Services

Health Risk
Assessment

Health risk assessments (HRA) rely on complex modeling software to translate toxic air contaminant (TAC) emissions into quantifiable health risks. Davenport Engineering has in-depth experience with California’s HARP software as well as the AB 2588 and air permitting regulatory programs that trigger an HRA. We can help you meet your HRA obligations, and beyond the basics, help you understand your risk sensitivities and possible risk reduction measures.

Health Risk Assessment

AB 2588 Health
Risk Assessments

Assembly Bill (AB) 2588, the Air Toxics “Hot Spots” Information and Assessment Act, was enacted in 1987 to identify, analyze, and respond to the health impacts of air toxic emissions from stationary sources in California. Under AB 2588, certain facilities that are deemed “high priority” are required to submit a Health Risk Assessment (HRA) to their air pollution control or air quality management districts.

In an HRA, emissions of toxic air contaminant (TAC) from all stationary sources at a facility are run through a model to determine the health risks to nearby offsite workers and residents. Based on the resulting risks, the facility may fall below action limits, or be required to notify the public, or be required to implement risk reduction projects. The specific thresholds and requirements for these actions are determined at the air district level and are not standardized throughout the state.

The California Air Resources Board (CARB) provides a comprehensive modeling software called the Hotspots Analysis and Reporting Program (HARP) to assist with the development of an HRA. HARP contains an air dispersion model to process TAC emissions, emission points, buildings, wind patterns, elevation, and other information into concentrations of each TAC at discrete points around a facility. It then uses the concentrations and health parameters of each TAC to calculate the cumulative acute, chronic, and cancer health risks at each discrete point.

Davenport Engineering has expertise preparing HRAs along with the detailed technical reports to satisfy air district AB 2588 requests. In addition, we can prepare internal HRAs to give you a clear understanding of your facility’s health risk status and sensitivities, and if necessary, provide insights on manageable solutions to meet your health risk targets.

Project Permitting Health
Risk Assessments

An important hurdle in permitting new and modified equipment is ensuring that potential health risks are below thresholds established in the air agency’s air toxics New Source Review (NSR) programs. Each air agency has its own air toxics NSR rules, which include Rule 1401 in the SCAQMD and Rule 2-5 in the BAAQMD. In many cases, these rules will dictate toxics best available control technology (BACT) before a permit can be issued.

Often, larger projects will require a rigorous health risk assessment prepared using CARB’s HARP modeling software. Procedurally, the same California guidelines apply to preparing an HRA as part of a permit application and preparing an HRA to comply with AB 2588. One of the main distinctions lies in the TAC emissions evaluated. HRAs conducted as part of a permit application generally evaluate the health risks associated with the project’s potential increase in TAC emissions. HRAs conducted to comply with AB 2588, on the other hand, evaluate the actual TAC emissions from the entire facility.

Davenport has considerable experience preparing HRAs and a deep understanding of the air toxics NSR requirements, both of which can help clear the path for a successful permitting project.