Chapter 173-340 WAC

Ecology plans to amend the administrative and procedural requirements for site cleanups under Chapter 173-340 WAC, Model Toxics Control Act (MTCA) Cleanup regulation (the Cleanup Rule). In this rulemaking we will not change the technical standards for site cleanups in Parts 7 and 9 of the rule, but we plan to: 

  1. Update the title of this chapter. 
  2. Modify the initial investigation, site hazard assessment and ranking, and public notice process in Parts 1 and 3 of the rule. 
  3. Update other administrative and procedural requirements of the cleanup program in Parts 1–6 and Part 8 of the rule. 
  4. Make changes in Parts 1–6 and Part 8 to streamline rule requirements, as well as minor corrections to improve rule clarity and consistency with other laws and rules. 
  5. Make changes in Parts 7 and 9 to clarify language and make corrections without changing the effect of the rule. 
  6. Incorporate changes to the cleanup program specified in Chapter 70A.305 RCW, Hazardous Waste Cleanup – Model Toxics Control Act, and Chapter 64.70 RCW, Uniform Environmental Covenants Act.

For more information about the long-range plan to update the rule, visit our Cleanup Rule exploratory rulemaking page.

Rulemaking timeline


Announcement phase (CR-101)

Filing date:
Dec. 20, 2018

Announcement documents

Rule development phase

Dec. 20, 2018 - Fall 2022

Public input & involvement

Additional languages

Español (Spanish) 中文 (Chinese) Tiếng Việt (Vietnamese) 한국어 (Korean)


To request ADA accommodation for disabilities, or printed materials in a format for the visually impaired, contact Ecology's ADA Coordinator by email at, or call 360-407-6831. People with impaired hearing may call Washington Relay Service at 711. People with speech disability may call TTY at 877-833-6341.