Bowen Island Municipality

Transcription

1 Bowen Island Municipality Hood Point Water System EOCP Small Water System # Drinking Water Quality Annual Report Calendar Year 2010 March 11, 2011

2 TABLE OF CONTENTS EXECUTIVE SUMMARY... 3 A. INTRODUCTION... 3 B. ADMINISTRATION... 3 BIM Staff... 4 Hood Point Water System Local Advisory Committee... 4 C. SYSTEM DESCRIPTION... 4 General... 4 Water Supply and Storage... 4 Treatment... 5 Distribution System... 5 D. WATER QUALITY TESTING... 6 Distribution System Water Quality Testing... 6 Results... 7 E. EVENTS, GRANTS, STUDIES AND REPORTS, SYSTEM IMPROVEMENTS... 8 Events... 8 Grants, Studies and Reports... 8 System Improvements in 2010:... 9 Future Planning for 2011:... 9 F. ADVISORIES... 9 Watermain Flushing Advisories... 9 G. OPERATOR QUALIFICATIONS... 9 H. SECURITY MEASURES I. EMERGENCY RESPONSE PLANS APPENDIX 1 MONITORING SITE MAP APPENDIX 2 - DISTRIBUTION SYSTEM WATER QUALITY APPENDIX 3 BCAT ANALYTICAL ANALYSIS APPENDIX 4 BCAT ENHANCED WATER POTABILITY ANALYSIS APPENDIX 5 - NOTIFICATION AND EMERGENCY RESPONSE PLAN APPENDIX 6 MUNICIPAL UTILITY OPERATORS CERTIFICATION APPENDIX 7 PERMIT TO OPERATE Page 2 of 24

3 EXECUTIVE SUMMARY This report has been prepared to support an application for an annual Ministry of Health Operating Permit issued by the Medical Health Officer as required by the Drinking Water Protection Act and Regulation. Since its incorporation in December of 1999, the Bowen Island Municipality (BIM) has undergone many changes. Those directly affecting water system operation include the changes to the internal staffing structure, and operating strategy, and operations contracting, all occurring late in These changes have begun to result in more consistent and accountable water quality reporting and infrastructure upgrade planning. The year 2004 was the first full calendar year with Municipal Staff responsible for the Hood Point Water System Operation and Maintenance. In May of 2010, the Bowen Island Municipality brought all maintenance and operations of the six municipal water systems in-house. Water quality issues such as turbidity management, chlorination, and the reduction of the risk of waterborne infection from organisms such as giardia and cryptosporidium are source water issues. BIM is working on a systematic approach to address these problems. There were no boil water advisories issued for the Hood Point Water System in A. INTRODUCTION The Hood Point water system is one of six water systems owned and operated by the Bowen Island Municipality (BIM). Water is supplied from a surface water source to approximately 87 residential connections in the Hood Point area, located on the northeast corner of Bowen Island. The distribution system consists of one pressure zone, all service connections are metered. Meters are read regularly, although seasonal meter-based billing is not in effect. Issues which challenge the system include the following: source water protection; treatment; fire protection; operational limitations; potential for water main freezing during winter. B. ADMINISTRATION The operation and management of the Hood Point water system is administered by BIM, with assistance from other organizations. For its water system operation and management, BIM relies on BIM staff, the Hood Point Water System Local Advisory Committee and the Water Systems Contractor. Page 3 of 24

4 BIM Staff The Superintendent of Utilities oversees the water system operations contract, interacts with the contractor and internal staff (commencing in May 2010) on operational issues on a daily basis, coordinates the supply and delivery of parts and supplies, and coordinates with engineering consultants. The ultimate responsibility for water system operation and maintenance lies with the Bowen Island Municipality. Hood Point Water System Local Advisory Committee The Hood Point Water System Local Advisory Committee is a sub-committee of the Municipal Council. It has advisory powers to Council regarding water system issues, and also reviews the operating and capital budgets for the utility. The committee was established prior to Municipal incorporation, when the system was administered as an Improvement District. C. SYSTEM DESCRIPTION General The Hood Point water system is one of six separate water systems owned and operated by the Bowen Island Municipality. The system is located on the east side of Bowen Island, and is set in a rural area amongst nature, abundant vegetation, and surrounding forest. Funding the through user fees, and is not subsidized by General Municipal or other funds. The system was originally constructed and operated as an Improvement District. The water system has been classified by the EOCP as being a Small Water Distribution System (System number 656). The Ministry of Health Planning has issued a Permit to Operate as Facility Number The replacement value of the water system infrastructure is roughly estimated to be $2 Million. Water Supply and Storage The source of water for Hood Point is from Honeymoon Lake located approximately 2.7 km to the west of Hood Point. The Municipality has over 120 separate water licenses on Honeymoon Lake and Creek for this water system. When the water system was originally set up, each property had Page 4 of 24

