Commencement Bay/Nearshore Tideflats Superfund Site

Commencement Bay/Nearshore Tideflats Superfund Site
Name	Commencement Bay/Nearshore Tideflats Superfund Site
Settlement type	Superfund site
Subdivision type	Country
Subdivision name	United States
Subdivision type1	State
Subdivision name1	Washington (state)
Subdivision type2	County
Subdivision name2	Pierce County, Washington

Commencement Bay/Nearshore Tideflats Superfund Site Commencement Bay/Nearshore Tideflats Superfund Site is a large contaminated industrial estuary complex in Tacoma, Washington that was listed on the National Priorities List under the Comprehensive Environmental Response, Compensation, and Liability Act in the late 20th century. The site encompasses harbor waters, intertidal flats, and adjacent uplands that historically supported heavy industry, railroads, and port facilities. Remediation has involved federal agencies, state authorities, local municipalities, and private entities coordinating long-term cleanup, monitoring, and redevelopment efforts.

Background and Location

The site occupies the southern shoreline of Puget Sound at the mouth of the Puyallup River in Tacoma, Washington, bordered by neighborhoods, the Port of Tacoma, and industrial corridors tied to Northern Pacific Railway and Union Pacific Railroad lines. Adjacent jurisdictions and stakeholders include Pierce County, Washington, the City of Tacoma, the Washington State Department of Ecology, the United States Environmental Protection Agency, and tribal governments such as the Puyallup Tribe of Indians. Nearby landmarks and infrastructure include Commencement Bay, Thea Foss Waterway, Wright Park Arboretum, and transportation routes like Interstate 5 and State Route 16.

Contamination and Sources

Contaminants originate from historic operations by shipyards, smelters, chemical plants, wood treatment facilities, and rail yards associated with companies including legacy industrial operators and shipbuilders linked to maritime activity in Elliott Bay and Seattle. Principal pollutants documented across sediments, soils, and groundwater include polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), mercury, arsenic, lead, dioxins, and petroleum hydrocarbons. Sources trace to ASARCO, wood-preserving works, creosote operations, heavy metals from smelting, runoff from impervious surfaces, and historic municipal and industrial discharges tied to American Smelting and Refining Company-type facilities. Investigations referenced federal statutes such as the Clean Water Act and evidence from environmental assessments under the National Environmental Policy Act informed source attribution and site characterization.

Environmental and Health Impacts

Contamination affected benthic ecology in Commencement Bay and trophic transfer to species including Chinook salmon, Pacific herring, and estuarine invertebrates important to the Puyallup River watershed and to tribal subsistence. Bioaccumulation of PCBs and mercury posed exposure pathways to humans through seafood harvesting and recreational activities in salt marshes and beaches near Point Defiance and harbor piers. Ecological risks implicated habitat for migratory species governed by the Endangered Species Act and regional conservation plans, with potential impacts to species managed by entities like the National Oceanic and Atmospheric Administration and regional fishery managers. Public health advisories were coordinated among the Washington State Department of Health, tribal health programs, and municipal agencies.

Remediation and Cleanup Efforts

Cleanup strategies combined dredging of contaminated sediments, capping, soil removal, groundwater treatment systems, and natural recovery monitored through adaptive management. Major remedial actions were planned and implemented by the United States Environmental Protection Agency, the Washington State Department of Ecology, the Port of Tacoma, private responsible parties, and contractors, using procurement frameworks influenced by Federal Facility Compliance Act precedents and cooperative agreements. Engineering controls integrated sediment containment, shoreline stabilization, constructed wetlands, and habitat restoration to meet targets consistent with Marine Mammal Protection Act considerations and regional habitat goals. Technical guidance drew on standards from the United States Geological Survey, ecological risk assessment methodologies used by the Agency for Toxic Substances and Disease Registry, and remediation technologies developed in collaboration with academic partners such as University of Washington researchers.

Regulatory and Legal Actions

The site generated complex legal and regulatory processes involving cost-recovery actions, consent decrees, and enforcement under the Comprehensive Environmental Response, Compensation, and Liability Act and state analogues administered by the Washington State Attorney General. Settlements allocated responsibilities among corporations, local governments, and port authorities; these negotiations invoked litigation history similar in regulatory complexity to cases involving Superfund sites nationally. Citizen groups, environmental organizations including The Nature Conservancy-affiliated partners, and tribal governments participated in public comment, administrative record reviews, and tribal consultation processes under federal trust responsibilities. Funding mechanisms utilized federal appropriations, state funds, and liable-party contributions structured by legal instruments enforced in United States District Court venues when necessary.

Current Status and Monitoring

Ongoing stewardship includes long-term monitoring of sediments, shoreline habitats, and groundwater using surveillance programs administered by the EPA Region 10 office, the Washington State Department of Ecology, and cooperative monitoring by the Port of Tacoma and tribal environmental programs. Remedial milestones report reductions in contaminant concentrations in targeted areas, accompanied by phased habitat restoration projects benefiting species tracked by NOAA Fisheries and state fishery managers. Public access, redevelopment, and port operations are balanced with institutional controls, signage, and fish consumption advisories coordinated by the Washington State Department of Health and tribal health authorities. Adaptive management continues with periodic Five-Year Reviews as required under federal law to evaluate protectiveness and address emerging science from institutions such as Environmental Defense Fund-linked research and regional universities.

Category:Environmental remediation Category:Superfund sites in Washington (state) Category:Puget Sound