Greater Victoria Drinking Water Quality 2014 Annual Report

Transcription

1 Greater Victoria Drinking Water Quality 2014 Annual Report Parks & Environmental Services Department Environmental Protection Prepared By Water Quality Program Capital Regional District 479 Island Highway, Victoria, BC, V9B 1H7 T: F: June 2015

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3 Greater Victoria Drinking Water Quality 2014 Annual Report Executive Summary This report is the annual overview of water quality testing conducted in 2014 within the Greater Victoria Drinking Water System (GVDWS) (Map 1). The test results indicate that Greater Victoria s drinking water continues to be good quality and is safe to drink. With a few minor exceptions, all the results were within the limits of both the Guidelines for Canadian Drinking Water Quality and the BC Drinking Water Protection Regulation. Samples and Tests. In 2014, the Water Quality Program collected 6,179 samples from the GVDWS and analyzed those samples for 29,852 individual tests. Approximately 300 different types of analyses were conducted on these samples. Data collected in 2014 are reported in the water quality data tables (see Appendix A, Tables 1, 2, and 3). Physical-Chemical-Radiological. All physical, chemical and radiological parameters were well within the Canadian Drinking Water Guideline limits except for summer water temperatures (aesthetic limit of 15ºC). In 2014, the weekly and monthly average water temperatures were above the 15 C limit for a period of about 2½ months from early August to mid-october (Figures 2 and 3). This is a typical pattern since the Sooke Lake Reservoir expansion. Previously, the water temperature was above the 15 C limit for about four months of the year. This cooler water is one of the benefits of raising the water level in Sooke Lake Reservoir and the ability to draw from deeper and cooler strata. Sooke Lake Reservoir water was again characteristic for its low alkalinity and softness and a neutral median ph of 7.2. Bacteria in Source Water. As in the past few years, the level of total coliform bacteria in the raw (untreated) source water entering the Japan Gulch Disinfection Plant continued to be higher during late summer and fall, peaking from mid-september to early October (Figure 3). An increase in total coliform counts was also observed when the Goldstream Reservoir System was used to supply water to the Japan Gulch Plant (December 1 5, 2014) during the Kapoor Tunnel shut down for the annual inspection. Nevertheless, the quality of the raw water entering the treatment plant continued to easily meet the E. coli limit of 20 colony forming units (CFU) per 100 ml at least 90% of the time, as stipulated in regulatory guidance and, therefore, continued to meet requirements to remain as an unfiltered surface water supply (Figure 3A). Treatment. Ultraviolet (UV) disinfection is used to treat the raw source water entering the distribution system, followed by the addition of free chlorine and then ammonia (to produce chloramines). The total chlorine residuals in the distribution system fluctuated seasonally, as well as geographically, in typical patterns generally within an acceptable range. However, the far extremities of the distribution system frequently experience low residual levels especially during the warm weather season (Figure 4). The monthly median total chlorine residual concentration at the entry point to the distribution system ranged from 0.80 to 1.35 mg/l. Bacteria at First Customer. Staff detected only one positive total coliform sample (in April 2014) from all samples collected at the first customer sampling location below the Japan Gulch Disinfection Plant during 2014 (Figure 4). The monthly total coliform-positive sample rate of 5% in April 2014 was still lower than the 10% limit as per Guidelines for Canadian Drinking Water Quality (Guidelines). No E. coli bacteria were found in any of the samples collected at the entry point to the distribution system. This fact provides assurance that Greater Victoria s primary disinfection process is working in a satisfactory manner. Bacteria in Distribution System. When all of the results from the various municipal distribution systems are grouped together (Figure 5), the percentage of total coliform-positive samples in the Greater Victoria distribution system did not exceed the 10% Guidelines limit during any month in 2014 and was, therefore, in compliance with the BC Drinking Water Protection Regulation. Over the last 20 years, monitoring indicates a broad reduction in total coliform bacteria detection and an overall improvement in the bacteriological quality of the water. The relatively low level of total coliform-positive samples (0.8%) reflects the balance maintained between reasonable concentrations of total chlorine in the distribution system and acceptable levels of positive bacterial samples. Greater Victoria Drinking Water Quality 2014 Annual Report Executive Summary Page i

