <0.1 0.6 0.7 <0.1 1.2 1.3
Dibromoacetonitrile (µg/L) <0.1 0.3 0.2 <0.1 0.4 0.3
1,1-Dichloro-2-propanone (µg/L) <0.1 0.4 0.5 <0.1 0.2 0.3
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.5 1.7 <0.1 1.0 0.8
Chloral Hydrate (µg/L) <0.1 0.6 3.4 <0.1 2.1 3.0
Chloropicrin (µg/L) <0.1 <0.1 0.1 <0.1 <0.1 0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 0.004 0.008
Total Organic Carbon (mg/L) 1.4 1.2 1.6 NA 2.4 2.2
Total Organic Halides (µg/L) <5 28 61 NA 63 40
NA = Not Analyzed
  • Municipality: Calgary, AB
  • Raw Water Source: Glenmore Reservoir (lake)
  • Water Treatment Process: screening - chlorine - fluoridation - flocculation (alum) - sedimentation -filtration (multi-media) - filtration (sand) - chlorine
  Winter (Mar 23 ' 93) Summer (Aug 23 ' 93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.5 16.7 9.1 0.5 33.4 41.9
Bromodichloromethane (µg/L) <0.1 1.5 <1.4 <0.1 <1.9 2.2
Chlorodibromomethane (µg/L) <0.1 0.2 0.3 <0.1 0.4 0.6
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 0.1 0.3
Total Trihalomethanes (µg/L) 0.5 18.3 10.8 0.5 35.7 45.0
Monochloroacetic acid (µg/L) 0.91 1.55 0.65 1.13 2.97 2.26
Dichloroacetic acid (µg/L) 0.23 16.51 6.03 0.69 26.26 25.14
Trichloroacetic acid (µg/L) 0.21 59.78 21.69 0.19 55.79 109.17
Monobromoacetic acid (µg/L) 0.15 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 <0.01 <0.01 0.05 0.04 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 4.1 1.6 <0.1 3.1 4.1
Bromochloroacetonitrile (µg/L) <0.1 0.3 0.2 <0.1 0.3 0.3
Dibromoacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 0.2 0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 0.5 0.2 <0.1 0.4 0.4
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.4 0.8 <0.1 2.5 2.9
Chloral Hydrate (µg/L) <0.1 6.0 3.1 <0.1 4.6 6.3
Chloropicrin (µg/L) <0.1 0.4 0.1 <0.1 0.3 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 0.007
Total Organic Carbon (mg/L) 1.9 1.5 0.8 2.4 1.9 2.0
Total Organic Halides (µg/L) 6 127 49 <5 135 171
  • Municipality: Edmonton, AB
  • Raw Water Source: North Saskatchewan (river)
  • Water Treatment Process: screening - flocculation (alum) - flocculation (lime) - sedimentation - chlorine dioxide - chloramine - fluoridation - filtration (multi-media)
  Winter (Mar 22 ' 93) Summer (Aug 16 ' 93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.5 1.0 1.0 0.3 2.7 2.7
Bromodichloromethane (µg/L) <0.1 0.2 0.2 <0.1 0.7 0.8
Chlorodibromomethane (µg/L) <0.1 0.3 0.2 <0.1 0.9 0.9
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 0.9 1.0
Total Trihalomethanes (µg/L) 0.5 1.4 1.5 0.3 5.1 5.3
Monochloroacetic acid (µg/L) 1.41 0.35 0.95 0.34 0.87 1.70
Dichloroacetic acid (µg/L) 0.23 1.25 1.17 0.57 6.68 7.60
Trichloroacetic acid (µg/L) 0.15 0.50 0.50 0.16 2.07 1.94
Monobromoacetic acid (µg/L) <0.01 <0.01 0.08 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 <0.01 0.01 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 0.5 0.5
Bromochloroacetonitrile (µg/L) <0.1 0.6 0.3 <0.1 0.5 0.6
Dibromoacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 0.4 0.4
1,1-Dichloro-2-propanone (µg/L) <0.1 0.3 0.3 <0.1 1.2 1.2
1,1,1-Trichloro-2-propanone (µg/L) <0.1 <0.1 <0.1 <0.1 0.1 0.1
Chloral Hydrate (µg/L) <0.1 0.1 0.2 <0.1 0.4 0.4
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 0.2 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 1.0 0.8 0.9 NA 2.0 1.9
Total Organic Halides (µg/L) 3 8 7 <5 27 20
NA = Not Analyzed
  • Municipality: Lethbridge, AB
  • Raw Water Source: Oldman (river)
  • Water Treatment Process: screening - flocculation (alum) - sedimentation - chlorine - filtration (multi-media) - fluoridation - chloramine
  Winter (Mar 17 ' 93) Summer (Aug 18 ' 93)
Water Type Raw| Treated System Raw Treated System
Chloroform (µg/L) 0.5 0.6 3.0 0.5 3.5 4.1
Bromodichloromethane (µg/L) <0.1 <0.1 0.6 <0.1 0.6 0.6
Chlorodibromomethane (µg/L) <0.1 <0.1 0.2 <0.1 0.3 0.4
Bromoform (µg/L) <0.1 <0.1 0.1 <0.1 0.3 0.6
Total Trihalomethanes (µg/L) 0.5 0.6 3.9 0.5 4.7 5.7
Monochloroacetic acid (µg/L) 1.04 2.04 2.19 0.82 1.19 1.33
Dichloroacetic acid (µg/L) 0.36 3.46 2.43 0.44 5.27 5.90
Trichloroacetic acid (µg/L) 0.29 1.90 2.80 0.27 3.54 2.16
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.02 0.02 0.03 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 <0.1 0.8 <0.1 0.7 1.0
Bromochloroacetonitrile (µg/L) <0.1 <0.1 0.4 <0.1 0.4 0.5
Dibromoacetonitrile (µg/L) <0.1 <0.1 0.3 <0.1 0.2 0.2
1,1-Dichloro-2-propanone (µg/L) <0.1 <0.1 1.4 <0.1 1.3 1.5
1,1,1-Trichloro-2-propanone (µg/L) <0.1 <0.1 0.3 <0.1 0.4 0.2
Chloral Hydrate (µg/L) <0.1 <0.1 0.6 <0.1 0.6 0.5
Chloropicrin (µg/L) <0.1 <0.1 0.2 <0.1 0.2 0.5
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA <0.002 0.022
Total Organic Carbon (mg/L) 2.5 1.9 2.2 NA 2.7 2.5
Total Organic Halides (µg/L) <5 15 26 NA 37 41
NA = Not Analyzed
  • Municipality: Red Deer, AB
  • Raw Water Source: Red Deer (river)
  • Water Treatment Process: screening - carbon adsorption (as required) - flocculation (alum) - flocculation (lime) - sedimentation - chlorine - pH adjustment - fluoridation - filtration (multi-media) - chloramine
  Winter (Mar 22 ' 93) Summer (Aug 17 ' 93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.6 13.4 16.6 0.3 22.8 27.0
Bromodichloromethane (µg/L) <0.1 1.8 1.7 <0.1 1.6 1.4
Chlorodibromomethane (µg/L) <0.1 0.7 0.6 <0.1 0.5 0.3
Bromoform (µg/L) <0.1 0.6 0.5 <0.1 0.6 0.2
Total Trihalomethanes (µg/L) 0.6 16.5 19.4 0.3 25.6 28.9
Monochloroacetic acid (µg/L) 0.51 2.50 2.40 0.65 1.59 1.27
Dichloroacetic acid (µg/L) 0.16 19.08 16.24 0.51 11.92 10.61
Trichloroacetic acid (µg/L) 0.18 26.05 26.89 0.23 35.54 31.94
Monobromoacetic acid (µg/L) <0.01 <0.01 0.02 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.02 0.04 0.04 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 2.6 3.0 <0.1 3.4 3.4
Bromochloroacetonitrile (µg/L) <0.1 0.5 0.5 <0.1 0.3 0.4
Dibromoacetonitrile (µg/L) <0.1 0.2 0.3 <0.1 0.3 0.4
1,1-Dichloro-2-propanone (µg/L) <0.1 0.8 0.8 <0.1 0.8 1.3
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.3 1.1 <0.1 2.1 1.7
Chloral Hydrate (µg/L) <0.1 2.0 1.9 <0.1 3.4 3.3
Chloropicrin (µg/L) <0.1 0.4 0.5 <0.1 0.3 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA 0.009 <0.002
Total Organic Carbon (mg/L) 3.1 2.0 2.0 NA NA NA
Total Organic Halides (µg/L) <5 77 88 NA 108 102
NA = Not Analyzed
  • Municipality: Chilliwack, BC
  • Raw Water Source: Wells and creeks
  • Water Treatment Process: screening - chlorine
  Winter (Mar 18 ' 93) Summer (Aug 11 ' 93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.5 4.6 14.7 0.3 11.0 17.8
Bromodichloromethane (µg/L) <0.1 0.3 0.9 <0.1 1.4 1.4
Chlorodibromomethane (µg/L) <0.1 <0.1 <0.1 <0.1 0.3 0.1
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.5 4.9 15.5 0.3 12.7 19.3
Monochloroacetic acid (µg/L) 0.25 2.26 1.24 1.33 0.72 2.81
Dichloroacetic acid (µg/L) 0.17 5.04 6.72 1.79 5.50 18.89
Trichloroacetic acid (µg/L) 0.10 6.01 10.57 <0.01 18.82 42.99
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 0.01 <0.01 <0.01 0.03 0.03
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.5 0.8 <0.1 0.6 1.0
Bromochloroacetonitrile (µg/L) <0.1 0.1 <0.1 <0.1 0.2 0.2
Dibromoacetonitrile (µg /L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 0.9 0.4 <0.1 0.2 0.2
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.6 0.7 <0.1 0.6 0.8
Chloral Hydrate (µg/L) <0.1 0.4 1.2 <0.1 1.3 2.0
Chloropicrin (µg/L) <0.1 0.2 0.4 <0.1 0.1 0.2
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 1.6 1.7 0.8 0.6 0.4 0.6
