CWA subject to enforcement action, including third party citizen suits." The benefit of an NPDES permit is that it provides some level of certainty to CAFO owners and operators. "Compliance with the permit is deemed compliance with the CWA... and thus acts as a shield against EPA or State CWA enforcement or against citizen suits under... the CWA." In addition, the "upset and bypass" provisions of the permit can give permitted CAFO owners a legal defense when "emergencies or natural disasters cause discharges beyond their reasonable control." Under the CWA, the EPA specifies the maximum allowable amounts of pollution that can be discharged by facilities within an industrial category (like CAFOs). These general "effluent limitations guidelines" (ELG) then dictate the terms of the specific effluent limitations found in individual NPDES permits. The limits are based on the performance of specific technologies, but the EPA does not generally require the industry to use these technologies. Rather, the industry may use "any effective alternatives to meet the pollutant limits." The EPA places minimum ELG requirements into each permit issued for CAFOs. The requirements can include both numeric discharge limits (the amount of a pollutant that can be released into waters of the United States) and other requirements related to ELGs (such as management practices, including technology standards). History of regulations The major CAFO regulatory developments occurred in the 1970s and in the 2000s. The EPA first promulgated ELGs for CAFOs in 1976. The 2003 rule issued by the EPA updated and modified the applicable ELGs for CAFOs, among other things. In 2005, the court decision in Waterkeeper Alliance v. EPA (see below) struck down parts of the 2003 rule. The EPA responded by issuing a revised rule in 2008. A complete history of EPA's CAFO rulemaking activities is provided on the CAFO Rule History page. Background laws The Federal Water Pollution Control Act of 1948 was one of the first major efforts of the U.S. federal government to establish a comprehensive program for mitigating pollution in public water ways. The writers of the act aimed to improve water quality for the circulation of aquatic life, industry use, and recreation. Since 1948, the Act has been amended many times to expand programming, procedures, and standards. President Richard Nixon's executive order, Reorganization Plan No. 3, created the EPA in 1970. The creation of the EPA was an effort to create a more comprehensive approach