How the cleanup process works

Cleanup sites are construction projects that remove harmful contamination from our environment and put properties back into use. Sites can be as small as a gas station spill, or as large and complex as the Tacoma Smelter Plume that impacts thousands of acres. The Model Toxics Control Act (MTCA) drives the process to clean them up.

The Model Toxics Control Act guides our work

Our Toxics Cleanup Program uses steps laid out in MTCA to conduct formal cleanups. Property owners who conduct independent cleanups might not follow all these steps but still must meet MTCA's cleanup standards.

The difference between “formal” and “independent” cleanups

  • Ecology conducts or supervises formal cleanups when property owners are under court order or decree, or when cleanups are funded by legislative initiatives. You can provide input during public meetings and comment periods.
  • Property owners can conduct independent cleanups on their own or with help from our Voluntary Cleanup Program (VCP). Owners set their own timelines. They can ask for our help through the VCP but don't have to. They only need to hold public meetings or comment periods if a site is being removed from the Hazardous Sites List.

Both formal and independent cleanups must meet MTC standards. ​Read more about cleanup options.

The steps in the MTCA cleanup process

  1. Discovery & Initial Investigation. Find a hazardous spill or suspect one happened in the past?Report it to Ecology and we’ll investigate. Owners may clean it up at this stage. If not, we'll add it to our Confirmed & Suspected Contaminated Sites List.
  2. Hazard Assessment. We'll rank the site’s hazard by comparing it to known sites. If it’s a threat, it goes on our Hazardous Sites List.
  3. Remedial Investigation & Feasibility Study. Scientific studies show us how far contamination traveled and help us develop cleanup options.
  4. Cleanup action plan. We’ll collaborate to develop a plan that specifies standards, methods, and schedules.
  5. Cleanup. We’ll work with the responsible people to clean up and remove sources of pollution.
  6. Extra steps and legal actions. We’ll take steps to make sure cleanups protect your health and the environment.
  7. De-listing. We'll remove the site from the Hazardous Sites List after it meets cleanup standards and requirements.

Find more detail about each step and relevant law and policy below.