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[Portal ID #1987]

Cleanup Levels and Risk Calculation (CLARC)

Summary of the project

Logo for Washington State Department of Ecology 

Welcome to the EZView library for the Cleanup Levels and Risk Calculation (CLARC). 

CLARC master spreadsheet was updated August 2023. Download the Excel or PDF.  Learn what changed on the first tab/first pages of each file, or by opening August 2023 updates. Learn more about CLARC on our homepage.

NOTE: New guidance for CLARC was added in December 2022 called Guidance on the Use of Method A, B, and C Cleanup Levels and Mixing Methods. You'll also find this link in the August 2023 CLARC Master spreadsheet. 

Logistics about August 2023 spreadsheet

  • The August 2023 spreadsheet posted on August 10, 2023, and replaces the January 2023 file. 
  • You can download the spreadsheet as Excel or PDF, which is bookmarked for easier navigation.          
  • For details about all the updates, visit What's New in CLARC (August 2023 updates).  
  • The next major CLARC revision is scheduled for Fall 2023. 
  • If you have questions, please visit Ecology's CLARC webpages or contact Andy Kallus, Toxicologist, Washington State Department of Ecology @ 360-878-2952.

What is CLARC?

Cleanup Levels and Risk Calculation (CLARC) is a compendium of technical information related to calculating cleanup levels under Washington's MTCA Cleanup Regulations, Chapter 173-340 WAC. The Washington State Department of Ecology maintains CLARC on Ecology's website as a service to staff and the public. CLARC is a living document and we typically make major updates every six to twelve months, with minor updates throughout the year to reflect new data. Minor updates will reflect in an "Errata" tab at at top of "What's New" page.

How does this EZView website support CLARC?

All of the documents found here are the same documents found on CLARC's pages on Ecology's website. We store CLARC's technical documents in this EZView Library so we can link them on Ecology's wepbages. You can use these documents in combination with CLARC's data tables and guidance to help you establish cleanup levels for chemicals found at your contaminated site.

Why do cleanup levels matter?

Cleanup levels help determine what actions (if any) may be needed to protect the health of people, animals, and plants from chemical contamination at a hazardous waste site that's being cleaned up under our state's environmental law, the Model Toxics Control Act (MTCA), Chapter 70A.305 RCWMTCA's regulations, known as the MTCA Cleanup Rule, set standards to make sure cleanups protect your health and environment.   

Learn more about Washington's contaminated sites: 


FOR BEST DISPLAY RESULTS:  Download files using Adobe Pro.

DISCLAIMER:  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. 

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