Major Great Lakes Watershed Sewage Spill Investigated

07/16/2002
Toronto Star

ELMIRA - Ministry of Environment investigators continue to probe the cause of a massive sewage spill that flowed into the Grand River last week.

Initially it was believed a hydro crew severed power and phone lines to an Elmira pumping station, setting the stage for the release of one million litres of raw sewage into the Canagagigue Creek.

Now, ministry officials wonder if the phone lines that control an overflow alarm were cut as earlier believed.

The probe is focussing on what other problems may have led to the alarm failure at the station, operated by Woolwich Township.

The flow of raw sewage went unnoticed for 19 hours.

John Cooke, district supervisor at the ministry's Guelph office, said the station has a two-stage alarm but neither was triggered.

There were no back up alarms as part of the system, but Cooke wondered if that would have mattered anyway.

"These to me are a unique set of circumstances that I haven't come across in my (27 year) career with the ministry," he said.

"This might just be a one-time event that could have been avoided by making sure that power wasn't interrupted to the station in the first place."

In an earlier interview a ministry official suggested Waterloo North Hydro didn't follow its own protocol.

"You are supposed to do a locate before you do any drilling or digging," said Randy Wenzel.

Dave Gosnay, director of planning and engineering for Woolwich Township, said the township is exploring ways to prevent this from happening again.

"We met with the MOE today and Friday. We don't have any answers yet...we are looking at possibilities for a back-up to the back-up...we are looking at all available options."

Gosnay said the long-term answer is to eliminate pumping stations altogether and replace them with systems that rely on gravity.

"But that costs $400,000 to $500,000 (per station)," and the township has three.

"The system we have was appropriate but it didn't allow for both (alarm systems) failing at the same time."

Meanwhile, Waterloo Region officials claim their detection systems are more robust.

Dave Andrews, manager of wastewater treatment for the region, said all regional pumping stations are equipped with standby generators that provide back-up power and alarm systems that work even if phone lines are knocked out.

The regional stations are generally larger than those operated by municipalities like the one that failed.

No decision has been made on whether the incident should be considered for charges.

Dwight Boyd, senior water resources engineer at the Grand River Conservation Authority, said the spill came at a bad time because water levels were unusually low.

Water was added to dilute flows to the Grand River and to flush the sewage through the river system.

Boyd said there were no visible signs of damage to aquatic life in the Grand.

And any sewage spilled would have reached Lake Erie by late Sunday. Communities including Waterloo Region that use water from the Grand closed intakes at water treatment plants as a precaution until the threat passed.

"Any effect would be more local to the Canagagigue Creek," Boyd said.

Ministry and conservation authority officials were in Elmira yesterday trying to assess damage and better understand what went wrong.

The good news is that a system to notify downstream water users worked well and reservoirs the authority operates had ample water to meet the challenge, Boyd said.