Particulate matter is very small solid or liquid material. Particles smaller than 10 micrometers in diameter are known as PM10.

Why should I be concerned about PM10?

When PM10 is in the air, we breathe it into our lungs. These small dust particles can become trapped in the lungs, where it can damage tissue and impair the lungs' ability to function. The elderly, children and people with chronic lung disease, such as asthma, are especially sensitive to high levels of PM10.

How can we reduce the levels of dust in the air in Maricopa County?

In an effort to address agriculture's contribution to PM10 the Governor's Agricultural Best Management Practices Committee was created and charged with developing a general permit that would require farmers to take action to reduce PM10 from agricultural operations. The committee developed a list of Best Management Practices (BMPs) for control of PM10 from agricultural land. These BMPs are effective, common sense practices that minimize negative impacts on local agriculture.

The committee is composed of five local farmers, the director of the Arizona Department of Environmental Quality, the director of Arizona's Department of Agriculture, the state conservationist for the Natural Resources Conservation Service (NRCS), the vice dean of the University of Arizona College of Agriculture and a soil scientist from the University of Arizona.

What does the general permit require?

The new permit requires that farmers implement at least one BMP for each of the following three categories: tillage and harvest activities, non-cropland (areas like farm roads) and cropland (between the time one crop is harvested and the next crop emerges from the soil).

When will farmers have to comply with the general permit?

The permit was adopted in May 2000 and each commercial farmer has until the end of 2001 to put in place the BMPs selected for that farm. During this period, the committee will provide farmers with information about the permit requirements and provide assistance to those who may need it. After December 31, 2001, commercial farmers who do not comply with the permit may be subject to enforcement actions.