The Northwest Pipe and Casing/Hall Process Company site is a 53-acre former industrial property in Clackamas, Oregon. Pipe manufacturing and coating operations ran there from 1956 to 1985. Improper waste disposal left soil and groundwater contaminated with solvents, polychlorinated biphenyls (PCBs), coal tar, polycyclic aromatic hydrocarbons (PAHs), and oils. EPA placed the site on its National Priorities List (NPL) in October 1992.
Cleanup is organized into two main operable units. One targets soil contamination and one targets groundwater. Soil cleanup included demolishing buildings, excavating and disposing of more than 32,000 tons of contaminated soil off-site, placing a two-foot clean soil cap, and installing a groundwater treatment system. Additional contaminated soil was removed between 2009 and 2015. Construction of the soil remedy was completed in June 2004. Groundwater contaminants of concern include tetrachloroethene, trichloroethene, vinyl chloride, and arsenic. EPA selected an updated groundwater remedy in November 2023. It uses in-situ (in-place) biological and chemical treatment, injecting amendments directly into the ground to break down contaminants. The goal is a 90 percent reduction in perchloroethylene and tetrachloroethylene concentrations, reaching safe levels within 10 years of treatment. Groundwater remedial action began in September 2024 and is expected to continue through 2030.
Vapor intrusion has been evaluated at nearby Oregon Department of Transportation (ODOT) facilities. Indoor air testing in 2017 found no exceedances of risk-based screening levels for key contaminants including PCE, TCE, and vinyl chloride. Human exposure is currently considered under control. However, groundwater migration is not yet under control, and the site has not achieved sitewide cleanup goals. Institutional controls restrict groundwater use until it meets drinking water standards. The most recent five-year review, completed in September 2021, found the site protective of human health in the short term but noted the groundwater remedy needs improvement for long-term goals. The next five-year review is scheduled for late 2026.
The site is actively reused. Seven businesses on the property employed 143 people and generated about $16.2 million in annual sales as of December 2024. Tenants include Oregon Department of Transportation facilities and warehouse and office spaces. Community members may notice trucks, trailers, and drill rigs on site during ongoing injection well installation and groundwater monitoring work. EPA finalized a Community Involvement Plan in July 2023. For questions about cleanup, contact the EPA Remedial Project Managers or Community Involvement Coordinator.
