GSA ENGINEERING AND ENVIRONMENTAL DIVISION BURWELL AWARD: MANUFACTURED GAS PLANT REMEDIATION—A CASE STUDY

Between roughly 1800 and 1950 the worldwide gas industry used manufactured gas plants (MGPs) to produce gas from coal, oil or other feedstocks to supply gas for public illumination, industrial fuel, and domestic needs. The byproducts and wastes of these plants contained numerous persistent toxic constituents, and many MGP sites still present risks to public health and the environment.

This publication is the first detailed statewide study of the manufactured gas industry and its modern environmental legacy, focusing on Massachusetts as an example of nationwide patterns. Massachusetts was selected in part because by the early 1900s the statewide gas industry was the second-largest in the US, surpassed only by New York. We located and researched a core population of approximately 200 confirmed gas industry related sites in Massachusetts, plus a larger population of suspect coal-tar sites. We compiled 19^th and 20^th Century historical information, such as regulatory filings and engineering documents, together with current land use and regulatory status. The sites were then mapped using GPS/GIS methods cross-referenced to historic mapping and other referenced sources. Our findings were summarized as part of an overall narrative history of the state’s gas industry from its origins through to the modern management of environmental legacy issues, supplemented by discussions of historic MGP operational information.

The 'core population' of confirmed and located sites we reviewed included 95 former utility manufactured gas plants; one byproduct coke plant, 18 private fuel gas plants; and numerous appurtenant sites such as district gasholder stations, off-plant dump sites, and other facilities. MGP-related contaminants have been encountered at typical sites of each type. Approximately 70 of these sites are documented in the historical record as having been used by the gas industry, but are not yet listed with MassDEP as “Disposal Sites,” the state’s regulatory term for properties subject to regulatory assessment and remediation requirements. Roughly 50% of the former MGPs remain in utility hands, with the remainder of the MGPs and most of the non-plant sites now in private or municipal ownership. The non-MGP sites are in aggregate more numerous than the MGPs themselves. Roughly a quarter of the total reported sites have attained permanent regulatory closure, consistent with the typical former MGP profile as a challenging and expensive site to remediate.