Senior Geologist Benjamin T. Timme stood in loose earth overlooking a crater left behind after BDL Environmental Consultants Inc removed more than 2,500 tons of soil from 77 Main Street.

Board members of Newtown Volunteer Ambulance Association, which owns the site, hope to sell the property — previously a Chevron gas station that the association took over in the early 1970s, said trustee Robert S. Grossman, MD. In order to sell, they had to clean the site, a requirement not in place when they bought the property more than 40 years ago.

Testing had revealed “grossly contaminated” soil. The environmental team has been removing the soil where years worth of oil changes and other contaminants have seeped into the ground, Mr Timme said.

The process began several weeks ago. Among the items found buried there were two 6,000-gallon gas tanks, car parts including one old crank engine. Digging took the team down about 23 feet, leaving a hole at least 50 feet wide.

More recent testing of the “floor” and “sides” has begun to come back clean, and Mr Timme anticipated they would be able to begin backfilling by Friday, January 15, or by next week. He is waiting for an analysis on clean fill, he said.

The process, not funded by the town but by the ambulance association, has already cost $100,000, said Dr Grossman. As much as $75,000 worth of work remains, added Dr Grossman, who is looking into grants to help with costs.

The 2.59-acre property at 77-79 Main Street is listed with Atherton Associates for $399,000

A new ambulance garage is now located at Fairfield Hills. NVAC moved into its new location in October 2014.