The Board of the Suffolk County Water Authority has voted unanimously to no longer approve applications for water service that use open loop geothermal heating and cooling systems.
Unlike closed loop geothermal systems which continuously circulate the same water, open loop systems pump large amounts of groundwater through a geothermal heat pump before discharging the water into a well on the property. The systems use an enormous amount of water—one recent application would require 45 gallons of water per minute to operate—and that water in many cases does not replenish the aquifer.
“For SCWA ratepayers, for the environment, it’s time to ban the use of high-quality public water to run wasteful open loop geothermal systems,” said SCWA Chairman Patrick Halpin. “This action will protect the sole source aquifer that provides all of our drinking water and protect the water rates of the vast majority of SCWA customers.”
The recommendation to ban these types of systems was made by the Long Island Commission for Aquifer Protection (LICAP) in their groundbreaking Groundwater Research Management Report, which was recently issued.
“Geothermal technology has tremendous promise as a green energy source, but open loop systems can waste enormous amounts of water from our precious underground drinking water supply, and I’m therefore proud to support this initiative,” said SCWA Board Member Mario Mattera. “It’s the right thing to do for the environment and the right thing to do for SCWA ratepayers.”
“Protecting and ensuring the smart use of the only water supply of the nearly 2.8 million people that the sole source aquifer serves is critical,” said Suffolk County Legislator Bridget Fleming. “The cost to Long Island’s sole-source aquifer does not outweigh the benefits of the open loop geothermal heating and cooling systems. I applaud the SCWA Board decision to ban the use of these systems that do not replenish the aquifer with the significant amounts of water they use.”
“I am a supporter of renewable energy and other initiatives that decrease fossil fuel use, but open loop geothermal systems tax the public water supply, particularly during peak usage periods,” said Suffolk County Legislator Al Krupski, who has been active in LICAP’s Water Conservation Subcommittee. “I think SCWA is making a prudent change in their policy.”
The financial impact of the use of open loop systems can be immense. SCWA recently constructed a new pump station on Deerfield Road in Noyac that added 1,300 gallons-per-minute of water capacity to the system at a capital cost of $2.1 million. The portion of the capital cost that would serve a home with a 45 gallons-per-minute open loop system would be more than $72,000—far more than that home would pay in water rates. Additionally, it would take fewer than 30 homes with similar systems to deplete all the capacity added from one new pump station.
But the environmental impact of homes using public water to run such systems is enormous as well. The high-quality water provided by SCWA has gone through an extensive treatment process and been pumped at great expense to the home. This process is energy-intensive and produces greenhouse gases.
Of equal importance is the impact on Long Island’s sole source aquifer of the use of such systems at homes near the shoreline. Water used by these homes is pumped in from mainland areas where the aquifer is deep. This water at many homes near the shore is then discarded into shallow wells where it never replenishes the aquifer system; it is simply wasted.
The SCWA ban on the use of public water for open loop geothermal systems went into effect on July 1. The ban also prohibits current customers with open loop systems using a private well from ever switching to the use of SCWA water.
LICAP estimates there are between 4,000 and 5,000 geothermal systems in use in Nassau and Suffolk Counties, of which 70% are estimated to be open loop systems. A number of municipalities throughout Long Island have either banned geothermal systems outright or taken other prohibitive measures against them.
The Suffolk County Water Authority is an independent public-benefit corporation operating under the Public Authorities Law of the State of New York. Serving approximately 1.2 million Suffolk County residents, the Authority operates without taxing power on a not-for-profit basis.