Protecting aquifers, Long Island’s only source of drinking water

More than 100 billion gallons of water will be used for lawn maintenance alone across Long Island this summer — enough to fill 150,000 Olympic-sized swimming polls — and the cost shows up in more than just your water bill.

It’s also hitting the ecology hard, according to officials, which is why the Long Island Commission for Aquifer Protection is urging neighbors to be mindful of their water usage.

“The heat wave has to make us realize that water, particularly in Nassau County, is a finite resource,” Adrienne Esposito, executive director of Citizens Campaign for the Environment, told reporters last week at the West Hempstead Water District.

“It is all of our responsibility to protect that water supply.”

The entirety of Long Island’s drinking water comes from natural aquifers. They’re like giant underground sponges — when it rains, the water seeps underground and is absorbed by sand and gravel, creating natural reserves of freshwater. 

“In Nassau County, we're experiencing what's called groundwater mining, which means that we're taking more water out of the groundwater system than the rain is able to replace naturally,” Esposito said. “This is not a good recipe for sustainability.”

The groundwater serves three vital functions, explained Bret Bennington, chair of Hofstra University’s Department of Geology, Environment and Sustainability. First, it’s pumped to the surface to be used as freshwater. Then it directly feeds just about every lake, stream and tributary on Long Island. Finally, when it travels to the shoreline and is released along the coast, it prevents saltwater from moving in underneath the island.

In other words, as long as groundwater is continually flushing outward, the saltwater doesn’t intrude upon Long Island’s natural freshwater resources, which could ultimately destroy this vital reservoir.

There needs to be enough groundwater to adequately perform all three of those functions, Bennington explained. So, the problem isn’t that Long Island will entirely run out of water — it’s that the more neighbors drain these natural reserves, the more significant consequences they’ll see on the entire groundwater system.

Lakes and rivers become dry. Saltwater contaminates the fresh water under the island, rendering the reserves undrinkable. To compensate, more drinking water must be pumped from other reserves. The process snowballs into a vicious cycle — and it shows up on water bills.

“The more we pump, the more it costs to treat,” said Jason Belle, who chairs the aquifer protection commission. “So, by reducing our pumps, not only do they reduce their water bill, it reduces the district’s bill, which will in turn keep the rates low.”

So how can people do their part? As the island approaches the peak season of water usage, officials said, perhaps the best way for residents to be efficient with their landscape-related water usage may be to adopt smart irrigation.

Smart irrigation is a “holistic approach to using water” in landscaping, said Mike Dwyer, director of the Irrigation Association of New York.

If someone notices a brown spot on their lawn, Dwyer said, don’t just turn up the sprinklers run time. Check out the sprinklers in that zone to see if they’re running efficiently.

Are the nozzles clogged? Are the sprinklers blocked by plant growth? Are the heads rising fully out of the grass?

Plus, not all brown spots are from lack of water — insects or disease may be culpable.

And rather than relying on timers, he added, switch to a controller based on evapotranspiration — or ET — which adjusts how long sprinklers will run depending on how wet the ground already is.

Why water your lawns on a rainy day? 

“We’re not here to tell people to not water their lawns,” Belle said. “All we’re saying is that you can have the best of both worlds — a nice healthy lawn, while also reducing the amount of water to achieve it.”

“There are many good reasons to preserve groundwater, whether it's for drinking water, for our ecology, or for our sustainability,” Esposito said. “We're asking people to start now. Don't wait until August when we're in another summer heatwave and a drought. Start good water conservation practices today.”

Those who take the conservation pledge on Long Island Commission for Aquifer Protection’s website has a chance to enter a contest to win a smart sprinkler controller. For more information, visit OurWaterOurLives.com.