EPA Superfund Site

QUENDALL TERMINALS

WA | EPA ID WAD980639215

About this site’s exposure pathways: As of September 2024, the Quendall Terminal Superfund site is considered Human Exposure Not Under Control because surface and subsurface soil, groundwater, and off-shore sediments are contaminated with coal tars, creosote, creosote by-products and arsenic. Mobile Dense Non-Aqueous Phase Liquid (DNAPL) has been transported by groundwater to off-shore sediments. Dissolved constituents of DNAPL are still being transported by groundwater and upwelling through lake sediments. The risk assessment indicates that use of groundwater for drinking water, dermal contact with surface and subsurface soils, vapor intrusion into occupied buildings, and consumption of even modest quantities of shellfish would all pose unreasonable risks to humans. Benthic organisms, benthic macroinvertebrates, and terrestrial and aquatic-dependent wildlife are all subject to unacceptable ecological risks. No one is currently using contaminated water as a drinking water supply; installation of wells is currently prohibited; and the site is vacant, fenced, and posted, thus limiting human exposure to contaminated soils. However, children may be exposed to contaminants when wading and, most importantly, EPA is concerned about shellfish consumption by the local community. Although there are no fishing advisories specific to the site, the state health department has issued one for Lake Washington to limit Polychlorinated Biphenyls (PCB) consumption. EPA and the Responsible Parties (RPs) signed an Administrative Settlement Agreement and Order on Consent (ASAOC) for Remedial Design in September 2024. EPA anticipates that Remedial Design will be completed by 2027, and Remedial Action will occur from 2029 until 2033. Human Exposure Under Control is anticipated to be reached by the end of 2033.