Smoke plume near Worley/photo Jessica Caplan/SAFE
In its decision effectively tossing out the state of Idaho's ability to allow grass field burning in Northern Idaho, the 9th Circuit Court of Appeals remarks, "The current treatment of field burning in the Idaho SIP [state implementation plan, a revised version of which allows the burns] came about as the result of a thirty-five-year regulatory evolution." An evolution from one set of intents (and one kind of politics) to another it certainly was; but it was the fact of the evolution, as much as anything else, that led the court to its conclusion.
Field burning has been used for many years as part of grass seed production, not just in Idaho (it is used in parts of the souther Willamette Valley as well), and is thought to improve the quality of the crop. There are arguments that it has beneficial environmental effects. There's no question, though, that it also produces air pollution - very visibly, and easily smelled. It is obvious enough that one of the farmers' biggest adversaries long has been Duane Hagadone and his news organizations; Hagadone well understands what tourists think of smoked-up lakefronts, such as where his resort and gold course are located. But the most powerful arguments come from people with respiratory impairments; some of them are literally put at risk of their lives from the smoke. There is a care active organization battling the burns, called Safe Air For Everyone, which has picked up a number of larger allies.
When the Clean Air Act was passed in 1970 and Idaho, like other states, submitted an implementation plan - which, once adopted and approved by the EPA, has the effect of federal law - it mentioned the burns. The burns were allowed, with limitations, such as that "When such burning creates air pollution or a public nuisance, additional restrictions may be imposed to minimize the effect upon the environment." In 1993, Idaho proposed and the EPA accepted a revision of the implementation rules that deleted field burns from the list of acceptable burns in the state. There were more minor, technical, changes in 2003.
In 2005, the state of Idaho Idaho made another revision, to add this: "“The open burning of crop residue on fields where the crops were grown is an allowable form of open burning if conducted in accordance with the Smoke Management and Crop Residue Disposal Act and the rules promulgated pursuant thereto.” There were protests to the EPA, but the agency approved the change.