Revised OEHHA Risk Assessment Methodology and AB2588: How Will This Affect Your Facility?

Earlier this year the Office of Environmental Health Hazard Assessment (OEHHA) adopted a revised set of guidelines for estimating cancer risk and health impacts from toxic air pollutants. These changes may impact the priority designation of some facilities, therefore altering their reporting and analysis requirements. Read on to find out whether your facility may be impacted.

Background

On March 6th, 2015, OEHHA adopted the revised “Air Toxics Hot Spots Program Guidance Manual for Preparation of Health Risk Assessments” (OEHHA, 2015), commonly referred to as the Revised OEHHA Guidelines.  These guidelines establish the methodology for estimating cancer risk and non-cancer health impacts resulting from emissions of toxic air pollutants.  

For some sources of toxic air pollutants, use of the Revised OEHHA Guidelines will result in a higher estimated potential cancer risk than would been calculated with the 2003 OEHHA Guidelines for the same conditions and emissions.  The new residential potential cancer risk from the Revised OEHHA Guidelines may be approximately 1.5 to 3 times higher than estimates using the previous methodology.

AB 2588

The Revised OEHHA Guidelines have an impact on state and local air district programs, including the Assembly Bill (AB) 2588 Air Toxics Hot Spots Program.  The AB 2588 Program is designed to collect emissions data and establish a risk reduction program for facilities that meet certain criteria regarding toxic emissions. Facilities commonly subject to AB2588 requirements include, but are not limited to, manufacturing facilities, such as metal fabrication and plating facilities, hospitals, food processing facilities, refineries, and bulk terminals.  Facilities subject to AB 2588 are required to submit a comprehensive toxic emissions inventory, and certain facilities, depending on their emissions and proximity to potential receptors, are required to prepare a health risk assessment (HRA), notify the public within a designated distance of the facility, and prepare a facility risk reduction plan.  

AB 2588 requires local air districts to designate high, intermediate, and low priority categories, and include each facility within the appropriate category.  High priority facilities are required to update their emission inventory and prepare an HRA every four years, intermediate priority facilities are only required to quadrennially update their emission inventory, and low priority facilities are exempt from the AB2588 Program.  The thresholds that designate priority, a.k.a priority score thresholds, vary from district to district.  

Impact: Will This Increase Your Reporting Requirements?

A facility’s priority score is determined using risk calculations based on the OEHHA Guidelines.  As a result of the recent revisions to the OEHHA Guidelines, a facility’s priority score may increase even if its emissions have not changed.  In turn, facilities previously within the low priority category may be increased to the intermediate category, and facilities previously within the intermediate category may be increased to the high category.  Higher priority status triggers additional analysis and reporting requirements. In addition, high priority facilities that were not required to prepare a risk reduction plan may be required to develop and implement a plan due to their revised HRAs.

Next Steps

On July 13th, 2015, the California Air Resources Board (ARB) and the California Air Pollution Control Officers Association (CAPCOA) released the “Proposed Risk Management Guidance for Stationary Sources of Air Toxics” (ARB, 2015).  The proposed document was approved by ARB during their board meeting on July 23rd, 2015.  Once the final version has been released, this document will provide guidance for California’s local air districts to incorporate the Revised OEHHA Guidelines in each district’s respective air toxics and AB 2588 programs.

Many districts are waiting for the final ARB/CAPCOA document to be released before revising their air toxics rules and programs.  However, the South Coast Air Quality Management District (SCAQMD) has already adopted rule amendments to incorporate the Revised OEHHA Guidelines.  SCAQMD Rule 1402, revised June 5th 2015, outlines AB 2588 requirements for facilities within SCAQMD.  The revised rule states that all future AB 2588 analysis and reports must use the revised OEHHA methodology, and each facility’s priority score will be calculated using the new methodology.  Facilities within SCAQMD jurisdiction that prepare quadrennial toxic emissions inventories need to be informed on the revised rules and potential impacts.

Have questions?  Call us at 562-497-5777.

References

• California Air Resources Board (ARB), 2015.  Proposed Risk Management Guidance for Stationary Sources of Air Toxics. July 13.
  
• Office of Environmental Health Hazard Assessment (OEHHA), 2015.  Air Toxics Hot Spots Program, Risk Assessment Guidelines, Guidance Manual for Preparation of Health Risk Assessments. February.
  

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