The U.S. EPA could offer large industrial livestock farms amnesty from the federal Clean Air Act and Superfund laws, according to people involved in agency-industry talks. Rather than enforce the laws, the EPA would monitor pollution levels at roughly 30 large hog and chicken operations, a plan environmentalists and former enforcement officials say is far too lenient — so lenient than local environmental regulators pulled out of the talks in protest. Huge livestock farms can spew foul odors and fecal dust into the air, as well as hydrogen sulfide, ammonia, and methane from open-air cesspools. After the EPA began bringing cases against factory farms for clean-air violations in 2001, industry groups started approaching the agency asking for amnesty in exchange for agreeing to be monitored. In 2002, enforcement officials were told not to pursue any more clean-air cases against factory farms without approval from outside the agency’s enforcement office, a move that was called unprecedented by Eric Schaeffer, the former head of civil enforcement for the EPA who resigned in protest over other issues last year.