The State of Long Island’s Drinking Water

Nitrogen pollution on Long Island has increased by as much as 200 percent in the last decade. 

Why does this matter? 

In 2017, every major bay and estuary across Long Island was afflicted by toxic algal blooms or oxygen-starved waters or both. For generations, nitrogen from leaky septic systems has leaked into our underground aquifer, resulting in impaired drinking water, beach closings, toxic algal blooms, shellfish die-off and more. Industrial pollution and harmful man-made chemicals like 1,4-dioxane have also found their way into our aquifer, further contaminating Long Island’s water resources.

What can we do? 

Have your septic system or cesspool routinely pumped to prevent clogging and overflowing. 60-70 percent of the nitrogen entering our water is from septic systems or cesspools. If you are building a new home or your septic system needs to be replaced, consider new nitrogen reducing technologies. For more information on reducing nitrogen loading visit •

If you’re using lawn fertilizers, use organic ones with slow-release nitrogen. Once nitrogen from fertilizers passes the root zone where plants absorb it as food, it continues to seep further into the ground until it reaches our aquifer. Up to 30 percent of nitrogen from fertilizer makes its way into our groundwater. Consider organic slow-release fertilizers like Espoma Organic Lawn Food, which may be purchased from many local garden centers.

Don’t flush over-the-counter or prescription medications down the toilet or drain. These pharmaceuticals, even in small amounts, can pollute our drinking water and negatively affect aquatic wildlife, especially fish populations. Check with your local pharmacy or police station to see whether pharmaceutical drop boxes are available – the Glen Cove Police Department and the Greenvale Pharmacy & Homecare store have them.

If you choose to spray your property for ticks, mosquitos or other insects, consider using all-natural or organic products that are safer for you and our aquifers such as garlic barrier for your lawn and Osana soap for your skin. Many insect repellents contain toxic chemicals such as DEET.

Watering your lawn every day is unnecessary according to experts. Ensuring sufficient water quantity is an important part of protecting our water source. The Sustainability Institute at Molloy College recommends watering infrequently, but deeply. Think about installing a water gauge on your sprinkler system that waters only when the ground is dry. For more information on healthy watering, visit Molloy College’s website page on watering https://bit. ly/2Wtjtvf.

Plant native plants and trees on your property. Not only do native plantings protect the genetic integrity of Long Island, they also require less water and nitrogen fertilizer once established. Two great sources for Long Island native plants are the Long Island Native Plant Initiative ( and Long Island Natives (

You can read this article in our 2019 Spring Conservation News newsletter.