The group contends lead poisoning from ammunition frequently kills not only condors but eagles, swans, loons and other birds that feed on dead animals in the wild. The lawsuit, filed in U.S. District Court in Washington, D.C., asks the EPA to start a public process to determine whether that ammunition can be controlled but does not outright ask for a ban.
"The agency refuses to address this needless poisoning," said Jeff Miller, of the Tucson-based Center for Biological Diversity. "We've removed toxic lead from gasoline, paint and most products exposing humans to lead poisoning. Now it's time to do the same for hunting ammunition to protect America's wildlife."
The EPA declined to comment Thursday, citing pending litigation. But the agency responded in April to a petition filed by the groups, saying it does not have the authority under the Toxic Substances Control Act to regulate lead ammunition. Furthermore, the agency said the petition was similar to one filed by some of the groups in 2010 and declined to review the latest one.
Miller said the agency is mistaken, and the groups now want a judge to decide.
Lead poisoning has long been recognized as the top killer of the condors, which once numbered in the thousands across North American but were nearly extinct in the early 1980s. The final 22 were captured in California, and a breeding program started. Today, there 405 condors flying free and in captivity.
Since the condor reintroduction program began in Arizona in 1996, 22 of the 73 condor deaths in Arizona and southern Utah have been blamed on lead poisoning, according to the Arizona Department of Game and Fish. As scavengers, North America's largest land bird feasts on the carcasses of deer, coyotes and other game left behind by hunters.
Predation from coyotes and golden eagles took the No. 2 spot in condor deaths, with 14.
Eighty condors fly in a range that stretches from Arizona's Grand Canyon to southern Utah's Zion National Park, while others are in California and Mexico.
Although the lawsuit doesn't ask for a ban on lead ammunition, it's something environmentalists want.
California has prohibited the use of lead ammunition in the 15 counties considered condor territory since 2008, but many ranch owners ignore the directive, and some have said that's because they believe it subjugates their rights.
Arizona has a voluntary program that has reported participation rates of 80 percent to 90 percent over the past five years. Utah is set to implement a voluntary program this fall that will provide hunters with vouchers to replace lead ammunition.
Kathy Sullivan, condor program coordinator for Arizona's Department of Game and Fish, said the Utah program will be key to helping the condors thrive. A ban would only create conflicts between state officials and hunters, she said.
"That would have huge ramifications, and there are a lot of people who are going to push back on that," she said.
Chris Parish, head of the Peregrine Fund's condor recovery program in Arizona, said some hunters do not recognize that lead poisoning is a problem and need to be educated. If the first thing they hear is that people are trying to restrict the ammunition they use, it's going to be a tough hurdle to overcome, he said.
"It's a disservice to Arizona, specifically, because we have so much support," he said. "If that support decreases, then we have to go restrike that fire while trying to put out the others created by these lawsuits."