In February 2015, Halifax Water undertook a stakeholder consultation in support of an application to implement a Seasonal Disinfection Program. Since 2017, Halifax Water has turned off the Ultraviolet (UV) systems annually between November 1 and April 30 at the Halifax, Dartmouth, Eastern Passage, and Herring Cove Wastewater Treatment Facilities (WWTFs). Prior to 2020, UV systems at all of these facilities were turned back on between December 24 and January 2 to provide disinfection during the Polar Bear swim in the Herring Cove area.
During the two pilot trials from 2015 to 2017 that were required to permit the Seasonal Disinfection Program in our operating Approvals issued through Nova Scotia Environment and Climate Change (NSECC), the majority of bacteria levels detected remained below recreational swimming limits for E.coli, Fecal Coliform, and Enterococci. However, Halifax Water continued to turn the UV systems on at each facility for the swim in the Herring Cove area. Please click the following link for sample results.
In 2020, NSECC adjusted Approvals to allow for the UV systems to remain off continuously between November 1 and April 30 at Halifax, Dartmouth and Eastern Passage WWTFs. Given the distance these outfalls are away from Herring Cove and the fact that the measured bacteria levels from these facilities are generally within the acceptable swimming limits, this adjustment does not impact water quality in the Herring Cove area. The UV system at Herring Cove WWTF continues to be turned back on between December 25 and January 2 each year.
Halifax Water uses the time when UV systems are turned off at each facility to undertake extensive maintenance and cleaning of the systems to ensure they are properly operating during the summer months when recreational activities are increased. Without the need for the annual two-week period of turning the UV systems back on (between December 25 and January 2) at Halifax, Dartmouth and Eastern Passage WWTFs, impacts to the efficiency of these maintenance activities have decreased. It should also be noted that turning the systems off also reduces the greenhouse gases (GHG) produced by operations at each of the WWTFs.
For more information visit - Seasonal Disinfection | Halifax Water