Where Does It All Go? Plumbing The Depths Of Wastewater

Jul 25, 2016

Environmental scientists say that almost three-quarters of Suffolk County homes use a septic system. But what happens when that wastewater goes down the drain?

While in a septic system, wastewater separates into solid sludge and liquid greywater.

Bacteria in the system break down organic parts of the waste and add nutrients like nitrogen and phosphorous to the wastewater.

This nutrient-rich wastewater eventually drains into the soil.

When the system works correctly, the nutrients promote plant growth. Even the waste in the water is nullified by the soil.

Terence Daly, vice president of operations at Go Green Environmental Services, says. “If you’re servicing the system appropriately, then the effluent that gets into the overflow is fine. It’s just graywater, it’ll filter out through the sand and the natural bacteria process, it’ll get denitrified. Totally fine.”

The septic system only becomes a problem when it is poorly maintained.

“It’s like an oil change. If you don’t do your oil change at 3,000 miles, you can probably drive to 7,000 miles, but you’ll seize the engine. That’s what could happen to pools. Every now and then we’ll get a call where someone hasn’t done it for 15 years, and the septic tank or the cesspool is totally filled with solids and then some of that solid waste starts to get into the overflow pool.”

If the soil has an excess of the nutrients though, they can enter the groundwater and cause illness.

Once in the groundwater, the nutrients can begin killing aquatic ecosystems by starting harmful algal blooms in nearby bodies of water.

Researchers are currently working on passive ways to remove the nutrients from wastewater before letting it back into the environment.

Suffolk County recommends that septic tanks be inspected once per year and receive maintenance every two to three years.

In a statement, Dr. Christopher Gobler, Associate Dean of the School of Marine and Atmospheric Sciences at Stony Brook University, told WSHU:

Septic tanks and cesspools are the main source of nitrogen to groundwater and ultimately surface waters in Suffolk County.  Importantly, since 75% of the nitrogen in wastewater is from urine and since all Suffolk County household systems are designed to allow liquids to quickly drain into the ground, all septic tanks and cesspools leak nitrogen to groundwater - new systems, old systems, well-maintained systems, never maintained systems. While having a septic system inspected and maintained will help assure it does not fail, it will not prevent it from leaching nitrogen into groundwater.  The New York State Center from Clean Water Technology at Stony Brook University is currently developing septic systems for Suffolk County that leach significantly less nitrogen.