Total Organic Halides (µg/L) <5 44 44 5 42 62
NA = Not Analyzed
  • Municipality: Kamloops, BC
  • Raw Water Source: South Thompson (river)
  • Water Treatment Process: screening - chlorine - fluoridation
  Winter (Mar 19 ' 93) Summer (Sep 30 ' 93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.8 13.1 37.8 0.3 15.5 27.4
Bromodichloromethane (µg/L) <0.1 0.3 1.2 <0.1 1.0 1.9
Chlorodibromomethane (µg/L) <0.1 <0.1 <0.1 <0.1 0.4 0.4
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 0.2 1.7
Total Trihalomethanes (µg/L) 0.8 13.4 39.1 0.3 17.2 31.4
Monochloroacetic acid (µg/L) 1.36 1.64 1.23 1.20 2.00 1.03
Dichloroacetic acid (µg/L) 0.20 5.54 1.25 0.52 12.50 13.95
Trichloroacetic acid (µg/L) 0.21 10.73 21.19 0.08 13.65 26.91
Monobromoacetic acid (µg/L) <0.01 0.14 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.2 1.5 <0.1 1.9 2.3
Bromochloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 0.2 0.4
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 0.2 0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 0.3 0.6 <0.1 1.0 0.9
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.5 0.7 <0.1 2.5 3.2
Chloral Hydrate (µg/L) <0.1 0.4 <0.1 <0.1 4.0 5.8
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 0.2 0.2
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 1.8 1.4 1.2 <1.1 <1.9 1.9
Total Organic Halides (mg/L) <5 52 85 NA 40 73
NA = Not Analyzed
  • Municipality: Nanaimo, BC
  • Raw Water Source: South Fork (reservoir) and Jump (lake)
  • Water Treatment Process: screening - chlorine
Winter (Mar 25 ' 93) Summer (Aug 12 ' 93)
Water Type: Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 4.5 19.1 0.2 5.8 28.1
Bromodichloromethane (µg/L) <0.1 0.5 1.1 <0.1 1.7 5.2
Chlorodibromomethane (µg/L) <0.1 0.1 <0.1 <0.1 0.6 0.5
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 0.3 <0.1
Total Trihalomethanes (µg/L) 0.3 5.1 20.2 0.2 8.4 33.8
Monochloroacetic acid (µg/L) 0.28 1.53 1.95 0.76 4.23 3.20
Dichloroacetic acid (µg/L) 0.24 13.58 8.60 1.03 19.45 44.76
Trichloroacetic acid (µg/L) 0.20 12.97 55.06 0.26 11.60 78.80
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 0.01
Dibromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 0.01 0.07
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.3 0.7 <0.1 0.8 2.9
Bromochloroacetonitrile (µg/L) <0.1 0.1 <0.1 <0.1 0.3 0.4
Dibr omoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 0.8 0.7 <0.1 1.0 0.8
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.1 2.0 <0.1 1.0 2.6
Chloral Hydrate (µg/L) <0.1 0.7 2.5 <0.1 1.2 5.3
Chloropicrin (µg/L) <0.1 0.1 0.2 <0.1 0.1 0.2
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 0.006 <0.002
Total Organic Carbon (mg/L) 1.9 1.9 1.7 NA 1.2 1.1
Total Organic Halides (µg/L) <5 39 106 NA 51 124
NA = Not Analyzed
  • Municipality: Penticton, BC
  • Raw Water Source: Okanagan (lake)
  • Water Treatment Process: screening - chlorine
Winter (Mar 19 ' 93) Summer (Aug 10 ' 93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) NA 9.4 21.1 NA 3.6 12.8
Bromodichloromethane (µg/L) NA 0.9 2.9 NA 1.1 2.9
Chlorodibromomethane (µg/L) NA <0.1 0.2 NA 0.4 0.3
Bromoform (µg/L) NA <0.1 <0.1 NA 0.3 0.1
Total Trihalomethanes (µg/L) NA 10.3 24.2 NA 5.4 16.1
Monochloroacetic acid (µg/L) NA 1.33 1.99 NA 1.16 1.27
Dichloroacetic acid (µg/L) NA 2.72 6.66 NA 3.73 10.39
Trichloroacetic acid (µg/L) NA 4.71 15.27 NA 5.81 15.75
Monobromoacetic acid (µg/L) NA <0.01 <0.01 NA 0.11 <0.01
Dibromoacetic acid (µg/L) NA <0.01 <0.01 NA 0.08 0.03
Trichloroacetonitrile (µg/L) NA <0.1 <0.1 NA <0.1 <0.1
Dichloroacetonitrile (µg/L) NA 0.2 0.5 NA 0.7 1.3
Bromochloroacetonitrile (µg/L) NA <0.1 <0.1 NA 0.4 0.3
Dibromoacetonitrile (µg/L) NA <0.1 <0.1 NA 0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) NA 0.2 0.4 NA 0.7 0.6
1,1,1-Trichloro-2-propanone (µg/L) NA <0.1 <0.1 NA 0.6 1.0
Chloral Hydrate (µg/L) NA 0.2 0.6 NA 0.4 1.0
Chloropicrin (µg/L) NA <0.1 <0.1 NA <0.1 <0.1
Bromide ion (mg/L) NA <0.01 <0.01 NA <0.002 <0.002
Total Organic Carbon (mg/L) NA 2.9 2.8 NA 3.1 3.3
Total Organic Halides (µg/L) NA 18 68 NA 41 72
NA = Not Analyzed
  • Municipality: Vancouver, BC
  • Raw Water Source: Seymour (lake)
  • Water Treatment Process: screening - chlorine
  Winter (Mar 18 ' 93) Summer (Aug 11 ' 93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 4.2 15.4 0.2 3.6 24.7
Bromodichloromethane (µg/L) <0.1 0.3 0.5 <0.1 0.5 0.8
Chlorodibromomethane (µg/L) <0.1 <0.1 <0.1 <0.1 0.3 <0.1
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 0.3 <0.1
Total Trihalomethanes (µg/L) 0.4 4.4 15.9 0.2 4.6 25.5
Monochloroacetic acid (µg/L) 0.78 1.20 2.09 1.53 2.02 1.85
Dichloroacetic acid (µg/L) 0.25 7.07 20.64 1.15 14.14 18.99
Trichloroacetic acid (µg/L) 0.15 7.74 43.40 0.16 8.38 21.70
Monobromoacetic acid (µg/L) <0.01 0.09 0.10 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.5 0.9 <0.1 0.3 1.4
Bromochloroacetonitrile (µg/L) <0.1 0.1 <0.1 <0.1 0.3 <0.1
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.4 1.3 <0.1 1.0 1.2
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.0 2.3 <0.1 1.7 2.4
Chloral Hydrate (µg/L) <0.1 0.7 2.3 <0.1 0.8 2.7
Chloropicrin (µg/L) <0.1 0.1 0.2 <0.1 0.1 0.2
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA <0.002 <0.002
Total Organic Carbon (mg/L) 1.3 1.4 1.4 1.4 1.5 1.4
Total Organic Halides (µg/L) <5 31 67 NA 59 116
NA = Not Analyzed
  • Municipality: Victoria, BC
  • Raw Water Source: Sooke (lake) and Goldstream (river)
  • Water Treatment Process: screening - chloramine
  Winter (Mar 25 ' 93) Summer (Aug 12 ' 93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 2.7 3.0 0.4 2.4 3.6
Bromodichloromethane (µg/L) <0.1 0.5 0.5 <0.1 0.4 0.6
Chlorodibromomethane (µg/L) <0.1 <0.1 <0.1 <0.1 0.1 0.1
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.4 3.3 3.5 0.4 2.9 4.2
Monochloroacetic acid (µg/L) 1.02 1.37 4.26 0.72 1.46 3.07
Dichloroacetic acid (µg/L) 0.32 8.32 13.02 0.88 7.75 12.35
Trichloroacetic acid (µg/L) 0.14 5.17 5.00 0.25 3.33 3.45
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.3 0.4 <0.1 0.4 0.4
Bromochloroacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 0.2 0.2
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.0 1.2 <0.1 1.8 1.9
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.6 0.6 <0.1 0.4 0.5
Chloral Hydrate (µg/L) <0.1 0.5 0.5 <0.1 0.3 0.3
Chloropicrin (µg/L) <0.1 0.2 0.2 <0.1 <0.1 <0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 0.006 0.008
Total Organic Carbon (mg/L) 2.2 2.1 2.3 NA 2.1 2.1
Total Organic Halides (µg/L) 6 33 33 6 28 41
NA = Not Analyzed
  • Municipality: Letellier, MB
  • Raw Water Source: Red (river)
  • Water Treatment Process: screening - flocculation (alum) - carbon adsorption - flocculation (lime) - sedimentation - filtration (multi-media) - fluoridation - chlorine
Winter (Mar 10 ' 93) Summer (Aug 31 ' 93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 11.3 12.9 0.4 38.2 44.5
Bromodichloromethane (µg/L) <0.1 14.4 16.7 <0.1 20.5 23.6
Chlorodibromomethane (µg/L) <0.1 8.4 9.0 <0.1 6.1 6.5
Bromoform (µg/L) <0.1 1.4 1.3 <0.1 0.1 0.2
Total Trihalomethanes (µg/L) 0.3 35.4 39.8 0.4 64.9 74.7
Monochloroacetic acid (µg/L) 0.85 4.02 3.20 0.78 3.99 2.61
Dichloroacetic acid (µg/L) 0.18 7.23 7.77 0.73 36.49 36.36
Trichloroacetic acid (µg/L) 0.19 13.40 15.00 0.14 63.58 68.67
Monobromoacetic acid (µg/L) <0.01 7.66 9.22 <0.01 2.30 1.85
Dibromoacetic acid (µg/L) 0.01 1.30 1.85 0.01 1.26 1.31
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 3.2 3.6 <0.1 7.3 7.9
Bromochloroacetonitrile (µg/L) <0.1 2.4 2.4 <0.1 3.7 3.7
