Mass Audubon wins amended permit to reshape Pawtucket Farms pond, add ephemeral pool and resize detention basin

At its July 16 meeting, the Lowell Conservation Commission voted unanimously to approve an amended notice of intent from the Massachusetts Audubon Society to alter stormwater and habitat features at Pawtucket Farms, 141–1415 Barnum Ave. Mass Audubon’s senior director of capital assets and planning, Elizabeth Stetson, told commissioners the amendment would expand the existing pond’s footprint, create an ephemeral pool and reduce the size of a previously proposed upslope rain garden while resizing the stormwater detention basin to reflect new site information. “We feel that groundwater runoff is also a significant, contributing factor to the pond overflowing,” Stetson said, describing new observations and additional soil testing performed since the original filing. Commission staff and the project engineer said the additional soil testing found sandy, highly infiltrative (“Type A”) soils upslope, which reduced expected surface runoff and allowed a smaller subsurface infiltration system. Jonathan Hedlund of Niche Engineering said the revised design reduces the need for cutting into a steep slope, creates gentler pond edges for more diverse vegetation and meets Lowell stormwater standards. The applicant also addressed questions about an unrelated petroleum release found in the farmhouse basement. Stetson said the underground tanks had been removed and that O’Reilly Talbot & Oaken Associates (OTO) — led on the project by licensed site professional Laurie McCarthy — prepared a release abatement measures (RAM) plan that will be submitted to MassDEP before excavation begins. She said soil sampling will occur during demolition and that the excavated volume is estimated at about 30 cubic yards. Impacted soils are expected to be “below MassDEP standards,” and OTO will provide on-site monitoring and immediate off-site removal of any contaminated soils; stockpiling is not anticipated. Stetson added the contaminated soil is limited to the farmhouse footprint and is estimated to be about six to seven feet below grade, so the project team does not anticipate adverse impacts to proposed turtle habitat. After asking follow-up questions and reviewing the revised plans, commission members took public comment, closed the hearing and moved to approve the amended notice of intent. A motion to approve and to issue the City of Lowell standard order of conditions passed with all commissioners voting in favor. The approved changes combine stormwater-management adjustments with habitat and educational improvements: the expanded pond edge and ephemeral pool are intended to create gentler slopes and varied wetland vegetation for amphibians, turtles and other species while providing outdoor teaching opportunities. The RAM plan and MassDEP submittal are required before demolition and excavation commence. The commission did not add special conditions beyond issuing a standard order of conditions. Project proponents said they will continue site monitoring and implement measures the licensed site professional requires.