Iowa Experience With Agricultural Drainage Well Inspection, Testing, Permitting, and Closure

The Iowa Department of Natural Resources (IDNR) adopted rules to minimize contamination potential of Agricultural Drainage Wells (ADWs). Iowa’s water rights law was modified to permit the "diversion" of surface water into an aquifer, which precisely included ADWs. Agricultural drainage wells were constructed in Iowa in the early 1900s to provide outlets for surface runoff and tile drainage from cropland areas. Because ADWs discharge water directly to aquifers, they are routes for movement of contaminants. Cost-share funds allocated to close 400 of these wells on a priority basis. Alternative drainage outlets are developed to surface streams needed to replace these wells. Alternative drainage outlets are typically developed through formation of drainage districts. Environmental risk associated with ADWs in proximity to earthen waste storage units has been eliminated. About 155 were continued use permits. These permits were valid for ten years; most expired in 2009. For renewal, physical on-site inspections and water quality testing was required. Results from the on-going closure program and the re-inspection program have reduced the well number to 30. Legal and regulatory issues to reduce risks from ADWs, expanding discussion about lessening the nutrient loading to streams, since IA shifted discharge of pollutants from subsurface to surface.