According to the current proposed CARB’s regulation, the total risk from multiple stationary diesel engines at a facility can be estimated using the risk tables provided in CARB’s Diesel Website. For existing AB 2588 facilities, the estimated cancer risk from the stationary diesel engines will be added either to their priority score (facilities without HRA) or their cancer risk (facilities with HRA) to obtain an overall facility risk estimate. For facilities with an estimated cancer risk above 10 per million, AQMD staff will ask the facility to prepare a more refined health risk analysis using HARP and site-specific information including local meteorological data. Since the tables were developed using a health-conservative estimate of risk, facilities may find that their risk is substantially less when a more refined analysis is completed. Facilities with the calculated overall facility cancer risk of less than 10 per million and greater than 1 in a million will not have to do any further risk analysis, since the public notification and risk reduction thresholds are not exceeded. However, they will be placed in the “District Tracking” category and will be required to update their inventory once every four years. Facilities with an overall facility cancer risk of less than one in a million will be exempt from the AB 2588 requirements and any associated fees.
Under the current CARB’s proposal, “Diesel Engine-Only” facilities that reduce their total operating hours and amend their permits for their diesel engines to less than 20 hours per year combined total for all engines (for non-emergency operations) are not subject to the AB2588 requirements.
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