By MARK SARDELLA
WAKEFIELD — The Conservation Commission likes the latest plan presented for the subdivision at 181 Salem St., but Brian McGrail, the attorney for the developer, Thursday asked commissioners to keep the hearing open for one more meeting. Town Engineer Michael Collins is finishing up his review of the drainage, McGrail explained, asking the ConCom to hold off on closing in case Collins had any concerns.
The project has undergone some changes as it has made its way through the approval process with the Conservation Commission and the Planning Board. It was originally planned as a three-home subdivision, with one pre-exiting house and two proposed new homes. The plan was subsequently scaled back to just one new home in addition to the existing house. A new roadway has been reduced to little more than a driveway.
Last week, McGrail and engineer Michael Laham reviewed for the commission the latest changes that had been made to the drainage plan for the project. A previous plan involving a gravel and pea stone swale to the left of the roadway gave rise to concerns over future maintenance.
The new plan calls for a grass and vegetated swale sloping from the driveway down toward the wetland. Bearberry will be planted as a ground cover. Laham said that the vegetated swale would work better. The newly proposed system will also include a 12-inch perforated pipe connecting several landscape drains with check dams along the length of the driveway. Laham said that this would assure that all flow goes into the gravel drainage trench.
Laham told the commission that a lot of water infiltration would happen in the swale itself and that the landscape drains would bring flow from larger storms into the swale.
In response to a question from ConCom Chairman Frank J. Luciani Jr. about the capacity of the proposed system, Laham said that it could handle 1,463 cubic feet of water or 11,000 gallons. Laham added that the system meets the standards for reducing runoff from a 100-year storm.
The commission was happy with what they heard last night.
“It looks like a good plan to me,” Luciani said.
Commissioner Frank Calandra said that he had received some of the data that he had requested from the Massachusetts Department of Environmental Protection related to past testing of Lake Quannapowitt for contaminants. The commission is interested in knowing how far the Lake is from being safe for swimming and was looking for existing data from past testing in order to get a baseline.
Calandra gave a preliminary report on data he had received from a “risk assessment to human health” conducted in 2007. He said that that test found “no significant risk.” Calandra said that he doubted that the toxicity values would have changed significantly since then.
Chemical toxicity is just one of the factors in determining if the Lake is safe for swimming. A major concern for the commission and the Lake Quannapowitt Water Quality Committee has been the proliferation of blue-green algae, which can produce its own toxins and impact the overall health of the Lake.
The commission looked at information compiled by Conservation Agent Rebecca Davis regarding town-owned parcels that could be considered for conservation land.
Two other hearings scheduled for last night were postponed and continued to the commission’s Nov. 20 meeting. One concerned a Notice of Resource Area Delineation for 94 Butler Ave. The other continued hearing related to a Notice of Intent to construct a single-family home at 0 Stark Ave.