4 Parasites. Monitoring results indicated low concentrations of Giardia cysts detected in three out of six samples in the raw water entering the Japan Gulch Disinfection Plant including one sample that contained viable Giardia cysts (Figure 6). None of the 2014 samples contained Cryptosporidium oocysts (Figure 7). The 10-year average concentrations were only total Giardia cysts and total Cryptosporidium oocysts per 100 L, respectively (Figures 6 and 7). While these are extremely low values for a surface water supply, the addition of UV disinfection provides assurance that no infective parasites can enter the GVDWS. Inorganic and Organic Chemicals. All inorganic chemicals, including metals and non-metals, were within Guideline values at the entry point to the distribution system. There were no organic chemicals detected in the raw water entering the treatment plant with the exception of trace levels of phenol, which can be found naturally at trace levels in soil and water due to decomposing animal waste and vegetation. Disinfection Byproducts. Total trihalomethanes (TTHM), byproducts of the chlorine disinfection process, were well below (range of μg/l for TTHM) the Canadian Guideline limit of 100 μg/l in the chloraminated distribution system (Figure 8). Similarly, a second group of disinfection byproducts, haloacetic acids (referred to as HAA5 because the limit is based on the concentration of a group of five haloacetic acids), were low in the chloraminated distribution system (typical HAA5 range of μg/l with one sample result of 62.1 μg/l) (Figure 9). The Canadian Guideline limit for HAA5 of 80 μg/l was introduced in Sooke Reservoir Biological Activity. The overall level of algal activity in Sooke Lake Reservoir is measured using chlorophyll-a, a component of all algal cells (Figure 10). Since the reservoir level was raised in 2003, the chlorophyll-a concentration shows a slight but steady decline. In 2014, the chlorophyll-a concentration peaked in early 2014 and early winter for both the south and north basins as a result of the typical seasonal turn-over events (see inset Figure 10). Phosphorus. The primary contributor to the higher levels of the chlorophyll-a observed in Sooke Lake Reservoir in 2004 through 2007 was higher levels of total phosphorus, a nutrient that is needed for the algae to grow. The median concentration of total phosphorus between 2003 and 2007 was approximately 70% higher than in the years before the inundation of the new shoreline in both the north and south basins of Sooke Lake Reservoir (Figure 11). However, the levels of total phosphorus are declining and the median concentration from 2008 through 2014 was only 12% higher than in the years before the inundation. The highest phosphorus levels coincided with the flooding of the newly cleared lands around the margin of Sooke Lake Reservoir when the reservoir was expanded. In 2014, the phosphorus levels were similar to the previous two years and at a comparable level to the pre-inundation era. Algae. In Sooke Lake Reservoir, it is not uncommon for algal species to become dominant at different times of the year. This trend continued in 2014 with three main peaks of algae, all of which occurred in the first half of the year (Figure 12). An extended dominance of the diatom Urosolenia eriensis occurred from February through to June (Figure 13). This fragile alga is not of significance to drinking water quality. A short peak in the concentration of the golden-brown (Chrysophyte) alga Uroglena spp. occurred in late spring which resulted in a slight fishy odour on the raw lake water as noted by Water Quality laboratory staff but was of no consequence to end users (Figure 14). Also in late spring there was a slight increase in the concentration of the diatom Asterionella formosa (Figure 15). Overall algae concentrations in the reservoir in 2014 were similar to the previous five years. Water Quality Complaints. The number and nature of water quality complaints received by CRD Water Quality staff was similar to what was experienced in previous years with no significant issues of concern. The majority of complaints were related to objectionable chlorine odour and/or taste and temporary water discolouration due to distribution maintenance activities. Page ii Greater Victoria Drinking Water Quality 2014 Annual Report Executive Summary

5 MAP 1. Greater Victoria Drinking Water Supply System Greater Victoria Drinking Water Quality 2014 Annual Report Executive Summary Page iii

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7 Greater Victoria Drinking Water Quality 2014 Annual Report Table of Contents 1.0 INTRODUCTION WATER QUALITY REGULATIONS MULTIPLE BARRIER APPROACH WATER SYSTEM DESCRIPTION SOURCE WATER WATER DISINFECTION TRANSMISSION SYSTEM DISTRIBUTION SYSTEM DISTRIBUTION SYSTEM RESERVOIRS OPERATIONAL CHANGES AND EVENTS USE OF GOLDSTREAM WATER SOOKE LAKE RESERVOIR WATER TEMPERATURE CHLORINE DOSAGE WATER QUALITY MONITORING WATER QUALITY MONITORING PROGRAMS SAMPLING FREQUENCY AND PARAMETER TESTING WATER QUALITY RESULTS INDICATOR BACTERIA AND CHLORINE RESIDUAL PARASITES PHYSICAL-CHEMICAL-RADIOLOGICAL DISINFECTANTS AND DISINFECTION BYPRODUCTS ALGAE AND SOURCE WATER NUTRIENTS WATER QUALITY COMPLAINTS CONCLUSIONS List of Figures and Appendix Figure 1 Water Level Elevation in Sooke Lake Reservoir, Figure Temperature of Raw Water Entering Japan Gulch Plant (Weekly Average)... 6 Figure 3 Raw Water Entering Japan Gulch Plant Total Coliforms and Water Temperature in Figure 3A... E.coli in Raw Water Entering Japan Gulch Plant in Figure 4 Treated Water at First Customer below Japan Gulch Plant Monthly Total Coliforms and Chlorine Residual in Figure 5 Greater Victoria Distribution System Combined Annual % Samples with Total Coliforms Present, Figure 6 Annual Average Viable and total Giardia Cysts Levels in Raw Water entering Japan Gulch Plant, Figure 7 Annual Average Total Cryptosporidium Oocysts Levels in Raw Water Entering Japan Gulch Plant, Figure Trihalomethanes in Greater Victoria Distribution System Figure Haloacetic Acids in Greater Victoria Distribution System Figure 10 Chlorophyll-a Concentrations in Sooke Lake Reservoir Before and After Inundation ( ) Figure 11 Total Phosphorus Concentrations in Sooke Lake Reservoir Before and After Inundation Figure 12 ( ) Total Algae by Division in Sooke Lake Reservoir, South basin, 1 m depth (SOL-01-01) Figure Urosolenia eriensis in Sooke Lake Reservoir, South basin, 1 m depth (SOL-01-01) Figure Uroglena spp. in Sooke Lake Reservoir, South basin, 1 m depth (SOL-01-01) Figure Asterionella spp. in Sooke Lake Reservoir, South basin, 1 m depth (SOL-01-01) Appendix A Tables 1, 2 and

