Remediation plan delivers regulatory closure in under a year at former manufactured gas plant site

Client challenge

The city of Lynn, 8 miles north of Boston, has 300 acres of prime waterfront, but the city’s 100,000 residents had no access to it. The area was mainly a former landfill that was failing and surrounded by brownfields and other industrial properties. In addition to the restoration of the failing landfill, the presence of a former manufactured gas plant (MGP) posed a particular challenge to development: how to address the historical contamination from coal tar, heavy metals, and other major contaminants.

For more than 40 years, the MGP site sat unused because of the expense and the effort required for the cleanup. Charter Development Company finally came in with a plan to transform the site and the adjacent former landfill into a public park. The park would reconnect the city’s residents — more than 93 percent of whom live in environmental justice-designated census tracts — with their own waterfront and catalyze investment in mixed-use property development.

To execute the remediation portion of this plan, Charter needed a partner with MGP site experience who could execute safely in a dense urban environment. They turned to Haley & Aldrich because of our long, trusted relationship and remediation expertise.

Our approach

Haley & Aldrich joined a large team of consultants working on the project, which Charter managed through a novel environmental public-private partnership delivery model that aligned the interests of the city, the state, and Charter itself. We led the remediation of the MGP area adjacent to the landfill.

We implemented a remediation plan that would bring the site to regulatory closure within Charter’s target time frame — under a year — without sacrificing safety or quality. Although it would be unprecedented to achieve an MGP site’s regulatory closure so quickly, we worked closely with Charter on an approach to accomplish this.

Our team used in situ stabilization to remediate coal tar-impacted soils as deep as 20 feet below grade by blending soils with a cement mixture to immobilize the contaminants. We worked in small sections to avoid destabilizing the adjacent roadway and utilities. Our long partnership with Charter meant we were aligned on safety behaviors, which helped us collaborate to be successful quickly without incident.

Value delivered

• Reconnected the city of Lynn’s 100,000 residents to their waterfront for the first time in more than a century
• Catalyzed nearly $1 billion in adjacent residential and mixed-use private development, with one residential developer citing the park as a major driver of institutional capital investment
• Achieved full regulatory closure in under a year with no safety incidents or lost time