Cambridge Drive: Filling operation on track, need more water

MONROE, CT — The filling of a massive hole on industrial property at 64 Cambridge Drive is going well, but valves must be adjusted to get water to all five wetland irrigation zones, according to a third party report.

A graveling operation had left the hole and damaged wetlands and vernal pools. The Inland Wetlands Commission approved a remediation plan to regrade the property and restore the wetlands.

“In my opinion, the big picture is the fill’s going in,” said Bill Heiple, a third party monitor hired to ensure the property owner is carrying out the plan properly. “The right stuff is going in. They look to be doing a good job managing it, compacting it. They’re even doing dust control and so on — and so I think the filling process is going quite well.”

Heiple, a professional engineer and licensed environmental professional with EnSafe, shared his monthly report at the commission’s meeting Wednesday night.

Last week, Arnold Karp, managing partner of the two LLCs that own the site, which also includes 4 Independence Drive, walked the property with Heiple and commissioners.

Heiple is monitoring the performance of the water supply well and the wetland restoration, the backfilling and grade restoration, and inspecting onsite materials — especially demolition material from Stratford High School.

“We’re going to ramp up inspections to make sure there is only good material coming from that pile and going back in the hole,” he told the commission.

EnSafe is also evaluating the quality of fill coming in to ensure it is clean fill.

Heiple said about 90,000 cubic yards of fill, mostly from a large rock dust pile from the southeast part of the site, was used to fill the massive hole. The fill area is now at an approximate elevation of 406 feet. He estimates it will take two weeks or so to reach the goal of 411 feet.

Two gallons a minute

A bedrock well near the scale house, which is about 500 feet deep, is pumping water to five irrigation zones. A totalizer reading found the well has been averaging two-gallons-per-minute, “pretty consistently since it started,” according to Heiple.

The water is being piped underground to the zones where hoses are providing irrigation.

“I’m calling them zones,” Heiple said. “Zone One is getting a fairly good amount of water. I’m not seeing as much water in the other zones.”

He said he believes valves can provide a better distribution of water. “Step one is getting the water to those places and I think we’re on the right track now,” Heiple said, “and then we can observe the effect and understand better how it is working.”

Karp said one or two timers in the zones are not working properly and two were “mysteriously missing.” New timers were ordered and will be reinstalled “no later than prior to this weekend,” he said.

“We will also check the line tomorrow for any leaks or anything else,” Karp said. “We’re getting some good water, but not some great water, so we’re going to take a little look at it with Bill’s oversight and have a more in-depth view of it next month.”

Chairman B.J. Hall noted that drought conditions this summer has also presented a challenge for hydrating the wetlands.

Hall said a key part of the restoration process will be the conditions of the various wetlands and vernal pools. He asked if Bill Kenny, the property owner’s soil scientist, could provide periodic reports to the commission.

Karp said he will try to have Kenny attend the commission’s Aug. 24 meeting if he is available. If not, he said Kenny will get a report to commissioners well-before the meeting, when Karp or Heiple can answer questions.