The biggest success of our water quality testing in Mamaroneck last summer was the discovery of a broken sewer pipe that was leaking raw sewage into Otter Creek, near where it empties into Mamaroneck Harbor.
The bacterial counts here were through the roof. We reported the break to Village officials, who quickly required the owner of the sewer – the Mamaroneck Beach and Yacht Club– to make a temporary repair. Last Wednesday, the Village Planning Board began its review of a proposal for a permanent solution.
The Village and the club’s owners have decided that the permanent repair should include replacement of the entire sewer – a force main that connects to the Village’s sewers and to the Mamaroneck sewage treatment plant – and a pump station on the club grounds.
The club already has a proposal before the Mamaroneck Planning Board to build a 5,800-square-foot recreation building; a 5,500 square-foot yacht/dockmaster’s building; and18 seasonal apartments in a 13,500-square foot building. Save the Sound is not taking a position on that expansion.
The Planning Board is considering the replacement of the sewer and pump station as part of the larger proposal, and so the sewer project requires its own supplemental environmental review.
The proposal is for the new force main to follow the route of the existing force main. Alternative routes must be studied as part of the supplemental environmental impact statement. Under that plan, according to the club’s engineer, they will bore a tunnel at least six feet under Otter Creek, and then run a 4-inch polyethylene pipe inside a protective sleeve through the tunnel; the pipes are one piece – no joints or connections to break or come apart.
According to the club’s engineer, the tunnel will start far enough from the banks of the creek so that the wetlands and critical environmental area are not disturbed, and the pipe will be pulled through the tunnel. Elsewhere on the route they will use typical trenching to lay the pipe. The club’s engineer said the life expectancy of the pipe is about a century. All of this will be detailed in the environmental review and subject to public review and comment.
Last Wednesday, the Planning Board held a public hearing on the supplemental review’s scope – essentially the outline for the review. Excerpts of Save the Sound’s letter are below:
We write in strong support of the replacement of the force main and sewage pump station owned by the Mamaroneck Beach and Yacht Club. [Our] sole purpose in this comment is to ensure a permanent solution to the force main break that plagued Otter Creek and Long Island Sound with raw sewage. Considering the age of the force main and the pump station, we believe it is highly likely that they are in a severely degraded condition and will leak raw sewage into groundwater and streams if they are in use when the club resumes full operations in summer. …
… Otter Creek is a critical environmental area with significant natural resources, including tidal mud flats; every precaution must be taken during the project’s construction to ensure that the work is done carefully, that it is timed to do the least damage to wildlife in the area, and that disturbed areas are restored to their previous condition or improved upon.
Our position that the force main and pump station must be replaced is based on several factors:
- the severity of the leak in the force main that our water quality testing uncovered in August 2013;
- the reality that throughout Mamaroneck Village aging, decrepit sewer infrastructure is leaking raw sewage into groundwater and into tributaries of the Sound;
- the probability that the pump station and other sections of the force main are in similarly decrepit condition.
… [It] is essential that the Planning Board determine definitively if other sections of the existing force main have deteriorated to the point where they are leaking sewage into ground water; and if the existing pump station is allowing stormwater to infiltrate the sanitary sewer system. If those problems exists and are extreme, the replacement must be expedited to ensure that the new infrastructure is in use when the club reopens for the summer.
Click here to read the full letter.
– Posted by Tom Andersen, New York Program and Communications Coordinator for Save the Sound