Engineering firm boosts $3.8 million project: Recommends Klenawicus Airfield for Center wastewater system

Residents got a first look at an engineering report for a wastewater management system to reduce nitrogen levels in several Center buildings that could cost $3.8 million.

Professional Engineer Pio Lombardo of Massachusetts-based Lombardo Associates told the Town Board at its Dec. 14 work session that his team was aiming to find the best solution to meet immediate needs in the Center, and provide long-term needs.

If the price tag is surprising to some, the report completed by engineers for the location of the wastewater treatment system — Klenawicus Airfield — is likely to raise more eyebrows.

But Lombardo has served the Town successfully on other projects, including water quality in Fresh Pond, and has decades of experience providing engineering studies in other communities.

The recommendation is to use the “NitrexTM” wastewater treatment system that has been approved by Suffolk County.

NitrexTM system was approved for installation by the County at the Scully Estate County Park Environmental Center. The results were “exceptional, commonly reducing nitrogen to the range of two to three milligrams per liter of wastewater discharge,” according to the report. The New York State standard calls for not more than 10 mg of nitrogen per liter of wastewater discharge to be considered safe in drinking water.

Mr. Lombardo said his team looked at four possible sites. Before recommending the airfield, they examined other locations at:

• 90 North Ferry Road where discharges would be in the groundwater, affecting drinking water quality for an estimated 50 years.

• North Menantic and Bowditch roads where a former landfill exists.

• The Shelter Island County Club’s golf course, where a public water supply would be affected by the recharge area.

Locating a viable treatment system in the Center would require the Town to acquire private properties north of the library, Mr. Lombardo said. There is room for a treatment system to be located on Center Fire Department property, but that would require agreement from the Board of Fire Commissioners.

None of the sites in the Center would result in diminishing the negative impact on the aquifer, Mr. Lombardo said.

Aside from the negative aspects of the rejected sites, there are significant advantages to the airfield in that it would diminish nitrates by 90% to 95% and afford the opportunity for expansion of the filtration system in the future to treat other areas beyond the Center, he said.

As previously reported, the intent of the system would be to treat wastewater from buildings, including the Town Hall complex and an adjoining house on Route 114 meant to eventually provide added office space; the Police headquarters and Justice Court; the Center Firehouse; Shelter Island Library; the Community Center; and, as of last week, Shelter Island School.

The school had been among the Center buildings initially listed as part of the project, but the Board of Education pulled out, deciding on a project of its own. Then, last week, school officials reversed that decision, deciding to rejoin the area-wide effort as long as it can move forward quickly.

Town Board members and others peppered Mr. Lombardo with questions, including concerns that some runoff from the treatment system placed at the airfield would drain into Coecles Harbor. Mr. Lombardo said, because of the effectiveness of the wastewater treatment, the impact would be negligible. He emphasized that the team was looking for a holistic solution.

Town Engineer Joe Finora applauded the study, with Mr. Lombardo saying, “The one we’re proposing is the way to go.”

The report is available on the Town website at shelterislandtown.us and will be subject to further discussions before a decision is made.