CLARC data tables and other technical information

The CLARC data tables contain information to help cleanup project managers and other stakeholders determine cleanup levels for hazardous waste sites. Stakeholders could include site managers, the regulated community, consultants, and the public.  On this page, you'll find:   

  • Method A Table cleanup levels.
  • Default human health cleanup levels for soil, groundwater, surface water, and air that are calculated using the standard Method B and Method C equations from the Model Toxic Control Act (MTCA) regulation (which is also known as the Cleanup Rule).
  • Information about the physical parameters and toxicity of chemicals used to calculate the cleanup levels. 
  • Federal and state legal standards that must be considered when selecting cleanup levels.
  • A table of noncancer toxic effects of chemicals as listed in the U.S. Environmental Protection Agency (EPA) IRIS database.


CLARC is not mandated by law, but rather is provided as a service to staff and the public. While the information provided in CLARC is extensive, it is not exhaustive and the user may need to obtain information from additional sources for certain hazardous substances. Although CLARC has undergone review to ensure the quality of the information provided, there is no assurance that CLARC is free from errors. If necessary, calculation results and values obtained from applicable state and federal laws and literature sources should be verified independently and confirmed by consulting Ecology's site managers. CLARC cannot be relied on to create rights, substantive or procedural, enforceable by any party in litigation with the State of Washington.