It is unfair to believe everything we hear about lawyers, some of it might not be true. -- Gerald F. Lieberman


The Clean Water Act (CWA) employs three general types of standards: technology-based standards, ambient or water quality-based standards, and in the case of a small number of toxic compounds, health-based effluent standards.

Technology-based standards.
The CWA employs four technology-based water pollution control standards. "Best practicable control technology currently available" (BPT) sets uniform, industry-wide effluent standards that approximate the average amount of control achieved from existing technology in the specific industry. BPT sets the initial national floor applicable to all existing industrial sources of water pollution. "Best available technology economically achievable" (BAT) applies primarily to certain toxic pollutants, 33 U.S.C. sec. 1317, nonconventional pollutants, 33 U.S.C. sec. 1311(b)(2)(F), and thermal pollution, 33 U.S.C. sec. 1326. "Best conventional pollutant control technology" (BCT), which is essentially the best available technology modified to reflect only those technologies where the benefits of pollution control are greater than the costs, applies to certain "conventional pollutants, including biochemical oxygen demand (BOD), total suspended solids (TSS), fecal coliform, and pH. "Best available demonstrated control technology" (BACT) forms the basis for new source performance standards (NSPS). BACT incorporates the "greatest degree of effluent reduction achievable," which is set according to different categories of industrial and agricultural activities. 33 U.S.C. sec. 1316.

Water Quality-Based Standards.
Ambient, water quality-based standards may also form the basis for a federal water permit. Water quality-based standards are imposed when the technology-based standards are not expected to provide sufficient protection for local water quality, given local water conditions and uses. States must classify all state waters according to specific uses and then set an ambient water quality standard to protect that use. Once the standard is set, the total maximum daily load (TMDL) of a particular pollutant is set at a level that will not violate the standard. The TMDL is then translated into specific numerical limits in particular permits. The states identify the uses, set the water quality standards, and determine how to allocate the TMDL among different users. The federal role is limited to reviewing the standards or developing replacement standards for states that fail to meet minimum federal requirements. 33 U.S.C. sec. 1313; 40 C.F.R. pt. 131. EPA also retains, but has rarely used, the authority to impose more stringent water quality limitations if necessary to meet the national goal of fishable and swimmable waters.

Health-Based Standards.
Where the BAT standard is not sufficient to achieve an "ample margin of safety" in protecting the environment and public health from certain toxic pollutants, EPA has the authority to issue toxic pollutant effluent standards. 33 U.S.C. sec. 1317. In setting these standards, the agency has no authority to consider economic factors. Toxic pollutant effluent standards have been set for six chemicals: aldrin, DDT and related compounds, endrin, toxaphene, benzidine, and polychlorinated biphenyls. 40 C.F.R. pt. 129.

State Standards.
States have the explicit right to enact any water quality standard or limitation that is more stringent than those required by federal statute. 33 U.S.C. sec. 1370. Most states have enacted separate state water pollution control laws and regulations. The states also take the lead role in setting water quality-based standards, which from the basis for both federal National Pollutant Discharge Elimination System (NPDES) and state permits. The states must also be given an opportunity to review any federal NPDES permit before it is issued. If the proposed NPDES permit does not meet state standards, it cannot be issued. 33 U.S.C. sec. 1341.

From Summary of Enviromental Law in the United States - CEC

Brought to you by - The 'Lectric Law Library
The Net's Finest Legal Resource For Legal Pros & Laypeople Alike.