Could Long Island’s water supply become undrinkable? It’s hard to imagine, but environmental groups say that the island’s underground aquifers are being polluted by nitrogen and other substances.

Long Island’s almost 3 million residents are completely dependent on groundwater for their fresh water supply. But the island’s drinking water aquifers are being polluted by leaking septic systems, which have caused nitrogen levels to soar, say advocates.

Take a look at this interview with Bill Ulfelder, executive director of The Nature Conservancy in New York, which was broadcast on WNET’s MetroFocus last week.

“If trends continue the way they are,” says Ulfelder, “the water will eventually become undrinkable.” Ulfelder did not provide any specifics on how close we are to the point in which the island’s drinking water could not be consumed safely.

Nitrogen is Also Impacting Long Island’s Waterways

Long Island’s surface waters are also experiencing nitrogen pollution, caused by outdated sewage treatment facilities and even fertilizer runoff. This has led to hundreds of beach closures and shellfish die-off.

Is there a solution? Yes, says Ulfelder. Nitrogen removal technology can be installed in both septic systems and wastewater treatment plants.

Government is beginning to address the problem. Ulfelder said that almost a billion dollars of post-Sandy recovery funds have been directed toward upgrading area sewage treatment plants.

The next step, says Ulfelder, is to make it easier for homeowners to upgrade their septic systems.

The state Department of Environmental Conservation says it is working with Suffolk County, the Town of Southampton and SUNY Stony Brook, to develop and implement a $6 million plan for nitrogen treatment pilot projects at individual homes or small subdivisions that are not easily reachable by sewer lines.

“This plan will include a research program on methods to improve the effectiveness of nitrogen treatment systems, reduce their cost and footprint, and simplify operations and maintenance,” the DEC said.