Nelson’s public works director says the volume of a sewage leak into the Kootenay River on March 27 was “negligible.”
In an April 4 news release, Charlie Henderson said the leak occurred in a pipe that transports sewage from the city to the sewage treatment plant at Grohman Narrows. The pipe is located about 30 metres below the surface of the Kootenay River.
About one million litres of sewage per day leaked into the Kootenay River between March 27 and April 3.
“For context, the Kootenay River flow in this location is 36 million cubic metres per day,” Henderson said. “Even though the leak was minor, the City of Nelson, along with the co-ordination team, took this event very seriously.”
The incident was reported by B.C.’s environment ministry on its website on March 28. The ministry reported in an email on April 4 that the leak was repaired on April 3 by a dive team.
“Given the minor scale of the leakage and the rapid response, the team deemed it unnecessary to issue an immediate public advisory,” said Henderson.
Henderson explained that “the displacement of a gasket resulted in an opening not much bigger than the size of a loonie.”
The gasket “naturally repositioned itself back into place, stopping the leak even before the divers arrived on site,” he said.
“It is essential to clarify that there was no pipeline failure.”
Mayor Janice Morrison echoed Henderson’s praise of dive team and staff in the statement. “Remarkably, in this scenario, the solution was found in dilution.”
Henderson agreed with the environment ministry on the daily volume of the leak of 1,000 cubic metres, or about one million litres.
As for the duration of the leak, Henderson said it was four days, while an email to the Nelson Star from the environment ministry said the leak was discovered on March 27 and plugged on April 3, a minimum of five days.
“Health authorities expect the potential impact to human health to be low,” the environment ministry’s incident report states. “Private and public water extraction points from the Kootenay River are a significant distance from the point of release.”
The sewage treatment plant is located on the shore of the Kootenay River at Grohman Narrows and releases its effluent into the river after primary and secondary treatment. This week’s leak consisted of untreated sewage that had not yet reached the facility.
The city is in the planning stages of a new treatment plant and sewage infrastructure, but the design and construction is expected to take several years.
The aging plant has long been acknowledged by city management staff to be operating beyond its capacity.
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