NEW BEDFORD — For an active hazardous waste cleanup, the Sullivan’s Ledge Superfund site was quiet in January.
No people nor footprints nor tire tracks could be seen in the snow dusting the surface of the former industrial landfill. Chunks of ice melted from rows of solar panels, as wind rattled the chain-link fence surrounding 11 acres of the dump.
Yet below ground, work progressed as normal. Toxics leached from the landfill’s waste pits, spreading northeast through groundwater in bedrock below. As they reached the site’s northern edge, thin metal wells pumped the water up to a beige building nearby — the site’s 24-year-old treatment plant. Inside, machinery pushed the toxic groundwater through filters and chemical treatment systems before discharging it to the sewer, whirring without stopping. At least, for now.
Sullivan’s Ledge, an industrial landfill for local industry through the early 1970s, has been recognized as a U.S. Environmental Protection Agency Superfund site — a hazardous waste site needing long-term remediation — since 1984. The groundwater treatment facility, built in 1999, contains and reduces concentrations of hazardous materials in groundwater at the site.
Yet it requires frequent repairs, which the city of New Bedford has to pay for. Parts of the aging plant, which has operated for more than 20 years, are becoming worn and obsolete.
Replacing the system could cost millions. An overhaul of the treatment facility, which city officials say would benefit the site, would also be costly. The consent agreements mandating the potentially-responsible polluters — 14 EPA-identified companies — pay for the remedy are considered dated, and the EPA and these parties may disagree on who should pay for a major solution. So in 2020, EPA officials, New Bedford and these settling parties organized a trial shutdown of the plant to see if it is still needed.
The verdict is that the site still needs the treatment plant to operate, according to a late 2023 EPA report.
New Bedford officials turned the Sullivan’s Ledge treatment plant back on in May 2023, after groundwater monitoring data showed hazardous material concentrations in the wells surrounding the site rebounding above EPA action levels.
EPA and New Bedford officials say there is no human health risk from contaminated groundwater at Sullivan’s Ledge, since there are no structures on the site, the landfill is capped, and the groundwater is not used as drinking water. Yet the EPA is requiring the polluters to monitor for impacts to wetlands and aquatic life at the adjacent Whaling City Golf Course — where the groundwater surfaces.
EPA leaders say the reactivated plant is reducing contamination in on-site groundwater once again. Yet they will not determine if it has fully regained control over toxics in the plume, or if additional cleanup measures are needed, until 2025.
“We have to look and see what is practical, feasible and necessary,” said Michele Paul, New Bedford’s director of resilience and environmental stewardship. “Because the project isn’t over yet.”
Video credit: Antonio Beltran / The New Bedford Light
Capped contamination
Sullivan’s Ledge, New Bedford’s second Superfund site, may not be as well known as the New Bedford Harbor. Yet, like the harbor, the landfill is an example of the EPA’s once-common practice of leaving toxics behind at hazardous waste cleanups.
When planning a parking lot on the site in 1982, the Massachusetts Department of Transportation identified “chemicals of concern” in surrounding groundwater, sediment, and soils, including high levels of volatile organic compounds (VOCs). These chemicals — like benzene, vinyl chloride, and trichloroethylene (TCE) — are commonly found in industrial paints and solvents. Exposures to them can affect kidney and liver function, and cause cancers.
MassDOT reported these findings to the EPA, which listed the site in its Superfund National Priorities List. In the mid-1980s, the federal agency discovered significant VOC contamination in soils and groundwater at the site, far above safe drinking water levels. Soon after, the EPA determined it would be “technically impracticable … to clean up … onsite and offsite groundwater to … drinking water standards,” given VOC contamination in hard-to-reach deep bedrock aquifers.
Site leaders set an alternate goal of “significantly reducing the mass of contaminants in groundwater … [and] minimizing the threat posed to the environment from contaminant migration in the groundwater.” They determined this goal would be met when VOCs in on-site groundwater reached steady state concentrations between 1 and 10 parts per million.
“The goal was to get to a point where contamination was no longer leaving the site,” said Kimberly White, the EPA remedial project manager for Sullivan’s Ledge. “Or if it was leaving the site, it was at a level that did not have an ecological impact.”
In 1998, contractors began working on the EPA’s remediation plan. The project was funded by New Bedford and the group of identified potentially-responsible parties at Sullivan’s Ledge, who settled a lawsuit with the agency.
Workers capped more than 47,000 cubic yards of contaminated sediment and soils from the site over the landfill pits without treating it. They also built a groundwater treatment plant, passive groundwater collection infrastructure, and a set of extraction and monitoring wells around the perimeter of the cap to treat toxic groundwater leaching from the dump.
The EPA further required New Bedford and the Massachusetts Department of Environmental Protection to create site restrictions prohibiting groundwater use at the site, and development that would disturb the impermeable landfill cap preventing human exposures.
