Duane Hicks
An excessive amount of groundwater on Sunday evening required the town’s sewage treatment plant to go into bypass mode and discharge chlorinated waste water into the Rainy River to relieve stress on its system.
While 33 mm of steady rain was to blame, the fact some residents still haven’t switched their sump pumps to “summer mode” exacerbated the problem, Operations and Facilities manager Doug Brown said at Monday night’s council meeting.
“I just want to remind everyone that has the ability shouldn’t being dumping any more groundwater from their sump pump into the sanitary sewer system,” he remarked.
“It’s time to go into summer mode,” Brown stressed, adding the town has a bylaw in place stating residents must have their sump pumps in “summer mode” right now in order to prevent rainwater from being discharged into the sanitary sewer system.
This means having your sump pump outputting water four feet from your house and onto the road, where it goes to the curb, into the catch basins, and eventually into the river.
“It’s time to switch that over,” reiterated Brown, noting that not putting your sump pump into summer mode means you’re continuing to put water into the sanitary sewer system, as opposed to outdoors and into the storm sewer system, thus increasing the burden on the sewage treatment plant.
To provide an example of the flow rates Sunday, Brown said the demand on the water system (i.e., how much people used) that day was 3,310 cubic metres.
But the total amount of water discharged from the sewage treatment plant was 15,241 cubic metres—a difference of 11,331 cubic metres (or 2.25 million Imperial gallons) of groundwater the town did not need to treat.
Brown added 3,694 cubic metres of groundwater didn’t go through the treatment process, but was bypassed, went over the weir, and went through a chlorination process before being discharged into the river.
He again stressed that having one’s sump pump tied to the sanitary sewer system is in contravention of a town bylaw.
“We know that people do it in the wintertime. We’ve kind of turned a blind eye,” Brown noted.
“It’s going to catch up with us someday, and really this [Sunday] was just the start of the wet season,” he remarked.
Brown said the town is looking at how to eliminate the infiltration of groundwater into the sanitary sewer system, and an infiltration and in-flow investigation study is ongoing.
“Our biggest restriction with the town, from a growth point of view, is how we’re taxing the sanitary sewer system and the treatment process,” Brown noted.