Dibromoacetonitrile (µg/L) <0.1 1.7 1.5 <0.1 0.8 0.9
1,1-Dichloro-2-propanone (µg/L) <0.1 0.7 0.8 <0.1 0.7 0.7
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.6 1.8 <0.1 4.9 5.9
Chloral Hydrate (µg/L) <0.1 2.2 2.3 <0.1 7.5 10.5
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 0.1 0.2
Bromide ion (mg/L) <0.01 <0.01 <0.01 0.061 0.022 0.025
Total Organic Carbon (mg/L) 9.8 5.7 5.9 NA 4.5 4.6
Total Organic Halides (µg/L) 11 92 111 NA 210 242
NA = Not Analyzed
  • Municipality: Portage-La-Prairie, MB
  • Raw Water Source: Assiniboine (river)
  • Water Treatment Process: screening - potassium permanganate - chlorine dioxide (when required) - ozone - flocculation (lime) - sedimentation - pH adjustment - filtration (sand) - fluoridation - chlorine
Winter (Mar 11 '93) Summer (Aug 30 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 1.4 2.8 4.3 0.6 27.1 53.5
Bromodichloromethane (µg/L) <0.1 1.1 2.8 0.2 19.9 29.8
Chlorodibromomethane (µg/L) <0.1 0.8 2.3 0.1 12.4 19.8
Bromoform (µg/L) <0.1 0.7 1.9 <0.1 1.7 2.7
Total Trihalomethanes (µg/L) 1.4 5.5 11.2 0.8 61.2 105.8
Monochloroacetic acid (µg/L) 0.34 0.37 1.91 0.75 2.59 2.29
Dichloroacetic acid (µg/L) 0.20 2.71 4.84 0.68 22.57 21.99
Trichloroacetic acid (µg/L) 0.36 0.71 1.47 0.20 21.58 46.27
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 0.29 1.27
Dibromoacetic acid (µg/L) <0.01 0.18 0.54 0.02 1.02 1.90
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.6 0.7 <0.1 4.1 4.9
Bromochloroacetonitrile (µg/L) <0.1 1.2 1.6 <0.1 2.9 3.4
Dibromoacetonitrile (µg/L) <0.1 0.4 1.0 <0.1 1.2 1.4
1,1-Dichloro-2-propanone (µg/L) <0.1 1.2 1.2 <0.1 1.3 1.0
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.2 0.3 <0.1 2.6 1.8
Chloral Hydrate (µg/L) <0.1 0.2 0.6 <0.1 3.4 7.0
Chloropicrin (µg/L) <0.1 0.1 0.2 <0.1 0.6 0.9
Bromide ion (mg/L) 0.2 0.2 0.2 0.069 0.027 0.031
Total Organic Carbon (mg/L) 6.6 4.7 4.3 8.5 5.9 5.1
Total Organic Halides (µg/L) 7 39 65 NA 225 87
NA = Not Analyzed
  • Municipality: Selkirk, MB
  • Raw Water Source: Red (river)
  • Water Treatment Process: chlorine - flocculation (lime) - flocculation (polymer) - pH adjustment - chlorine - filtration (sand)
  Winter (Mar 9 ' 93) Summer (Sep 1 ' 93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 0.5 0.5 0.3 0.3 0.4
Bromodichloromethane (µg/L) <0.1 0.6 0.7 <0.1 0.2 0.1
Chlorodibromomethane (µg/L) <0.1 1.4 1.5 <0.1 0.3 0.2
Bromoform (µg/L) <0.1 3.1 3.3 <0.1 0.8 0.2
Total Trihalomethanes (µg/L) 0.4 5.6 5.9 0.3 1.6 0.9
Monochloroacetic acid (µg/L) 1.02 0.40 0.57 0.73 0.68 0.84
Dichloroacetic acid (µg/L) 0.20 0.26 0.31 0.59 0.71 0.71
Trichloroacetic acid (µg/L) 0.05 0.09 0.12 0.05 0.04 0.11
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 0.10 <0.01 0.03
Dibromoacetic acid (µg/L) 0.01 0.54 0.81 0.02 0.06 0.05
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.1 0.1 <0.1 <0.1 <0.1
Bromochloroacetonitrile (µg/L) <0.1 0.6 0.6 <0.1 0.3 0.2
Dibromoacetonitrile (µg/L) <0.1 1.1 1.2 <0.1 0.3 0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
1,1,1-Trichloro-2-propanone (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Chloral Hydrate (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Bromide ion (mg/L) 0.50 0.40 0.50 0.07 0.32 0.49
Total Organic Carbon (mg/L) 1.2 0.7 0.7 1.7 1.2 1.3
Total Organic Halides (µg/L) 7 6 11 NA 8 23
NA = Not Analyzed
  • Municipality: Grand Bend, ON (feeding London, ON)
  • Raw Water Source: Huron (lake)
  • Water Treatment Process: chlorine - screening - flocculation (alum) - sedimentation - filtration (multi-media) - chlorine - pH adjustment
  Winter (Mar 8 ' 93) Summer (Sep 28 ' 93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 4.0 6.6 4.3 5.0 7.6
Bromodichloromethane (µg/L) <0.1 3.7 5.5 3.0 4.3 5.1
Chlorodibromomethane (µg/L) <0.1 1.8 2.5 1.6 2.5 2.7
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 0.4
Total Trihalomethanes (µg/L) 0.3 9.5 14.5 8.9 11.8 15.8
Monochloroacetic acid (µg/L) 1.33 3.08 2.20 1.22 0.91 2.01
Dichloroacetic acid (µg/L) 0.21 3.19 3.85 1.67 3.08 7.88
Trichloroacetic acid (µg/L) 0.07 3.51 5.89 1.43 2.80 4.50
Monobromoacetic acid (µg/L) <0.01 1.87 2.08 <0.01 0.12 0.41
Dibromoacetic acid (µg/L) <0.01 0.35 0.42 0.09 0.20 0.35
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.9 1.3 1.3 1.4 1.2
Bromochloroacetonitrile (µg/L) <0.1 0.6 0.8 0.4 0.7 0.6
Dibromoacetonitrile (µg/L) <0.1 0.3 0.3 <0.1 0.4 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 0.3 0.3 0.5 0.4 0.3
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.4 0.8 0.8 1.1 1.1
Chloral Hydrate (µg/L) <0.1 1.1 1.9 2.6 2.7 3.2
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 0.1 <0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA NA NA
Total Organic Carbon (mg/L) 1.7 1.2 1.2 NA 1.4 1.2
Total Organic Halides (µg/L) <5 23 23 NA 13 66
NA = Not Analyzed
  • Municipality: Mississauga, ON
  • Raw Water Source: Lakeview Plant, Ontario (lake)
  • Water Treatment Process: chlorine - screening - flocculation (alum) - sedimentation - filtration (multi-media) - chloramine - fluoridation
  Winter (Feb 3 ' 93) Summer (Aug 4 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 3.6 4.7 0.4 5.1 5.5
Bromodichloromethane (µg/L) <0.1 4.2 5.2 <0.1 5.1 5.4
Chlorodibromomethane (µg/L) <0.1 2.7 3.1 <0.1 3.1 3.2
Bromoform (µg/L) <0.1 0.8 0.7 <0.1 0.5 0.5
Total Trihalomethanes (µg/L) 0.3 11.4 13.7 0.4 13.8 14.6
Monochloroacetic acid (µg/L) 0.71 1.34 1.47 3.20 2.55 1.63
Dichloroacetic acid (µg/L) 0.35 3.29 3.23 1.90 7.05 4.15
Trichloroacetic acid (µg/L) 0.17 3.84 3.82 0.43 7.95 3.39
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.02 0.48 0.43 0.01 0.28 0.17
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 1.1 1.3 <0.1 1.5 1.4
Bromochloroacetonitrile (µg/L) <0.1 1.1 1.2 <0.1 1.7 1.3
Dibromoacetonitrile (µg/L) <0.1 0.7 0.8 <0.1 0.5 0.4
1,1-Dichloro-2-propanone (µg/L) <0.1 0.3 0.3 <0.1 0.3 0.3
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.4 0.5 <0.1 0.6 0.6
Chloral Hydrate (µg/L) <0.1 1.4 0.8 <0.1 3.1 2.5
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA 0.022 0.025
Total Organic Ca rbon (mg/L) 2.3 1.0 1.0 NA 1.9 1.9
Total Organic Halides (µg/L) <5 65 74 NA 65 47
NA = Not Analyzed
  • Municipality: North Bay, ON
  • Raw Water Source: Trout (lake)
  • Water Treatment Process: chlorine - screening - fluoridation - pH adjustment
  Winter (Mar15 '93) Summer (Sep 30 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 5.5 7.2 0.5 15.1 14.2
Bromodichloromethane (µg/L) <0.1 1.5 1.9 <0.1 2.1 2.1
Chlorodibromomethane (µg/L) <0.1 0.7 0.7 <0.1 0.1 0.1
Bromoform (µg/L) <0.1 0.6 0.6 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.4 8.3 10.4 0.5 17.3 16.3
Monochloroacetic acid (µg/L) 0.20 2.31 0.92 0.31 2.34 2.75
Dichloroacetic acid (µg/L) 0.11 7.77 9.04 0.26 6.48 14.65
Trichloro acetic acid (µg/L) 0.12 12.80 17.71 0.06 16.27 23.40
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.01 0.02 0.03 <0.01 <0.01 0.02
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.9 1.2 <0.1 1.8 1.9
Bromochloroacetonitrile (µg/L) <0.1 0.3 0.3 <0.1 0.1 0.1
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 0.8 1.0 <0.1 1.2 1.2
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.1 1.3 <0.1 1.9 1.9
Chloral Hydrate (µg/L) <0.1 0.5 0.7 <0.1 3.1 2.4
Chloropicrin (µg/L) <0.1 0.1 0.2 <0.1 0.3 0.2
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 0.003
Total Organic Carbon (mg/L) 2.4 2.4 2.3 NA 2.6 2.6
Total Organic Halides (µg/L) NA NA NA NA 57 98
NA = Not Analysed
