Today Council Received a Memo on FAQ on the Water Ban…
Reason to Issuing the Outdoor Water Use Ban:
· The water level in the South Colchester/Harrow Water Tower was at a lower than normal service level due to a weather event known as upwelling (described below).
· If an increased demand in water were to occur with current water levels below the service standard, the water levels could be depleted in the Water Tower causing decreased water pressure and a Boil Water Advisory (required).
Technical Specifications:
· The lower-than-normal water level is due to an upwelling event (“turnover”) occurring in our area that is bringing low dissolved oxygen water to the area of the Colchester Plant intake. This low dissolved oxygen upwelling also brings a large shift in water temperature and in pH of the water. These swings in water temperature and pH often results in “upsets” within the water treatment coagulation process, which can cause rapid plugging of treatment plant filters thus requiring repeated backwash of the filters to unplug them. The more you must backwash the filters, the less potable water you can produce. During prolonged lake “turnover” events and associated coagulation process upsets, it can be a challenge to produce enough water to meet existing demand, especially for small treatment plants that only have a couple filters. Infrastructure is not in question, but at a higher usage level than normal.
· The issue began approximately one week ago. Every second day, the operators have been able to replenish but each time not fully to the desired service level.
· Capacity of the system is sufficient to meet current population and needs with the reduction a result of the weather event.
· The safety of the water is maintained, and the issue is that of supply only.
Protocol
· Increased by-law enforcement of the lawn watering by-law
· Continually monitoring the water and PH level
· Once at a level of concern, follow bylaw 485 which includes Council’s authority to issue a declaration restricting external water use.
Preventative measures in the future
· A weather event is often not preventative in nature and therefore responsible consumption must occur throughout the year.
· Ensure residents are abiding to the Lawn Watering Bylaw (485)
What happens in the event of a “severe shortage”:
· Consulted with Union Water Supply to open supply to the South Colchester/Harrow Plant which they agreed to in this situation.
Next Steps:
· Continually monitor the water and PH levels as well as track the weather event until regulation has occurred.
· Once this has occurred the Mayor will lift the declaration.
