Wisconsin’s water quality regulators failed to follow their own policies on enforcement against polluters more than 94 percent of the time over the last decade, the state’s nonpartisan Legislative Audit Bureau said in a report released Friday. From 2005 to 2015, there was a general decline in state Department of Natural Resources enforcement activity to protect lakes, streams and groundwater from large livestock farms, factories and sewage treatment plants that discharge liquid waste, according to the bureau’s 124-page report. During a period when elected officials from both political parties have decreased DNR staffing, notices of violations were issued to polluters in just 33 of 558 instances serious enough for such citations under DNR policies, the audit found.