The Department of Pesticide Regulation’s (DPR) plan to improve air quality by reducing volatile organic compound (VOC) emissions from pesticide applications has been approved by the U.S. Environmental Protection Agency’s Pacific Southwest Region, DPR Director Brian R. Leahy announced.

Amendments to the State Implementation Plan, or SIP, were approved Aug. 14, including regulations to reduce VOC emissions from fumigant pesticides in several areas of the state that do not meet federal air quality standards.

“California is the first state in the nation to specifically regulate agricultural pesticide applications to improve air quality,” Leahy said. “VOC emissions from fumigant pesticides declined significantly in the two years after the regulations took effect in 2008.”

He recognized growers for meeting the restrictions by modifying their application methods to suppress emissions, including using tarps, irrigating following fumigation and making applications through drip irrigation systems. County agricultural commissioners, who enforce pesticide regulations at the local level, worked closely with growers to help them comply.

The federal Clean Air Act requires each state to develop a SIP for achieving and maintaining federal air quality standards for ozone, a major air pollutant. VOCs combine with nitrogen oxides in sunlight to form ozone.

Although pesticides contribute only 2 percent of statewide VOC emissions, DPR is proud of its contributions to improving air quality while balancing the needs of farmers to implement changes necessary to reduce these emissions, Leahy said. The sources of most VOC emissions include vehicles, manufacturing and industrial activities and consumer products not regulated by DPR.

U.S. EPA approved the SIP based on DPR’s restrictions on fumigant pesticide applications in the five non-compliant areas and commitment to further reduce VOC emissions from nonfumigant pesticides in the San Joaquin Valley. DPR’s plans to reduce VOCs vary by region because these areas are different in terms of geography, weather, grower and crop diversity and other factors.

DPR initially targeted fumigants because they are a significant pesticide contributor to VOCs, only six are registered for use in California and they are controlled through permits issued by county agricultural commissioners. Fumigants are gaseous pesticides applied to the soil before planting to control disease, weeds and other soil-borne pests.

In contrast, there are hundreds of nonfumigant pesticides registered in California. Most do not require a permit to use.

DPR proposed regulations this spring on nonfumigants in the San Joaquin Valley, where 76 percent of pesticide emissions were from nonfumigants in 2010. DPR is currently evaluating comments submitted on the draft regulations.

The valley currently complies with VOC emission reductions specified in the SIP. DPR proposed more restrictions to reduce emissions even more and ensure the SIP obligations are met even in years with high pesticide use.

Depending on the area, VOC emissions from fumigant pesticides declined from 48 percent to 81 percent in 2008 and 2009 compared with the two years prior to the regulations.

Leahy noted that DPR is working with industry to develop agricultural practices that require less and more benign pesticides, including a partnership with the California Strawberry Commission, to explore ways to grow strawberries in peat or substances other than soil.

DPR also convened the Nonfumigant Strawberry Production Work Group to develop a five-year action plan by the end of the year to accelerate the development of practical and cost-effective ways to grow strawberries without soil fumigants.