<P> Point sources may not discharge pollutants to surface waters without a permit from the National Pollutant Discharge Elimination System (NPDES). This system is managed by the United States Environmental Protection Agency (EPA) in partnership with state environmental agencies . EPA has authorized 46 states to issue permits directly to the discharging facilities . The CWA also allows tribes to issue permits, but no tribes have been authorized by EPA . In the remaining states and territories, the permits are issued by an EPA regional office . (See Titles III and IV .) </P> <P> In previous legislation, Congress had authorized states to develop water quality standards, which would limit discharges from facilities based on the characteristics of individual water bodies . However, these standards were only to be developed for interstate waters, and the science to support this process (i.e. data, methodology) was in the early stages of development . This system was not effective and there was no permit system in place to enforce the requirements . In the 1972 CWA Congress added the permit system and a requirement for technology - based effluent limitations . </P> <P> The 1972 CWA created a new requirement for technology - based standards for point source discharges . EPA develops these standards for categories of dischargers, based on the performance of pollution control technologies without regard to the conditions of a particular receiving water body . The intent of Congress was to create a "level playing field" by establishing a basic national discharge standard for all facilities within a category, using a "Best Available Technology ." The standard becomes the minimum regulatory requirement in a permit . If the national standard is not sufficiently protective at a particular location, then water quality standards may be employed . </P> <P> The 1972 act authorized continued use of the water quality - based approach, but in coordination with the technology - based standards . After application of technology - based standards to a permit, if water quality is still impaired for the particular water body, then the permit agency (state or EPA) may add water quality - based limitations to that permit . The additional limitations are to be more stringent than the technology - based limitations and would require the permittee to install additional controls . Water quality standards consist of four basic elements: 1) Designated uses; 2) Water quality criteria; 3) Antidegradation policy and 4) General policies . </P>

State or local governments set pollutant standards for most sources of drinking water