The proposed spring cleanup of a downtown site once used to manufacture home heating, cooking and lighting gas will involve treating groundwater, capping and excavating, including within the adjacent Little River.
The Haverhill Conservation Commission heard plans by Boston Gas Thursday to address more than 170 years of coal gas-related contamination at 284 Winter St., a site now occupied by a Haffner’s gasoline station. (For a history of coal gas manufacturing in Haverhill see WHAV’s “Haverhill’s Gilded Age Robber Barons: Haverhill Gas Light Co.”)
Billie Jo-Gauley, of Anchor QEA, design and engineering firm for the in-river portion of the site, said the goal of the is to “advance the site toward a permanent solution.” She said air will be pumped below groundwater, which would allow air above the groundwater that contains volatile compounds to be removed and treated.
“The intent is to decrease the concentrations [of volatile compounds] in the subsurface,” she said. “This work will include the relocation of an electric line that’s located above a former (gas) holder that’s located on the site as well as some limited soil excavation to remove some hardened coal tar deposits,” she told commissioners.
She said the temporary cap in the Little River could mitigate air emissions from work upland (See map below).
The work will be conducted on a wetland resource area, which Gauley believes will have “temporary impacts.” The designer and engineer for the upland portion of the site is GZA GeoEnvironmental.
Haverhill Gas Light Co.’s gas manufacturing plant, 284 Winter St., in 1949. The photograph was taken after a train derailment.
As WHAV reported almost a decade ago, the site was owned by Haverhill Gas Light Co., later known as Essex County Gas Co., from 1853 to 1970. Essex County Gas was purchased by Boston Gas, now National Grid, in 1998. Current work was prompted, officials said, by the appearance of a “sheen” on Little River in 2015.
Commission Clerk Thomas Wylie asked whether abutters would be impacted by the project.
“All of the staging will occur on this site. Work that will be occurring off the site is construction of the armor mattresses,” Gauley said. “Those are currently anticipated to be constructed at the contractor’s yard. Those will be trucked to the site and offloaded for placement, so that will save on any staging area on this site itself. Because it is a relatively small site.”
She added, “there will be some anticipated closures of the car wash which will be coordinated with the property owner.” Gauley clarified that the gas station on the site “would be able to stay open during the work.”
Wylie questioned whether work at the site would coincide with work to remove Little River Dam, which as only WHAV reported, recently received an approximately $99,000 grant to help pay for removing the dam.
“For this work, we don’t anticipate our work occurring at the same time. The river work is limited to the temporary cap which we anticipate can be installed this fall or winter depending on approvals.”
Wiley called the project a “mini step for a big step.” Gauley detailed what that involves.
“This portion is more to address the upland position of the site and to decrease the concentrations in the soil and groundwater, which in turn do impact the sediment in the Little River,” she said. “We’re trying to decrease those concentrations so we can better manage the impacts in the Little River. The full-scale remedy in the river after this system has been active and been able to reduce those contaminants.”
The commission voted unanimously to seek a peer review of the project and to continue discussions to its Oct. 24 meeting.
Map showing 284 Winter St. site and cleanup locations.