Suffolk Water Authority Limits Geothermal Systems

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.

The agency said that, 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, the agency said, with one recent application that would have required 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.

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  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.

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