The City of Ottawa is considering a $57-million upgrade to the Robert O. Pickard Environmental Centre that would allow the sewage treatment plant to generate all its own power, making it less vulnerable to grid failures caused by natural disaster.
The facility in Beacon Hill in Ottawa's east end treats 415 million litres of waste water a day before pumping it back into the Ottawa River.
The plant already has three co-generation engines that turn some methane into heat and power, but they're 22 years old and need to be replaced.
"Let's say those [co-generation] engines that are well beyond life expectancy start to fail — then we'd have big problems at the plant, so this is a critical renewal," said Kevin Wylie, general manager of public works and environmental services.
The idea is to build four new 1,000-kilowatt engines by 2024 that can produce all the heat and power the plant needs.
"We'll be able to totally island off the plant from the electrical grid in the case of some kind of catastrophic event that would cause the electricity to go out," said Wylie.
Right now, backup diesel generators can do the job for 12 hours. After that, sewage would bypass the plant and go straight into the Ottawa River, although that hasn't happened in 25 years, Wylie noted.
Less GHG, lower bills
Wylie said the new co-generation engines will also save the city $80 million over 25 years on its hydro and natural gas bills, and reduce greenhouse gases at the same time.
Right now, for instance, the plant is unable to use 30 per cent of the methane that's produced from water treatment process, so it's flared off.
By installing the fourth engine and rerouting heating loops so they can serve the whole plant, the city thinks it can cut greenhouse gas emissions by an extra 1,565 tonnes, or the equivalent of taking 328 vehicles off the road.
The city already has $15.4 million set aside for the upgrades, but would have to fund the other $41.8 million from a waste water reserve fund. Councillors on the city's environmental protection, water and waste management committee suggested Wylie and his staff also seek out grants to help fund the project.
If city council gives its approval on Oct. 23, the upgrades would be done by Envari Energy Solutions Inc., an arm of Hydro Ottawa, and be completed by 2024.