Calling for more stringent regulations to control manure runoff from large-scale farms, three environmental organizations filed suit against the U.S. EPA on Friday. The current rules, which were approved last month and will be phased in by 2006, require concentrated animal feeding operations, or CAFOs, to obtain water-pollution permits every five years, have a waste-management plan, and file annual reports on their operations. Poultry and farm associations beat environmentalists to the punch in suing over the regulations, which they claim are too strong. The Sierra Club, Natural Resources Defense Council, and Waterkeeper Alliance responded with a suit countering that the rules essentially allow CAFOs to write their own waste-management plans with limited public review, thereby undermining Clean Water Act protections and posing a threat to public health.