By: Krug Stillo

Scientists at Stony Brook University say they’ve developed a relatively low-cost way to upgrade hundreds of thousands of aging septic systems across Long Island — a breakthrough that could sharply improve drinking water quality, according to the NY Post.

Researchers at the university’s Center for Clean Water Technology told the NY Post they’ve created a retrofit system designed to tackle one of the region’s most persistent environmental problems: toxic nitrogen leaking from outdated septic tanks into groundwater, streams, rivers, and coastal bays.

Lead researcher Thomas Varley said Long Island’s reliance on septic systems has had devastating consequences for both drinking water and surface waters, the NY Post reported.

“Whatever comes out of our septic tanks is going directly into the ground,” Varley told the NY Post, explaining that the contamination eventually makes its way into wells and surrounding waterways.

According to Varley, excess nitrogen has already fueled algae blooms, depleted oxygen levels, triggered fish kills, poisoned shellfish, and contributed to toxic blue-green algae outbreaks, as the NY Post reported.

The team’s innovation centers on a prototype that can be installed inside existing septic tanks. Unlike conventional systems, it includes a newly designed chamber filled with wood chips that aggressively strips nitrogen from wastewater before it escapes into the soil, the NY Post reported.

Varley said the retrofit not only beats every septic system currently on the market, but removes nearly 10 milligrams more nitrogen per liter than the most advanced systems now in use, according to the NY Post.

Traditional septic systems — which can cost homeowners about $35,000 to purchase and install — often release roughly 80 milligrams of nitrogen per liter, Varley said. Even Suffolk County’s newer low-nitrogen standard allows up to 19 milligrams per liter, the NY Post reported.

By contrast, Stony Brook’s prototype has consistently tested at under 10 milligrams per liter and costs about $17,000, according to the research team and figures cited by the NY Post.

“People don’t realize how much of an impact just one home can have,” Varley told the NY Post, adding that widespread adoption could significantly cut nitrogen pollution across the region.

Unlike modern low-nitrogen systems, which require homeowners to dig up their yards and replace entire tanks, the Stony Brook design retrofits what’s already underground. The system can be installed through a manhole cover, saving time, money, and disruption, the NY Post reported.

The retrofit converts existing tanks into multiple chambers. Wastewater is first treated, then routed into a second chamber packed with wood chips, where bacteria grow and neutralize nitrogen before it reaches groundwater, streams, rivers, or bays, according to the NY Post.

The potential impact is massive. Suffolk County alone has about 360,000 homes using septic systems — roughly 75% of the county — compared with Nassau County, where most homes are connected to sewers, Varley told the NY Post.