CLARC—Ecology’s Cleanup Levels and Risk Calculation resource—is a compendium of technical information that helps site managers and stakeholders determine cleanup levels for contaminated sites. CLARC’s 2019 update is now available with several changes that make it easier to navigate:

1. CLARC’s new 2019 data tables include new toxicity values, chemicals, and tabs for cleanup levels and Applicable or Relevant and Appropriate Requirements (ARARs) for soil, groundwater, surface water, and air. CLARC data tables in Excel & PDF:

2. CLARC’s new home on Ecology’s website has streamlined content, revised guidance, and an updated glossary:

3. CLARC’s new EZView library contains supporting documents such as the spreadsheet, guidance, and background materials. All of these documents are also linked from CLARC’s website:

Frequently Asked Questions:

The last major update to CLARC was in 2015. Can I still use that spreadsheet? No. The 2019 spreadsheet and data tables contain the most recent information and should be used going forward.

What if I bookmarked the older CLARC webpages? You should be automatically redirected to CLARC’s new homepage. The redirect web address will be in place for about a year.

What about links to CLARC in Ecology’s older publications and guidance? The links should automatically redirect to CLARC’s new homepage for about a year.

What’s next for CLARC? CLARC is a living document. We’ll make minor updates and corrections as needed. Every six months in spring and fall, we may make major updates that align with Environmental Protection Agency’s updates to their regional screening levels (RSL) tables.

How can I stay on top of CLARC updates?

1. Always use the most recent data tables on CLARC’s data tables page:

2. Check out what’s new in CLARC, which can also be found in the master spreadsheet’s first tab:

3. Subscribe to the Site Register Listserv at

Who should I contact if I have questions about CLARC?

Andy Kallus
Toxics Cleanup Program
PO Box 47600
Olympia, WA 98504