Pond sediment will be mixed with compost and reused in medians on Columbia Street in the City of Waterloo. The medians will then be planted with a mix of rye and feskew grasses. This is part of a groundbreaking pilot project to save the municipality money and divert the sediment from landfills, said Jessica Kellerman, project manager of water resources.
The city received a $350,000 grant from the Ministry of the Environment and Climate Change for the pilot project. Construction costs for the project came in at a bid price of $745,000, said Kellerman.
“We shouldn’t be putting this stuff into landfills because it’s taking up space and it’s costing municipalities a lot of money to take this stuff and put it into a landfill when it can actually be reused in other places,” she said.
The first stage of the two-part project involves retrofitting Creekside stormwater management pond 53 with a forebay to allow heavier particles to settle out of the water earlier. This results in “not having to go clean out the entire pond volume all at the same time,” said Kellerman.
“And then the second part of the pilot study is to do the beneficial reuse study on the sediment itself,” she said.
A greenhouse growth study on sediment from Pond 53 was completed in 2016, said Kellerman. “So this step is to look at it in the field and see if we can beneficially grow this on a field-scale in a real-life scenario.”
Kellerman hopes to have the medians planted by the end of July or early August. She said the plantings will be monitored for two growing seasons. Reports will be submitted to the MOECC at the end of each growing season.
“At that point, it’s make a case for and set a precedent for future projects,” she said. Future projects will be evaluated on a case-by-case basis.
“If this is successful, future plans would be to evaluate every storm clean-out that we do in the city for beneficial reuse and making that application for future ponds,” said Kellerman. “The main one that we have in mind coming up is Silver Lake. Silver Lake has over 30,000 cubic metres of material in it right now and to dispose of that with the tipping fees and hauling rates that we have right now is going to be quite a high cost.”
Kellerman also said that if successful, this will be the first reuse of pond sediment in Canada.
The trail between Birchmount Drive and Laurelwood Drive will be closed to pedestrian traffic while the sediment is excavated from pond 53.
Kellerman estimates that the work will take about two months.