Pacific Wood Treating Corp

The last two phases of yard soil replacement in 15 yards and rights of way, located east of the Port’s property, are planned to begin in mid-2025. This cleanup will prevent people from being exposed to dioxins. Dioxin contamination is from the Pacific Wood Treating facility, which has already been cleaned up. Ecology and the Port of Ridgefield's (Port) consultant, Maul, Foster, Alongi (MFA) have already reached out to the remaining 15 homeowners in the neighborhood affected by dioxin-contaminated soil.

We plan to begin yard soil replacement for ten properties and rights of way in Phase 1 in mid-2025. Preconstruction work for the five properties and rights of way in Phase 2 will begin in early 2025. Phase 2 soil replacement will begin when funding is secured.

We used several years of sampling results to choose which properties need cleanup. The Port of Ridgefield’s consultant, Maul Foster & Alongi, Inc. (ridgefieldyardcleanup@maulfoster.com) will manage the soil replacement work. Our plan for cleaning up yards with dioxins in soil is to:

1. Remove about 12-24 inches of soil
2. Add a layer of clean soil and restore landscaping

We accepted public input on Agreed Order DE 12769, the Draft Off-Property Cleanup Action Plan, Draft Off-Property Remedial Investigation and Feasibility Study, and State Environmental Policy Act Determination of Non-Significance. 

The comment period was from January 9, 2025, to February 10, 2025. We received no comments. There were no changes to the documents.

The residential neighborhood affected by dioxins-contaminated soil, located east of the Port’s waterfront property.

Orange: 10 properties and rights of way will be cleaned up in Phase 1, planned for mid-2025.

Blue: 5 properties and rights of way will be cleaned up in Phase 2, with new funding.

Green: 29 properties and rights of way have already been cleaned up.

Gray: Areas that do not need to be cleaned up.

Dioxins transported by dust tend to stay in the upper layer of soil until they are disturbed. If you or your family are concerned, you can reduce exposure to potentially contaminated soil by doing healthy actions.

• Wash your hands after working or playing outside and before eating
• Remove shoes when you come inside the house
• Wear gardening gloves while gardening or landscaping
• Wash food from the garden
• Vacuum regularly and dust with a damp cloth
• Wash children's toys often
• Use grass or other ground covers to help prevent exposure. Landscaping and development can also dilute dioxins in soil.

From 1964 to 1993, Pacific Wood Treating (PWT) operated in the general area of 111 West Division Street in Ridgefield. At the facility, PWT pressure-treated wood products and poles using a variety of hazardous chemicals, including pentachlorophenol. Commercial pentachlorophenol is a mixture that contains dioxins, which is formed when pentachlorophenol is manufactured. In 1993, PWT stopped using pentachlorophenol, when the facility closed and declared bankruptcy. In 1996 the port started cleanup of the facility. By 2015, cleanup at the former PWT plant site was completed.

Starting in 2009, Ecology and the port sampled soil in the neighborhood east of the port's property to find the extent of contamination from PWT that moved beyond the plant's boundary. Dioxins were the only contaminant found in soil above state cleanup levels in the area outside the port property. Dioxin-contaminated soil likely came from airborne dust from PWT operations. Dust may have blown off the port property, been tracked onto roads from truck tires, and come off trucks hauling treated wood on Ridgefield city streets.

Past On-Property Cleanup Work

This work occurred at the Port waterfront property at 111 W Division St. 

From June 2014 to 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 undergrounds. 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.

Dioxins are made naturally by forest fires and volcanoes. They are also the unintentional by-product of burning from fireplaces, wood stoves, and exhaust from diesel engines. Dioxins are found everywhere because they do not break down easily in the environment. Most people are exposed to very low levels of dioxins when they consume food or milk, breathe air, or have contact with dioxin-contaminated soil.

Dioxins do not pose an immediate health risk. But long-term exposure to elevated levels increases the risk of health problems. Young children are more at risk than adults. The health risk comes from accidentally swallowing or breathing in the dust from contaminated soil over a long period. We recommend you protect yourself and your family by practicing healthy actions.