LITTLE ROCK — Attorney General Dustin McDaniel said Monday he has filed a motion to intervene in a lawsuit filed by environmental advocacy groups seeking what McDaniel called "unnecessary and unreasonable" regulation of pollution in the Mississippi River.

The groups are asking a federal judge to require the Environmental Protection Agency to establish and enforce stricter limits on nitrogen and phosphorous discharges in Arkansas and the entire Mississippi River watershed.

They allege that nitrogen and fertilizer runoff from farm fields adversely affects water quality in the Mississippi River basin and causes a "dead zone" in the Gulf of Mexico, an area of oxygen-starved water that forms off the coast of Louisiana each summer where marine life must flee or die.

McDaniel joined attorneys general from nine other states in a court filing Friday in the U.S. District Court for the Eastern District of Louisiana.

"Arkansas is abiding by federal clean water regulations already in its management of pollution within the Mississippi River watershed," McDaniel said in a news release. "We are protecting our waters. We do not need more burdensome and costly federal regulation that will threaten important agricultural jobs in the Delta, result in higher sewer bills and negatively impact our overall economy."

McDaniel said the lawsuit is similar to one in Florida that resulted in a settlement in which the EPA agreed to set numeric criteria for that state’s water. Those criteria will cost between $298 million and $4.7 billion to implement, he said.

McDaniel said the Florida Department of Agriculture and Consumer Services has estimated that the EPA’s new regulations in that state will cost 14,500 jobs in the agriculture sector and that capital projects required to achieve the new standard will increase sewer bills $570 to $990 per year.

An Arkansas official with the Sierra Club, one of the groups that filed the suit, referred questions to the Sierra Club’s national office in San Francisco, which did not immediately return a call seeking comment Monday.