Pasco Landfill

From April 2021 – June 2022, over 35,000 drums of hazardous waste were removed from Zone A of the closed Pasco Landfill and taken to Grand View, Idaho, and Arlington, Oregon, for safe disposal. Since April 2024, underground thermal treatment has removed and destroyed about 8,100 pounds of chemicals from contaminated soil around the area where the drums were buried. 

Recently, some chemicals being removed from the treatment process were not fully captured by the system and traveled to groundwater. Groundwater is not a source of drinking water in the area, and people are not currently at risk. Increased chemical recovery in Zone A is underway to correct this situation.

The amended Enforcement Order requires the parties responsible for cleanup to: 

• Increase groundwater monitoring and treat the new groundwater contamination to contain it
• Protect air quality in nearby buildings by assessing whether contaminant levels in groundwater could cause unsafe levels of contaminants to build up indoors

The amended Enforcement Order includes the Cleanup Action Plan, scope of work, and schedule for completing the new activities.

Learn more

• Review the Enforcement Order amendment.
• Visit our Pasco Landfill cleanup site page.

Next steps

The Enforcement Order amendment went into effect November 20, the day we issued it. The parties responsible for cleanup have already begun the required work to address the situation as quickly as possible. We are working closely with them to ensure public safety.

We planned a 60-day comment period to allow people more than 30 days to respond after the community receives the public notice in the mail. We will hold a public meeting if 10 or more people request it.