Some of these programs are statewide in application, many are delegable to local governments or conservation districts. Other states regulate forest practices through erosion and sediment control laws. Even more common are forestry-related requirements establishing riparian buffer zones, limiting percentage of vegetation that may be removed near a waterway, special rules for timber operations in wetlands, and similar targeted requirements. While these approaches all rely on prescriptive enforceable requirements, another approach has been adopted by a handful of states. While licensing does not itself limit nonpoint source pollution, it can serve as a means to have timber operations designed and supervised properly, and assures familiarity of operators with BMPs.
Agriculture is the most problematic area for enforceable mechanisms.
Many laws of general applicability, as noted above, have exceptions for agriculture. Where state laws exist, they often defer to incentives, cost-sharing, and voluntary programs. Nevertheless, about a fifth of the states have some statewide sediment requirements applicable to agriculture, often administered by local governments or soil and water conservation districts. Enforceable regulation of agricultural nutrients presents a mixed picture. Finally, a number of states have enforceable provisions allowing districts or agencies to order abatement of agricultural pollution.