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9 Greater Victoria Drinking Water Quality 2014 Annual Report 1.0 INTRODUCTION This report is the annual overview of the results from water quality samples collected in 2014 from the GVDWS (Map 1). The report contains data from the water sources, the CRD-operated Juan De Fuca Water Distribution System and the municipal distribution systems for which the CRD provides water quality monitoring services. 2.0 WATER QUALITY REGULATIONS The CRD Integrated Water Services Department (IWS) and the municipal water suppliers in the GVDWS must comply with the British Columbia Drinking Water Protection Act and Drinking Water Protection Regulation. However, due to the limited number of water quality test parameters included in the Regulation, the Water Quality Program also uses the much larger group of water quality parameters listed in the current version of the Guidelines for Canadian Drinking Water Quality for compliance purposes. These limits are provided in Appendix A, Tables 1, 2 and 3 under the column titled Canadian Guidelines. In addition to the provincial and federal regulations, on a voluntary basis, CRD IWS also complies with most of the United States Environmental Protection Agency (USEPA) rules and regulations. Some of the limits in the USEPA rules are used as the basis for the department s water treatment goals. The water quality limits in the Guidelines for Canadian Drinking Water Quality 1 following five categories: fall into one of the 1. Maximum Acceptable Concentration (MAC). This is a health-related limit and lists the maximum acceptable concentration of a substance that is known or suspected to cause adverse effects on health. Thus, an exceedence of a MAC can be quite serious and require immediate action by the water supplier. 2. Aesthetic Objectives (AO). These limits apply to certain substances or characteristics of drinking water that can affect its acceptance by consumers or interfere with treatment practices for supplying good quality drinking water. These limits are generally not health related unless the substance is well above the AO. 3. Parameters without Guidelines. Some chemical and physical substances have been identified as not requiring a numerical guideline because data currently available indicate that it poses no health risk or aesthetic problem at the levels currently found in drinking water in Canada. These substances are listed as No Guideline Required in Appendix A, Tables 1, 2, and Archived Parameters. Guidelines are archived for parameters that are no longer found in Canadian drinking water supplies at levels that could pose a risk to human health, including pesticides that are no longer registered for use in Canada, and for mixtures of contaminants that are addressed individually. Some of these parameters are still being included in the current water quality monitoring program because the analytical laboratory includes them in their scans. These parameters are listed as Guideline Archived in Appendix A, Tables 1, 2, and Operational Guidance (OG). The limit was established based on operational considerations and listed as an Operational Guidance Value. For example, the limit for aluminum is designed to apply only to drinking water treatment plants using aluminum-based coagulants. It should be noted that not all of the water quality parameters analyzed by the Water Quality Program have Canadian Guideline limits, since some of these parameters are used for operational purposes. Where the Guidelines are silent for a particular parameter, the limit for that parameter is left blank in Appendix A, Tables 1, 2, and 3. 1 (see Greater Victoria Drinking Water Quality 2014 Annual Report Page 1

10 3.0 MULTIPLE BARRIER APPROACH CRD IWS and the municipalities that operate their distribution systems use a multiple barrier approach to prevent the drinking water in the GVDWS from becoming contaminated. Multiple barriers can include procedures, operations, processes and physical components. In a drinking water system, any individual contamination barrier used in isolation has an inherent risk of failure and may result in contamination of the drinking water. However, if a number of individual barriers are used together in combination with each other and, especially if they are arranged so that they complement each other, these multiple barriers are a very powerful means of preventing drinking water contamination. All large drinking water utilities use the multiple barrier approach to prevent drinking water contamination. The exact types and applications of barriers are unique for each system in order to address the system-specific risks. The following barriers are used in the GVDWS to prevent the drinking water from becoming contaminated: 1. Good Water System Design. Good water system design is one of the preeminent barriers to drinking water contamination as it allows all of the other components within the water system to operate in an optimal fashion and does not contribute to the deterioration of the quality of the drinking water contained within the system. Good water system design includes such aspects as drinking water treatment plants that are easy to operate, piping appropriately sized to the number of users being supplied and the use of appropriate pipe materials. All new designs are designed by qualified professionals registered in BC, reviewed and approved by qualified CRD staff, and approved and permitted by a Public Health Engineer from Island Health. This acts as a multiple check on good system design. 2. Source Water Protection. CRD IWS uses what is considered the ultimate in source water protection: ownership of the catchment (watershed) lands surrounding the source reservoirs. This land area is called the Greater Victoria Drinking Water Supply Area (GVDWSA). Within this area, no public access, commercial logging, farming, mining, or recreation is permitted and no use of herbicides, pesticides, or fertilizers is allowed. This source water protection barrier eliminates many of organic and inorganic chemicals that can contaminate the source water and virtually eliminates the potential for human disease agents being present. Very few drinking water utilities in Canada and United States can claim this type of protection. In addition, the Watershed Protection Division operates a complete and comprehensive watershed management program that provides additional protection to the quality of Greater Victoria s source water. 3. Water Disinfection. The GVDWS is an unfiltered drinking water system that continues to meet the stringent USEPA criteria to remain an unfiltered surface water supply. The treatment process consists of primary disinfection (ultraviolet light and free chlorine) of the raw source water entering the treatment plant and secondary disinfection (chloramination) that provides a disinfectant residual in the distribution system. Although the water treatment barrier used in Greater Victoria is not as rigorous as that provided by most drinking water utilities using a surface water supply, the microbiological quality of the source water is exceptionally good and the Chief Medical Health Officer for Island Health has approved this treatment process as providing safe drinking water for the public. 4. Distribution System Maintenance. All water suppliers in the GVDWS provide good distribution system maintenance, including activities such as: annual water main flushing, hydrant maintenance, valve exercising, leak detection, and reservoir cleaning and disinfection. This barrier helps to promote good water quality within the distribution system. 5. Infrastructure Replacement. The timely replacement of aging water system infrastructure is an important mechanism to prevent the deterioration of water quality in the pipes and provides a continual renewal of the water system. 6. Well Trained and Experienced Staff. All water system operators must receive regular training and be certified to operate water system components. In addition, the laboratory staff cannot analyze drinking water samples in accordance with the BC Drinking Water Protection Regulation unless the laboratory has been inspected by representatives of the BC Ministry of Health and issued an operating certificate. Page 2 Greater Victoria Drinking Water Quality 2014 Annual Report