  • Municipality: Ottawa, ON
  • Raw Water Source: Britannia Plant, Ottawa (river)
  • Water Treatment Process: chlorine - flocculation (alum) - sedimentation - filtration (multi-media) -pH adjustment - fluoridation - chloramine
  Winter (Feb 25 '93) Summer (Aug16 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.6 8.8 10.3 0.4 60.2 60.1
Bromodichloromethane (µg/L) <0.1 0.8 0.8 <0.1 3.5 3.4
Chlorodibromomethane (µg/L) <0.1 0.1 <0.1 <0.1 0.5 0.4
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 0.2 0.2
Total Trihalomethanes (µg/L) 0.6 9.7 11.1 0.4 64.4 64.1
Monochloroacetic acid (µg/L) 0.63 1.44 2.27 0.49 1.95 1.48
Dichloroacetic acid (µg/L) 0.45 14.38 16.26 0.27 11.08 10.93
Trichloroacetic acid (µg/L) 1.48 8.65 11.76 1.86 13.82 14.22
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 0.04 <0.01 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.6 0.7 <0.1 1.8 1.5
Bromochloroacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 0.5 0.7
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 0.3 0.2
1,1-Dichloro-2-propanone (µg/L) <0.1 1.4 1.6 <0.1 1.9 1.7
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.1 0.8 <0.1 1.9 1.5
Chloral Hydrate (µg/L) <0.1 0.7 0.7 <0.1 4.1 3.7
Chloropicrin (µg/L) <0.1 0.2 0.3 <0.1 0.3 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 0.002 0.002
Total Organic Carbon (mg/L) 5.6 2.3 2.2 NA 3.0 3.0
Total Organic Halides (µg/L) 12 62 57 16 207 112
NA = Not Analyzed
  • Municipality: Ottawa, ON
  • Raw Water Source: Lemieux Island Plant, Ottawa (river)
  • Water Treatment Process: chlorine - flocculation (alum) - sedimentation - filtration (multi-media) -pH adjustment - fluoridation - chloramine
  Winter (Feb 25 '93) Summer (Aug16 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 9.6 9.8 0.4 67.8 67.5
Bromodichloromethane (µg/L) <0.1 0.8 0.8 <0.1 3.8 3.8
Chlorodibromomethane (µg/L) <0.1 <0.1 <0.1 <0.1 0.6 0.7
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 0.4 0.4
Total Trihalomethanes (µg/L) 0.3 10.5 10.7 0.4 72.5 72.4
Monochloroacetic acid (µg/L) 0.24 1.81 1.41 0.78 2.22 1.48
Dichloroacetic acid (µg/L) 0.49 14.49 13.88 0.55 16.98 15.25
Trichloroacetic acid (µg/L) 1.46 10.53 8.93 4.24 85.88 71.53
Monobromoacetic acid (µg/L) <0.01 <0.01 0.02 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 <0.01 0.05 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.6 0.7 <0.1 2.2 1.4
Bromochloroacetonitrile (µg/L) <0.1 0.1 0.2 <0.1 0.7 0.7
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 0.2 0.2
1,1-Dichloro-2-propanone (µg/L) <0.1 1.5 1.5 <0.1 2.4 2.1
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.4 1.2 <0.1 0.4 <0.1
Chloral Hydrate (µg/L) <0.1 0.9 0.8 <0.1 5.1 5.0
Chloropicrin (µg/L) <0.1 0.2 0.2 <0.1 0.3 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA 0.003 <0.002
Total Organic Carbon (mg/L) 4.2 3.2 2.7 NA 3.3 3.2
Total Organic Halides (µg/L) 15 50 44 NA 196 199
NA = Not Analyzed
  • Municipality: Peterborough, ON
  • Raw Water Source: Otonabee (river)
  • Water Treatment Process: screening - chlorine - flocculation (alum) - sedimentation - filtration (multi-media) - chlorine - fluoridation - pH adjustment
Winter (Mar 9 '93) Summer (Sep 23 '93)
Water Type Raw Treate System| Raw Treated System
Chloroform (µg/L) 0.3 31.8 50.2 0.4 66.0 99.6
Bromodichloromethane (µg/L) <0.1 3.1 3.6 <0.1 5.0 6.3
Chlorodibromomethane (µg/L) <0.1 0.8 0.2 <0.1 0.3 0.2
Bromoform (µg/L) <0.1 0.6 <0.1 <0.1 0.1 <0.1
Total Trihalomethanes (µg/L) 0.3 36.3 54.1 0.4 71.4 106.2
Monochloroacetic acid (µg/L) 1.37 4.10 3.39 0.48 2.64 1.44
Dichloroacetic acid (µg/L) 0.17 24.55 26.63 0.37 29.70 9.04
Trichloroacetic acid (µg/L) 0.10 88.94 103.23 0.08 73.58 171.04
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 0.01 0.01 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 0.2 0.1
Dichloroacetonitrile (µg/L) <0.1 5.4 7.6 <0.1 6.5 7.6
Bromochloroacetonitrile (µg/L) <0.1 0.8 0.5 <0.1 0.8 0.5
Dibromoacetonitrile (µg/L) <0.1 0.6 0.3 <0.1 0.2 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.6 2.4 <0.1 1.5 0.9
1,1,1-Trichloro-2-propanone (µg/L) <0.1 4.3 6.1 <0.1 6.7 5.5
Chloral Hydrate (µg/L) <0.1 5.4 9.4 <0.1 11.6 14.2
Chloropicrin (µg/L) <0.1 0.5 0.5 <0.1 0.2 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA <0.002 <0.002
Total Organic Carbon (mg/L) 4.7 2.7 2.7 5.5 3.5 4.2
Total Organic Halides (µg/L) <5 173 141 NA 207 241
NA = Not Analyzed
  • Municipality: St. Catharines, ON
  • Raw Water Source: Erie (lake)
  • Water Treatment Process: chlorine - screening - carbon adsorption - flocculation (alum) -sedimentation - filtration (multi-media) - chlorine
Winter (Mar 8 '93) Summer (Sep 22 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 3.7 4.1 0.3 5.6 4.7
Bromodichloromethane (µg/L) <0.1 3.9 4.4 <0.1 5.3 4.7
Chlorodibromomethane (µg/L) <0.1 2.2 2.5 <0.1 2.7 2.5
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 0.4 0.3
Total Trihalomethanes (µg/L) 0.4 9.7 11.0 0.3 14.0 12.2
Monochloroacetic acid (µg/L) 0.88 1.55 0.94 0.48 0.93 0.54
Dichloroacetic acid (µg/L) 0.19 2.32 2.54 0.52 0.97 1.95
Trichloroacetic acid (µg/L) 0.30 2.49 3.35 0.22 2.12 12.30
Monobromoacetic acid (µg/L) <0.01 1.22 1.03 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 0.42 0.57 <0.01 0.07 0.09
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 1.1 1.2 <0.1 0.8 0.9
Bromochloroacetonitrile (µg/L) <0.1 0.7 0.7 <0.1 0.6 0.7
Dibromoacetonitrile (µg/L) <0.1 0.3 0.4 <0.1 0.2 0.2
1,1-Dichloro-2-propanone (µg/L) <0.1 0.4 0.3 <0.1 0.2 0.3
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.6 0.6 <0.1 0.8 0.8
Chloral Hydrate (µg/L) <0.1 1.0 1.1 <0.1 1.6 1.5
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 0.020 0.004 0.005
Total Organic Carbon (mg/L) 1.9 1.1 1.3 NA 1.4 1.5
Total Organic Halides (µg/L) 7 22 53 7 52 55
NA = Not Analyzed
  • Municipality: Sudbury, ON
  • Raw Water Source: Wanapitei (river)
  • Water Treatment Process: chlorine dioxide - flocculation (alum) - sedimentation - filtration (multi-media) - fluoridation - chlorine - pH adjustment
Winter (Mar15 '93) Summer (Sep 30 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 12.7 16.3 0.4 14.1 22.8
Bromodichloromethane (µg/L) <0.1 0.8 0.8 <0.1 1.3 1.8
Chlorodibromomethane (µg/L) <0.1 0.3 <0.1 <0.1 0.1 0.1
Bromoform (µg/L) <0.1 0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.3 13.9 17.1 0.4 15.5 24.7
Monochloroacetic acid (µg/L) 0.97 3.53 4.61 0.63 2.49 2.28
Dichloroacetic acid (µg/L) 0.15 22.51 32.28 0.24 9.39 14.25
Trichloroacetic acid (µg/L) 0.11 18.84 54.38 0.06 10.48 17.14
Monobromoacetic acid (µg/L) <0.01 <0.01 0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 0.02 0.01 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.8 1.9 <0.1 2.4 2.6
Bromochloroacetonitrile (µg/L) <0.1 0.2 0.1 <0.1 0.2 0.1
Dibromoacetonitrile (µg/L) <0.1 0.3 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.6 1.8 <0.1 1.9 1.9
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.5 2.7 <0.1 3.8 4.6
Chloral Hydrate (µg/L) <0.1 1.4 3.0 <0.1 4.0 4.8
Chloropicrin (µg/L) <0.1 0.2 0.3 <0.1 0.3 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 0.003
Total Organic Carbon (mg/L) 3.5 1.6 1.5 NA 2.2 1.7
Total Organic Halides (µg/L) <5 70 100 n/d 69 102
NA = Not Analyzed
  • Municipality: Toronto, ON
  • Raw Water Source: R.L. Clark Plant, Ontario (lake)
  • Water Treatment Process: chlorine - screening - flocculation (alum) - sedimentation - filtration (multi-media) - fluoridation - chloramine
Winter (Feb 3 '93) Summer (Aug 4 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 2.7 3.1 0.6 4.3 4.6
