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.