The groundwater remedy chosen, called “pump-and-treat,” was common among EPA Superfund decisions in the 1980s. Studies show these systems are one of the only ways to treat deep bedrock contamination. They limit human and environmental exposures to contaminated groundwater by containing its spread. They can even reduce bedrock groundwater contamination significantly over time.
Yet pump-and-treat systems fell out of style, because maintaining them can be expensive, and treatment may need to stretch decades if a source of contamination is not cleaned up. Also, the only way to determine when pump-and-treat systems can stop is to turn the treatment plant off, and test for a rebound, which requires long-term monitoring.
The EPA’s 1989 record of decision stated that the Sullivan’s Ledge treatment plant could be shut down to test whether a “significant reduction” of contaminants at Sullivan’s Ledge had been achieved. It stated that a shutdown and a three-year post-monitoring period could start if groundwater data in certain wells showed concentrations of 1 to 10 parts per million of VOCs for four consecutive quarters.
New Bedford, the EPA and the settling parties signed a set of consent decrees in the early 1990s, agreeing that the city would handle operations and maintenance costs for the site, while the settling parties would handle environmental monitoring and capital improvements.
The groundwater treatment system, which cost more than $3 million to build, began operating in 1999. The impermeable landfill cap and wetlands restoration were completed in 2000.
“This closes a chapter of the book on one of EPA’s oldest Superfund sites, and offers a brighter future for New Bedford,” said former EPA New England regional administrator Mindy Lubber in a 2000 release.
A tricky treatment plant
By 2013, EPA officials said that the plant had “significantly” reduced the size and concentrations of the toxic groundwater plume on the site. Many wells showed concentrations of VOCs in the groundwater declining below 10 parts per million for more than a year.
Yet operations and maintenance issues at the plant were also common from the first five years onward. The plant experienced regular “periods of downtime,” and often operated at less than full capacity due to issues with extraction wells and chemical treatment systems.
New Bedford spent between $150,000 and $500,000 per year on operations and maintenance at the facility over its first 15 years, while the settling parties averaged $300,000 to $600,000 per year on environmental monitoring and capital improvement costs over the same period.
In 2013, the settling parties requested to shut down the plant “to demonstrate that the cleanup criteria have been achieved and can be maintained without the treatment plant operating.” And in May 2020, after VOC concentrations continued to meet performance standards, EPA officials granted the request. In July that same year, New Bedford officials turned the plant off.
Paul, New Bedford’s environmental stewardship director, added that “there is some merit to temporarily shutting down, to see what the reaction of the groundwater is.”
An ‘obligation for the remedy’
In May 2023, New Bedford officials turned the Sullivan’s Ledge treatment plant back on after MassDEP data showed VOC concentrations “consistently” rebounding and exceeding performance standards in wells on the site. The largest rebounds were in intermediate and deep bedrock wells north and east of the landfill, bordering the Whaling City Golf Course.
New Bedford and EPA officials are confident there is no direct human health risk from the contamination. Nor is there evidence of impact to the golf course thus far. Yet the remedy is not functioning as intended without the treatment plant operating, EPA officials said.
The treatment plant requires “extensive repairs and part replacements,” New Bedford wastewater superintendent James Costa said in the 2023 EPA report. He said the site “would benefit from an overhaul or replacement of the facility.”
Pump-and-treat systems like the one at Sullivan’s Ledge generally cost millions of dollars, according to a 2001 EPA analysis.
Moreover, the EPA’s site remedy “has not addressed the source of contamination,” which will require the plant to operate “for an indeterminate period of time,” said MassDEP project manager Dorothy Allen. She added that “design of a more appropriate long-term remedy is necessary.”
It will be roughly two years before the EPA determines if reactivating the treatment plant will ensure the remedy remains protective of human and environmental health, or if other cleanup measures are needed in the future.
“We have an obligation for the remedy,” White said. “My role is to make sure that those goals are met.”
Email Adam Goldstein at agoldstein@newbedfordlight.org
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I TOOK A PICTURE OF THE TIRE DUMP BEFORE THE FIRE…I WAS IN HIGH SCHOOL AND TOOK PICTURES OF POLLUTION AROUND THE CITY
I am wondering with all the solar panels at Sullivan Ledge why the city can’t put Charge point stations there for hybrid cars and recoup some of their operating expenses. There are so few charge point stations around that I am not able to charge my hybrid on a regular schedule.
Maybe instead of erecting a statue that romanticized the extinction of marine creatures(whales), the money could be diverted to real, necessary issues like this one!
Let’s not forget other vital areas of New Bedfords infrastructure that have been neglected for far too long
And now they want to put up a statue of Melville, like this city doesn’t focus too much on 50 years of its 250 years already.