WILLIAMSTOWN, Mass. — The Planning Board last week discussed a way to allow geothermal wells in town while protecting the aquifer that supplies drinking water to the town of 7,000.

 

The issue came up this summer when Public Works Director Craig Clough informed the board of a resident’s plan to install a geothermal system in their home in the Water Resource District.

 

Clough pointed out that there currently are no regulations at the state or local level for where such systems can go. And he informed the panel that some closed-loop geothermal systems incorporate the use of propylene glycol as an antifreeze.

 

"Twenty-three gallons [of propylene glycol] in one system is not a lot, right?" Clough said in August. "But if we get 30, 40 of these systems all on a hillside, 10 years down the road or whatever — I don't know how long these things last. It's a closed loop system, but what if it were to leak? There are too many what-ifs in my mind."

 

Community Development Director Andrew Groff, who serves as the town planner, developed a draft bylaw to cover the issue after consulting with a colleague at town hall.

 

"[Health Inspector Ruth Russell] and I sat down and tried to look at what these systems do, what is the technology, what sorts of coolants and heat exchange fluids are used," Groff said. "It seems like for these closed-loop systems, the propylene glycol seems to be the most common and least, probably, environmentally hazardous fluid.

 

"We came to the conclusion this is technology that town hall staff doesn’t have a good grasp on. We need expertise to make decisions on what we should allow, if anything at all, in our aquifer recharge district."