The Arizona Department of Environmental Quality issued proposed revisions to Emissions from Existing and New Nonpoint Sources and Emissions from Mobile Sources (New and Existing). The department is considering clarifying the "reasonable precautions" requirement to address U.S. EPA concerns regarding the enforceability of the rules as written. http://www.azsos.gov/public_services/Register/2008/20/docket.pdf pp. 1844-1845.