Clean Earth/Burlington Environmental - Kent

Last updated June 2025

This site is currently preparing to go out for public comment from July 14 - August 15, 2025. Documents for review will include the draft agreed order, draft cleanup action plan, draft SEPA/DNS) State Environmental Policy Act/Determination of Non-Significance and the draft public participation plan.

The site must follow regulations set by Washington’s Model Toxics Control Act (MTCA), which sets a standard process for cleaning up contaminated sites.

Ecology approved the Remedial Investigation (RI) and Feasibility Study (FS) for this site in 2018. The RI and FS are important steps in Ecology's cleanup process. Ecology did not receive any comments from the public and approved the RI/FS study on March 20, 2018.

Remedial Investigation (RI)
The purpose of the RI is to define the nature and extent of contamination at the site.

Feasibility Study (FS)
The FS used the results from the RI to evaluate and propose measures to cleanup contamination.

Ecology selected cleanup Alternative 1 which includes:

Monitored Natural Attenuation (MNA)
MNA requires that the soil and groundwater contamination be monitored under the natural conditions to ensure that it is breaking down at an appropriate rate.

Institutional Controls
The site is securely fenced and public access is controlled. Institutional controls are outlined in section 8.1.1 of the Final Feasibility Study.

Dangerous Waste Permit
The site is closing several of its Treatment, Storage and Disposal (TSD) dangerous waste units. They are completing this work under the federal Resource Conservation and Recovery Act (RCRA) through their TSD Part B Permit. Ecology oversees permits required by RCRA for facilities that deal with hazardous wastes.

A number of spills and leaks of hazardous substances have occurred at the site since the facility began operations. Most of the spills and leaks are from the tank farm area. While most of these releases remained within secondary containment, several resulted in the release of contamination to soil and groundwater at the site.

In the soil, contaminants of concern are:

Vinyl chloride

benzene

Petroleum products (diesel, lube oil, and gasoline)

Polycyclic Aromatic Hydrocarbons (PAHs)

Arsenic

Cyanide

In the groundwater, contaminants of concern are:

Arsenic

Cyanide

Hexavalent chromium

Iron

1980
The site was developed as a commercial treatment and storage facility for oily wastewater. The facility was used for commercial storage and transfer of polychlorinated biphenyl (PCB) contaminated materials. Other hazardous waste management activities at the facility included the processing and treatment of:


-Acids
-Caustics
-Oily wastes
-Phenols
-Cyanide
-Sludges
-Aqueous metal-bearing wastes

2015
Ecology approved a Resource Conservation and Recovery Act (RCRA) permit modification for this hazardous waste treatment, storage, and disposal (TSD) facility. The permit included relocating operations to Tacoma.

Other changes to the permit included:

- Construction upgrades.
- Relocation of various operations to the Tacoma facility.
- Removing several dangerous waste units.
- Changing the facility name from “PSC-Kent” to “Stericycle-Kent.”
- Closure of several holding tanks that held non-regulated oily wastewater.

2017
The site started moving its hazardous waste activities from its facility in Kent to their facility in Tacoma. The Tacoma facility is located in a highly industrial area in the Tacoma tide flats. There will be no change in the number of trucks going to and from the Tacoma facility.