The sewage leak that sent at least 800 gallons of sludge onto Cove Island in Stamford has been fixed, according to a report released by the Darien Department of Public Works on Friday, Feb. 28.

Darien had been aware of the leak since Valentine’s Day, but problems with valves and delays in shipping of new parts kept the leak active for the past two weeks. However, Darren Oustafine, assistant director of public works, said the leak that had been ongoing since the initial repair was not sewage, but groundwater, which was being siphoned by a septic truck.

When “we cut the pipe to install new pieces, we found that no sewage was leaking from the open ends of the pipe,” Oustafine stated in an email. “Valves were tight after all. Pipe was isolated. The leakage that we saw, could have been residual pressure (initially) and then ground water seeping in and out of the pipe after the joint was made ‘loose’ by destructive investigating. We only noticed leakage when we pumped down the water in the excavated hole.”

The amount of sewage lost was estimated to be 800 gallons, although it’s unclear how long the leak was active before it was discovered by a passer-by, who took about a week before he contacted Darien, according to the public works department. Officials declined to comment on how they estimated the 800 gallons. Earlier guesses indicated the leak was spewing about 4,000 gallons daily, according to Carlos Esguerra, a sanitary engineer at the state Department of Energy and Environmental Protection, which would equal 28,000 gallons over a week-long period.

Jayme Stevenson, first selectman, said any guess as to how much leaked before it was discovered would be “pure speculation.”

“The only thing I can say with tremendous certainty, is there absolutely is no way to know how much sewage could have leaked,” Stevenson told The Times. Oustafine has said the town had trucks on the scene within an hour of being notified.

“I think the leak was very, very small,” Stevenson said, referencing her conversations with Public Works officials. Oustafine confirmed that the leak was small, and health department officials weren’t concerned that the leak warranted further investigation.

One resident, however, told The Darien Times she was concerned the leak was bigger than reported. The woman, a resident of Holly Pond, said her dog, along with visiting dogs, got sick after wallowing in her yard, which frequently floods from Holly Pond. She said she washed her dog, and it “smelled awful,” and wondered what covered her animal. She also found a dead duck on her property covered in similar sludge.

Kristin Derosia-Banick, an environmental analyst with the Bureau of Aquaculture and Laboratory Services, the state agency that manages shellfishing, earlier told The Times that Holly Pond has been closed for at least several months due to high bacteria levels unrelated to the sewage spill. The state temporarily closed the perimeter of the Long Island Sound for two miles around the leak.

In a later email, Derosia-Banick clarified her statement, saying that Cove Harbor has been closed for months, and Holly Pond has been closed for shellfishing for years.

“Because Holly Pond is so enclosed, there is not as much tidal flushing as would be required to meet the requirements for shellfishing,” Derosia-Banick said.

The Holly Pond resident questioned whether her neighbors are aware of the pond being closed for shellfishing, noting that many people fish and swim in the pond during the summer months, and some people eat the fish.

“As the Bureau of Aquaculture, we regulate shellfishing only (harvest of clams, oyster, mussels), and cannot speak to the other recreational uses of the pond,” Derosia-Banick said, such as swimming, fishing or “contact recreation.”

“We do post signs in the prohibited areas, usually on utility poles in areas that are accessible by the public,” she said. “These signs are sometimes removed by the public, and we revisit these areas periodically to post them as being closed.”

David Knauf, the towns’ health director, affirmed Derosia-Banick’s assessment, saying that Holly Pond has “never been open for shellfishing and advisory posters have been placed in various locations by the state” around the pond.

“A single dead bird is not a justification for health department investigation,” Knauf stated in an email. “As for sick dogs, there are lots of reasons that could occur. If there [is] widespread illness in the area, of course we would investigate but the best information available indicates that the spill was minor in scope, was contained and is not considered to have an adverse impact on the pond.”

The town does not test for bacteria levels at Holly Pond. The Health Department only checks for bacteria at Pear Tree Point and Weed beaches, and occasionally at Tokeneke, and also only checks during months the beaches are used, Knauf said.

Stevenson said if the town decides to test the pond, it would have to be in concert with Stamford, since the pond splits the two municipalities.

“Water quality in Noroton River and Holly Pond has been a very longstanding issue,” she said, adding that there are several industrial-zoned parcels along the river in Stamford. Stevenson requested information from the Southwestern Regional Planning Agency to determine if Stamford has done any water quality studies on the Noroton River.

“Obviously sewage leaks of any kind are of significant concern,” Stevenson said. However, she added, “the small leak at Cove Island was most probably unrelated to the sick dog and dead duck. I leave it to our health department professionals to make a determination about the need for testing.”

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 and Stamford 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.

It will have cost Darien around $25,000 to fix the Cove Island leak, according to Bob Steeger, public works director.

Originally published in The Darien Times.