ADEQ Issues New and Revised Rules Regarding Agricultural Best Management Practices to Reduce Particulate Matter Emissions in Arizona Non-Attainment Areas

The Arizona Department of Environmental Quality (ADEQ) has announced new and revised rules, effective as of July 2, 2015, regarding agricultural best management practices (BMPs) to reduce particulate matter air emissions in Arizona’s non-attainment areas. The revised rules may be found here.

As background, the Clean Air Act requires Arizona to maintain a State Implementation Plan that provides for the implementation, maintenance, and enforcement of National Ambient Air Quality Standards for several specific air pollutants. In Arizona, the NAAQS for two types of particulate matter have been especially troublesome: PM-10 (particulate matter below 10 micrometers in diameter) and PM-2.5 (particulate matter below 2.5 micrometers in diameter).

ADEQ’s new rulemaking is necessary as part of Arizona’s State Implementation Plan to comply with the particulate matter NAAQS. Importantly, ADEQ designed the rules to facilitate and improve enforcement by the agency as well as the Arizona Department of Agriculture. The new rules provide greater specificity with respect to the various BMPs required to be utilized by commercial farms—defined as ten or more contiguous acres of land used for agricultural purposes—and commercial animal operations in Arizona’s particulate matter non-attainment areas such as Maricopa and Pinal Counties. For example, the revised rules impose precise moisture content thresholds for BMPs that relate to soil tillage. As revised, each respective non-attainment area now has its own separate rule describing the required BMPs that must be implemented by the particular agricultural business. Importantly, ADEQ also designed the rules to be easier to enforce by the agency as well as the Arizona Department of Agriculture.

ADEQ’s rulemaking also implements new regulations with respect to agricultural activities occurring in irrigation districts within the regulated non-attainment areas. These new rules, located at A.A.C. §§ R18-2-612 and -612.01, now require BMPs for agricultural activities in irrigation districts with respect to canals, unpaved operation and maintenance roads, and unpaved utility access roads.

Although the new rulemaking may assist Arizona with complying with the Clean Air Act and its State Implementation Plan, Arizona’s various agricultural industries also may incur greater costs to remain compliant with these rules. Likewise, it is possible the regulated industries could face heightened enforcement from the various agencies. Accordingly, stakeholders may wish to monitor the effect of these new rules and their impact on the regulated community.