In the latest move in years of legal battling, environmental groups have challenged a Florida Department of Environmental Protection’s plan for carrying out controversial water-quality standards. The Florida Wildlife Federation, the Environmental Confederation of Southwest Florida, St. Johns Riverkeeper Inc., and the Sierra Club filed a case last week in the state Division of Administrative Hearings, contending that DEP did not properly go through a formal rule-making process. The issue centers on standards known as “nutrient criteria,” which are aimed at better protecting waterways from runoff that can cause damaging algae outbreaks. After years of court fights about the issue, DEP and the Florida Environmental Regulation Commission last year approved standards and submitted them to the U.S. Environmental Protection Agency. At the prompting of federal officials, the DEP in September submitted a highly detailed “implementation” plan for carrying out the standards. But the environmental groups contend in the new challenge that several parts of that plan are rules that have not gone through a required rule-making process or been approved by the Environmental Regulation Commission. The groups are asking an administrative law judge to order DEP to “immediately cease and desist relying upon these unadopted rules for any purpose.