Grit removal system renovations approved but not to save Detroit River

By Alexandra Latremouille

 

Windsor’s manager of pollution control said the proposal to renovate the city’s grit removal system has been approved by Windsor City Council.

The $7.4 million investment will be used to refurbish the system’s aerated grit tanks, classifier and grit separators, according to Chris Manzon. He said the original structure, created in 1969, has been renovated only once, in 1980. This has caused grit, inorganic material such as sand and gravel, to clog equipment.

The city’s manager of environmental quality said the material is also causing another problem.

“It can cause premature wear on equipment, mainly pumps, in the waste water treatment process,” said Paul Drca. “Want to remove the grit as one of the first steps when we treat waste water.”

According to Manzon, these renovations will be completed in late 2016 or early 2017. He and Drca said the refurbishments are only being made to protect the treatment system, not to prevent grit buildup in the Detroit River. This is because it is removed before reaching the water.

“Grit would be considered part of the suspended solids in the sewage which we are required to remove,” said Manzon. “It would be removed within the overall treatment process.”

Although the material cannot discharge into the river through the sewer, it is a pollutant. However, a researcher at the Great Lakes Institute for Environmental Research said it is a minor one.

“Essentially, it can cause the degradation of aesthetics,” said Ken Drouillard. “You can have a buildup of materials along the shoreline which won’t necessarily be pleasing as we’re trying to improve our shoreline’s quality.”

According to a 2014 report by Environment Canada, the material also contributes to the river’s poor index of biological integrity. This index classifies how polluted waterbodies are.

In spite of this, Drouillard said raw sewage is a larger pollutant than grit. Unlike grit, sewage can overflow into the river during heavy rainfall. This happens when rainwater overloads the treatment plant, causing some of the sewage to bypass the plant and go into the river, according to a municipal video about waste water.

Because of this, Drca said Windsorites should be mindful of what they flush into the sewer, rather than focusing on grit.

“What matters is what goes in at the source,” said Drca. “We don’t want people disposing of things like grease, oils, cooking fats or baby wipes into their drains. It isn’t good for their homes or the environment.”

In 2011, a $110 million project to increase Lou Romano’s primary treatment capacity and add secondary treatment was completed, allowing it to better handle raw sewage.

Although it will not reduce pollution, Drca said the restoration of the grit removal system is as equally important.