Bromodichloromethane (µg/L) <0.1 3.4 3.9 <0.1 4.6 4.6
Chlorodibromomethane (µg/L) <0.1 2.6 2.9 <0.1 3.1 3.0
Bromoform (µg/L) <0.1 0.8 0.8 <0.1 0.5 0.5
Total Trihalomethanes (µg/L) 0.4 9.5 10.7 0.6 12.5 12.6
Monochloroacetic acid (µg/L) 0.99 1.36 1.24 1.08 1.91 1.22
Dichloroacetic acid (µg/L) 0.37 3.19 3.81 1.19 9.78 6.28
Trichloroacetic acid (µg/L) 0.38 3.19 3.79 0.25 2.86 4.71
Monobromoacetic acid (µg/L) <0.01 0.04 0.12 <0.01 0.26 0.25
Dibromoacetic acid (µg/L) 0.17 0.61 0.85 0.02 0.62 0.44
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.9 0.9 <0.1 1.2 1.3
Bromochloroacetonitrile (µg/L) <0.1 0.8 0.9 <0.1 1.1 1.0
Dibromoacetonitrile (µg/L) <0.1 0.6 0.6 <0.1 0.3 0.4
1,1-Dichloro-2-propanone (µg/L) <0.1 0.3 0.3 <0.1 0.4 0.4
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.4 0.4 <0.1 0.5 0.6
Chloral Hydrate (µg/L) <0.1 0.7 0.5 <0.1 1.6 1.5
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Bromide ion (mg/L) <0.01 0.08 0.06 NA 0.019 0.022
Total Organic Carbon (mg/L) 0.9 1.2 1.8 1.8 1.7 1.8
Total Organic Halides (µg/L) 7 60 63 NA 47 51
NA = Not Analyzed
  • Municipality: Drummondville, QC
  • Raw Water Source: St. Francois (river)
  • Water Treatment Process: flocculation (alum) - sedimentation - potassium permanganate -chlorine - filtration (multi-media) - chlorine
Winter (Feb 25 '93) Summer (Sep 16 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 1.4 20.8 33.1 0.4 74.6 91.1
Bromodichloromethane (µg/L) <0.1 1.7 2.7 <0.1 3.5 4.0
Chlorodibromomethane (µg/L) <0.1 0.2 0.1 <0.1 0.2 0.2
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 0.1 0.1
Total Trihalomethanes (µg/L) 1.4 22.7 35.9 0.4 78.5 95.4
Monochloroacetic acid (µg/L) 1.10 2.27 2.27 0.47 4.01 3.22
Dichloroacetic acid (µg/L) 0.39 17.70 16.95 0.48 46.64 41.75
Trichloroacetic acid (µg/L) 5.04 49.95 70.37 3.40 80.35 112.66
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.02 0.03 0.02 <0.01 0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 0.1 0.1
Dichloroacetonitrile (µg/L) <0.1 4.3 5.7 <0.1 8.1 9.5
Bromochloroacetonitrile (µg/L) <0.1 0.3 0.3 <0.1 0.6 0.7
Dibromoacetonitrile (µg/L) <0.1 0.3 <0.1 <0.1 0.1 0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.3 1.0 <0.1 1.2 1.0
1,1,1-Trichloro-2-propanone (µg/L) <0.1 2.4 3.5 <0.1 5.8 7.0
Chloral Hydrate (µg/L) <0.1 3.2 4.7 <0.1 12.3 14.5
Chloropicrin (µg/L) <0.1 0.5 0.6 <0.1 1.1 1.2
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 3.8 2.4 1.5 NA 3.4 3.4
Total Organic Halides (µg/L) 47 267 237 18 211 335
NA = Not Analyzed
  • Municipality: Gatineau, QC
  • Raw Water Source: Ottawa (river)
  • Water Treatment Process: screening - flocculation (alum) - pH adjustment - sedimentation -chlorine - filtration (multi-media) - chlorine
Winter (Mar16 '93) Summer (Sep 27 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.6 12.0 17.2 0.4 51.8 91.4
Bromodichloromethane (µg/L) <0.1 1.3 1.7 <0.1 3.4 4.3
Chlorodibromomethane (µg/L) <0.1 0.3 0.1 <0.1 0.2 0.1
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.6 13.5 19.0 0.4 55.4 95.8
Monochloroacetic acid (µg/L) 1.52 2.01 1.43 0.50 6.63 1.82
Dichloroacetic acid (µg/L) 0.35 12.77 13.17 0.37 37.08 10.79
Trichloroacetic acid (µg/L) 0.53 18.53 24.65 0.91 30.14 36.62
Monobromoacetic acid (µg/L) <0.01 0.35 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 0.01 <0.01 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 1.4 2.2 <0.1 3.0 1.5
Bromochloroacetonitrile (µg/L) <0.1 0.2 0.1 <0.1 0.3 0.1
Dibromoacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 0.8 0.8 <0.1 0.6 0.6
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.5 2.2 <0.1 3.5 0.1
Chloral Hydrate (µg/L) <0.1 1.7 2.3 <0.1 5.3 7.9
Chloropicrin (µg/L) <0.1 0.3 0.3 <0.1 0.4 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 4.9 1.4 2.2 5.6 4.0 3.5
Total Organic Halides (µg/L) 13 104 123 NA 289 238
NA = Not Analyzed
  • Municipality: Granby, QC
  • Raw Water Source: Yamaska (river)
  • Water Treatment Process: chlorine dioxide - screening - flocculation (alum) - sedimentation - carbon adsorption - chlorine - filtration (sand) - pH adjustment - chlorine dioxide
Winter (Mar 3 '93) Summer (Sep 13 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.2 20.1 26.0 0.3 42.7 54.1
Bromodichloromethane (µg/L) <0.1 3.0 3.6 <0.1 5.9 6.9
Chlorodibromomethane (µg/L) <0.1 0.3 0.3 <0.1 0.4 0.5
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.2 23.4 29.9 0.3 49.0 61.5
Monochloroacetic acid (µg/L) 0.50 2.89 2.18 12.06 9.54 9.72
Dichloroacetic acid (µg/L) 0.19 18.92 18.92 0.50 19.24 7.97
Trichloroacetic acid (µg/L) 0.11 38.93 46.59 0.19 0.85 45.68
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 0.12 0.32 <0.01
Dibromoacetic acid (µg/L) 0.01 0.05 0.04 0.01 0.03 0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 3.1 3.8 <0.1 4.9 5.3
Bromochloroacetonitrile (µg/L) <0.1 0.3 0.3 <0.1 0.6 0.5
Dibromoacetonitrile (µg/L) <0.1 0.2 0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.1 0.9 <0.1 0.6 0.6
1,1,1-Trichloro-2-propanone (µg/L) <0.1 2.9 3.5 <0.1 4.8 4.7
Chloral Hydrate (µg/L) <0.1 4.2 5.9 <0.1 9.4 11.9
Chloropicrin (µg/L) <0.1 0.8 0.9 <0.1 0.6 0.7
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 5.5 2.8 2.5 6.8 3.5 3.7
Total Organic Halides (µg/L) 35 72 87 8 172 181
NA = Not Analyzed
  • Municipality: Laval, QC
  • Raw Water Source: Des Prairies (river)
  • Water Treatment Process: screening - chlorine - flocculation (alum) - flocculation (silicate) -sedimentation - filtration (multi-media) - ozone - chlorine - pH adjustment
Winter (Feb 15 '93) Summer (Sep 15 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.5 11.1 13.5 0.4 69.3 100.8
Bromodichloromethane (µg/L) <0.1 1.2 1.3 <0.1 5.2 6.6
Chlorodibromomethane (µg/L) <0.1 0.1 0.1 <0.1 0.3 0.4
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.5 12.3 14.9 0.4 74.9 107.8
Monochloroacetic acid (µg/L) 0.67 2.29 1.72 0.79 4.82 1.54
Dichloroacetic acid (µg/L) 0.42 15.02 9.35 0.85 47.58 10.69
Trichloroacetic acid (µg/L) 0.85 12.52 12.82 2.88 30.95 13.30
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.02 0.02 0.02 0.01 0.03 0.02
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 1.3 1.2 <0.1 3.1 1.7
Bromochloroacetonitrile (µg/L) <0.1 0.1 0.1 <0.1 0.3 0.4
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 2.3 1.8 <0.1 1.5 0.9
1,1,1-Trichloro-2-propanone (µg/L) <0.1 3.1 3.1 <0.1 8.1 1.5
Chloral Hydrate (µg/L) <0.1 2.9 3.3 <0.1 14.5 5.0
Chloropicrin (µg/L) <0.1 0.3 0.4 <0.1 1.7 2.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 0.010 0.003
Total Organic Carbon (mg/L) 3.7 1.7 1.7 5.1 2.8 2.0
Total Organic Halides (µg/L) <5 112 80 NA 194 210
NA = Not Analyzed
  • Municipality: Lévis, QC
  • Raw Water Source: St. Lawrence (river)
  • Water Treatment Process: screening - chlorine - flocculation (alum) - sedimentation - filtration (multi-media) - chlorine
Winter (Feb 25 '93) Summer (Sep 9 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.7 8.1 16.6 0.5 20.7 40.3
Bromodichloromethane (µg/L) <0.1 4.3 6.7 <0.1 8.1 14.0
Chlorodibromomethane (µg/L) <0.1 1.4 1.5 <0.1 1.8 2.8
Bromoform (µg/L) <0.1 0.7 <0.1 <0.1 0.1 <0.1
Total Trihalomethanes (µg/L) 0.7 14.5 24.8 0.5 30.7 57.1
Monochloroacetic acid (µg/L) 0.21 2.06 1.52 0.59 1.24 1.74
Dichloroacetic acid (µg/L) 0.21 8.02 14.02 0.80 10.19 3.96
Trichloroacetic acid (µg/L) 1.09 13.88 34.76 0.45 11.91 19.75
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 0.05 0.06
Dibromoacetic acid (µg/L) 0.02 0.13 0.23 0.01 0.10 0.02
