WILLIAMSTOWN - The collapse of a section of the Hoosic River's bank has exposed a piece of the Hoosac Water Quality District (HWQD) sewer line that runs underneath The Spruces Mobile Home Park property.
"There's about 35 to 40 feet of pipe that's exposed," Chief Operator Bradley Furlon said Tuesday. "We're still collecting bids from contractors, but a rough estimate is $85,000 to $95,000 for emergency repairs to support the exposed section."
The exposed section of pipe is underneath a field on the west side of the 114-acre parcel, Furlon explained, not near the mobile home units. A roughly 220-foot-long stretch of the embankment will need to be reinforced using riprap, a permanent covering of stones and sediment that strengthens a riverbank, he said.
Furlon said the collapse most likely occurred from the area being saturated with water. It was hard to tell exactly when the collapse occurred, he said, but it was noticed this past weekend.
The pipe is a main interceptor line 42 inches in diameter, Furlon said, and carries wastewater from Clarksburg and North Adams to the water treatment plant on Simonds Road. The wastewater flows at an average rate of 3.5 million gallons a day, he added.
Furlon said the section of riverbank with the exposed pipe is under a large amount of stress from the Hoosic River.
"It's right on a 90-degree bend in the river, and the full force of the river is on it," he said.
Furlon said several agencies have been notified of the collapse, including the Williamstown Conservation Commission, the Department of Environmental Protection and the Army Corps of Engineers. Representatives from engineering firm Tighe and Bond have been on the site to make preliminary observations, he said.
Furlon said collapses on the riverbank have been frequent since Tropical Storm Irene in August 2011.
"I've been inspecting the sewer line frequently since then," he said.
Following the storm, HWQD repaired three sections of riverbank where riprap was washed away from floodwaters in North Adams and Williamstown. One of the sections exposed was on The Spruces property behind the mobile home units. The total cost of the project was $214,250, with the Natural Resources Conservation Service reimbursing HWQD at 75 percent.
As a result of the same storm, the HWQD had to repair 600 feet of steel sheeting covering a section of banking around the wastewater treatment plant. The sheeting, which was covering electrical infrastructure for the plant, had begun to slide as the banking underneath had washed away.
To reach Edward Damon, email