Starting this month, the Vernon Water Reclamation Centre (VWRC) will be forced to discharge reclaimed water through a deep outfall to British Columbia’s Okanagan Lake after several factors continue to prevent officials from using the water for irrigation.
While the population of just over 40,000 in B.C.’s Okanagan region generates some 13 million litres of influent every day for treatment at the centre, the last four years have been marked by challenges around using the treated water for irrigation, such as wet weather in spring and summer; cooler temperatures; increased cloud cover; smoke from wildfires; atypical rainfall; and now, higher than average snowpacks.
The reclaimed water is piped 10 km to the MacKay Reservoir, which is typically used to irrigate local golf courses, baseball diamonds, soccer pitches, agricultural land used for grazing and hay production, seed orchards, nurseries and plantations.
Unable to use the water from the MacKay Reservoir, Vernon officials say they’re forced to discharge treated water from it as it nears its maximum storage capacity elevation of 1,939 feet above sea level for the second time in as many years.
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The treated water is mostly residential and commercial, but also includes some industrial wastewater, officials explained. Some local environmental advocacy groups have raised concerns that pesticides, pharmaceuticals and other minute quantities of chemicals could be involved that affect aquatic life and human health.
The wastewater undergoes primary, secondary and tertiary treatment at the VWRC. Treatment works include fine screening, grit removal, primary clarification, biological nutrient removal, secondary clarification, and during irrigation season (May-October), sand filtration and ultraviolet disinfection.
Under the city’s Operating Certificate issued by the Ministry of Environment, Vernon officials are permitted to redirect the flow of treated reclaimed water from the VWRC directly to Okanagan Lake through a deep lake outfall located 60 metres below the water’s surface “when there are unforeseen circumstances that do not allow the city to draw down the water in MacKay Reservoir,” officials said.
“The highly treated reclaimed water irrigation program has a long history in Vernon, and the city is proud of our ability to irrigate local agricultural and recreational lands, while reusing this precious and irreplaceable resource,” said Vernon Mayor Victor Cumming in a statement. “The city is committed to continuing the spray irrigation programs for reclaimed water and is regularly looking for opportunities to expand or adjust the program to make it even better,” he added.
The VWRC was established in the 1930s. Over the years, it has been expanded and upgraded a number of times.