11 7. Cross Connection Control. Cross connection control provides a barrier to contamination by assisting in the detection of conditions that have the potential to introduce contaminants into the drinking water from another type of system. Therefore, in cooperation with the other water suppliers, in 2005, CRD Water Services implemented a regional Cross Connection Control Program throughout the GVDWS. 8. Water Quality Monitoring. Rigorous water quality monitoring can be considered a barrier not only because it verifies the satisfactory operation of other barriers and detects contaminations quickly, but comprehensive monitoring data may also allow water suppliers to see trends and react proactively before a contamination occurs. 4.0 WATER SYSTEM DESCRIPTION In 2014, the GVDWS supplied drinking water to approximately 350,000 people and is the third largest drinking water system operating in British Columbia. 4.1 Source Water Drinking water for the GVDWS comes from a protected watershed called the Greater Victoria Water Supply Area (Map 1). This area, which is approximately 11,000 hectares in size, is located about 30 km northwest of the city. The five reservoirs in the supply area have been used as a source of drinking water since the early 1900s. Sooke Lake Reservoir, the largest of the reservoirs, is the primary water source for the city, supplying approximately 98% of Greater Victoria's drinking water. The four reservoirs in the Goldstream system (Butchart, Lubbe, Goldstream, and Japan Gulch reservoirs) are typically offline and are used only as a backup water supply. Controlled releases from the Goldstream Watershed provide water for salmon enhancement in the lower Goldstream River. Water at the southern end of Sooke Lake Reservoir enters the intake tower and is screened through stainless steel screens (openings of 0.5 mm). From the intake tower, the water passes through two 1200 mm-diameter pipelines to the Head Tank and then through the 8.8 km-long, 2300 mm Kapoor Tunnel and then into 1525 mm and 1220 mm diameter pipes connecting the Kapoor Tunnel to the Japan Gulch Disinfection Plant where it is disinfected. Drinking water for Sooke and East Sooke is also supplied from Sooke Lake Reservoir, but travels a different route. This water is passed through a newly constructed 14.5 km-long (9 miles), 600 mmdiameter PVC pipe and ductile iron from a point just above the Head Tank through to the Sooke River Road Disinfection Plant. During the brief period of its use (typically used only during the winter when the Kapoor Tunnel is out of service for inspection by CRD IWS staff), water in the Goldstream River Watershed is released from Goldstream Reservoir and flows down the upper reaches of Goldstream River into Japan Gulch Reservoir. Water from Japan Gulch Reservoir enters the Japan Gulch Intake Tower through a low-level intake gate and enters the Japan Gulch Intake Tower, passing through a 14-mesh, stainless steel screen and is then carried in a 1320 mm-diameter pipe into the Japan Gulch Disinfection Plant. 4.2 Water Disinfection The disinfection process in the GVDWS is both simple and effective and uses two disinfection facilities to provide disinfected drinking water to two large service areas: Japan Gulch Disinfection Plant supplies the Greater Victoria Service Area (municipalities of Central Saanich, Colwood, Langford, Metchosin, North Saanich, Oak Bay, Saanich, Victoria, View Royal; a small portion of the Highlands is provided water for fire suppression) Sooke River Road Disinfection Facilities supply the Sooke and East Sooke Service Area The GVDWS Service Area receives water from the largest treatment plant, the Japan Gulch Disinfection Plant, whereas Sooke and East Sooke receive water from the smaller Sooke River Road Disinfection Plant, which uses the same disinfection process as the Japan Gulch Disinfection Plant. Greater Victoria Drinking Water Quality 2014 Annual Report Page 3

12 At the Japan Gulch Disinfection Plant, the water passes through a three-part disinfection process in sequential order two primary disinfectant steps that provide disinfection of the water entering the system followed by a secondary disinfectant step that provides continuing disinfection throughout the distribution system: 1. UV Disinfection. Ultraviolet (UV) disinfection provides the first step in the primary disinfection process (disinfection of the raw source water entering the plants) and inactivates parasites such as Giardia and Cryptosporidium, as well as reducing the level of bacteria in the water. 2. Free Chlorine Disinfection. Free chlorine disinfection provides the second step in the primary disinfection process using a free chlorine dosage of approximately 1.6 to 2.0 mg/l and a minimum of 10 minute (depending upon flow) contact time between the free chlorine and the water. The free chlorine disinfection step inactivates bacteria and provides a 4-log (99.99%) kill of viruses. 3. Ammonia Addition. The secondary disinfection process consists of the addition of ammonia to form chloramines at a point downstream where the water has been in contact with the free chlorine for approximately 10 minutes or more. The ammonia is added at a ratio of approximately 1 part ammonia to 5 parts chlorine. In the water, these chemicals combine to produce a chloramine residual (measured as total chlorine). This residual remains in the water and continues to protect the water from bacterial contamination (secondary disinfection) as it travels throughout the pipelines of the distribution system. In Metchosin, CRD IWS rechloraminates the water at Rocky Point Reservoir to boost the chlorine residual provided to the extremities of that system. Currently, there are no provisions to rechloraminate the water at the far reaches of the distribution system on the Saanich Peninsula. 4.3 Transmission System There are seven large diameter transmission mains in the GVDWS that are used to deliver bulk quantities of disinfected water to the municipal distribution systems. These transmission mains range in diameter from 1525 mm down to 460 mm and transfer water from the disinfection plants to the distribution systems listed in the next section. The Saanich Peninsula Trunk Water Distribution System receives water at two points on the Saanich Peninsula from the regional transmission system and supplies it to the three municipalities on the Saanich Peninsula. 4.4 Distribution System The GVDWS contains eight individual distribution systems. Six distribution systems are separately owned and operated by the municipalities of Central Saanich, North Saanich, Oak Bay, Saanich, Sidney, and Victoria. Victoria owns and operates the distribution system in Esquimalt. Two distribution systems are owned by the CRD and operated by CRD IWS. These latter two systems include the combined distribution system in the West Shore communities of Langford, Colwood, Metchosin, and View Royal, and a separate system supplying water to Sooke and parts of East Sooke. Each distribution system operator is called a water supplier and is responsible for providing safe water to their individual customers. 4.5 Distribution System Reservoirs Twenty-six distribution system reservoirs are scattered throughout the Greater Victoria distribution system with many of these reservoirs containing multiple cells (45 cells in total). These reservoirs balance out consumption fluctuations during the diurnal cycle, provide emergency storage for incidences like leaks and water main breaks, and provide water storage for firefighting purposes. Page 4 Greater Victoria Drinking Water Quality 2014 Annual Report

