It was an experience they never want to repeat.
On the afternoon of June 27, 2012, staff at Salmon Arm’s sewage treatment plant noticed a tidal wave of liquid flowing into the plant.
“Staff found a huge amount of water, almost double our flows,” explains Rob Niewenhuizen, the city’s director of engineering and public works. “Basically from that point on, we went into emergency mode to make sure there were no other problems. Everything was under water; we ended up doing a dye test to see if anything was leaking.”
He says dye was put into a manhole to see where it would go in the system. In this case, it ended up going to the plant.
“No water was getting out of the pipes… Because the pipes were under water, the water was forcing its way into the pipe,” he said, noting the plant was able to keep up with the subsequent large flows so no untreated sewage entered the lake.
Canoe was flooded at the time, and it was suspected that perhaps a manhole lid was off along the foreshore, allowing infiltration. Niewenhuizen said the provincial Ministry of Environment was informed, and city staff went out looking for leaks and displaced manhole lids.
“On July 3, we actually found and isolated the leak. It was in the foreshore piping, along the trail, close to Raven,” Niewenhuizen said, noting a portion of pipe had collapsed inward and a crew was able to repair it.
“We don’t know exactly why it broke. It could have been the weight of the water above it. It could have been an anomaly… It could have been a rock sitting on the pipe. It’s very hard to determine.”
The city has been dealing with the incident through the Provincial Emergency Program, he noted, given that the June flooding had an impact.
The pipe in that area is about 50 years old, installed in the ’70s.
“Some is not in the best of locations as it’s at the foreshore,” he said, noting that today, such a location would not be allowed for environmental reasons.
A section of the pipe was taken out and sent to the Coast for analysis; he is not expecting the results back for three to four weeks.
Asked about the length of time to come up with a plan of action, with the 2013 freshet approaching, Niewenhuizen explained that in August and September, the city worked with its consultant on a post-flood report which was required as part of a submission to PEP and the disaster financial assistance program.
“Based on this information, the decision was made to undertake a more detailed investigation of the piping in the foreshore.
He said staff received city council approval to undertake what’s called the foreshore sanitary sewer interceptor replacement investigation on Dec 10. It is under that investigation that the pipe was sent to the Coast.
“This investigation will help in determining the condition of the foreshore sanitary sewer interceptor pipe (3.5 km of pipe from Raven to the wharf); however, prior to starting any work in the foreshore area many levels of approval were required (Ministry of Environment, DFO, Worksafe BC, etc),” he wrote in an email.
The consultant is studying the pipe as well as examining soil conditions surrounding it, and will look at options and provide recommendations.
Depending on what’s required, the work would have to be done during freeze-up or low water, he said. One option is relocating the pipe.
“We do have some light at the end of the tunnel,” he said, noting the pipe in question is not of the best quality, but he’s hoping it’s just that one section. He said he’s not really worried now that the pipe has been exposed and some testing has been done.
In the longer term, however, it could potentially be an expensive project.
“There is always a price tag to it and, the older it gets, the more chances of things happening. It’s a pretty important main for the city, a pretty important part of the infrastructure.”
Everything east of the wharf flows through it – Raven, Appleyard, the hospital and more.
Although there was no public notification at the time, Niewenhuizen said council was apprised of the problem while staff worked to rectify it.
“It was a serious incident, but it was handled very well by staff. Utilities staff worked many, many, many hours trying to find the leak. We had staff and volunteers out in kayaks looking for potential whirling pools. And the treatment plant was dealing with regulating the plant to keep up with flows. There were lots of sleepless nights but they were handling it very well. They were able to find it before we lost treatment in the plant.”
Mayor Nancy Cooper said council was very concerned at the time.
“The problem here is we have aging infrastructure all over – and it’s not unique to Salmon Arm.”
She said the city can’t take further action until it knows the extent of what needs to be done.