- BC Games
Sewage leak into Cowichan River reported Sept. 3, now under control
A sewage spill into the Cowichan River last week is under control, city brass says after water samples were analyzed and malfunctioning equipment replaced.
"With the information available, the Vancouver Island Health Authority does not believe there is any public health risk based on results of the river water sampling that has been conducted," city CAO Peter deVerteuil says in Friday's press release.
"On Tuesday (Sept. 3) at 3 p.m. a local resident reported witnessing sewage entering the Cowichan River from a storm water pipe between the Silver Bridge and the Black Railway Bridge.
"It is estimated approximately 200 to 260 litres per hour could have been discharged, but it is difficult to know how long this had been occurring before it was noticed," he says.
The city crew was immediately sent to investigate.
"All indications are that the system, which was constructed many years ago, overflows into the storm-water river outfall for the Duncan Mall area if there is a significant enough backup in the Cowichan Way sewer main," de Verteuil says.
Investigation revealed a compressor malfunction at the city's Cowichan Way Sewage Pump Station.
The works crew immediately restarted the compressor and started drawing down the sewage level in the pump station.
"By 4 p.m. the sewer water level was at a level below the sewer overflow pipe invert and the situation was under control."
It was found the visual warning device on the top of the pump station was malfunctioning. This warning device identifies when the pump station has reached the high-water mark which is normally long before any crucial level.
City staff was unaware of any similar incidents in the past.
Wednesday morning saw crews collect three water samples — one upstream, one downstream, and one at the river outfall to be tested for fecal, coliform and ecoli.
"The crew did not find any remnants of sewer debris in the surrounding area or shoreline, that morning (Sept. 4)," he says.
The Provincial Emergency Program (PEP), Ministry of Environment, and Vancouver Island Health Authority (VIHA) were all informed of the incident.
On Friday morning, crews plugged the overflow pipe to prevent such incidents from happening again.
Crews have also been directed to monitor the pump station daily, and the city is working to connect the station to its newly activated SCADA system.
On Thursday, results of the water samples were returned and provided to VIHA.
"VIHA staff are not concerned about the results, which were within reasonable limits due to sufficient dilution in the river. Follow up samples were taken on Friday morning," de Verteuil says.
"This incident is obviously extremely serious, and I can assure residents that it is the city's highest priority to prevent such an incident in the future."
Cowichan Tribes has been notified by Health Canada and they have posted a warning at a small beach along the river downstream for precautionary purposes only.
The city can be called at 250-746-6126.