13 5.0 OPERATIONAL CHANGES AND EVENTS 5.1 Use of Goldstream Water In 2014, the Goldstream Supply System was only used to supply water to the system from December 1 5, during the time that the Kapoor Tunnel was subject to the annual inspection. 5.2 Sooke Lake Reservoir In 2014, Sooke Lake Reservoir started the year at approximately m above sea level (full service level is m; Figure 1) lower than in previous years due to a dry early winter. Sooke Lake Reservoir reached full service level on March 5, 2014 and remained full until mid-may, after which there was a steady decline throughout the summer months. Sooke Lake Reservoir reached its lowest level ( m) in late October By year s end, the water level was m, 0.13 m below full service level. 188 Figure 1. Water Level Elevation in Sooke Lake Reservoir, Current Full Service Level m Daily Water Level Elevation (m above sea level) Pre 2004 Full Service Level Jan 15-Jan 29-Jan 12-Feb 26-Feb 11-Mar 25-Mar 08-Apr 22-Apr 06-May 20-May 03-Jun 17-Jun 01-Jul 15-Jul 29-Jul 12-Aug 26-Aug 09-Sep 23-Sep 07-Oct 21-Oct 04-Nov 18-Nov 02-Dec 16-Dec 30-Dec m Figure 1 Water Level Elevation in Sooke Lake Reservoir, Greater Victoria Drinking Water Quality 2014 Annual Report Page 5

14 Figure Temperature of Raw Water entering Japan Gulch Plant (Weekly Average) Weekly Average Water Temperature (Degrees C) Water Temperature, Long Term Average 21 Water Temperature, (Avg 10.6 C) Water Temperature, Water Temperature, Water Temperature, C Water Temperature Limit (Avg 10.1 C) Long Term Average (10.6 C) (Avg 10.5 C) Jan 11-Jan 21-Jan 31-Jan 10-Feb 20-Feb 1-Mar 11-Mar 21-Mar 31-Mar 10-Apr 20-Apr 30-Apr 10-May 20-May 30-May 9-Jun 19-Jun 29-Jun 9-Jul 19-Jul 29-Jul 8-Aug 18-Aug 28-Aug 7-Sep 17-Sep 27-Sep 7-Oct 17-Oct 27-Oct 6-Nov 16-Nov 26-Nov 6-Dec 16-Dec 26-Dec Figure Temperature of Raw Water Entering Japan Gulch Plant (Weekly Average) 5.3 Water Temperature Similar to recent years, following the inundation of Sooke Lake Reservoir, the temperature of the water entering the Japan Gulch Disinfection Plant in 2014 was slightly cooler during the summer (Figure 2) than the long-term average. Before the expansion of Sooke Lake Reservoir, the water temperature entering the plant reached 15 C by mid-june. In 2014, the temperature reached 15 C in early August and remained above 15ºC until late October. Cooler water is beneficial in a distribution system because it reduces the potential for losses of chlorine residual and regrowth of bacteria. The water temperature stayed relatively high and above the long-term average for much of the fall of 2014; a phenomenon that is consistent with predicted climate change patterns and may be become prevalent in the future. 5.4 Chlorine Dosage During 2014, CRD IWS did not change the chlorine dosage rate, which remained at 2.0 milligrams per litre (mg/l) at the Japan Gulch Disinfection Plant (Figure 4). 6.0 WATER QUALITY MONITORING The Water Quality Program, CRD Parks & Environmental Services Department, is responsible for the collection, analysis and reporting of water quality information in all CRD-owned and operated portions of the GVDWS from the source reservoirs to the point of delivery (typically the water meter) to each consumer. While the municipal water suppliers are responsible for water quality and any potential corrective measures within their particular distribution system, CRD Water Quality staff provide water sampling and testing for regulatory compliance monitoring to these municipalities. 6.1 Water Quality Monitoring Programs The Water Quality Program has established three water quality monitoring programs that provide direction for the collection and analysis of water quality samples from the water system. Page 6 Greater Victoria Drinking Water Quality 2014 Annual Report

