HADLEY — Hadley officials are in the midst of defending a recently adopted bylaw allowing standalone energy storage systems in some parts of town, as a lawyer representing a renewable energy developer urges the state attorney general’s office to invalidate the measure.

The Planning Board is beginning to draft a formal response to correspondence from Tad Heuer, an attorney with Foley Hoag LLP of Boston, representing Zero-Point Development of Worcester. Heuer’s appeal, in a five-page memo to Assistant Attorney General Margaret J. Hurley, asks for the new bylaw and its siting requirements to be struck down.

The bylaw, adopted by Town Meeting in May, bars standalone batteries of 150 kilowatt hours or more from all areas except the agricultural/ residential and industrial zones, with a further prohibition on siting within the aquifer protection overlay zone, encompassing a large swath of town.

“Zero Point writes to make clear that Article 23 would preclude meaningful development of ESS projects in Hadley without justification, in clear contravention of prior decisions of the Attorney General,” Heuer writes, citing both definitions in state law and decisions the office has made in similar cases. “Though drafted to appear otherwise on its face, in practice Article 23 would effectively — and was intended to — ban ESS on over 97% of the land in Hadley.”

Town counsel Mead, Talerman & Costa notified the Planning Board and other town officials after it was copied Heuer’s letter challenging the legitimacy of battery storage bylaw, as it would leave only about 350 acres for such development. A preferred site for Zero-Point’s 5-megawatt project is a gravel pit on Breckenridge Road near both homes and Zatyrka Park, but it’s in the aquifer protection overlay and thus couldn’t be developed.

During the Planning Board’s June 18 meeting, planners began considering a response, and will likely finalize it during a discussion at the July 2 meeting.

Planning Board Clerk William Dwyer has put together a draft response stating that Heuer’s contention that Hadley is attempting to ban battery-only facilities “inverts the truth,” since the superseded zoning prohibited battery storage, except when in conjunction with solar arrays.

“To the contrary, the zoning bylaw adopted at the annual town meeting actually enables the siting of battery-only storage facilities in appropriate locations,” Dwyer writes.

“The specific site proposed by Zero-Point happens not to be in such a location.”

The draft response also notes the risks of contamination, such as how one of the town’s Mount Warner wells was ordered closed in 2004 due to high levels of perchlorate, a chemical found in rocket fuels, explosives and fireworks. In preparing the bylaw, planners had also observed that in the 1980s the town of Whately had residential wells contaminated by pesticides ethylene dibromide and Temik, and that leaks from lithium ion phosphate batteries, and chemicals used to keep them cool, could cause similar problems.

During the board’s brief discussion the previous week, Dwyer said he anticipated that the talking points in the response will include that the bylaw is more expansive than what currently exists, with standalone battery storage not allowed at all, and to allow such fixtures in appropriate locations.

In addition, the response will state there is available acreage for such projects, and will place a burden of proof on the developer to show there is no risk to the aquifer.

Zero-Point’s officials have repeatedly contended that no dangers are posed to health and well-being by battery storage projects, which will help to hold power from renewable sources, such as solar and wind.

Planning Board member Mark Dunn said the legal memo seems hyperbolic about the intentions of town planners.

“We were trying to protect our constituents and allow it in certain areas,” Dunn said.

Planning Board Chairman James Maksimoski also disputed that any ban was being considered, as planners want to give developers the ability to site such systems. “The intent was not to prohibit, the intent was to allow it,” Maksimoski said.