Suffolk Closeup: Long Island water 101

PETER REICH PHOTO A water-colored dawn.
PETER REICH PHOTO A water-colored dawn.

Suffolk County government has, at long last, embraced the “advanced” wastewater treatment systems that remove substantial amounts of nitrogen that leach from traditional cesspools.

This is an important step toward protecting groundwater and surface waters, where excess nitrogen causes brown tide, red tide and otherwise triggers eutrophication, or excessive nutrients in water bodies and aquifers.

This is a water quality issue, notes environmentalist John Turner, who says Kevin McAllister, founding president of the Sag Harbor-based organization Defend H20 “deserves much credit for fighting” to get “advanced” wastewater systems accepted by Suffolk government. “During the early years, he was truly a voice in the wilderness.”

Now, not only are these technological breakthroughs in wastewater treatment fully accepted by the Suffolk Department of Health Services, the county executive’s office and the Suffolk Legislature, but local governments — such as Shelter Island — are joining with the county in financial programs to assist in the installation of the systems.

Also of prime importance for Suffolk County, says Mr. Turner, is “water quantity.” With the Seatuck Environmental Association, where he is conservation policy advocate, he’s been leading a campaign to get action on this. He’s also former head of Brookhaven Town’s Department of Environmental Protection and a foremost Long Island naturalist, author of “Exploring the Other Island: A seasonal guide to nature on Long Island.”

There now is movement on the water quantity issue, making Mr. Turner a happy man. Earlier this month, a new entity, the Long Island Nitrogen Acton Plan, had its first meeting. Held at the Suffolk County Water Authority Education Center, it’s being chaired by the New York State Department of Environmental Conservation and includes representatives of Citizens Campaign for the Environment, The Nature Conservancy, health departments of Nassau and Suffolk, U.S. Geological Survey, Long Island Farm Bureau, Riverhead Sewage Treatment Facility, the office of Suffolk Legislator Al Krupski, the Water Authority and, of course, Seatuck.

Put simply: Long Island, along with Shelter Island, sits in the sea where the sole source of potable water is underground aquifers. There is an interface between the fresh water of these reservoirs and the surrounding saltwater. Lowering the level of fresh water underground can — and has — resulted in saltwater intrusion and loss of potable water and the lowering and drying up of streams, rivers and lakes.

Saltwater intrusion is a large part of how Brooklyn and Queens on the western portion of Long Island lost their potable water supply years ago. They now must rely on the system of man made reservoirs and pipes to bring water from upstate.

Or as John Turner explains: “There’s the water we don’t see, the freshwater beneath our feet, stored in the sandy aquifers that underlie Long Island. This layered system of water-saturated sand, silt, gravel and clay sits atop a basement of bedrock … that slants to the southeast and contains no water. In the middle of Suffolk County, the aquifers, replenished only by rain and snowmelt, are about 1,000 feet deep. These tiered sets of aquifers — the groundwater reservoir — is our drinking water supply and the sole source for meeting all our water needs .

“Near the coast, the oozing water from the aquifers is what supplies the base flow of streams and rivers, while in the middle part of the island the freshwater moves vertically, recharging the groundwater system before eventually turning sideways and discharging into the saltwater that surrounds the island…

“Imagine the groundwater reservoir to be a balloon of a certain size and due to pumping of water and coastal discharge of the wastewater the size of the balloon lessens. Some significant things happen. First, as the water table drops, the top of the balloon, the surface water bodies such as streams, lakes and rivers either dry up or are significantly diminished … Second, the salty water surrounding the island pushes landward in a process known as saltwater intrusion, contaminating the edges of the aquifer. If we continue on the path were on, the patient will get sicker…”

Shelter Island, Mr. Turner notes, “is a microcosm of the Long Island system — and even more vulnerable. Shelter Island doesn’t have the three-aquifer system underlying most of Long Island. The bottom of the freshwater is much shallower on Shelter Island. Also, there is the configuration of the Island. The arm of land constituting Ram Island presents even more vulnerability with its tinier aquifer.”

Next week: How all over Long Island sewage treatment plants, including the one servicing    Shelter Island Heights, in Sag Harbor and Greenport, are discharging wastewater into bays, rivers, the ocean and Long Island Sound.