The Gloucester (Massachusetts) Gas Light Company (GCLC) operated a manufactured gas plant (MGP) facility on the Gloucester waterfront from 1854 to 1952 and produced coal gas and then carbureted water gas for lighting and other purposes in the surrounding community. When the plant shut down in 1952, the land was sold, and the buildings demolished. In the 1960s, the area was part of an urban renewal project, which included re-configuring the Harbor Loop and Rogers Street, and the development of commercial properties in the area.
In 2003, an unknown quantity of “creosote oil” was released during pile driving for a new dock at 17 Harbor Loop. Additional sediment impacts were identified during the collection of sediment borings that were part of a Phase I Initial Site Investigation. The site received a Tier I disposal site classification, issued under the Massachusetts Contingency Plan in September 2006.
Between 2007 and 2011, multiple field investigations were conducted in the upland areas of the site and in adjacent portions of Gloucester InnerHarbor by GZA GeoEnvironmental, Inc. (GZA), Anchor QEA, and Arcadis. Subsurface infrastructure and oil and/or hazardous materials (OHMs) related to the MGP operations were identified at multiple privately and publicly-owned properties that comprised the former MGP site, as well as within adjacent harbor sediments. This included coal tar, which was a by-product of the gas manufacturing process. A Phase II Comprehensive Site Assessment summarizing the nature and extent of impacts was submitted to the Massachusetts Department of Environmental Protection (MassDEP) in July 2011. A Phase III Remedial Action Plan, submitted to MassDEP in February 2012, evaluated and selected feasible remedial alternatives.
The responsible party for the site, Massachusetts Electric Company dba National Grid, embarked on a $30 million cleanup and restoration of the area to meet the requirements of the Massachusetts Contingency Plan (MCP, 310 CMR 40.0000).
National Grid is an investor-owned energy company that serves Massachusetts, New York, Rhode Island and the U.K.
Because of its size and layout, the site was divided into Marine and Upland Areas. The Upland Area was further subdivided into the Southern Area and the Northern Area, and the Marine Area was subdivided into the Nearshore Area and the Offshore Area.
A comprehensive remediation of the site began in 2015 and was substantially completed within two seasons. Anchor QEA provided design and oversight of the marine activities, and GZA designed and oversaw the upland response actions and provided Licensed Site Professional (LSP) and construction management services. Construction contracting, including dredging, seawall demolition and reconstruction, and upland remediation, was performed by Charter Contracting Company, LLC of Boston. Charter established a field office in the National Grid-owned building on Harbor Loop adjacent to the harbor, and Anchor QEA and GZA worked from offices in the same building.
The Public Archeology Laboratory, Inc. of Pawtucket, Rhode Island and marine archeological consultant David S. Robinson and Associates, Inc. of Jamestown, Rhode Island supported cultural and historical documentation for handling of the two marine railways built circa 1850, the original granite seawalls and other possible items revealed during the remediation activities.
The Anchor QEA team included Paul LaRosa as P.E. of Record for the marine portion of the project; Jaime Harrison Rice, P.E., project manager; Billie-Jo Gauley, geologist and Mark Mahoney, engineer, the latter two involved with sediment evaluations at the site starting in 2005. The others joined the team at the feasibility phase, where they evaluated remedial alternatives, and then into design, remedial construction, and long-term monitoring of the Phase IV Remediation activities. They are located in the Amesbury and Beverly, Massachusetts offices of Anchor QEA.
Dredging activities included mechanical and suction dredging of approximately 28,000 cy of MGP-impacted material from approximately 7.6 acres of the Nearshore and Offshore Areas of the site. The Offshore Area is located within the federal navigation channel, and the Nearshore Area includes multiple structures such as docks, piers, and an active marine railway.
To facilitate dredging, the northern and southern hauling piers associated with the active marine railway and the decking of the Maritime Gloucester main pier were removed. Prior to dredging in the Nearshore Area, debris including lines, cables, piles, and portions of an abandoned marine railway was removed and transported offsite for disposal.
Riverside and Pickering Marine Contractors, using a barge-based Komatsu PC1250 with environmental dredge bucket outfitted with a HYPACKTM bucket positioning system, conducted the majority of the mechanical dredging in the Offshore Area. Charter Contracting self-performed the mechanical dredging in the Nearshore Area using a combination of barge-based equipment (Komatsu PC1250, PC600, and PC300). Dredging was conducted within turbidity curtains (either stand-alone curtains or a mobile resuspension system) to minimize impacts to surface water outside the work area.
Suction dredging was conducted to remove impacted material inaccessible to mechanical dredge equipment from around structures, such as the marine railway and wooden pile supported piers, in portions of the Nearshore Area. Semper Diving and Marine conducted the suction dredging using a 6-inch Godwin Diesel Dri-Prime Pump. The slurry was pumped into geotextile tubes inside a hopper barge. Dewatering water was pumped to a water treatment system managed by Lockwood Remediation Technologies on the upland portion of the site.