15 Aquatic Ecology Monitoring Program. The goal of the Aquatic Ecology Monitoring Program is to understand and document the components that affect or may affect the natural cycles of the source streams and reservoirs. The source reservoirs and streams in the Greater Victoria Water Supply Area (Map 1) are monitored according to the requirements of the Aquatic Ecology Monitoring Program as there are no legislated requirements for either sampling frequency or parameter selection for these water bodies. In recent years, the sampling program has been expanded to provide water quality data on the impacts of raising the water level in Sooke Lake Reservoir. Samples are also collected during severe weather. Compliance Monitoring Program. The goal of the Compliance Monitoring Program is to ensure that water quality from source to consumer meets the relevant drinking water regulations and guidelines. This program is audited by staff from Island Health. The Compliance Monitoring Program provides direction on most sampling locations in the water system including the raw water entering the plants, treated water at the first customer sampling location, sampling locations in the large transmission mains (Map 1), sampling locations in the municipal distribution systems, and individual cells of distribution reservoirs. Under this program, sampling frequency and parameter selection for these various sampling locations conform to requirements of the Guidelines for Canadian Drinking Water Quality. Water Quality Complaint Monitoring Program. The goal of the Water Quality Complaint Monitoring Program is to determine the cause of customer water quality complaints and address those complaints in a manner that is satisfactory to the customer. Water samples are collected from taps within individual houses or facilities in response to complaints from customers about the quality of water being received at their address. In addition, the Water Quality Program provides an audit function on all water quality-related aspects of the GVDWS including performance monitoring of the treatment plants and distribution system. 6.2 Sampling Frequency and Parameter Testing In 2014, the Water Quality Program collected 6179 samples from the GVDWS and analyzed those samples for individual tests. Approximately 300 different types of tests were conducted on these samples. The target sampling frequency for the individual parameters tested is shown in the last column in the tables listed below. These tables can be found in Appendix A. Table 1 Table 2 Table Untreated (Raw) Water Quality Entering Japan Gulch Disinfection Plant 2014 Treated Water Quality below Japan Gulch Disinfection Plant 2014 Treated Water Quality below Sooke Disinfection Plant Source Water Bodies In 2014, Sooke Lake Reservoir, the primary source of water for the GVDWS, was sampled approximately every two weeks throughout the year. The secondary reservoirs in the Goldstream Watershed were sampled less frequently as were the tributary streams to these reservoirs. The parameters tested included routine physical-chemical parameters, nutrients, metals, mercury and phytoplankton (commonly called algae). In 2014, over 300 samples were collected from the source tributaries and source reservoirs Raw Water Entering Disinfection Plants In 2014, the raw source water entering both the Japan Gulch and the Sooke disinfection plants were tested throughout the year on a routine sampling schedule of five days per week for Japan Gulch and once per week for Sooke. As both of these plants were supplied primarily from the same source of water (Sooke Lake Reservoir) most of the testing was conducted on the raw water entering the Japan Gulch Disinfection Plant. This is the sampling point in the GVDWS where the most extensive testing of the water is conducted although not all parameters are tested every year. In 2014, these tests included 15 physical parameters (see Appendix A, Table 1), 17 non-metallic inorganic chemicals, 31 metallic inorganic chemicals, 3 bacteriological parameters, 2 parasites, 7 radiological parameters, 74 pesticides and herbicides, 17 polycyclic aromatic hydrocarbons (PAH), 13 phenolics, and 80 other synthetic organic chemicals. Two hundred forty-two samples were collected at the sampling point where the raw water Greater Victoria Drinking Water Quality 2014 Annual Report Page 7

16 enters the Japan Gulch Disinfection Plant and 52 samples at the point where the water enters the Sooke Disinfection Plant UV Treated Water At the Japan Gulch Disinfection Plant, the water downstream of the UV treatment units was sampled on a routine sampling schedule of five days per week. Tests included the bacteriological parameters of total coliforms, E. coli, and heterotrophic plate count bacteria. In 2014, 240 samples were collected at this location Treated Water at First Customer At the first customer sampling location below the Japan Gulch Disinfection Plant, testing included most of the parameters used to monitor the raw source water except that many of the organic scan parameters were not included while all of the parameters associated with the treatment process were added. These latter tests included the disinfectant residuals (3 parameters) and the byproducts of disinfection (17 parameters). As the disinfection process was essentially the same at both the Japan Gulch and Sooke plants, the more extensive list of disinfection byproducts was tested only at the first customer location below the Japan Gulch Plant (see Appendix A, Table 2). In 2014, 295 samples were collected from the two first customer sampling locations (below Japan Gulch and below Sooke Plant) Transmission System Eighteen permanent sampling locations have been established on the large diameter transmission mains although not all of these sampling locations are used each year. Monitoring is comprised primarily of chlorine residual testing and bacterial indicator analyses (total coliforms and E. coli). In 2014, 440 samples were collected from 12 sampling locations on the transmission mains Distribution System In the various municipal distribution systems, the Water Quality Program has established approximately 150 permanent sampling locations. At these sampling locations, water quality monitoring was comprised primarily of chlorine residual testing and bacterial indicator analyses (including heterotrophic bacteria for locations having low chlorine residuals). In 2014, 2512 samples were collected from 100 sampling locations (including 10 locations from the Sooke distribution system). Disinfection byproducts were also sampled at select locations within the distribution system Distribution System Reservoirs Twenty-one of 23 reservoirs located in the distribution system were sampled by the Water Quality Program with 36 permanent sampling station locations being sampled in Again, the monitoring program focused on chlorine residuals and indicator bacteria testing. In 2014, 958 samples were collected from these reservoirs. 7.0 WATER QUALITY RESULTS The overview results of the 2014 water quality monitoring program for the GVDWS are provided below. Figures 1 14 provide a graphical presentation of selected parameters at specific sampling locations for comparison to previous years. Water Quality data are listed in Appendix A (Tables 1, 2, and 3). Note that the median (middle value between the high and low) is used in these tables rather than the average value as the median eliminates the effect of extreme values (very high or very low) on the average value and provides a more realistic representation of typical conditions. Page 8 Greater Victoria Drinking Water Quality 2014 Annual Report

