What is the Air Toxics "Hot Spots" Process?
The California Air Resources Board (CARB) compiles and maintains a list of
substances posing chronic or acute health threats when present in the air. The
Act identifies by reference over 600 substances, which are subject to the
program.
A facility is subject to the Act if it:
manufactures, formulates, uses, or releases a substance subject to the Act
(or another substance, which reacts to form such a substance) and emits 10 tons
or more per year of total organic gases, particulate matter, nitrogen oxides or
sulfur oxides, or;
is listed in any district's existing toxics use or toxics air emission
survey, inventory or report released or compiled by a district, or;
manufactures, formulates, uses, or releases a substance subject to the Act
(or substance, which reacts to form such a substance) and emits less than 10
tons per year of criteria pollutants and is subject to emission inventory
requirements.
Emission Inventory Plans and Reports:
Facilities meeting the applicability criteria must prepare air toxics
emission inventory plans and emission inventory reports. CARB's Emission Inventory Criteria and Guidelines provide assistance in preparing these
documents.
Facilities must submit a proposed emission inventory plan to the Sac Metro Air District
detailing how emissions will be measured or calculated, which the Sac Metro Air District must
approve, modify, or return the inventory plan to the operator for revisions
within 120 days.
Once the Sac Metro Air District approves a plan, the facility operator must implement the plan
and submit the emission inventory within 180 days.
Facilities subject to the program must update their emission inventories
every four years.
Risk Assessment:
After reviewing emission inventory data, the Sac Metro Air District must rank facilities for
purposes of risk assessment into high, intermediate, and low priority
categories. Facilities will be re-prioritized if their inventory update shows
any significant changes.
The Sac Metro Air District priority categories consider potency, toxicity, quantity, and
volume of hazardous materials released, and a facility's proximity to potential
receptors. Additional information on prioritization along with guideline
documentation can be found at http://www.arb.ca.gov/ab2588/prioritization.htm
Within 150 days of designation, high priority facilities and other facilities
identified by the Sac Metro Air District must prepare and submit a health risk assessment (HRA) to
the Sac Metro Air District. The HRA includes a comprehensive analysis of the dispersion of
hazardous substances, the potential for human exposure, and a quantitative
assessment of both individual and population wide health risks. OEHHA's Air Toxics Hot Spots Program Guidance Manual for Preparation of
Health Risk Assessments supersedes previously published risk assessment
methods.
Public Notification:
Once the HRA is reviewed by OEHHA and approved by the Sac Metro Air District, the facility must
notify all exposed persons of the risk assessment results if the Sac Metro Air District determines
that there is a potentially significant health risk.
ARB provides general and specific data on toxics at http://www.arb.ca.gov/toxics/cti/cti.htm. ARB also provides
facility inventory data at http://www.arb.ca.gov/app/emsinv/facinfo/facinfo.php. More up
to date data may be available from the Sac Metro Air District depending upon the facility's
reporting cycle.
Risk Reduction:
Facilities determined to have a significant risk must conduct an airborne
toxic risk reduction audit and develop a plan to implement risk reduction
measures. These facilities must submit the audit and plan to the Sac Metro Air District within 6
months of the determination. The documents must describe the risk reduction
methods the facility will use to reduce its risk below the level of significance
within 5 years. The Sac Metro Air District may shorten or lengthen the time period under certain
conditions.
The Act prescribes penalties for failure to comply or for knowingly
submitting false information. Civil penalties range from $500 to $25,000 for
each day in violation. The Act also penalizes for facilities for failure to
submit a complete audit and plan or failure to implement the measures set forth
in the plan.
