Aug. 11 Sewage Leak Causes Concern, Deemed Isolated Incident
By Leslie Rott

One of the air release manholes located on the line, which had leakage issues Thursday, August 11.

A leak in the sewer system discovered Thursday, August 11, which caused foul odor along Annex Road, resulted from testing a new pumping control and should not happen again, said Department of Public Works Director Bruce Zimmerman.

James Dunnigan, who witnessed the leak, said it occurred just off Annex Road, where the Allouez and Louisignon trails meet. He and Penny Barr were riding horses along the trails when they heard running water.

Mr. Dunnigan said a one foot geyser of water was spewing from what is technically called an air release manhole, which is several feet off the ground at the highest point in the pipeline. It had flooded the trail.

The two pumps, running simultaneously Thursday, August 11, caused sewage effluent to leak from an air release manhole along the line being taken from the Wastewater Treatment Plant to the Biddle Point Pumping Station and then out to Lake Huron.

Residents in the area notified the DPW.

Mr. Zimmerman said the leak was caused when a new control system was being installed for the outfall pumps at the Wastewater Treatment Plant, near Stonecliffe. It was being tested at the plant to make sure that two pumps could be run at once, as an emergency procedure.

Operating the two pumps at once, he said, caused the line to be “hydraulically overloaded.”

“It is not normal to run both pumps at once,” he said, but added that the purpose of an air release manhole is to release excess water and air and prevent damage to the pipe.

When notified of the leakage, he told employees at the Wastewater Treatment Plant to suspend testing.

Mr. Zimmerman was under the impression that the leak occurred at the air release manhole near Great Turtle Lodge, but residents said the flooding was west of that. He said that since all three of the air release manholes are on the same line, it really doesn’t matter, since the problem was controlled from the Wastewater Treatment Plant.

As for what was coming out of the manhole and pipe, Mr. Zimmerman said that it was treated, finished effluent on its way to Lake Huron.

“It might not have been sewage, but it smelled like sewage,” Mr. Dunnigan said. He described the water coming out of the manhole as murky.

While some residents noticed an odor in the area the night before, Mr. Zimmerman said the leak took place for only five minutes before the plant was alerted and stopped testing.

He said there were no broken pipes or other malfunctions and that the issue has been addressed and should not happen again.

“It’s unfortunate that anyone saw it,” Mr. Zimmerman said.