AUBURN – The town of Lisbon is suing the Massachusetts firm it hired to operate its wastewater treatment plant after some equipment was damaged during repairs.

According to the complaint filed in Androscoggin County Superior Court, the town hired Earth Tech Inc. in 1998 to run its plant along with the town’s pumping stations and collection system.

Later that year, Earth Tech hired the Maine company Webster Engineering Corp. to install a lifting ring on one of the treatment plant’s pumps, the suit said. The ring was to be used to lift the pump out of its well for easier service at one of the town’s pumping stations in the future. Earth Tech specified that the ring would have to be able to hold one ton.

The Maine company put a stainless steel ring on the pump. It measured nine-sixteenths of an inch in thickness and was about 13 inches in diameter.

On June 17, 2003, Earth Tech was raising the pump from its well to perform maintenance when the ring failed and the pump fell roughly 20 feet back into the hole, the suit claimed.

The town is suing both Earth Tech, Inc. and Webster Engineering Corp., the former, alleging breach of contract and negligence, and the latter alleging:

• negligence;

• breach of implied warranty of merchantability;

• breach of warranty for a particular purpose;

• breach of express warranty;

• strict liability: and

• negligent misrepresentation.

Webster Engineering filed a response to the suit, denying each of the counts. Through its attorneys, the company admitted to manufacturing the lifting ring to Each Tech’s specifications.

Attorneys for Earth Tech have not yet filed a response to the suit.