Proposed Amended Rule 223 – Requirements for Confined Animal Facilities

Rule 223 controls ammonia and volatile organic compound (VOC) emissions from large confined animal facilities (LCAFs). Proposed Amended Rule 223 (PAR 223) is designed to implement Control Measure BCM-08 from the 2024 PM2.5 Attainment Plan and comply with federal Clean Air Act Most Stringent Measures requirements by reducing the applicability thresholds for dairy, poultry, and duck farms to 500 milking cows, 400,000 chickens, and 400,000 ducks, respectively. Implementation of PAR 223 will require up to 12 additional dairy facilities to obtain South Coast AQMD permits and select from a menu of mitigation measures to reduce emissions from their operations, many of which are currently being implemented as best practices or as required by other rules and regulations. As a result, very few, if any, physical modifications are expected to occur. No additional chicken or duck farms currently exceed the proposed thresholds. Implementation of PAR 223 is anticipated to benefit public health and ambient air quality by reducing ammonia emissions by 0.17 ton per day by 2029.