It could cost Darien upwards of $25,000 to fix a sewage leak that sent possibly several thousand gallons of raw sewage trickling onto the beach at Cove Island Park in Stamford over the past two weeks.

The state Department of Agriculture’s shellfishing division also closed shellfishing for two miles around the site, although Holly Pond, the water body next to the sewage spill, has been closed for several months due to high bacteria levels unrelated to the spill, according to Kristin Derosia-Banick, an environmental analyst with the Bureau of Aquaculture and Laboratory Services.

“When dealing with a forced-main spill, it could have been enormous,” Derosia-Banick said. “This was pretty minor.”

The pipe began spilling sewage when a flange connecting a plastic pipe to a metal pipe failed, according to public works officials. Officials have said there is little risk to human health, given the time of year and the presence of other fecal bacteria in the natural environment.

The leak was discovered when a man was walking his dog at the park and noticed something seeping up through the sand. It took about a week before Darien was informed, after the man contacted several agencies before notifying the town, said Darren Oustafine, assistant director of public works.

“We mobilized and we had trucks and backhoes there within an hour,” Oustafine told The Darien Times. “We’ve accepted full responsibility.”

However, when public works staff arrived to turn the valve and redirect the flow, sewage continued to seep out as the valve failed to operate properly. The valves were rebuilt in 2008, but Oustafine said he wasn’t sure if they’ve been exercised since then, to ensure they’re functional.

Carlos Esguerra, a sanitary engineer at the state Department of Energy and Environmental Protection, or DEEP, told The Times that towns that don’t treat their own wastewater generally have a less rigorous maintenance program for pipe systems than areas that have dedicated wastewater authorities. Darien’s public works department has numerous functions.

To mitigate the remaining leak after it was discovered and partially fixed, the town hired a septic truck to pump the wastewater while they waited for specific parts to arrive from Texas. The pumping has lasted for more than a week, and the sludge is being dumped into Stamford’s sewer. As of presstime Wednesday, the truck was still pumping the leaking wastewater.

Before Darien knew about the leak, initial estimates claimed that 4,000 gallons of sewage was leaking from that point per day, but revised estimations put that at 800 gallons daily, said Derosia-Banick of the aquaculture bureau. From these numbers, the amount of leaked sewage would be between 28,000 and 5,600 gallons over the week prior to Darien’s intervention.

It’s unclear how much the truck has pumped out over the last week or more. Bob Steeger, director of the town’s public works department, said he’s unsure of this quantity, and he’s also unsure how the town will be billed for this service. A phone call to S&S Industries, the company hired to pump the sewage, was not immediately returned.

It’s also unclear how long the leak was spewing before the park visitor found it. The spill sits about 150 feet from the park’s path and is at the mouth of a small peninsula — about 50 to 75 feet from water on either side. Weed Beach lies just across the mouth of Holly Pond from the spill site.

The town informed DEEP, the state Department of Health and the Bureau of Aquaculture once they learned of the leak, Oustafine added. Esguerra, the DEEP sanitary engineer, said that “recreation is not an issue,” since the spill happened in the winter.

The $25,000 estimation to pay for the fix, Steeger said, would probably have to be transferred from a reserve fund within the sewage budget to cover the cost. The sewage budget is separate from the public works operating budget.

“It’s happened in the past,” Steeger said of sewage leaks. “It doesn’t it happen that frequently.”

The last leak happened in October of 2012 on Long Neck Point Road when a contractor drilled through a low pressure sewer while installing underground cable service, according to public works records. The leak was repaired within a day and the town was reimbursed for repairs by the contractor.

Further fixes at the Cove Island location include covering the connection with an easy-to-access manhole, so if a future leak occurs it will be easier to reach. The cost of that project has yet to be determined, Steeger said. Darien’s Sewer Commission meets on Tuesday, March 5, and public works officials said they will likely have that plan in place.

Darien pays Stamford to treat its wastewater, and budgeted to spend $2.9 million on sewage management this fiscal year. The Stamford facility discharges treated wastewater water into the east branch of the Stamford Harbor.

The Stamford Water Pollution Control Authority has a record of sewage spills far worse than Darien’s at Cove Island. The facility, which is where Darien’s wastewater is treated, failed to report 25 instances that sent untreated sewage into the Long Island Sound since 2006, according to a 2011 Environmental Protection Agency report.

Additionally, Bureau of Aquaculture records show that equipment failures at the Stamford plant have caused 26 sewage leaks over a two-year period ending in October of 2012, including a 40 million gallon spill into the Long Island Sound in November of 2011.

Originally published in The Darien Times.