EPA Regional Screening Levels Updated to Incorporate New IRIS Toxicity values for Benzo(a)pyrene and the Trimethylbenzene isomers
Late in the day on June 21, 2017, the United States Environmental Protection Agency (EPA) released its updated Regional Screening Levels (RSLs) for use in initial data screening of soil and groundwater for potentially significant human health exposures at contaminated sites in the US (e.g., CERCLA sites). This update included incorporation of EPA's January 19, 2017, and September 9, 2016, Integrated Risk Information System (IRIS) program's final assessment of benzo(a)pyrene (BaP) and the trimethylbenzenes (TMB). These final toxicity values from EPA's IRIS have the potential to reduce the need for remediation of BaP, and other carcinogenic polycyclic aromatic hydrocarbons (PAHs), and TMBs.
These updated tables include the higher criteria for BaP and TMB reported by GHD on February 22, 2017 on our website.
The RSLs can be found onilne here.
Updated Non-Residential Soil Lead PRGs using EPA Update to the Adult Lead Methodology's Default Baseline Blood Lead Concentration and Geometric Standard Deviation Parameters
On May 17, 2017, the United States Environmental Protection Agency (EPA) completed an Update to the Adult Lead Methodology's (ALM's) Default Baseline Blood Lead Concentrations and Geometric Standard Deviation Parameters (OLEM Directive 9285.6-65) based on the most recent six years of data (2009-2014) from the National Health and Nutrition Examination Survey (NHANES). The revision to these parameters slightly lowers EPA's Preliminary Remediation Goal (PRG) for non-residential soil exposure from 2,737 mg/kg to 2,518 mg/kg. The memorandum also confirms that EPA has not updated its target blood lead level of 10 µg/dL.
This updated criterion has the potential to slightly increase the need for remediation of lead in soil. This criterion differs somewhat from the generic non-residential screening levels in EPA's Regional Screening Levels (RSLs), which uses the baseline blood lead concentration and geometric standard deviation parameters from the NHANES based on data from 1988 to 1991 (also known as NHANES III).
How can GHD help?
Please contact a GHD Risk Assessor for more information on how these RSLs and PRGs integrate into your environmental investigation and to help determine the most appropriate path forward to optimize environmental investigation or cleanup at your site.
For more information, please contact:
Francis C. Ramacciotti | Associate, Risk Assessment Services
1140 Welsh Road, Suite 120, North Wales, PA 19454
E: francis.ramacciotti@ghd.com | T: +1 215 853 3281
Steven Harris | Principal, Risk Assessment Services
651 Colby Drive, Waterloo, ON N2V 1C2
E: steve.harris@ghd.com | T: +1 519 884 0510 ext 3513