Cleaner yards, cleaner future: Ridgefield neighborhood enters last stage of soil contamination cleanup

If you visited the general area of 111 West Division Street in Ridgefield during the last 10 years, you would have noticed the sounds and sights of cleanup crews and landscapers digging up yards and putting them back together. As strange as that sounds, there's an important reason why most of the eligible homeowners signed on for this activity to happen in their yard: to remove toxic soil in yards.

During 2025, workers completed 10 yards, bringing the total number of residential yards cleaned up to 39. And as of March 2026, only four yards and portions of certain sidewalk areas (called right of ways) in Ridgefield still require cleanup. Through a combination of settlement and grant money, $4.2 million was secured for the final phase of off-property cleanup.

This yard cleanup program is reaching a pivotal cleanup step spring 2026 as it decontaminates the last participating yards in a Ridgefield neighborhood. But the soil there wasn't always toxic - it changed over time because of its close location to an industrial site.

How did the industrial site impact its neighbors?

The neighborhood was established near a large industrial wood-treating site called Pacific Wood Treating (PWT) that did much of its industrial work from 1964-1993. The formerly industrial site is now a cleaned-up waterfront area, thanks to the Port of Ridgefield's planning and efforts. But decades ago, it was a working site for treated wood products such as planks, poles, and boards that required certain chemical applications before they could leave the site. The chemical? Pentachlorophenol.

Large trucks carrying pentachlorophenol-treated wooden planks or poles (similar to telephone poles) routinely left the site and trucked through the nearby residential neighborhood on their way to buyers. A pole treated with pentachlorophenol, though, isn't something you want moving through your neighborhood. A wood preservative, pentachlorophenol gets applied to wooden poles or planks to help them avoid rot or degradation. However, once dried, it puts off a toxic byproduct chemical that doesn't belong in yards where children play, gardens grow, and families live. In 2022, the Environmental Protection Agency (EPA) banned it due to health risks.

How did the soil get contaminated?

As trucks came through over time, the toxic byproduct chemical increased in yards, affecting the soil and creating a layer of toxic dust on top of green grass, curbside dirt, and the sides of roads and sidewalks. This toxic dust from the industrial site also blew into the neighborhood. During the Vietnam War, the demand for treated wood products was high and that meant the transportation and production was rushed. Instead of waiting for the treated wood to fully dry before transporting - which would have limited how much dried toxic dust blew off the wood - the drivers took them through neighborhoods before the drying process was complete.

Because the treated wood was wet during transportation, pentachlorophenol could drip from pieces of wood and then dry in place where it landed. The leftover toxic chemicals that remain are dioxins and furans, which we commonly refer to as just dioxins. Wet or dry, it's not a chemical you want hanging out in your yard, especially since this chemical degrades so slowly.

Almost all dioxins increase cancer risk, harm how the liver functions, and adversely impact human health over time.

Marian Abbett, section manager of Ecology's Southwest Regional Office Toxics Cleanup Program, said it's a concern when dioxins accumulate because larger amounts pose higher health risks over time.

"Dioxins in soil are not an immediate health concern, but can impact the health of you and your family over time," Abbett said. "Even if you're doing something as simple as gardening carrots outside, if you're growing them in the ground instead of in a raised bed with clean soil, that soil is potentially laden with these dioxins. If you don't wash your fruits and vegetables thoroughly, you may be eating dioxin contaminated soil, too. It's why this cleanup program has been so important - it restored dozens of yards to create cleaner and safer living for families."

Ready, set, cleanup

Ecology started cleanup plans on the industrial wood treating site before discovering the contamination in the adjacent neighborhood. Workers discovered the neighborhood pollution after Ecology and the Port of Ridgefield tested the soil across the street. Once we learned there was a need for two cleanups, we partnered with local government entities to do work on both sites.

Ecology and the Port assessed individual yards and public sidewalks and rights of way during multiple rounds of sampling to determine which sections of land needed cleanup. Homeowners in the neighborhood had the right to refuse this service, which meant they were excluded from the cleanup.

It takes about two months on average for one yard to go from start to finish. Workers start by surveying the homeowner's yard to better understand the location of existing plants, structures, and what needs to get excavated. Once workers complete the survey and capture the information, a landscape architect works directly with homeowners to create a restoration plan. This plan makes sure workers replace or return the removed plants to a proper location. Using the collected data points, they dig down about 1.5 to 3 feet across the entire yard, around any sidewalks, and as close to the house's foundation as possible. That toxic soil gets removed and then replaced with healthy soil. Finally, landscaping starts to restore the yard to how it used to look.

Cleanup started in 1996. Ecology was able to offer the Port of Ridgefield approx. $83 million from multiple grants through the Model Toxics Control Act, various settlements, and loans to support the work. The Port of Ridgefield is the primary entity that cleaned up both sites.

Neighboring waterfront cleanup

Penny Hughes, environmental project manager for the Port of Ridgefield, said the port's waterfront has been cleaned, thanks to help from Ecology. The cleanup started in 1996 and ended in 2015. Where Pacific Wood Treating once operated, specialists removed:

• 24,800 gallons of liquid contamination
• More than 1.5 million pounds of contaminated sludge
• Contamination from over 1 million gallons of groundwater
• 5,392 cubic yards of contaminated soil

Finally, the area of approximately 41 acres was capped with clean soil, restoring the land for development.

"After 30 years, we are hoping to officially conclude cleanup after this summer," Hughes said. "While I wasn't here from the beginning of the cleanup as an employee, I grew up in Ridgefield and watched from the sidelines. The Port's waterfront has gone from an industrial area, that was not open to the public, to going through an extensive cleanup that now is open to the community and enjoyed year-round. And now, with the neighborhood cleanup reaching a milestone, we're proud to be part of the community's safer future."

To help educate homeowners and hear from them, Ecology held a public comment period for this last phase of the cleanup. Most homeowners are pretty familiar with the project since the construction has been happening in the neighborhood since 2017. Once a yard is clean, the homeowners receive a small package with a document that says this cleanup happened so that the homeowner can prove how the Port and Ecology addressed the contamination.

For those yards getting new soil, Abbett said it will be safer for families and pets to dig in the soil in the backyard.

"We couldn't have done this work without the partnership from the city of and Port of Ridgefield," Abbett said. "The city and Port cleaned up on behalf of the public, and this decade-long effort has made the community healthier - one yard at a time."

Want to know about other cleanups?

You can look at other cleanup sites through our online "What's in my Neighborhood" map. You can find contaminated sites across the state including sites that have been cleaned up. You can also search for sites near an address or in a zip code, or find specific sites by name.