California air toxic emissions have decreased by at least 75 percent since 1990, according to California Air Resources Board (CARB) staff, even though the economy, vehicle ownership and total population levels have grown. Facilities have been installing control equipment and CARB has been adopting mobile emission controls for new vehicles.

CARB adopted new Risk Management Guidance for Stationary Source Air Toxics at its July 23, 2015 meeting. This guidance supports the 35 individual air districts in meeting the requirements of the previously revised Office of Environmental Health Hazards Assessment (OEHHA) Air Toxics Hot Spots Program Guidance Manual for Preparation of Health Risk Assessments (revised OEHHA Manual) released February 2015 (available here). This revised methodology reflects advances in science about increased cancer risk from higher air toxic exposure levels to children and elderly. The CARB's July 2015 Risk Management Guidance supports California air district health risk programs including stationary source permitting (Risk Management Review), California Environmental Quality Act (CEQA) compliance and AB2588 compliance. Some air districts have already updated their air toxics thresholds and rules (e.g., San Joaquin Valley Air Pollution Control District [SJVAPCD], and South Coast Air Quality Management District [SCAQMD]); many more air districts will be updating their air toxics rules and thresholds over the next 12 to 24 months. SCAQMD updated its Toxic Air Contaminant (TAC) rules, i.e. Rule 1401, 1401.1 and 1402. The averaging period for maximum individual cancer risk was revised from 70 years to 30 years. Under Rule 1401, spray booths and retail gasoline transfer and dispensing facilities may continue to use old OEHHA guidelines. For existing facilities, emission reporting thresholds have been updated for specific TACs. The SJVAPCD recently revised its health risk thresholds for air permits and CEQA projects from 10 in a million to 20 in a million for cancer risk; its AB2588 thresholds remain at 10 in a million for cancer risk.

The revised OEHHA Manual is predicted to lead to 1.5 to 3 fold increase in predicted cancer risk for the same emission levels. More facilities will be subject to public notification and emission reduction requirements under the new OEHHA Manual for AB2588 compliance even though their operations in 2015 will be the same as 2014. As a result, many existing facilities, new projects and project modifications, which previously might have had no air toxic triggers, could now be required to:  (1) provide more complex AB2588 reporting; (2) prepare a health risk assessment or risk management review; or (3) trigger a CEQA project review with its next air permit modification. This CARB guidance focuses on communication challenges from anticipated higher predicted cancer risk levels and more complex permitting and regulatory compliance.

The California Air Pollution Control Officers Association will be updating its Risk Communication Guidelines. If your facility now requires a preliminary risk evaluation or a health risk assessment or other expanded AB 2588, air permit, or CEQA compliance as a result of your air toxic emission risk levels, contact Trinity at (949) 567-9880.