4. Bacterial Contamination of the Distribution System The Comox Valley Water System is sampled weekly. Consult with VIHA regarding E. Coli presence in water samples. If there is E. Coli detected in any of these samples proceed as follows:
4.1 Test for free chlorine levels present at sample site. Determine that adequate levels are present.
4.2 Flush the sample tap and ensure there is no local contamination of the site. Resample the site that had the presence of Total Coliform.
4.3 Results of these samples will show any indication of growth in 24 hours. Complete test takes 48 hours. If there is any indication of Total Coliform in further samples, flushing of the affected area and resampling will be required.
4.4 Continue flushing and sampling until no presence of Total Coliform is indicated.
E. Coli Contamination or High Turbidity Levels
4.5 Contact the Vancouver Island Health Authority. Any water samples that indicate the presence of E. Coli or High Turbidity Levels could require a boil water notice (see APPENDIX ‘A’) to the users of the Comox Valley water system.
4.6 Evaluate operational adjustments designed to reduce turbidity levels (i.e. temporarily isolate the water system from the source (river) and supply water from reservoirs only, etc).
4.7 Commence daily turbidity sampling and testing at all reservoirs to measure turbidity levels in the system, as well as the incoming turbidity from the source. (If turbidity results acceptable to VIHA, and not trending higher, then daily testing required only on week-days. Terminate daily testing after turbidity drops below 1 NTU.)
4.8 Determine the area affected and flush the system until acceptable chlorine or turbidity levels are found. Resample throughout the area.
4.9 Evaluate a communication strategy. It may be necessary to notify specific sites by hand delivering or faxing notices. i.e. hospitals, long-term care facilities and schools etc. Key communication issues – boil water notice, higher chlorine taste, water colour, etc.
4.10 Once the cause of the problem has been determined and corrected, three consecutive negative tests must be received. Consult with VIHA to determine when the boil water notice may be rescinded. (See APPENDIX ‘B’.)
4.11 Evaluate need for a communications strategy.
5. Contamination of the Water Supply In the event that there is contamination or suspected contamination of the water system occurs, including suspected reservoir intrusion:
5.1 Contact the manager of water services or other supervisor and advise the Vancouver Island Health Authority that contamination of the water supply has occurred.
5.2 Assess the source and the extent of the contamination within the water system. It may also be necessary to issue a boil water notice (APPENDIX ‘A’) or other restrictive use notices such as water use restriction notice (APPENDIX ‘C’) and/or do not consume the water notice (APPENDIX ‘E’) to the users of the water system through the media. Additional advisories may be required after determining the cause of contamination.
5.3 If the contamination is from the source, close the penstock valves to isolate the water system from contamination. If the distribution system is contaminated, isolate the affected area. If the contamination is determined to be hydrocarbons leaking into the water source, the risk to the water supply must be assessed as soon as possible. This assessment will determine the appropriate response.
5.4 Water staff, in consultation with the Vancouver Island Health Authority, will need to determine a sampling strategy for hydrocarbons and assess the threat to the water supply.
5.5 If the source is contaminated, contact the Provincial Emergency Plan (PEP) and advise them of the nature of the emergency. Phone 1-800-663-3456.
5.6 If the source contamination can be contained with absorbent floating booms, there is one available at the Comox Valley Regional District Puntledge pump station.
5.7 BC Hydro may need to be contacted to stop water flow into the penstock (to prevent contamination of the penstock). It may be necessary to install a protective boom at the entrance to the penstock to divert contaminants.
5.8 In all cases sampling and testing of the water will be needed to determine the extent of the contamination.
5.9 It may also be necessary to flush the system if it is determined that there is contamination of the water supply.
5.10 After flushing, resample and determine that there is no contaminated water in the system. When the Vancouver Island Health Authority is satisfied that the water meets the drinking water standards, the system can be put back into normal operation.
5.11 Issue a removal of boil water notice (APPENDIX ‘B’) a removal of water use restriction notice (APPENDIX ‘D’) and/or a removal of do not consume the water notice (APPENDIX ‘F’) through the media
5.12 Clean up equipment and restock any supplies used.
5.13 Contact all agencies involved to ensure that proper controls are in place to prevent future events and that the procedures for controlling contamination are adequate.