St. Clair appears to be in dark about plans

Heather Wright/The Independent

Clean Harbors is building a new process water storage pond on what the Ministry of the Environment calls ‘virgin land’ next Petrolia Line.

And it appears St. Clair Township officials we not aware the project was in the works.

The hazardous waste disposal company has already been given approval for the project through the Environmental Compliance Approval process.

In Oct. 2025, the US-based company filed its application for the project. The technical briefs to install the pond two phases were submitted to the ECA branch in May 2025 and July 2026.

The notice of the project was posted on the Environmental Registry of Ontario Nov. 18, 2025 and closed Jan. 2, 45-days later, as is the usual practice.

The ERO notice says “The pond is to be used as contingency pond and be limited to emergency overflow situations during extreme weather events that exceed the capacity of the previously existing Process Water Pond system or as additional capacity storage of Process Water during extended incinerator maintenance shutdown events.”

Donna Ayer, vice president of government and public affairs for Clean Harbors said in an email, “We have experienced increasingly significant rainfall events, which, when combined with spring snowmelt, can create conditions that increase the potential for flooding in these areas. The pond will provide additional capacity to temporarily store this water during high-rainfall events, helping prevent flooding and supporting the safe and compliant operation of the facility.”

Ayer added it is “important to note is that all process water is managed on site through the facility’s incinerator. Water stored in the proposed pond will not be discharged off site.”

The first phase, which according to the documents filed by Clean Harbors could store up to 51,000 cubic meters of process water runoff – about the size of 16 Olympic-sized pools. The second, which the Ministry of Environment, Conservation and Parks, will hold another 31,000 cubic meters of runoff.

“The first phase will double the facility’s existing process water storage capacity. A second phase would only be constructed if the facility determines that additional contingency storage is needed in the future,” Ayer said in the email.

“Rainwater collected from the facility’s process areas will be pumped to the pond during high-rainfall events, providing temporary contingency storage and helping prevent flooding conditions. The pond is designed as part of the facility’s existing water management system Ayer said.

It’s not clear when exactly the construction will take place. But it will be a new build at the 300-acre site. Currently about the hazardous waste facility covers about 138 acres of the property according to the Ontario government website.

The new storm water management pond will be built at the corner of Petrolia Line and Telfer Road, to a similar depth as the ponds already on the site and with berms approximately as high as those now that protect the property near Petrolia Line.

“The pond will be constructed on previously undeveloped land in the northwest corner of the facility, outside the existing landfill footprint,” said Ayer. “Construction timing will be determined based on the project schedule and applicable regulatory approvals.”

How the pond will be construction is also not immediately clear. The Independent asked the office of Environment Compliance Approvals for all the documents filed by Clean Harbors. By press time it had not received a reply from the ECA branch.

The Independent asked Clean Harbors if the construction of the holding pond was similar to that of landfill, with a non-permeable liner. Ayer answered “The pond will be constructed in accordance with third-party geotechnical engineering reports, with construction activities observed by an independent third-party geotechnical team. “

While the project was posted for public comment in November, the environmental registry shows not one comment was submitted about the project.

Monday, St. Clair Township Mayor Jeff Agar said he was unaware of the project and planned to find out what was going on.

Holly Foster, the township councillor who sits on the Clean Harbors community advisory board was also unaware of the project which received final approval in a letter dated Sept. 20. She did not recall hearing about it during the advisory meetings.

At press time, St. Clair Township officials had not answered The Independent’s questions about whether the municipality was aware of the plans, if it submitted a response to the project or whether it would consider an appeal before the 15-day appeal period ends.

The letter from Mohsen Keyvani, Director of Environmental Compliance Approval Branch does lay out a testing regime for the new process storm water ponds including once a month for the first four months after the project is complete and then on a weekly basis when the stormwater first flows into the new ponds.

After that, Clean Harbors will be required to test the new pond every three months.

The company also has to provide a financial assurance for the new pond – between $2.5 million up to $21 million should both phases of the ponds be filled.