Background:
The Riverside Square PCB site is located along the northern bank of the Lower Neponset River within the Riverside Square area in Hyde Park. From the 1930s through the 1970s, several industries using PCBs operated in the Neponset River Basin, one of the most industrialized basins in the United States. In 1962 and 1964, to control flooding, the river was dredged by the Metropolitan District Commission, now a part of the Massachusetts Department of Conservation and Recreation. Dredging is the process of cleaning out the bed of the river by scooping out sediment (mud) and debris with a machine called a dredge. The dredged materials, or “spoils,” were placed in several locations along the banks of the river, essentially creating new land. The Riverside Square PCB site is one of those riverbank locations. In October 2022, Massachusetts Department of Environmental Protection formally requested that EPA perform further investigation of the spoils at the Riverside Square PCB site.
What Has Been Done to Cleanup the Site?
Cleanup activities began in October 2024 and continue to date. Tree and brush clearing have been conducted across the Site. Soil contaminated with polychlorinated biphenyls (PCBs) and heavy metals (mostly lead) are being excavated and stockpiled in a dedicated soil staging area. The stockpiled soils are secured with a reinforced polyethylene cover during nonworking hours throughout the removal action activities. Water is used to suppress dust while moving/using equipment, throughout all excavation, staging and loadout for disposal.
What is the Current Site Status?
As of November 2025, EPA completed the first and second rounds of disposal transporting 3000 tons of contaminated soil to EPA-approved landfills. Transportation and Disposal is performed adhering to an EPA, City of Boston, and Town of Milton pre-approved traffic plan.
For more information, please see the most recent factsheet in the document section of this website.
