Pacific Car & Foundry Co

The Pacific Car & Foundry Co property is located in the City of Renton, Washington, about 1/2-mile northeast of the downtown area.  Roadways bounding the property include Garden Avenue North on the west, Houser Way North on the east, North 4th Street on the south, and North 8th Street on the north.  The property is approximately 82 acres in size.  The northern 40 acres were initially remediated to allow construction of the Kenworth Truck Plant.  The truck plant began operations in 1993.  Since that time, the R&D Building was built in 2004 and the Parts Distribution Center was built in 2016.

PACCAR, Inc., formerly PACCAR Defense Systems, makes Peterbilt and Kenworth trucks, and formerly owned Al’s Auto Parts.  The company began on the Renton Site in 1907 as Pacific Car & Foundry, making rail cars.  They made Sherman Tanks in World War II, and fabricated the legs of the Space Needle.  When the rail car business declined, they started making military vehicles.  PACCAR decommissioned that facility in 1988.

The Site was placed on the U.S. Environmental Protection Agency (EPA) National Priorities List (NPL) on February 21, 1990.  Ecology is responsible for the oversight management of the Site as stipulated by an agreement with EPA Region 10.  Ecology prepared the Cleanup Action Plan (CAP), and PACCAR and Ecology entered into a consent decree to implement the CAP in November 1991.

Approximately 105,000 cubic yards of TPH-contaminated soil were biotreated, 30,000 cubic yards of metals-contaminated soil was solidified, less than 5,000 cubic yards of PCB- and cPAH-contaminated soil were disposed of off-Site, and 105,000 cubic yards of soil with contamination at levels between cleanup levels (CULs) and hot spot action level (HSAL) were moved by grading and ultimately placed beneath structural fill as cover.  The stabilized soil cells were placed in multiple locations on the property.  The soil cleanup actions were completed by 1997.

Compliance monitoring for groundwater and surface water (stormwater) has been occurring since then.  Arsenic, lead, vinyl chloride, and benzene were identified as the groundwater constituents of concern (COCs).  Chromium VI (hexavalent chromium), lead, copper, nickel, and zinc were identified as the surface water COCs.  Both the MTCA CULs and HSALs/MCLs are used to evaluate groundwater quality at the conditional points of compliance (the property boundary).  The 1991 CAP and 1997 Confirmational Monitoring and Inspection Plan (CMIP) describe which actions are required based on exceedances to CULs vs. HSALs/MCLs.

The remedy (which focused on soil remediation) has significantly reduced impacts to groundwater, but groundwater CULs for arsenic and vinyl chloride have not been achieved in all compliance wells at the conditional point of compliance.  Monitoring must continue as long as contaminants are present above CULs in all media.

A Restrictive Covenant implementing the required institutional controls was recorded in 1991.

The 2021 Periodic Review concluded:

• The remedy (which focused on soil remediation) appears to have significantly reduced impacts to groundwater, but groundwater cleanup levels (CULs) for arsenic and vinyl chloride have not been achieved in all compliance wells at the conditional points of compliance. Monitoring must continue as long as contaminants are present above CULs.  The cleanup action is considered an interim action until CULs are met at the conditional point of compliance. Therefore, the remedy is not protective of human health and the environment at this time. However, the remedy continues to be protective of human health and the environment with regards to preventing exposure to contaminated soils via ingestion and direct contact. 

• Arsenic exceeds the groundwater hot spot action level (HSAL), which is set at the Maximum Contaminant Level (MCL), in compliance wells LW-9S and MW-3I. Therefore, the cause of the elevated arsenic in groundwater needs to be evaluated per the Contingency Plan. 

• Surface water CULs for copper, hexavalent chromium, lead, and zinc have not been consistently achieved in stormwater sampling locations SW-3, SW-5, and SW-6 at the conditional point of compliance. Monitoring must continue as long as contaminants are present above CULs. The cause of the elevated metals in stormwater needs to be evaluated per the Contingency Plan. 

• The 1994 amended consent decree required PACCAR Inc. to record an amended Restrictive Covenant with the King County Recorder’s Office, but a recorded copy could not be found. A recorded copy of the amended Restrictive Covenant needs to be provided to
Ecology.

• Additional details can be found in the 2021 Periodic Review report