California Air Toxic "Hot Spots" (AB 2588) Program

There are five steps to implementing the ATHS program. Guidelines have been developed for all five steps to establish a consistent, science-based, methodology for implementing the program. The five steps are briefly described as follows: 

• Air Toxics Emissions Inventory: Subject facilities are required to prepare and submit a comprehensive emissions inventory plan followed by a toxics emissions inventory report. Each facility’s emissions inventory must be updated on a regular basis (in order to reflect changes in equipment, materials, and production levels at the facility). The BAAQMD has integrated toxics inventory reporting within the annual update and permit renewal process. 
• Prioritization: Each facility is evaluated for potentially significant health impacts based on the quantity and toxicity of emissions, and the proximity of nearby residents and workers. Emission rates are weighted by unit risk factors and reference exposure levels; carcinogens and noncarcinogens are scored separately. Facilities that have a prioritization score of 10 or greater are designated as “high priority”. This prioritization process assures that health risks will be assessed at any facility that has the potential of causing a significant risk. 
• Health Risk Assessment: High priority facilities are required to prepare a comprehensive Health Risk Assessment (HRA). HRAs must be prepared using guidelines adopted by Cal/EPA’s Office of Environmental Health Hazard Assessment (OEHHA). The BAAQMD and OEHHA review the HRAs. 
• Public Notification: If health risks resulting from the facility’s emissions exceed action levels established by the BAAQMD, the facility is required to perform notification to all exposed persons regarding the results of the HRA. The BAAQMD has established a cancer risk of 10 in a million and a noncancer Hazard Index of one as ATHS public notification thresholds. 
• Risk Reduction: If the health risks resulting from the facility’s emissions exceed significance levels established by the air district, the facility is required to conduct an airborne toxic risk reduction audit and develop a plan to implement measures that will reduce emissions from the facility to a level below the significance level within five years. The BAAQMD has established a cancer risk of 100 in a million and a noncancer Hazard Index of ten as ATHS mandatory risk reduction levels. The District is currently considering adopting new risk reduction levels.