Regulation 2, Rule 5: New Source Review of Toxic Air Contaminants

Regulation 2, Rule 5 replaced the District’s Risk Management guidelines on July 1, 2005. This rule provides preconstruction review for potential health impacts from new and modified sources of toxic air contaminants. Toxic emissions are estimated for all sources within a proposed project; if emissions from a proposed project exceed the trigger levels in Table 2-5-1, a Health Risk Screening Analysis (HRSA) is required to determine project risk and risk from each source. Risk standards are:

2-5-301 Best Available Control Technology for Toxics (TBACT) Requirement:

The applicant shall apply TBACT to any new or modified source of TACs where the source risk is a cancer risk greater than 1.0 in one million (10 E-6), and/or a chronic hazard index greater than 0.20.

2-5-302 Project Risk Requirement:

The APCO shall deny an Authority to Construct or Permit to Operate for any new or modified source of TACs if the project risk exceeds any of the following project risk limits:

302.1 A cancer risk of 10.0 in one million (10 E-6).

302.2 A chronic hazard index of 1.0.

302.3 An acute hazard index of 1.0.

HRSA Form – Health Risk Screening Analysis:

A HRSA form is required for each source within the proposed project. Maps should be included to clarify locations of site, sources, buildings, and receptors.

Health Risk Screening Analysis Guidelines:

If an HRSA is required by Regulation 2, Rules 1 or 5, the analysis will be conducted in accordance with the District’s Health Risk Screening Analysis Guidelines. These guidelines are maintained on the District’s web site and specify, or contain references to, the procedures for determining acute hazard index, chronic hazard index, and cancer risk. In general, these guidelines conform to the Health Risk Assessment Guidelines established by OEHHA for use in the Air Toxics Hot Spots Program. The District HRSA Guidelines will be periodically updated, typically after significant changes have been made to OEHHA’s HRA Guidelines.