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 1.7 3.6 <0.1 2.7 4.1
Bromochloroacetonitrile (µg/L) <0.1 0.6 0.7 <0.1 0.9 1.0
Dibromoacetonitrile (µg/L) <0.1 0.5 0.2 <0.1 0.1 0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 0.8 0.9 <0.1 0.9 0.6
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.5 2.8 <0.1 2.3 3.1
Chloral Hydrate (µg/L) <0.1 1.9 3.9 <0.1 3.0 6.1
Chloropicrin (µg/L) <0.1 0.2 0.2 <0.1 0.3 0.4
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA 0.004 0.008
Total Organic Carbon (mg/L) 2.4 1.6 1.1 NA 2.10 1.90
Total Organic Halides (µg/L) 15 196 209 NA 96 103
NA = Not Analyzed
  • Municipality: Pierrefonds, QC
  • Raw Water Source: Des Prairies (river)
  • Water Treatment Process: flocculation (alum) - sedimentation - filtration (multi-media) - ozone -chloramine
Winter (Feb 16 '93) Summer (Sep 15 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.6 9.2 13.0 0.4 56.4 90.2
Bromodichloromethane (µg/L) <0.1 1.6 2.1 <0.1 5.6 7.0
Chlorodibromomethane (µg/L) <0.1 0.2 0.2 <0.1 0.4 0.5
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.6 11.0 15.4 0.4 62.4 97.8
Monochloroacetic acid (µg/L) 1.31 1.04 0.67 0.94 4.38 4.95
Dichloroacetic acid (µg/L) 9.81 12.50 0.42 0.38 24.93 12.06
Trichloroacetic acid (µg/L) 9.13 16.93 0.85 2.24 45.61 52.46
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.04 0.04 0.02 <0.01 0.02 0.02
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 1.3 1.6 <0.1 3.1 2.3
Bromochloroacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 0.8 0.4
Dibromoacetonitrile (µg/L) <0.1 0.1 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 2.1 2.1 <0.1 1.0 0.8
1,1,1-Trichloro-2-propanone (µg/L) <0.1 2.3 3.3 <0.1 5.2 1.2
Chloral Hydrate (µg/L) <0.1 2.8 5.8 <0.1 12.6 20.1
Chloropicrin (µg/L) <0.1 0.2 0.3 <0.1 1.5 1.9
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 4.1 1.7 1.7 5.0 2.3 2.4
Total Organic Halides (µg/L) <5 26 35 NA 156 192
NA = Not Analyzed
  • Municipality: Québec, QC
  • Raw Water Source: St. Charles (river)
  • Water Treatment Process: screening - chlorine - flocculation (alum) - sedimentation - filtration (multi-media) - ozone - chlorine - fluoridation - phosphate
Winter (Feb 24 '93) Summer (Sep 8 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 4.1 5.2 0.3 54.7 87.2
Bromodichloromethane (µg/L) <0.1 1.2 1.8 <0.1 2.4 3.6
Chlorodibromomethane (µg/L) <0.1 0.2 0.5 <0.1 0.2 0.1
Bromoform (µg/L) <0.1 0.1 <0.1 <0.1 0.1 <0.1
Total Trihalomethanes (µg/L) 0.3 5.7 7.5 0.3 57.4 90.9
Monochloroacetic acid (µg/L) 0.51 1.33 1.21 0.65 1.91 4.15
Dichloroacetic acid (µg/L) 0.20 6.43 7.58 0.41 28.97 42.60
Trichloroacetic acid (µg/L) 0.08 6.31 7.93 0.15 66.06 77.30
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) <0.01 0.05 0.09 0.01 0.01 0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.5 0.7 <0.1 4.1 5.0
Bromochloroacetonitrile (µg/L) <0.1 0.3 0.2 <0.1 0.4 0.4
Dibromoacetonitrile (µg/L) <0.1 0.1 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.0 1.2 <0.1 2.9 2.3
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.9 1.3 <0.1 9.2 10.4
Chloral Hydrate (µg/L) <0.1 0.5 1.2 <0.1 11.7 18.6
Chloropicrin (µg/L) <0.1 0.1 0.1 <0.1 0.7 1.0
Bromide ion (mg/L) <0.01 <0.01 <0.01 NA <0.002 <0.002
Total Organic Carbon (mg/L) 1.1 0.9 0.7 NA 2.0 2.0
(Total Organic Halides (µg/L) 61 90 85 NA 177 229
NA = Not Analyzed
  • Municipality: Repentigny, QC
  • Raw Water Source: L'Assomption (river)
  • Water Treatment Process: screening - ozone - carbon adsorption - flocculation (alum) - flocculation (polymers) - sedimentation - filtration (multi-media) - filtration (sand) -ozone - lime - chlorine dioxide - sodium silicate
Winter (Feb 22 '93) Summer (Sep 15 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.9 2.9 4.4 0.5 23.7 23.7
Bromodichloromethane (µg/L) <0.1 2.7 4.1 <0.1 7.2 7.4
Chlorodibromomethane (µg/L) <0.1 1.9 2.4 <0.1 2.0 2.0
Bromoform (µg/L) <0.1 <0.1 0.2 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.9 7.4 11.0 0.5 32.9 33.1
Monochloroacetic acid (µg/L) 0.62 0.66 0.68 1.22 3.29 0.94
Dichloroacetic acid (µg/L) 0.18 2.43 2.22 0.56 11.12 0.95
Trichloroacetic acid (µg/L) 0.45 1.39 2.34 0.48 4.21 4.37
Monobromoacetic acid (µg/L) <0.01 0.04 0.09 <0.01 0.32 <0.01
Dibromoacetic acid (µg/L) <0.01 0.15 0.09 <0.01 0.31 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.5 0.4 <0.2 0.9 0.2
Bromochloroacetonitrile (µg/L) <0.1 0.4 0.2 <0.1 0.5 0.1
Dibromoacetonitrile (µg/L) <0.1 0.2 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.1 0.8 <0.1 1.0 0.9
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.2 1.5 <0.1 4.1 1.8
Chloral Hydrate (µg/L) <0.1 2.6 2.6 <0.1 10.4 2.1
Chloropicrin (µg/L) <0.1 0.1 0.6 <0.1 2.2 1.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 0.009 <0.002 <0.002
Total Organic Carbon (mg/L) 3.9 2.4 2.3 5.3 2.3 1.8
Total Organic Halides (µg/L) 24 114 56 17 82 66
NA = Not Analyzed
  • Municipality: St-Jean-sur-Richelieu, QC
  • Raw Water Source: Richelieu (river)
  • Water Treatment Process: screening - ozone - flocculation (alum) - sedimentation - filtration (multi-media) - chlorine
Winter (Feb 23 '93) Summer (Sep 13 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 2.3 4.0 0.3 12.9 21.0
Bromodichloromethane (µg/L) <0.1 1.1 1.8 <0.1 3.1 4.0
Chlorodibromomethane (µg/L) <0.1 0.5 0.7 <0.1 0.8 1.0
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 0.4 4.0 6.5 0.3 16.8 26.0
Monochloroacetic acid (µg/L) 0.46 0.27 0.78 0.76 0.80 1.39
Dichloroacetic acid (µg/L) 0.13 1.63 2.71 0.77 7.73 7.54
Trichloroacetic acid (µg/L) 0.07 0.99 2.01 0.10 2.75 3.42
Monobromoacetic acid (µg/L) <0.01 <0.01 0.09 <0.01 0.10 0.16
Dibromoacetic acid (µg/L) 0.02 0.09 0.12 <0.01 0.14 0.09
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.9 1.2 <0.1 1.6 1.6
Bromochloroacetonitrile (µg/L) <0.1 0.4 0.4 <0.1 0.8 0.6
Dibromoacetonitrile (µg/L) <0.1 0.2 <0.1 <0.1 <0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 0.9 0.8 <0.1 0.5 0.4
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.8 1.3 <0.1 1.1 0.6
Chloral Hydrate (µg/L) <0.1 1.0 1.9 <0.1 3.6 5.6
Chloropicrin (µg/L) <0.1 0.2 0.3 <0.1 1.6 1.8
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 3.1 0.3 1.7 NA 2.8 2.9
Total Organic Halides (µg/L) 6 15 20 7 52 66
NA = Not Analyz ed
  • Municipality: Trois-Rivières, QC
  • Raw Water Source: St-Maurice (river)
  • Water Treatment Process: screening - flocculation (alum) - sedimentation - chlorine dioxide - filtration (multi-media) - fluoridation - chlorine dioxide - lime - polyphosphates
Winter (Feb 24 '93) Summer (Sep 16 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 3.7 19.6 19.9 0.8 34.5 38.7
Bromodichloromethane (µg/L) <0.1 0.9 0.9 <0.1 1.4 1.5
Chlorodibromomethane (µg/L) <0.1 <0.1 <0.1 <0.1 0.1 0.1
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Total Trihalomethanes (µg/L) 3.7 20.5 20.9 0.8 35.9 40.3
Monochloroacetic acid (µg/L) 0.53 3.26 1.19 0.45 1.27 2.20
Dichloroacetic acid (µg/L) 0.35 27.50 16.91 0.29 13.09 7.27
Trichloroacetic acid (µg/L) 3.84 45.51 33.04 1.09 24.30 24.48
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.02 0.02 <0.01 <0.01 <0.01 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 1.7 1.8 <0.1 2.4 2.5
Bromochloroacetonitrile (µg/L) <0.1 0.1 0.1 <0.1 0.3 0.3
Dibromoacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 1.2 1.4 <0.1 0.4 0.6
1,1,1-Trichloro-2-propanone (µg/L) <0.1 2.8 3.1 <0.1 2.0 1.8
Chloral Hydrate (µg/L) <0.1 2.4 3.0 <0.1 4.7 5.6
Chloropicrin (µg/L) <0.1 0.3 0.3 <0.1 0.5 0.5
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.005 <0.002 <0.002