Dredged material was placed into 2,500 cy capacity barges for transport to the processing facility in New Jersey. The facility removed debris before mixing the dredged material with Portland cement to facilitate dewatering. The material was then transported either to a thermal desorption facility or a non-hazardous waste landfill.
Marine activities were supported by multiple barges, hoppers, workboats, and a barged-based water treatment system. Movement of marine equipment and transport of barges to the processing facility in New Jersey was supported by Tucker-Roy Marine Towing and Salvage.
Additional seawall demolition and reconstruction activities were conducted to support upland remediation activities. Contaminated soil near the harbor was removed, where possible, and soil that could not be removed was isolated beneath an engineered barrier and an impermeable concrete wall. A vertical sand/organoclay barrier was installed to treat groundwater from the site, and automated pumping wells were installed to remove free-phase coal tar from 60 feet below the ground surface.
Following the completion of dredging, approximately 6,400 cy of sand backfill was placed in the nearshore area for residuals management and for structural stability purposes. Steel pipe piles were installed by Coastal Marine Construction and Sea & Shore Contracting to support a floating dock system for the City of Gloucester. The two wooden hauling piers were reconstructed by Boston Tug and Tow Marine Construction Company, and the wooden decking on the Maritime Gloucester main pier replaced.
An approximately 11,200 SF cap consisting of sand and organoclay placed in Tensar marine armor mattresses or placed alone as a mix was constructed to control contaminants dissolved in sediment porewater in a portion of the Nearshore Area on the USCG, City of Gloucester and National Grid properties. The use of MAMs was selected to provide sufficient scour protection in a thin layer application and to allow for future removal and replacement if there are changes in site operations or infrastructure.
The project required coordination of numerous elements. The marine activities included demolition and construction/reconstruction of historic waterfront structures; removal of submerged debris; operation of a barge-mounted 200 gpm temporary water treatment plant; removal of impacted sediment via both mechanical and suction dredging methods; placement of cap materials; and backfill of dredged areas.
The GZA project team overseeing the Upland work included Matt Barvenik as Licensed Site Professional; Vijay Radics, technical specialist; John Colbert, P.E., project manager; and Geoff Schwartz, P.E. construction manager. The former two have ushered the project from site investigation to remediation over the past nine years, beginning with data collection and analysis and strategy development during the Phase II upland assessment; the others brought their engineering skills to the project at the Phase III and Phase IV stage, respectively. They are located in GZA’s Norwood, Massachusetts office.
In the Upland Area, the project included demolition and reconstruction of an upland public park and granite block seawalls, removal or isolation of impacted soil, construction of a subsurface non-aqueous phase liquid (NAPL) recovery system, and construction and reconstruction of waterfront structures to meet the requirements of the historical commission.
Throughout the work, communication continued between the multiple stakeholders, including the USCG, the Harbormaster, Maritime Gloucester, Harbor users that include one of the largest commercial fishing fleets on the US east coast, and local city officials relating to the work schedule and sequence. Multiple permits from local, state, and federal offices were coordinated throughout, and site security was maintained to ensure the safety of impacted abutters, business owners and visitors.
Following completion of marine and upland remediation activities, a Phase IV As-built Construction and Final Inspection Report was submitted to MassDEP on December 27, 2018. Long-term monitoring and management of the NAPL recovery system is ongoing at the site.
In February 2018 the Association of General Contractors (AGC) presented Charter Contracting with its Construction Risk Partners Build America Award, the top prize in the Environmental Enhancement category, for the Gloucester project. “This project, performed in the oldest, active seaport in the United States, demonstrates Charter’s ability to partner with its clients to provide solutions that positively impact the environment for the benefit of the local community, visitors, residents, and surrounding businesses” the award stated.
Bob Delhome, president of Charter, said “The Gloucester MGP remediation project has been recognized by the industry as one of the most challenging and complex projects of its kind implemented over the past 20 years. It is meaningful to be recognized by our peers for successfully completing and delivering this challenging project. This successful outcome would not have been possible without the stewardship of the project’s responsible and committed owner, National Grid, and the support and expertise of the engineering partners, GZA GeoEnvironmental and Anchor QEA.”
In December 2018, ENR honored the Phase IV Remedy Implementation as New England’s Project of the Year and awarded the project the ENR Excellence in Safety Award of Merit. In March 2019 the Gloucester project was selected as one of the twenty Best of the Best and awarded the Best Water/Environment project of the year. “The complex multi-scope project was completed without incident in over 120,000 hours with a crew of 60+ working in a tight footprint, under harsh conditions, and in an active harbor,” the award stated.