5 its own water license and these have not been combined to reduce the cost of the licensing. The total catchment area of the lake is km 2. The existing useable storage volume of the lake is approximately 71,000 m 3 based on a depth of 2.49 m of storage below the crest of the spillway. A 30 m wide earth fill dam is located to the west of the lake. A concrete spillway controls the top water level of the lake. The reported spillway level at the lake is elevation ±172.5 metres. The lake intake consists of a 70 m long 200 mm Ø DR 32.5 HDPE pipe with a stainless steel well screen supported by a floating wooden raft. The screen provides coarse filtering of the water as it enters the supply main. The supply main consists of approximately 1525 mm of 150 mm Ø DR 35 HDPE and 1660 m of 100 mm Ø DR 21 to DR 9 pipes from the west side of Honeymoon Lake. Most of the HDPE supply main is located above ground and is subject to freezing during the winter. Treated water is stored in a 50,000 IGal concrete tank, located south of Hood Point. The top water level (TWL) of the tank is at elevation 96.5 metres. Treatment The water from the supply main is treated in a filtration and disinfection facility before storage in the tank. Water treatment consists of rapid sand filtration, UV disinfection and chlorination. The water is filtered through two USF AMM36-2F7D-CC multimedia filters. The filter tanks are fiberglass with a rated 225 l/sec (50 Igpm) capacity at a maximum system pressure of 100 psi. The media bed consists of anthracite, filter sand and garnet on a graded quartz support bed. The multimedia filters are rated for removal to 10 microns. A pressurized UV light system is installed after the filters, and before the chlorination system. Water treatment is by flow-paced injection of sodium hypochlorite into the water supply main with limited contact time and is UV disinfected. Turbidity is recorded by the SCADA system and monitored regularly by BIM System Operators. The treated water goes to the 50,000 gallon storage reservoir. Distribution System The system consists of one pressure zone which is controlled by the top water level in the reservoir. The distribution system consists of: Page 5 of 24

6 Approximately the following lengths of DR 13.5 and DR 11 HDPE pipe: m of 250 mm Ø pipe m of 200 mm Ø pipe m of 150 mm Ø pipe m of 100 mm Ø pipe m of 50 mm Ø pipe 10 fire hydrants 87 service connections 115 service connections (including vacant lots) All services are metered. D. WATER QUALITY TESTING BIM is responsible for ensuring monitoring and testing the raw and treated water quality as follows: Treated water quality samples: - Daily manual testing is performed for chlorine, - Weekly water samples are directly relayed to Vancouver Coastal Health Authority (North Shore) for testing for Total and Fecal Coliform - Annual THM and HAA testing Raw water quality samples: - Raw water sampling is performed twice a year. Distribution System Water Quality Testing BIM s sampling program is based on accepted protocols developed in consultation with the Medical Health Officer (MHO). The program provides bacteriological, chemical and physical testing to evaluate water quality. There are three sampling station located within the system to give an indication of the water quality throughout the distribution system, plus one sampling station at the treatment building for turbidity. Test locations within the distribution system are as follows: Test Locations Approximate Address Tested For No. 1 No. 2 No. 3 No Hood Point Road 284 Smugglers Road 1629 Eagle Cliff Road Water Treatment Plant Chlorine Residuals Turbidity Page 6 of 24

7 Maximum acceptable concentrations have been established for certain substances known or suspected to cause adverse effects on health. The standards have been derived to safeguard health on the basis of lifelong consumption and the use of the water for all usual domestic purposes, including personal hygiene. A description of all test parameters, allowable limits and a summary of the 2010 test results may be viewed in the Distribution System Water Quality section of the Appendices. Results a. Bacteria There were no boil water advisories issued for the Hood Point water system in b. Physical Water temperature and turbidity are beyond the control of the Hood Point water system. Of the 356 Turbidity readings taken, 4 (1.12%) read above 1NTU. c. Chemical As of April 2005, the operators began maintaining 0.2 ppm as a minimum target level. Sampling stations indicate that the recommended minimum chlorine residual of 0.2 ppm was generally maintained during Of the 728 readings taken at three locations, 8.6% of the readings failed (i.e. lower than 0.2 ppm chlorine residual). The historical trend for chlorine residual statistics is as follows: No. of Readings High (ppm) Low (ppm) Average (ppm) 1876 Hood Point Road No. Fail % Fail 27.08% 7.23% 6.34% 3.01% 4.11% 6.58% Page 7 of 24

