New London — Thousands of gallons of untreated wastewater have been emptying into the Thames River from the Coast Guard Academy’s field house over the last 20 years, apparently the result of faulty construction work that was only recently discovered.

The discovery that it has been polluting the river is embarrassing for the academy, which trains cadets to enforce environmental laws on the nation's waterways, among other missions.

“As soon as the problem was found the academy took steps to correct it,” David Santos, spokesman for the academy, said Monday. “It certainly wasn’t our intention. We tried to act as quickly as we could so there would be no further impact to the river.”

The discharge came from the showers, sinks and toilets in two locker rooms in Roland Hall, where physical education and sports competitions take place. The two locker rooms, which have been closed since the discovery on March 29, were used by women’s varsity teams and visiting teams, Santos said. Discharges from other locker rooms and bathrooms used by spectators at Roland Hall sporting events were not involved, he said.

Santos said design work for the repairs has begun. The work will cost an estimated $80,000 to $100,000, he said.

The academy informed the state Department of Energy and Environmental Protection about the discharge, he said. DEEP, however, does not have jurisdiction over sewage discharges from individual buildings, according to DEEP spokesman Dennis Schain. Instead, the local health agency, Ledge Light Health District, has jurisdiction.

Santos said the discharge is estimated at 100 to 130 gallons per day during the school year, but some experts are questioning whether that estimate is too low. The problem is believed to have started in 1997 when a contractor working on utility lines cross-connected the wastewater discharge into a storm drain, which empties directly into the river, instead of into the system that takes raw sewage to the city’s treatment plant, Santos said. The incorrect connection, located underground, was found with a scope used during an assessment of Coast Guard facilities, he said.

Stephen Mansfield, director of Ledge Light, said the public health agency just learned of the problem on Monday and is working to schedule an inspection of the site. It will also do its own calculations of the amount of the discharge.

Mansfield said the health district will also notify the state Bureau of Aquaculture about the outfall. A “restricted relay area” for clams is located near the outfall, he said. Shellfish cannot be harvested directly from those areas.

Mansfield said that while Ledge Light has jurisdiction over sewage discharges, it cannot issue violations or fines.

“But we can issue an order of correction,” Mansfield said.

Schain said DEEP will work with the health district to ensure that the problem is corrected as soon as possible.

“We don’t want to see wastewater or sewage getting into any water body,” he said. “This needs to get fixed right away.”

A large tidal estuary, the Thames has sufficient flushing to absorb this amount of discharge, he said, but it nevertheless should not be allowed to persist.

Santos said the problem was not discovered sooner because the utility lines are buried underground, with no access except at manholes.

j.benson@theday.com