California environmental regulators are considering rolling back the state’s hazardous waste disposal rules, potentially permitting some municipal landfills to accept more contaminated soil from heavily polluted areas. … Environmental groups say allowing nonhazardous waste landfills to accept chemical-laced soil would be a grave mistake. By dumping more toxic substances into the landfills, there’s a higher chance of chemicals leaking into groundwater or becoming part of airborne dust blowing into nearby communities.