By John L. Turner

Like all islands, Long Island is defined by water. Lapped on all sides — the Great South Bay on its southern flank, the thick finger of the Long Island Sound to the north, the bowl of the Peconic Bay filling between the forks, and one of the planet’s great oceans embracing all of this.  

And beneath us, in the pore spaces between the sand that make up Long Island (Long Island is basically a million-acre leaky sandbox) is a prolific aquifer system made up of several trillion gallons of freshwater that we depend upon, made available by scores of public water supply wells, for drinking and making coffee, washing cars, showering and brushing teeth, and from which water oozes to fill our ponds and lakes and makes our rivers and streams run — a freshwater groundwater system made up of three aquifers like layers in a sandwich, all resting on a basement of bedrock. 

It is OUR water supply — there are no other realistic possibilities to turn to: no ability to connect to New York City’s impressive surface water reservoirs and no river from New England that upwells into our sand under Long Island Sound (as one Long Island elected official once assured me, in explaining why we didn’t need to be concerned with the impacts of development). We are, hydrologically speaking, captains of our own fate.  

We may be captains but we haven’t been such good stewards of our groundwater supply as it is under stress like never before. More than two and one-half million Long Islanders live, work, and play above the water supply, and with gravity always at work, water, and whatever contaminants are dissolved in it, is always carried downward. 

The Upper Glacial Aquifer, the aquifer closest to the surface, has been rendered unusable in many places due to contamination.  In some areas this pollution has moved down into the thicker Magothy Aquifer below, the main source for drinking water today. And below the Magothy lies the Lloyd Aquifer, resting on a basement of bedrock, which has begun to feel the stresses of  over pumping and fingers of contamination.  

Some freshwater lakes and ponds are suffering quality issues too, the victims of “HAB’s” — harmful algal blooms. 

And in parts of Long Island we have a quantity problem, illustrated by lowered water table levels causing streams and ponds to shrink or dry out and allowing saltwater intrusion from salty water pushing in from sides of the groundwater supply. Hundreds of acres of wetlands have disappeared or been diminished by lowered water table levels, adversely affecting wetland dependent wildlife species.  

Nor have we been the stewards of the shallow coastal waters surrounding us that we should be. Driven by excessive nitrogen from sewage treatment plants (STP’s), home cesspools and septic tanks, and hundreds of thousands of fertilized lawns, the island’s coastal ecosystems are  showing significant stress. This stress is illustrated by numerous algae blooms or colored “tides,” perhaps made most visible by the green sheets of Ulva or sea lettuce which blankets the bottom of much of our tidal creek and bays. 

Some of these blooms involve algae species that are toxic to wildlife or are species that shellfish cannot eat to sustain themselves. Moreover, coastal waters containing excess nitrogen can weaken tidal marshes, a dangerous trend given their wildlife habitat, pollution control, and storm buffering value.

The good news is that we have the means to address these problems and one of them involves water recycling or reuse. As the name suggests, water recycling involves the use of highly treated wastewater discharged from sewage treatment plants for some other worthwhile purpose. And the Riverhead Sewage Treatment Plant water reuse project serves as an excellent example.  Here, during the warmer months (April to October), highly treated wastewater is diverted from discharge into the Peconic River/Bay and, instead, is pumped next door to Suffolk County Parks’ Indian Island Golf Course. The water, containing low levels of nitrogen, is used to irrigate the golf course, the nitrogen being taken up by the turf grass. The water is subject to UV disinfection which kills 99.9% of the viruses and bacteria that might remain in the wastewater from initial treatment. 

What’s the benefits you might ask of this water reuse project? The engineering consultants to the project estimate it will divert more than one ton of ecosystem-changing nitrogen annually from entering coastal waters with the nitrogen serving as fertilizer for the golf course grass. And it gets better — approximately 63 million gallons of water which used to be pumped out of the aquifer can stay in the ground, reducing stress on the groundwater system.  An added benefit is that it may also save taxpayer dollars due to decreased energy and fertilizer costs.

Given these dual quality and quantity benefits it is not surprising water recycling is commonplace in some states and in many other countries.  California, Florida, and Arizona are among the leaders as are countries like Israel in the Middle East. (You may have seen evidence of water reuse projects while traveling in these or other states since the pipes conveying the water are painted purple — the universal color for water recycling. I saw them a few years ago while traveling through Clearwater, Florida north of St. Petersburg). 

Today, more than 2.6 billion gallons of water are reused daily in the United States. And the potential on Long Island is great with several dozen golf courses being within two miles of a sewage treatment plant. 

There are other reuse applications besides irrigation of golf courses though… irrigation of agricultural crops and municipal ballfields, industrial cooling, wetland restoration, washdown water at sewage plants, even potable reuse which is now happening in California. Anyone want a beer brewed using highly treated wastewater? There are half a dozen brands now available, in Canada, Germany, and California, if you so desire!

To better understand and quantify this potential, and to provide a framework for prioritizing potential projects, the Seatuck Environmental Association, with funding kindly provided by the Greentree Foundation, hired Cameron Engineering to help develop a Long Island Water Reuse Road Map or Blueprint. This road map lists nearly 100 projects in which an STP is coupled with a target of the reclaimed wastewater — most typically a golf course or agricultural operation — situated within a two mile radius. They are listed in priority fashion based on the amount of water potentially saved, amount of nitrogen potentially reduced, and estimated cost for improvements needed to implement.        

Closer  to home, what might be some potential water recycling projects? One that jumps out (ranked #10 in the prioritized matrix) is using treated wastewater generated from the sewage treatment plant located on the SUNY Stony Brook campus to irrigate St. George’s Golf Course situated in close proximity on the east side of Nicolls Road. A successful project here would keep hundreds of pounds of nitrogen from entering Port Jefferson Harbor (the effluent from the SUNY SBU STP is piped to the Port Jefferson plant first before discharge into the harbor) and keep an estimated 34 million gallons of water in the aquifer.  

It is clear that with political support and adequate public funding, water reuse can significantly contribute to intelligent management of the water upon which we depend for drinking and water that we enjoy swimming in. As the LI Water Reuse Road Map has shown, water recycling, implemented comprehensively, can prevent tons of nitrogen from entering Long Island’s groundwater supply and adjacent coastal waters while keeping billions of gallons of freshwater in the ground. To borrow from an often used phrase: “That there’s a win-win situation” for all Long Islanders.

A resident of Setauket, John Turner is conservation chair of the Four Harbors Audubon Society, author of “Exploring the Other Island: A Seasonal Nature Guide to Long Island” and president of Alula Birding & Natural History Tours.