Water Industry News

United Water contains surprise flood water
By Tom Kasprzak - The Sun Staff

STONINGTON - Officials say they are still investigating why the borough sewage plant overflowed last weekend and are preparing to keep a close watch on the plant as heavy rains approach the region this weekend.

According to Harold Storrs, director of the Water Pollution Control Authority, the borough plant had never overflowed like it did last weekend. However, the plant is operating back at its normal capacity, Storrs said, and he is hoping the plant does not experience a similar event this weekend.

"We don't know," Storrs said of whether another overflow will occur. "We'll be looking at (the borough plant) very carefully."

All three plants in Stonington took on overwhelming volumes of water last weekend, according to Storrs.

Last Thursday, Storrs said, officials noticed capacity was up 10 percent at each of the plants, but the figure was nothing to be overly concerned with. He added that officials were concerned with the amount of rainfall the region was experiencing for the past week, and were perplexed as to why there was not more of a gradual influx of water into the plants.

"On Friday afternoon all hell broke loose in every one of the plants," Storrs said.

He said the Pawcatuck plant handled the overflow well because it only operates at half its capacity, and the Mystic plant was able to handle the overflow because of the way it is designed. Storrs said that the borough plant was the only facility that experienced overflow, but all the sewage was treated and none leaked into the harbor.

Some of the theories over why the plants experienced a surge in water all at once revolve around the heavily saturated ground, Storrs explained. He said some officials theorize that the ground was holding so much water for so long it finally gave way on Friday, much like someone squeezing out a sponge.

"Every treatment plant operating across the state is going through the same thing," Storrs said.

He added that because of the quick response from officials of United Water, workers were able to get pumps into the borough facility to treat the overflow.

"United Water did one hell of a job," Storrs said. They responded, and responded well."

He said a more in depth report of last weekend's overflow at the borough plant will be available at the WPCA's monthly meeting on Tuesday.

Note from regional manager, Ken Maltese:

It is incorrect to talk about an overflow since no untreated sewage escaped the system.  

The plant is designed for 600,000 gpd and our meter pegged at 2 mgd at 2:00 am.  Some of the dry well / wet well peneatrations that have dried out over the years from never being wetted were submerged and failed flooding the drywell and the pumps.  

When the operator turned the pumps on by hand at a high rate of speed to draw down the wet well he overflowed the primary clarifiers which backed up into the sludge handling room and basement. 

The plant design is to shut the inlet gates at 1.3 MGD and let it overflow.  We jury rigged bypass pumps to go around the primary  clarifiers and kept the plant going.