Total Organic Carbon (mg/L) 5.6 3.1 1.8 NA 2.7 2.7
Total Organic Halides (µg/L) 28 210 248 11 137 181
NA = Not Analyzed
  • Municipality: Montreal, QC (Verdun)
  • Raw Water Source: St. Lawrence (river)
  • Water Treatment Process: filtration (sand) - chlorine
Winter (Feb 15 '93) Summer (Sep 2 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 3.7 6.0 0.5 3.6 9.2
Bromodichloromethane (µg/L) <0.1 3.9 5.4 <0.1 3.6 8.3
Chlorodibromomethane (µg/L) <0.1 2.3 2.2 <0.1 2.4 4.6
Bromoform (µg/L) <0.1 0.1 <0.1 <0.1 0.4 0.6
Total Trihalomethanes (µg/L) 0.3 10.1 13.6 0.5 9.9 22.6
Monochloroacetic acid (µg/L) 0.47 0.67 0.18 0.64 0.60 0.59
Dichloroacetic acid (µg/L) 3.36 5.70 0.22 0.40 1.74 2.55
Trichloroacetic acid (µg/L) 3.73 10.05 0.79 0.32 1.44 2.81
Monobromoacetic acid (µg/L) 0.04 0.11 <0.01 <0.01 0.05 0.08
Dibromoacetic acid (µg/L) 0.33 0.29 <0.01 <0.01 0.36 0.43
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.9 1.2 <0.1 0.7 1.5
Bromochloroacetonitrile (µg/L) <0.1 0.7 0.6 <0.1 0.9 1.2
Dibromoacetonitrile (µg/L) <0.1 0.3 0.3 <0.1 0.2 0.4
1,1-Dichloro-2-propanone (µg/L) <0.1 0.4 0.4 <0.1 0.3 0.2
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.5 0.8 <0.1 0.4 0.8
Chloral Hydrate (µg/L) <0.1 0.3 0.5 <0.1 0.4 1.8
Chloropicrin (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 0.023 0.011 0.013
Total Organic Carbon (mg/L) 1.9 1.9 1.9 2.2 1.3 1.4
Total Organic Halides (µg/L) <5 24 44 NA 28 54
NA = Not Analyzed
  • Municipality: Moose Jaw, SK
  • Raw Water Source: Buffalo Pound (lake)
  • Water Treatment Process: screening - chlorine - aeration (when required) - flocculation (alum) -sedimentation - filtration (multi-media) - carbon adsorption (summer) -chlorine - fluoridation
Winter (Mar 18 '93) Summer (Aug 23 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 14.3 22.9 0.5 9.9 13.6
Bromodichloromethane (µg/L) <0.1 9.4 12.8 <0.1 1.3 4.3
Chlorodibromomethane (µg/L) <0.1 3.0 3.8 <0.1 0.4 2.9
Bromoform (µg/L) <0.1 <0.1 0.1 <0.1 0.1 0.7
Total Trihalomethanes (µg/L) 0.4 26.7 39.6 0.5 11.7 21.5
Monochloroacetic acid (µg/L) 2.61 0.52 0.46 0.74 0.65 0.69
Dichloroacetic acid (µg/L) 0.19 10.39 11.75 0.48 0.55 1.28
Trichloroacetic acid (µg/L) 0.47 27.28 45.12 0.48 0.47 1.75
Monobromoacetic acid (µg/L) <0.01 <0.01 0.03 <0.01 0.12 0.35
Dibromoacetic acid (µg/L) 0.01 0.19 0.34 <0.01 0.05 0.34
Trichloroacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/ L) <0.1 4.3 5.6 <0.1 <0.1 0.6
Bromochloroacetonitrile (µg/L) <0.1 1.4 1.5 <0.1 0.3 0.7
Dibromoacetonitrile (µg/L) <0.1 0.4 0.4 <0.1 <0.1 0.4
1,1-Dichloro-2-propanone (µg/L) <0.1 1.3 1.2 <0.1 <0.1 <0.1
1,1,1-Trichloro-2-propanone (µg/L) <0.1 1.6 2.6 <0.1 <0.1 0.4
Chloral Hydrate (µg/L) <0.1 5.1 8.4 <0.1 0.2 1.5
Chloropicrin (µg/L) <0.1 <0.1 0.1 <0.1 <0.1 <0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 0.017 <0.002 0.007
Total Organic Carbon (mg/L) 3.6 3.0 3.1 5.4 3.8 0.8
Total Organic Halides (µg/L) 9 91 111 <5 40 32
NA = Not Analyzed
  • Municipality: Prince Albert, SK
  • Raw Water Source: North Saskatchewan (river)
  • Water Treatment Process: screening - sedimentation - flocculation (alum) - pH adjustment -chlorine - filtration (multi-media) - fluoridation - chlorine
Winter (Mar 12 '93) Summer (Aug 26 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.3 4.1 10.8 0.4 9.9 0.3
Bromodichloromethane (µg/L) <0.1 1.5 3.4 <0.1 2.6 <0.1
Chlorodibromomethane (µg/L) <0.1 0.5 0.8 <0.1 0.6 <0.1
Bromoform (µg/L) <0.1 0.3 <0.1 <0.1 0.1 <0.1
Total Trihalomethanes (µg/L) 0.3 6.3 15.0 0.4 13.2 0.3
Monochloroacetic acid (µg/L) 0.27 1.53 1.24 0.39 1.00 0.26
Dichloroacetic acid (µg/L) 0.21 2.90 5.78 0.59 9.04 0.28
Trichloroacetic acid (µg/L) 0.63 3.84 16.95 0.04 7.41 0.08
Monobromoacetic acid (µg/L) <0.01 <0.01 0.02 <0.01 <0.01 <0.01
Dibromoacetic acid (µg/L) 0.02 0.03 0.10 0.01 0.08 <0.01
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 0.9 2.0 <0.1 1.3 <0.1
Bromochloroacetonitrile (µg/L) <0.1 0.5 0.6 <0.1 0.4 <0.1
Dibromoacetonitrile (µg/L) <0.1 0.3 0.2 <0.1 0.1 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 0.7 0.5 <0.1 0.8 <0.1
1,1,1-Trichloro-2-propanone (µg/L) <0.1 0.7 1.8 <0.1 1.0 <0.1
Chloral Hydrate (µg/L) <0.1 1.9 3.9 <0.1 2.2 <0.1
Chloropicrin (µg/L) <0.1 0.1 0.2 <0.1 <0.1 <0.1
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 0.002 0.005
Total Organic Carbon (mg/L) 1.3 1.0 0.7 NA 1.3 <0.1
Total Organic Halides (µg/L) <5 36 46 NA 55 <5
NA = Not Analyzed
  • Municipality: Saskatoon, SK
  • Raw Water Source: South Saskatchewan (river)
  • Water Treatment Process: screening - potassium permanganate - flocculation (alum) - flocculation (lime) - chlorine - fluoridation - sedimentation - filtration (multi-media) -filtration (sand) - chloramine
Winter (Mar 11 '93) Summer (Aug 26 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.4 11.5 13.1 0.5 21.3 25.3
Bromodichloromethane (µg/L) <0.1 5.1 5.6 <0.1 7.2 7.1
Chlorodibromomethane (µg/L) <0.1 1.3 1.4 <0.1 1.6 1.6
Bromoform (µg/L) <0.1 <0.1 <0.1 <0.1 0.5 0.8
Total Trihalomethanes (µg/L) 0.4 17.9 20.1 0.5 30.6 34.8
Monochloroacetic acid (µg/L) 0.19 2.09 0.84 0.45 0.65 0.34
Dichloroacetic acid (µg/L) 0.13 7.06 6.87 0.88 20.55 17.60
Trichloroacetic acid (µg/L) 0.21 10.50 10.63 0.17 10.62 12.71
Monobromoacetic acid (µg/L) <0.01 0.03 0.04 0.08 0.06 0.37
Dibromoacetic acid (µg/L) 0.02 0.25 0.25 0.05 0.20 0.18
Trichloroacetonitrile (µg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 2.0 2.0 <0. 1 3.2 3.7
Bromochloroacetonitrile (µg/L) <0.1 0.7 0.8 <0.1 1.2 1.2
Dibromoacetonitrile (µg/L) <0.1 0.2 0.2 <0.1 0.3 0.4
1,1-Dichloro-2-propanone (µg/L) <0.1 0.9 1.1 <0.1 1.4 1.0
1,1,1-Trichloro-2-propanone (µg/L) <0.1 2.0 2.0 <0.1 3.9 2.2
Chloral Hydrate (µg/L) <0.1 3.2 2.7 <0.1 5.7 5.2
Chloropicrin (µg/L) <0.1 0.1 0.1 <0.1 0.2 0.3
Bromide ion (mg/L) <0.01 <0.01 <0.01 <0.002 <0.002 <0.002
Total Organic Carbon (mg/L) 2.4 2.0 1.9 NA 1.4 1.2
Total Organic Halides (µg/L) 9 37 39 NA 93 91
NA = Not Analyzed
  • Municipality: Swift Current, SK
  • Raw Water Source: Duncairn (dam)
  • Water Treatment Process: screening - carbon adsorption - flocculation (alum) - flocculation (polymer) - sedimentation - chlorine - filtration (multi-media) -chlorine - fluoridation
Winter (Mar 18 '93) Summer (Aug 24 '93)
Water Type Raw Treated System Raw Treated System
Chloroform (µg/L) 0.5 29.4 71.3 0.5 42.6 95.4
Bromodichloromethane (µg/L) <0.1 8.1 11.7 <0.1 7.1 13.5
Chlorodibromomethane (µg/L) <0.1 1.4 1.2 <0.1 2.0 1.1
Bromoform (µg/L) <0.1 0.3 <0.1 <0.1 0.1 <0.1
Total Trihalomethanes (µg/L) 0.5 39.3 84.2 0.5 51.8 110.0
Monochloroacetic acid (µg/L) 0.52 4.59 1.58 0.40 2.57 0.39
Dichloroacetic acid (µg/L) 0.28 30.36 7.51 0.49 37.17 1.29
Trichloroacetic acid (µg/L) 0.39 139.81 228.27 0.54 107.80 4.44
Monobromoacetic acid (µg/L) <0.01 <0.01 <0.01 <0.01 0.19 0.04
Dibromoacetic acid (µg/L) <0.01 <0.01 <0.01 0.01 0.05 0.01
Trichloroacetonitrile (µg/L) <0.1 0.4 0.5 <0.1 0.1 <0.1
Dichloroacetonitrile (µg/L) <0.1 12.6 16.3 <0.1 7.7 2.3
Bromochloroacetonitrile (µg/L) <0.1 0.7 0.6 <0.1 1.3 0.1
Dibromoacetonitrile (µg/L) <0.1 0.8 <0.1 <0.1 0.4 <0.1
1,1-Dichloro-2-propanone (µg/L) <0.1 3.7 3.3 <0.1 2.5 0.8
1,1,1-Trichloro-2-propanone (µg/L) <0.1 5.4 7.3 <0.1 4.4 3.2
Chloral Hydrate (µg/L) <0.1 13.8 22.5 <0.1 11.3 3.6
Chloropicrin (µg/L) <0.1 1.2 1.6 <0.1 2.5 0.2
Bromide ion (mg/L) <0.01 <0.01 <0.01 0.009 0.004 0.010
Total Organic Carbon (mg/L) 8.0 5.1 5.1 NA 2.8 3.6
Total Organic Halides (µg/L) 14 240 435 NA 177 271
NA = Not Analyzed

