You can also find this information in the first tab of the May 2019 CLARC spreadsheet interim update.
1. Soil Cleanup Levels Protective of Groundwater. We now include soil cleanup levels protective of groundwater for many chemicals, calculated with the “fixed parameter three-phase partitioning model” (described in WAC 173-340-747(4) and based on MTCA Equation 747-1). These are available in the CLARC Master Excel in Data Tables [updated May 2019] in the “Soil Methods B & A unrestricted” tab and in the "Soil-Method B and Method A (unrestricted land use) PDF" CLARC Master PDF in Data Tables [updated May 2019]. A guidance document describing the Soil-to-Groundwater pathway and the derivation of the pre-calculated cleanup levels is available at Soil Cleanup Levels to Protect Groundwater, [updated April 2019] as well as from the guidance links at the top of the columns within the Excel and PDF documents and from the Guidance drop-down menu at the top of this page (Guidance→ Soil Cleanup Standards – Protection of Groundwater→ Guidance for Soil Protective of Groundwater) [menu disabled May 2019].
2. Vapor Intrusion Screening Level Table. Vapor intrusion screening levels are now included in the CLARC Master Excel Table [updated May 2019] and in separate PDF files with links on the CLARC Data Tables page. These are revisions of Table B-1 from Ecology’s draft 2009 document, Guidance for Evaluating Soil Vapor Intrusion in Washington State: Investigation and Remedial Action, Ecology Publication 09-09-047.
3. Toxicity Value Updates. Toxicity values in CLARC for the following hazardous substances have been changed to be consistent with those in EPA’s Regional Screening Level Tables:
< >Direct black 38 (CAS 1937-37-7)Direct blue 6 (CAS 2602-46-2)Direct brown 95 (CAS 16071-86-6)Ethyl acrylate (CAS 140-88-5)4. Corrections to Groundwater Cleanup Levels:
Summary of changes to CLARC made between June 2004 and September 2012
Policy & Technical Support Unit
Toxics Cleanup Program
360-407-7170 (main desk)