WESTPORT — Multiple local and state agencies handled a sewage leak, caused by an aging pipe that was in the process of being replaced, in town on Saturday that forced officials to advise residents not to swim in the Saugatuck River or any Westport beaches.

A health advisory about the leak was issued around 4 p.m. Saturday. State Sen. Will Haskell shared the same advisory on Twitter.

“The Westport Health Department advises that swimming in the river and Westport Coastal waters should be discontinued until the leak has been stopped and the water is determined safe for swimming,” the notice read.

Westport’s Assistant Fire Chief Matthew Cohen said it happened at 605 Riverside Ave. around 1:30 p.m. Around that time, as the fire department’s Marine Unit arrived for training on the river, personnel were notified of a reported sewage leak in the Saugatuck River in the area of the Interstate 95 overpass.

A responding fire engine “found what appeared to be sewage flowing up from under the river to the surface,” Cohen said.

The town’s Department of Public Works was notified and responded.

“This also set into motion other activities aimed at minimizing the impact of the spill and erring on the side of caution,” Cohen said. That mean the state Department of Energy and Environmental Protection as well as the U.S. Coast Guard were also alerted to what was happening.

Various department and agencies responded to develop a plan of action.

The Sewer Department ensured the pumps were shut down and called in multiple vacuum trucks to manually haul the sewage across the river to the treatment plant, Cohen said. After consulting with the Health Department and the First Selectman’s Office, a decision was made to close the beaches to swimming and broadcast a public advisory.

Westport police and Parks and Recreation members responded to the coastal beach areas to have people exit the water and stay onshore. Police also ensured no shell fishing took place.

Sherwood Island was closed to swimmers by DEEP personnel.

As of around 6:30 p.m., Cohen said, there was “still a controlled leak with additional pumping vehicles on their way.”

Officials have decided to keep Westport beaches, as well as Sherwood Island State Park, closed for swimming until proper testing can verify that the water is safe for swimming. The health department has scheduled testing for Monday.

Aquarion Water advised town officials there was “no cause for concern” regarding any kind of contamination of the public wells, Cohen said.

The need to replace the aging pipe was addressed years ago, officials said.

“We identified the need to replace the current sewer pipe three years ago and were very close to completion,” said a statement from First Selectman Jim Marpe. “My thanks go out to the town and state departments in their prompt and appropriate response to the incident.”

Cohen said a new pipe was already run under the riverbed and pumps were in the process of being installed to handle the increased capacity. Public works said the new pipe was scheduled to be put into service within the next two weeks. The process will be expedited to light of what happened Saturday, Cohen said.

The sewer department will continue to work with DEEP and any other state and local health department necessary to ensure the safety and health of residents and visitors remains paramount, Cohen said.