No partially treated NOTL sewage was dumped into Lake Ontario after any of the torrential downpours so far this summer, a senior Niagara Region official says.
That’s in contrast to what happened in Toronto when more than 1,300 megalitres of partially treated wastewater was released into the lake last week in what is known as a bypass event.
That was enough sewage to fill 500 Olympic-sized swimming pools.
However, the region’s manager of wastewater and compliance, Jason Oatley, said the heavy storms in Niagara-on-the-Lake on July 10 and 11 did not require any sort of bypass measures.
Niagara-on-the-Lake received 78.5 and six millimetres of rainfall on those days, respectively, he said.
That amount of precipitation sent about 27 million litres of water through the town’s sewer and storm drains, still well within the water treatment plant’s capabilities.
Oatley said the plant held up in the same manner during a torrential rainfall that hit town on June 18.
“Niagara-on-the-Lake doesn’t bypass (storm or sewer water) unless there is something physically wrong with it. The plant is pretty well brand new, so it has the capacity to treat a lot of wastewater there,” he said.
Comparing Toronto’s aging infrastructure and the size of the city with the same factors here isn’t a fair contrast, he added.
“In a larger city like Toronto they have a lot of combined sewers. The sanitary sewer and the storm sewer have the same pipe,” he said.
“But nowadays, everything that is built is called a separate sewer, so the sanitary sewer, like stuff from your toilets, goes in a separate pipe from the storm water.”
Oatley explained what constitutes partially treated wastewater, meaning what does get cleaned out of the water.
“When sewage bypasses some of the treatment, it still gets, for instance, de-screened, so that removes sticks and rags and things like that and it all gets disinfected, which means we add chlorine to it, to kill all the bacteria,” he said.
“But it wouldn’t get the full treatment so it wouldn’t remove, say, phosphorus, or a lot of the organic material.”
That might be concerning to people in Port Weller and St. Catharines.
Unlike in Niagara-on-the-Lake, over the past few years there have been instances of bypass events there, said Oatley — areas which are also popular summer spots for NOTL residents.
The Lake Report took photos from Ryerson Park looking west toward the wastewater plant and Niagara Shores Park on June 18 after that day’s heavy rainfall.
They appear to show a change in the water’s colour coming out from shore.
Oatley dispelled any concerns by pointing out that the water plant’s bypass pipes in that location extend 700 metres under the water and out into Lake Ontario, much farther out than the murky water seen in the photos.
“Those pictures … appear, to me, to be typical run-off from rainfall events,” he said, adding that they can still deposit bacteria, such as E. coli, into popular swimming areas.
The beach at Queen’s Royal Park is the only one in NOTL that is tested regularly. It was closed from Wednesday, July 17 through at least Tuesday, July 23 due to high E. coli counts.
When that happens, the region will notify the public via its website, signage on shorelines that indicates where overflow areas are located and through traditional and social media platforms with public health announcements, Oatley said.
“The general rule is try not to be in the water for 24 and 48 hours after a major rainfall event,” he said.