8 No. of Readings High (ppm) Low (ppm) Average (ppm) 1629 Eagle Cliff Road No. Fail % Fail 11.18% 9.70% 15.47% 8.64% 15.77% 10.74% d. THMs and HAAs The following analytical results are from the Hood Point water distribution system for: disinfection by-products (Haloacetic Acids and Trihalomethanes). This monitoring is required under the Water Quality Monitoring and Reporting Plan for Metro Vancouver and Member Municipalities. THM and HAA test results are provided in Appendix C, and summarized as follows: 2006 Dec Dec Dec Dec Dec14 Recommended Maximum THMs ppb HAAs <95 <59.8 <91.4 < ppb* *The recommended maximum for HAAs was raised in 2008 from 60 ppb to 80 ppb E. EVENTS, GRANTS, STUDIES AND REPORTS, SYSTEM IMPROVEMENTS The following events were noted regarding the Hood Point Water System: Events The Hood Point watermain froze on December 30, A temporary line was connected between Eagle Cliff water system and Hood Point water system supplying treated water. The Main was back in operation on January 5, Grants, Studies and Reports The municipality will continue to update its web site to include information about the water system as any future grants, studies or reports are completed. Page 8 of 24

9 System Improvements in 2010: Hood Point berm and landscape screen installed over Right of Way Future Planning for 2011: Upgrade the water storage dam berm at Honeymoon Lake Install jumper line form Eagle Cliff to Hood Point Honeymoon Lake access road upgrade Honeymoon Lake dam upgrade Upgrade meter reading software for ease of water usage F. ADVISORIES Watermain Flushing Advisories Public advisories were issued by the Municipality prior to watermain flushing which is completed once each year. An advisory was issued for the following period: October 16 to November 20, 2010 G. OPERATOR QUALIFICATIONS The following table summarizes the qualifications of BIM staff and contracted operators for the 2010 calendar year. Employee Position Courses/Qualifications Work Experience Bob Robinson Superintendent of Utilities, Bowen Island, BC, October 2003-present BIM STAFF EOCP Small Water System Operator Barry Dempsey Utility Operator EOCP Small Water System Operator Duy Son Utility Operator EOCP Small Water System Operator Gavin Arnott Utility Operator EOCP Small Water System Operator Page 9 of years watermain construction experience. 8 years Municipal Public Works experience. 8 mths Municipal Utility experience 8 mths Municipal Utility experience 8 mths Municipal Utility experience

10 Ed Weismiller Water System Operation Contractor (prior to May, 2010) Owner, BRS Paul Morgan Operations EOCP Small Water Systems Manager, BRS Operator Andrew Stone BRS, Staff EOCP Small Water System System Operator Operator Katherine Gish BRS, Staff EOCP Small Water System Operator System Operator 6 years with BRS 6 years with BRS H. SECURITY MEASURES Security measures for water systems typically concentrate on protection of water sources and reservoirs. BIM has not employed any extraordinary measures. Supply points (dam, main from dam to storage facilities, and treatment plant) could be the most vulnerable components of our system but in reality are no more vulnerable than fire hydrants and individual service connections. BIM will continue to be apprised of security issues and will implement operational changes as required. I. EMERGENCY RESPONSE PLANS BIM Notification and Emergency Response Plans are included in the Appendices. Affected staffs (Municipal and contractor) have been informed of the plan to prepare for appropriate action at critical moments. Page 10 of 24

11 APPENDIX 1 MONITORING SITE MAP Page 11 of 24

12 APPENDIX 2 - DISTRIBUTION SYSTEM WATER QUALITY The following provides a simple description of the sampling parameters: Sample Parameter Sample Description Fail Limit CL2Free mg/l Free Chlorine in milligrams per litre <.2 The chlorine residual within the water distribution system is the indicator for the effectiveness of the disinfection process. The goal is to maintain a minimum of 0.2 mg/l at the extremities of the distribution system. Fcoli MF/100mLs Fecal coliforms Membrane Filtered per 100 millilitres 0 The microbiological quality of water is measured by sampling the number of coliform organisms. Fecal coliforms are considered key indicators and could indicate sewage contamination. None of the coliform organisms detected should be fecal coliforms. In rare circumstances the fecal coliform test and the total coliform test will read MPN/100mLs. This indicates the sample was too turbid for the normal Membrane Filtration test and required an alternative method. MPN is an abbreviation of Most Probable Number. Tcoli MF/100mLs Total coliforms Membrane filtered per 100 millilitres >10 The microbiological quality of water is measured by sampling the number of coliform organisms. No sample should contain more than 10 total coliforms per 100 millilitres and 90 percent or more of the samples taken in a 30-day period must have zero coliform organisms. As well, no more than 2 consecutive samples from the same site should show the presence of coliform organisms. Page 12 of 24

13 Results The following charts illustrate the Chlorine Residual results at each sampling station and the Turbidity at the Hood Point Treatment Plant in Page 13 of 24

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15 APPENDIX 3 BCAT ANALYTICAL ANALYSIS Page 15 of 24

