srAr SIS J v UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460 G\v *c PrO^ PLC 3 1 2012 OFFICE OF SOLID WASTE AND EMERGENCY RESPONSE MEMORANDUM OSWER Directive 9200.1-113 SUBJECT: Compilation and Review of Data on Relative Bioavailability of Arsenic in Soil and Recommendations for Default Value for Relative Bioavailability of Arsenic in Soil Documents The purpose of this memorandum is to transmit the OSRTI Technical Report entitled "Compilation and Review of Data on Relative Bioavailability of Arsenic in Soil" and "Recommendations for Default Value for Relative Bioavailability of Arsenic in Soil". This report identifies and evaluates published literature relevant to estimating a relative bioavailability (RBA) value of arsenic in soil. Based upon the analysis and external independent peer review, the following conclusions have been determined: 1. Currently available research information suggests that an RBA of arsenic in soils can be expected to be less than 100%. 2. Based upon evaluation of current data sets of arsenic RBAs in the US, the upper percentile of the data set results in a default RBA value of 60%. 3. The default RBA for arsenic in soils should only be used if site-specific assessments for arsenic RBA are not feasible. FROM: Becki Clark, Director Assessment and Remediation Division, unice of Superfund Remediation and Technology Innovation TO: Superfund National Policy Managers, Regions 1-10 Internet Address (URL) • http://www.epa.gov Recycled/Recyclable • Printed with Vegetable Oil Based Inks on 100% Postconsumer, Process Chlorine Free Recycled Paper ------- 2 This report and other efforts related to addressing arsenic in soil can be found on the internet at http://epa.gov/superfund/bioavailability/guidance.htm. Please contact Michele Burgess at (703) 603-9003 if you have questions or concerns. Attachments 1. "Compilation and Review of Data on Relative Bioavailability of Arsenic in Soil" 2. "Recommendations for Default Value for Relative Bioavailability of Arsenic in Soil" cc: Mathy Stanislaus, OSWER Lisa Feldt, OSWER Barry Breen, OSWER Lawrence M. Stanton, OSWER/OEM Suzanne Rudzinski, OSWERORCR David Lloyd, OSWER/OBLR Reggie Cheatham, OSWER/FFRRO Carolyn Hoskinson, OSWER/OUST Elliott Gilberg, OECA/OSRE Dave Kling, OECA/FFEO John Michaud, OGC/SEWRLO OSRTI Managers Regional Superfund Branch Chiefs, Regions 1-10 Lisa Price, Superfund Lead Region Coordinator, Region 6 NARPM Co-Chairs TRW Committee Members ------- |