Though EPA Administrator Lisa Jackson told members of Congress last week that the agency has no intention to regulate farm dust, some lawmakers and their rural constituents aren’t convinced.

Farmers and ranchers told members of the U.S. House of Representatives subcommittee on Energy and Power Tuesday that some farmers already face limits on their operations because of dust regulations.

The committee started a debate on the Farm Dust Regulation Prevention Act of 2011, designed to define the difference between farm dust and dust from power plants and other industrial operations, and to leave any dust regulation to states and local governments.

The bill defines nuisance dust as that “generated from natural sources, unpaved roads, agricultural activities, earth moving, or other activities typically conducted in rural areas; or consisting primarily of soil, other natural or biological materials, windblown dust, or some combination thereof.”