Modeling and Health Risk Assessment

Ashworth Leininger Group’s health risk assessment (HRA) practice leverages our expertise in air toxics emissions inventory development, best available control technology for toxics (T-BACT) determination, and air dispersion modeling on behalf of industrial and regulatory clients. As illustrated below, ALG has the capabilities to:

  • Develop defensible toxic air contaminant (TAC) emission inventories under the California Air Toxics Hot Spots Program (AB 2588);

  • Use Geographic Information System (GIS) to develop key input data for HRAs;

  • Perform air dispersion modeling consistent with EPA, ARB, and local air district modeling guidelines;

  • Execute health risk assessment models that use the source emission rates developed in the emission inventory task and the output of the air dispersion modeling to quantify potential health effects;

  • Prepare comprehensive HRA reports; and

  • If necessary, provide assistance in making T-BACT determinations and developing Risk Reduction Plans

ALG has conducted health risk assessments and public warning analyses to support a wide range of air permitting requirements; examples include:

  • Performed preliminary air dispersion modeling for the potential expansion of an electric generating station. Designed a meteorological monitoring network to support refined complex terrain modeling and assisted in developing permitting strategies;

  • Prepared refined health risk assessments to comply with AB 2588, the California air toxic "hot spots" program, for a variety of facilities in Los Angeles, Santa Barbara, Ventura, Kern, and Monterey Counties, including a glass manufacturing plant, large fuel storage and distribution facilities, chemical plants, petroleum production facilities, a semiconductor manufacturing facility, a winery, and a major university;

  • Managed air quality impact analysis task for an expansion project at a glass container manufacturer. Calculated operational emissions for the proposed expansion. Performed air dispersion modeling and health risk assessment for the project to demonstrate that impacts are below significance thresholds established by the South Coast Air Quality Management District. Results of these analyses were incorporated into the EIR prepared by the city;

  • Completed a HRA and criteria pollutant ambient air impact analysis for a large scale refinery modification project in southern California that included mobile and construction emission sources;

  • Performed accidental release modeling of a variety of regulated toxic and flammable substances at a refinery. The offsite consequence analysis included worst-case releases and alternative release scenarios. Results were incorporated into the Risk Management Plans for the facility

For more information on ALG's HRA services please refer to our HRA brochure.

Environmental Consulting, HRA, AB 2588, Dispersion Modeling, CEQA, EIR

"Seasoned, experienced and personable with industry smarts, the whole ALG crew are THE "go to" air quality experts for all my industrial clients in California. Time and again, they have provided the technical underpinnings so necessary to "win the day" at air quality hearings, rule makings and enforcement proceedings."

- Environmental Lawyer, Los Angeles