The U.S. EPA unveiled new livestock-waste regulations yesterday designed to keep billions of pounds of unhealthful pollutants out the nation’s waterways annually. The rules, which were issued in compliance with a court mandate from a 1989 lawsuit brought by the Natural Resources Defense Council, will require some 15,500 factory farms to obtain government permits to dispose of livestock waste. Together, these farms are responsible for about 60 percent of the 220 billion gallons of liquefied manure produced by the agricultural industry every year. The EPA says the rule will eventually yield a 25 percent reduction in the amount of phosphorus, nitrogen, and metals released by factory farms every year. But critics say the rules are far weaker than those drafted by the Clinton administration; the new regulations require fewer farms to comply, grant livestock owners more leeway to draft their own pollution-management plans, relieve major corporations of financial liability for illegal spills by growers or subcontractors, eliminate measures to make use of new technology to combat pollution, and fail to mandate groundwater monitoring.