Particulate matter - dust

California almond growers strive to meet strict state and federal air quality standards. Of particular concern in the San Joaquin Valley is particulate matter (dust) - - tiny particles that are invisible to the eye.  Particulate matter (PM) is a generic term used to describe small airborne particles (dust) that can arise from a complex range of sources.  Very small particulates, PM10 and PM2.5, are regulated under the Clean Air Act.

PM10, used to describe particles of 10 micrometers or less, pollution has been a compliance issue in the San Joaquin Valley Air Basin.  The San Joaquin Valley Air Pollution Control District requires all farmers with 100 or more contiguous acres to implement and file Conservation Management Practices (CMPs) with the district. District Rule 4550 requires growers to implement one farming practice in each of five categories to help reduce PM10 emissions. Growers are able to substitute an extra farming practice in one of the five categories in order to complete their CMP. Dust control practices were implemented July 1, 2004. For a complete list of CMP practices, click here to download a brochure from the district.     

In 2006 EPA issued a tighter standard for PM2.5 -- particles less than 2.5 micrometers. PM2.5, very tiny particulates, can penetrate deeply into lungs and cause a variety of health issues. Sources of PM2.5 include burning of agricultural waste, burning of fossil fuels, some forms of NOx and sulfur compounds. The San Joaquin Valley Air District is currently developing regulations (as of June 2009) that will be part of a State Implementation Plan (SIP) for PM2.5. The latest status on the District's plan to develop PM2.5 regulations can be viewed by clicking here.

More information on both PM10 and PM2.5 can be found on the San Joaquin Valley Air District's website http://www.valleyair.org/air_quality_plans/PM_Plans.htm

The San Joaquin Valley Air Pollution Control District also restricts or prohibits the burning of tree removal or prunings in an effort to reduce a major source of both PM10 and PM2.5 particulates. See Burning for details

In addition to worrying about regulated PM10 and PM2.5, almond growers are working to reduce the amount of visible dust generated by various almond growing operations, such as harvest.