Pacific Wood Treating Corp
111 W Division St, Ridgefield, WA 98642

Phase 1 soil replacement areas
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Ecology and the Port of Ridgefield (port) removed dioxin contaminated soil in a total of 29 residential yards and some right-of-way areas in the neighborhood east of the port property (off-property area, see map on left).  We will be replacing soil in some Phase 2 area yards (see map below) and will update this website when we have more information on when cleanup will happen.

2017 Yard Replacement Factsheet

What Happens During Cleanup?

  • Remove dioxin contaminated soil up to 1.5 feet deep
  • Fill with clean soil
  • Replace/restore similar landscape

After we hold a public comment period for the remedial investigation, feasibility study, and the draft cleanup plan we will plan Phase 2 cleanup. We will work with homeowners and the city to plan the Phase 2 soil removal and replacement. Our cleanup work in Phase 1 was an interim action to start the cleanup.

Interim Action Plan

Off-Property Area
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We are continuing to sample soil in the Phase 2 area to find where contamination may exist.  We will use these samples to find the area of contamination and to determine which yards need soil replacement.

Yard Soil Dioxin Sampling

The yard soil sampling program found dioxin levels are not high enough to pose an immediate health risk, but could have long term health effects. We will continue testing soil in yards in the neighborhood, north of Maple Street, south of Mill Street, and east of Main Ave. (see map) until we find the extent of contamination.

The port discovered some soil contaminated with dioxins in the neighborhood near the port property. In 2009, the port began sampling in right-of-ways to define the extent of contamination in the Phase 1 off-property area. The initial samples found dioxin was the only contaminant found above cleanup levels. It was clear from the right-of-way samples that dioxins might also be in yards. The yard soil sampling program started spring 2015.  

You can read more about the investigation in the materials on the link to the right (View Electronic Documents).

Scope of Pacific Wood Treating cleanup
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The Pacific Wood Treating cleanup site is located at the Port of Ridgefield (port) property on Lake River in Ridgefield, WA. The property is near several important natural resources including the Ridgefield National Wildlife Refuge/Carty Lake and Lake River. The site is also close to the Ridgefield Marina, a railroad, and residences.

Pacific Wood Treating (PWT) operated on the site from 1964 to 1993. PWT pressure treated wood products with solutions containing
creosote, pentachlorophenol (PCP), and a water-based mixture of chromium, copper, and arsenic (CCA).

In 1993, the company declared bankruptcy. Contamination from PWT has been found in soil, sediments, and groundwater on and off the port property. 

From 1996 - 2013, the port cleaned up contamination on port property (see "Past Cleanups" below).   In 2013, Ecology and the port entered into a legal agreement for the port to clean up other areas with PWT contamination. The cleanup plan below describes past and future cleanup plans in more detail. Ecology and the port are funding the cleanup.


From June 2014 - early spring 2015, the port cleaned up:
  • Soil in the railroad overpass construction area
  • Sediments in Carty Lake/Ridgefield National Wildlife Refuge
  • Sediments in Lake River

From 1996 to 2012, the port did partial cleanups to remove contamination. The port used a steam enhanced remediation system to remove wood treating chemicals from underground. This system removed:

·         24,800 gallons of liquid contamination

·         1,545,000 pounds of contaminated sludge

·         Contamination from over 1 million gallons of groundwater

The port also removed 5,392 cubic yards of contaminated soil. They replaced the old stormwater system with new drains, piping, and outfalls. The port placed a clean soil cover over approximately 41 acres of land where PWT once operated, restoring the land for development.


You can read more in the information below or "View Electronic Documents" link on right.  


Ecology wants to keep you involved!  You will have the chance to review and comment on key documents during the investigation and cleanup process.  Documents will be at this web site and at the repository locations listed to the right as they become available. To get on the email notification list or if you have any questions please email


Map showing site location as Clark County, WA SITE INFORMATION


View Electronic Documents

Site Summary Report

Facility Site ID: # 1019

Cleanup Site ID: 3020

Ridgefield, Clark County

Status: Cleanup Started   Get definitions of Status terminology

Craig Rankine
Site Manager

Sheila Coughlan
Public Involvement Coordinator
(360) 407-6255

Document Repositories:

Southwest Regional Office
300 Desmond Dr SE
Lacey, 98503-1274

Ridgefield Library
210 North Main Avenue
Ridgefield, 98642