Trail council awarded local company West Kootenay Mechanical a $277,000 contract to complete UV (Ultra Violet) regulatory upgrades in the city’s WTP (Water Treatment Plant).
“There is a necessity to award the project as soon as possible,” Patrick Gauvreau, utilities superintendent advised council this week. “Due to long delivery times associated with the purchase of the necessary mechanical fitting and valves required to install the UV reactors.”
This is the final phase of improving the city’s water supply. The $1.2 million project has been on the books since a 2013 audit revealed water filtering processes fell below normal parameters.
Regulatory upgrades began last year with a $623,000 influx of federal dollars through the Clean Water and Wastewater Fund (Fund). The cost-sharing Fund had the province contributing 33 per cent, or $411,000, which trickled down ratepayers’ costs to approximately $211,000.
UV installation is the last stage of work after council approved a $169,000 contract for the purchase of two UV reactors in December.
Unlike chemical approaches to water disinfection, UV light provides rapid, effective inactivation of microorganisms through a physical process. When bacteria, viruses and protozoa are exposed to the germicidal wavelengths of UV light, they are rendered incapable of reproducing and infecting.
The application of UVGI (Ultraviolet germicidal irradiation) to disinfection has been an accepted practice, primarily for medical sanitation and sterile work facilities, since the mid-20th century. Increasingly it has been employed to sterilize drinking and wastewater, as the holding facilities are enclosed and can be circulated to ensure a higher UV exposure.
The first leg of work began in August 2017 when Trail council awarded a $590,000 contract to sole bidder Anthratch Western Inc. of Calgary. The scope of work included design, supply, installation and granular media filtration improvements to four existing top filters.
(Granular media filtration refers to the process for removal of suspended solids by passage of water through a porous medium.)
The city’s WTP filter beds are aging and less efficient than when originally designed, Public Works Director Chris McIsaac noted at the time.
“So much so, in fact, that the city will realize a 30 per cent increase in filter bed efficiency when the upgrade is completed,” he said. “This will result in energy savings, and a decrease in water consumed during the filter backwash processes.”
Work also includes upgrades to a control system infrastructure known as “SCADA.” Supervisory Control and Data Acquisition (SCADA) is a computerized system for the automated computer controls associated with the treatment plant and related operations.