A proposal environmentalists say would weaken the state’s water pollution rules was approved by a House panel Thursday.

The bill’s next stop is the House floor.

HB 7051 would allow Florida to override rigid federal water standards on the levels of nitrogen and phosphorous, known as nutrients. The proposed state standards would provide a more flexible “threshold,” which environmentalists say is unenforceable.

At issue is pollution from fertilizer, manure and sewage that make their way into the water, particularly during rainy season.

The result: Potentially toxic algae blooms that can contaminate drinking water and kill wildlife, sometimes causing epidemics such as red tide.

The bill’s survival in the House committees is the next step in a lawsuit-riddled saga that has dragged out more than three years and caused sometimes emotional clashes between the farm industries, utility companies, manufacturing companies that pollute, environmental groups and the state attorney general’s office.

Environmentalists contend that the battle won’t end in the Legislature.

The bill cannot be enacted until a lawsuit filed by environmental groups is resolved, and the national Environmental Protection Agency approves the new standards.

“We have to go with the courts and ask the courts to side with the original intent of the EPA and make sure the Clean Water Act is enforced,” said Frank Jackalone, of Sierra Club Florida.