17 7.1 Indicator Bacteria and Chlorine Residual The Water Quality Program analyzes drinking water samples for indicator bacteria including total coliforms, E. coli, and heterotrophic plate count bacteria. These bacterial groups are called indicators because their presence in water may indicate that disease-causing organisms are also present. Samples are collected five days per week from both the raw source water at the disinfection facilities and the treated water close to the first customer below those facilities. Where appropriate, the Canadian Water Quality Guideline concentration limits for these bacteria are listed in Appendix A, Tables 1, 2, and 3 under the column titled Canadian Guidelines. The description below provides an overview of the bacteriological water quality for broad categories of sampling locations Raw Water Entering Plant Total Coliform Bacteria. Similar to the past eight years, the concentration of total coliform bacteria increased in the raw (untreated) source water entering the Japan Gulch Disinfection Plant during the summer and early fall of 2014 (Figure 3). The total coliform counts declined in late October. The types of total coliforms present were not indicative of any particular type of contamination. E. coli Bacteria. During more than two decades of monitoring bacteria within the GVDWS, it has been found that virtually 100% of the fecal coliform bacteria detected in the source water and the distribution system are E. coli. In 2014, as in the period from , the low detection of E. coli bacteria indicated that the raw water entering the Japan Gulch Disinfection Plant from Sooke Lake Reservoir was good quality source water and complied with the fecal coliform limit in the USEPA Surface Water Treatment Rule to remain an unfiltered drinking water supply (Figure 3A). Annually ( ), only about 11% of the samples collected from the raw source water contain E. coli and those that are positive for E. coli have levels below 20 CFU/100 ml more than 99% of the time. Similar to previous years, in 2014, higher levels of E. coli were found during the period that the drinking water system was fed from Goldstream Reservoir (early December). Nevertheless, in 2014, the disinfection process at the two treatment plants provided satisfactory protection and at no time was the safety of the drinking water compromised. Greater Victoria Drinking Water Quality 2014 Annual Report Page 9

18 1000 Figure 3. Raw Water Entering Japan Gulch Plant Total Coliforms and Water Temperature in Daily Total Coliforms (count/100 ml) Water Temperature Limit 15C Water Temperature Total Coliform Bacteria Monthly Median Water Temperature (C) Figure 3 01-Jan Jan Jan Feb Feb Mar Mar Apr Apr May May Jun Jun Jul Jul Jul-14 Raw Water Entering Japan Gulch Plant Total Coliforms and Water Temperature in Aug Aug Sep Sep Oct Oct Nov Nov Dec Dec Dec-14 0 Figure 3A. E. coli in Raw Water Entering Japan Gulch Plant in E. coli (CFU/100 ml) E. coli (CFU/100 ml) Jan May-10 E. coli in Raw Water, Aug Dec Apr Aug Dec Apr Aug Dec Apr Aug Dec Apr Aug Dec-14 E.coli Positive Samples(%) % E.coli Exceeding 20 CFU/100mL Annual % E. coli Found, Jan Jan Jan Feb Feb Mar Mar-14 9-Apr Apr-14 7-May May-14 4-Jun Jun-14 2-Jul Jul Jul Aug Aug Sep Sep-14 8-Oct Oct-14 5-Nov Nov-14 3-Dec Dec Dec-14 About 11% E. coli positive annually % E. coli Exceeding 20, USEPA Limit to Remain Unfiltered USEPA Surface Water Treatment Rule Limit to Remain Unfiltered (Less than 10% of samples may exceed 20 E. coli CFU/100mL) On Goldstream Dec 1-5, 2014 Figure 3A E.coli in Raw Water Entering Japan Gulch Plant in 2014 Page 10 Greater Victoria Drinking Water Quality 2014 Annual Report

19 7.1.2 Treated Water at First Customer Bacterial Indicators. The data collected from the treated water sampling location near the first customer below the Japan Gulch Disinfection Plant indicated that the bacteriological quality of the disinfected water was good in all months of the year (Figure 4 and Appendix A, Table 2). In 2014, there was one total coliform-positive sample in the 247 samples analyzed (Figure 4). This is a continued reflection of the improved primary disinfection process implemented in October 2001 and the addition of UV disinfection in January In addition, no total coliform-positive samples were found in the 52 samples collected at the first customer sampling location below the Sooke Disinfection Plant. 100 Figure 4. Treated Water at First Customer Below Japan Gulch Plant Monthly Total Coliforms and Chlorine Residual in Monthly Total Coliform Bacteria Positive Samples (%) Total Chlorine Residual 5% Positive samples containing total coliform bacteria (1 sample) 10% Total Coliform Bacteria Limit Monthly Median Total Chlorine Residual (mg/l) 0 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 0 Figure 4 Treated Water at First Customer below Japan Gulch Plant Monthly Total Coliforms and Chlorine Residual in 2014 Chlorine Residual. The monthly average chlorine residual levels at the first customer sampling location below the Japan Gulch Plant is provided in Figure 4. From this figure, it can be seen that the monthly average chlorine residuals at the first customer sampling point varied somewhat throughout the year. The dosage rate was kept constant throughout 2014 at 2.0 mg/l. The annual median chlorine residual at the first customer was 1.11 mg/l (see Appendix A, Table 2). Compared to other chloraminated drinking water systems across North America, this is low Distribution System Water Bacterial Indicators. Considering all of the individual municipal distribution systems together as a single entity called the Greater Victoria Distribution System, during 2014, total coliform bacteria were detected during seven months of the year (January and May-October). However, the percentage of positive total coliform samples did not exceed the 10% total coliform limit during any month in 2014 and, therefore, was in compliance with the BC Drinking Water Protection Regulation. This was similar to the past 10 years (2000 onwards) and much better than in earlier years. In addition, the annual total coliform-positive percentage (0.8% in 2014) was quite low and similar to the low levels of coliform-positive samples found in the Greater Victoria Distribution System in the past 10 years (Figure 5). Greater Victoria Drinking Water Quality 2014 Annual Report Page 11