Appendix 4 - Drinking Water Guidelines

Excerpted from "Guidelines for Canadian Drinking Water Quality"

Total Trihalomethanes (TTHM)

The new lower guideline for TTHM was approved in 1993 by the Federal-Provincial Subcommittee on Drinking Water, and its parent Committee on Environmental and Occupational Health. Specific wording was approved for the new guideline which is reproduced below.

"The interim maximum acceptable concentration (IMAC) for total trihalomethanes (THMs) in drinking water is 0.1 mg/L (100 µg/L) expressed as a running annual average of quarterly samples. This IMAC is based on the risk associated with chloroform, the THM most often present and generally found in the greatest concentration in drinking water. The guideline is designated as interim until such time as the risks from other disinfection by-products are ascertained. It is not expected that all water systems will be able to meet the revised THMs guideline immediately. When water systems are expanded or upgraded, every effort should be made, not only to meet the revised guideline, but to reduce concentrations of THMs to as low a level as possible. The preferred method of controlling disinfection by-products is precursor removal, however, any method of control employed must not compromise the effectiveness of water disinfection.

Since the measurements made in our survey were only conducted in summer and winter, they cannot be used to calculate directly a "running annual average of quarterly samples" as described in the guideline. Nevertheless, if the TTHM value is in excess of the 0.1 mg/L (100 µg/L) guideline, you may wish to determine the annual average by taking quarterly samples. The risk associated with TTHM is due to some of them being classified as probable human carcinogens based on positive animal studies, and some positive, but weak, epidemiological data in humans. The risk of cancer at or close to the guideline value is very low with the estimated risk from lifetime exposure (70 years) being close to one in a million.

Excerpted from Guidelines for Drinking-Water Quality 2nd Edition Volume 1 Recommendations, World Health Organization, Geneva 1993.

Dichloroacetic Acid (DCAA)

DCAA produced neuropathy and liver toxicity in laboratory animals. The available evidence of liver tumour formation in mice was considered insufficient to classify DCAA as a carcinogen, and the WHO drinking water guideline was based on a no-observed-adverse-effect-level (NOAEL) for liver toxicity in mice. A provisional guideline was set at 50 µg/L.

Trichloroacetic Acid (TCAA)

TCAA has been shown to produce toxic effects in the liver of laboratory animals. It also induced tumours in the liver of mice and was reported to produce chromosomal aberrations, but was negative in in vitro mutagenicity assays. Due to the evidence of carcinogenicity being limited to one species, the WHO drinking water guideline was based on a lowest-observed-adverse-effect-level (LOAEL) for liver toxicity in mice. A provisional guideline was set at 100 µg/L.

Chloral Hydrate (CH)

CH has been used as a sedative or hypnotic drug in humans at doses up to 14 mg/kg body weight. No long-term study in animals was identified by the WHO and the guideline was based on a 90-day study in mice where liver toxicity was observed. The lowest-observed-adverse-effect-level (LOAEL) in the mouse study was used as the basis for setting a WHO drinking water guideline at 10 µg/L. The guideline value is designated as provisional because of the limitations of the available database.

Dichloroacetonitrile (DCAN)

DCAN has been shown to be teratogenic and to have body weight effects in rats. The no-observed-adverse-effect-level (NOAEL) in the rat study was used as the basis for setting a WHO drinking water guideline at 90 µg/L. The guideline value is designated as provisional because of the limitations of the available database.

Dibromoacetonitrile (DBAN)

DBAN has been shown to produce effects on body weight in a 90-day study in rats. The no-observed-adverse-effect-level (NOAEL) in the rat study was used as the basis for setting a WHO drinking water guideline at 100 µg/L. The guideline value is designated as provisional because of the limitations of the available database.

Trichloroacetonitrile (TCAN)

TCAN has been shown to be teratogenic and to have body weight effects in rats. The no-observed-adverse-effect-level (NOAEL) in the rat study was used as the basis for setting a WHO drinking water guideline at 1 µg/L. The guideline value is designated as provisional because of the limitations of the available database.