Proposed new state and federal regulations could have immediate and far-reaching effects on how and to what extent preplant soil fumigants are used in almonds and other California crops.

The U.S. Environmental Protection Agency and California Department of Pesticide Regulation are currently seeking public comment on two separate proposed soil fumigant regulations. These rules are likely to limit fumigant use during certain periods and require new application methods and mitigation measures.

Most critical in the short term, DPR has proposed rules to sharply reduce soil fumigant air emissions that are thought to contribute to smog-forming ozone in areas with poor air quality, which includes the San Joaquin Valley, Southeast Desert and Ventura County.

The regulations must be issued by Jan. 1, 2008 to bring DPR in compliance with a federal judge's ruling last fall. That ruling requires the state to reduce volatile organic compounds (VOC) emissions from pesticides by 20 percent from the 1991 emissions in non-attainment areas. DPR is targeting soil fumigants and emulsifiable concentrate (EC) formulations as the major contributors to pesticide VOC emissions.

These rules would cap total emissions of all soil fumigants in those non-attainment areas and also require application methods, such as tarping and water seals, that reduce emissions of VOCs during the peak ozone period from May 1 through Oct. 31.

Restrictions will apply to all soil fumigants: methyl bromide, metam-sodium, 1-3 dichloropropene, chloropicrin, dazomet, metam-potassium, and sodium tetrathiocarbonate.

The new proposal for allocation under the cap is: growers submit their planned soil fumigant use from May through October to the County Agriculture Commissioners in February. DPR will then calculate the potential emissions based on proposed rates and application methods. If the emissions exceed the cap there would be an across the board cut to all applicants in that non-attainment area.

Many details for implementation need further work, such as how to fund the staff needed, or how to reallocate unused fumigant efficiently.

The revised rules were to have been posted Oct. 1 with a 15-day public comment period. That means growers will need to act quickly to provide comment on how these proposals will impact their operations.

Can growers adequately estimate their fumigation needs by Mar. 1? What are the costs associated with using the methods allowed? Are there potential improvements on the process?

To see the proposed regulations and provide public comment, log on to the DPR web site at www.cdpr.ca.gov and click on the proposed regulations section.

The bottom line is that these regulations will make the use of soil fumigations more expensive, at least in the ozone non-attainment areas.

At the same time DPR is considering its new restrictions on soil fumigants, the EPA is also seeking public comment on a new set of mitigation measures intended to reduce worker and bystander exposure risks from soil fumigant applications.

EPA has released a range of risk mitigation measures, including buffers and tarps, and is seeking public input on how they would work, how much they would cost growers, and what impact they would have on current production practices. Public comment has been extended through Nov. 3, 2007. Details can be found at: www.epa.gov/oppsrrd1/reregistration/soil_fumigants/.