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17 APPENDIX 4 BCAT ENHANCED WATER POTABILITY ANALYSIS Page 17 of 24

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19 APPENDIX 5 - NOTIFICATION AND EMERGENCY RESPONSE PLAN Hood Point Water System Bowen Island Municipality Potential Emergency Situations and Responses Broken water main Bowen Island Municipal System Operators will isolate the affected part of the system, shut water off and arrange for repairs Notify the Public Works Manager Notify affected users of interruption in service Post emergency sign, if necessary Advise Bowen Island Fire Department Arrange alternate source if necessary (bottled water) Advise Vancouver Coastal Health Authority (North Shore) Contact affected users and Vancouver Coastal Health Authority (North Shore) when system has been repaired. Chlorinator failure Bowen Island Municipal System Operators will arrange for chlorinator repairs Notify the Public Works Manager Advise Vancouver Coastal Health Authority (North Shore) Notify all users to boil water or take other disinfection procedures in accordance with recommendations of local health officials Issue Boil Water Advisory to all users Post emergency sign, if necessary Contact users and the System Operator when Boil Advisory has been rescinded Pump failure Bowen Island Municipal System Operators will arrange for repairs Notify the Public Works Manager Notify users in the affected area of interruption in service Post emergency sign if necessary Arrange alternate source if necessary (bottled water/bulk hauler/storage tank) Advise Vancouver Coastal Health Authority (North Shore) Contact users and Vancouver Coastal Health Authority (North Shore) when pump has been repaired Power failure Bowen Island Municipal System Operators to arrange with BC Hydro for repairs if necessary Notify Public Works Manager Notify BC Hydro Post emergency sign, if necessary Notify affected users of interruption in service if the power shortage is going to be long enough that storage tank will run dry Arrange alternate source if necessary (bottled water/bulk hauler/storage tank) Contact Vancouver Coastal Health Authority to inform them of what happened. Page 19 of 24

20 Contamination of/or loss of source (e.g. spills, vandalism) Abnormal or suspect water quality result detected by System Operator Coliform count too high from samples Backflow or back siphonage Natural Disasters such as fire, flooding, earthquake, mudslide, dam failure. Bowen Island Municipal System Operators will put up emergency sign, if necessary, and shut down system Advise Public Works Manager Advise Vancouver Coastal Health Authority (North Shore) Prepare notice weekdays distribute notice via mail, weekends hand deliver or distribute the most efficient way possible Contact government agencies for advice and assistance (e.g., Provincial Emergency Preparedness, RCMP, Ministry of Environment, Department of Fisheries) Advise Media outlets Arrange alternate source if necessary (bottled water/bulk hauler/storage tank) Contact users and Vancouver Coastal Health Authority (North Shore) when problem has been resolved Advise Vancouver Coastal Health Authority (North Shore) immediately, and follow their directives. If users have to be notified, follow same procedure as when coliform count is too high from samples Bowen Island Municipal System Operators to initiate remedial measures as directed by Vancouver Coastal Health Authority (North Shore) Contact Public Works Manager Notify all users to boil water or take other disinfection procedures in accordance with recommendation of local health officials Post emergency sign if necessary Issue Boil Advisory to all users Contact users when Boil Advisory has been rescinded Bowen Island Municipal System Operators to isolate affected part of the system, arrange for repairs/corrections, and purge and disinfect lines as necessary after repairs/corrections have been made Advise Public Works Manager Advise Vancouver Coastal Health Authority (North Shore) Post emergency sign if necessary Contact affected users to boil water or take other disinfection procedures in accordance with recommendation of local health officials Issue Boil Advisory to affected users with the recommendations of the Local Health Officials Contact affected users when Boil Advisory has been rescinded Notify Bowen Island Fire Department Advise Public Works Manager. Advise Vancouver Coastal Health Authority (North Shore) Contact all users Contact government agencies for advice and assistance (e.g., Provincial Emergency Preparedness, RCMP, Ministry of Environment, Department of Fisheries) Arrange alternate source if necessary (bottled water/bulk hauler/storage tank) Page 20 of 24

21 Contact users and Vancouver Coastal Health Authority (North Shore) when system has been repaired Notification It is intended to notify the Public Works Manager, Bowen Island Fire Department, Vancouver Coastal Health Authority (North Shore), B.C. Hydro and various government agencies by phone, or fax. It is intended to notify the System Users by the following methods, as required: Phone Post emergency signage Written Notice distributed by mail Written Notice distributed door to door Written Notice posted in strategic locations Written notice in newspaper/local media Verbally by going door to door Public Notice through radio or television Other means as determined by severity of emergency Page 21 of 24

22 APPENDIX 6 MUNICIPAL UTILITY OPERATORS CERTIFICATION Page 22 of 24

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24 APPENDIX 7 PERMIT TO OPERATE Page 24 of 24