20 % Annual Total Coliform Bacteria Positive Samples % of Samples Figure 5. Greater Victoria Distribution System Combined Annual % Samples with Total Coliforms Present, % Total Coliform Bacteria Limit Seasonal Disinfection started Percentage of Samples with Chlorine Residual less than 0.2 mg/l min free chlorine contact time started UV Disinfection started % Monthly TC TC Present (%) Monthly % Samples with with Total Total Coliforms Coliforms Jan-95 Jan-92 Jan-96 Jan-93 Jan-97 Jan-98 Jan-94 Jan-99 Jan-95 Jan-00 Jan-01 Jan-96 Jan-02 Jan-97 Jan-03 Jan-04 Jan-98 Jan-05 Jan-99 Jan-06 Jan-07 Jan-00 Jan-08 Jan-01 Jan-09 Jan-10 Jan-02 Jan-11 Jan-03 Jan-12 Jan-13 Jan-04 Jan Figure 5 Greater Victoria Distribution System Combined Annual % Samples with Total Coliforms Present, Over this 20-year period of time, the reduction in total coliform detection (shown in the inset in Figure 5), and the improved bacteriological water quality can be attributed to a number of factors including 1990 Relining of old cast iron water mains in Oak Bay, Saanich, and Victoria 1993 Introduction of annual reservoir cleaning (Water Services Dept. and other water suppliers remove the sediment load in the reservoirs) 1995 Introduction of unidirectional flushing in a number of municipal systems to reduce the sediment load in the water mains 1995 Use of water quality as one of the criteria for replacing aging infrastructure (e.g., replaced old cast iron water main to William Head Institute) 1996 Introduction of the seasonal increase in chlorine dosage in summer months to provide better disinfection and chlorine residuals to the extremities 2001 Use of free chlorine for primary disinfection to provide improved bacteriological disinfection of the raw water entering the system 2002 Startup of Rocky Point Road rechloramination station 2004 Use of UV disinfection to provide improved parasite and bacteriological disinfection Chlorine Residual. The annual median chlorine residual for samples collected from the various sampling locations within the Greater Victoria and Sooke Distribution systems was 0.53 mg/l. This value is similar to the level observed in previous years. The level of chlorine residual in the distribution system ranged between 0 and 1.77 mg/l. The highest value observed (1.77 mg/l in Metchosin at Aquarius) was well below the 3.0 mg/l limit in the Canadian Guidelines for chloramines. Page 12 Greater Victoria Drinking Water Quality 2014 Annual Report

21 Nitrification. Nitrification occurs in many chloraminated distribution systems. Nitrification is a bacteriological process in which ammonia is oxidized initially to nitrite and then to nitrate. The process is a complex phenomenon caused by two groups of bacteria that have low growth rates relative to other bacteria. Water temperature appears to be a critical factor for nitrification in distribution systems as it has been almost exclusively associated with warm water temperatures. Nitrification is also associated with high water age (reservoirs, dead ends, low-flow pipes), and with sediment biofilms. Monitoring for nitrifying bacteria directly is inefficient; however, the extent of nitrification in the distribution system can be monitored by measuring chlorine residuals and nitrite (also nitrate, free ammonia). When the chlorine residuals drop (in the absence of any pipe break or plant disinfection failure) accompanied by increases of nitrite then nitrification is occurring. Since Greater Victoria s source water has no background nitrite, the presence of nitrite in the distribution system is the best indicator of nitrification. The control of nitrification in a chloraminated distribution system involves limiting the excess free ammonia leaving the disinfection plant, maintaining an adequate chlorine residual throughout the distribution system, minimizing water age in storage facilities and in the low-flow areas of the distribution system, and maintaining annual flushing routines to limit the accumulation of sediment and biofilm in the distribution system piping. Water Quality staff, in conjunction with operations and engineering staff, are undertaking projects to optimize the reservoir and pipe cleaning schedules to address nitrification and other water quality affecting processes throughout the distribution systems. 7.2 Parasites In 2014, parasite samples were collected approximately bimonthly as part of the Water Quality Program s routine Compliance Monitoring Program and sent to Hyperion Research Laboratories, a contract laboratory in Alberta. This reduced sampling frequency relative to previous years was made after an evaluation of long-term data showed extremely low detection of these organisms. In 2014, six samples were collected for parasite analysis from the raw water sampling location at the Japan Gulch Treatment Plant. Figure 6 and Figure 7 show the results of the parasite monitoring data collected by Water Quality staff. It should be noted that the efficiency of the analysis for detecting Giardia, and especially Cryptosporidium, is quite low (typically in the 15 25% range). Giardia and Cryptosporidium. In 2014, low concentrations of Giardia cysts were detected in three out of six samples on the raw water entering the Japan Gulch Disinfection Plant including one sample that contained viable Giardia cysts (Figure 6). None of the 2014 samples contained Cryptosporidium oocysts (Figure 7). The 10-year average total Giardia cyst and total Cryptosporidium oocyst concentrations were only cysts and oocysts per 100 L, respectively (Figures 6 and 7). While these are extremely low values for a surface water supply, the addition of UV disinfection provides assurance that no infective parasites can enter the GVDWS. All annual average concentrations were well below the disinfection limit specified by the USEPA Surface Water Treatment Rule and only require 2-log (99%) inactivation according to the USEPA rules. All of these parasite numbers are extremely low for a surface water supply and demonstrate the excellent protection provided to Greater Victoria s drinking water, not only by controlling activities in the Greater Victoria Water Supply Area, but also by the inability of the parasites to gain access to the intake tower from within the relatively large Sooke Lake Reservoir. Greater Victoria Drinking Water Quality 2014 Annual Report Page 13