The CWA has specific provisions for the National Pollutant Discharge Elimination System, categorizing pollutants, technology-based controls and effluent limitations, water quality standards, variances, nonpoint source controls, and dredge and fill permits. These provisions are discussed next.
The CWA controls water pollution primarily through its National Pollutant Discharge Elimination System (NPDES). Section 301 of the act states that "the discharge of any pollutant by any person shall be unlawful" except as provided by other sections within the act (33 USC §1311). Section 402 of the act establishes the main ex ception (33 USC §1342), which provides for issuing NPDES permits to control direct discharges of pollutants into U.S. waters. Direct dischargers include both industrial sources and publicly owned treatment works (POTWs). NPDES permits are issued through either the EPA or a delegated state (CWA §402[b], 33 USC §1342[b]). The EPA can delegate NPDES authority to a state if the state adopts a permit program which meets minimum federal criteria.
Permits must be obtained by any point source which discharges pollutants into waters of the United States. This regulation generally includes the two types of direct dischargers mentioned previously. A point source is defined in the CWA (40 CFR §122.2 ) regulations as "any discernible, confined, and discrete conveyance, including but not limited to, any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, landfill leachate collection system, vessel or other floating craft from which pollutants are or may be discharged." Pollutants and waters of the United States are also specifically defined in the regulations.
An applicant must obtain a permit from either the EPA or an authorized state agency. Point sources are regulated based on numerous factors including the type of pollutants discharged and the character of the receiving water. The permitting authority establishes effluent limits which are written into the permit. Before a permit is issued, both public notice and an opportunity to be heard are required. Permits typically have a five-year duration period and can be renewed.
The CWA generally uses technology-based effluent standards and water quality standards (also known as ambient water standards) to control water pollution. Technology-based effluent standards apply to all direct dischargers and require treatment of pollutants prior to discharge. The goal of technology-based effluent standards is to minimize actual pollutants going into the nation's waters by installing pollution control technology.
Water quality standards, on the other hand, are based on the receiving water's ability to absorb a given pollutant. They are not to be confused with ambient water quality-related effluent limits31 but are site-specific standards which vary according to the characteristics and designated uses of the regulated water segment.
The CWA divides pollutants into three categories and uses this framework to create effluent limits for dischargers. The three categories of pollutants are conventional, toxic, and nonconventional. Conventional pollutants include fecal coliform, biochemical oxygen demand, suspended solids, and pH. Toxic pollutants are listed in the CFR (40 CFR §401.15). They include chemicals which in small
31. See Clean Water Act, Sec. 302; U.S. Code. Vol. 33, sec. 1312.
amounts cause adverse effects on fish, wildlife, and humans. Finally, nonconventional pollutants include all non-toxic pollutants which are not categorized as conventional pollutants.
The regulating agency establishes technology-based effluent limits which can be incorporated into a facility's permit. These effluent limits are based on the SIC classification of the facility, the type of pollutant the facility discharges, and whether the facility is considered a new or an existing source.
The EPA publishes national effluent guidelines for categories and subcategories of industry types in the CFR. These guidelines establish technology-based effluent limits for standard pollutants discharged from the particular category or subcategory of an industry. The EPA has not yet created effluent guidelines for all categories and subcate-gories of industries.
At a minimum, existing sources must satisfy the best practicable control technology currently available (BPT) standard. BPT establishes a national floor for effluent treatment (CWA §304[b][A-B], 33 USC §1314[b][A-B]). Also existing sources must meet treatment standards according to the three categories of pollutants as follows:
Conventional pollutants are subject to the standard BCT standard (CWA §304[b][B], 33 USC §1314[b][B]). Toxic pollutants are subject to the more stringent best available technology economically feasible (BAT) standard, together with additional health-based standards (CWA §307, 33 USC §1317). Nonconventional pollutants are also subject to the BAT standard (CWA §301[b][F], 33 USC 1311[b][F]).
New sources are regulated pursuant to a different set of technology-based controls. The CWA (§306[a], 33 USC §1316[a]) defines a new source as one whose construction began after new source performance standards (NSPS) were proposed for it, provided those standards were adopted. The act declares that NSPS be established "through the best available demonstrated control technology, processes, operating methods, or other alternatives, including, where practicable, a standard permitting no discharge of pollutants" (CWA §306[a], 33 USC §1316[a]). The EPA is required to compile a list of categories of new sources for which it must propose and publish NSPSs (CWA §306[b][A], 33 USC§1316[b][A]). The EPA must also publish toxic effluent standards (CWA §307[a], 33 USC§1317[a]) and water quality-related effluent limits (CWA §302, 33 USC §1312).
The EPA has not established a national effluent guideline for every industry which requires a permit. In these cases, the EPA or authorized state permit writers establish a technology-based limit according to their best professional judgment (BPJ). This limit is known as a BPJ permit limit.
Water quality standards are an additional control to protect waterbodies. Generally, water quality standards focus on the receiving water's ability to integrate, dilute, or absorb pollutants. A facility may have to install controls beyond those required to achieve technology-based standards to meet water quality standards.
States must adopt water quality standards and submit them to the EPA for all bodies of water within the state (CWA §303[a], 33 USC §1313[a]). The standards are based upon state designated uses for specific bodies of water together with water quality criteria for the designated use. The EPA reviews the state standards and replaces them if they fail to meet minimum federal requirements (CWA §§303[c][3-4], 33 USC §§1313[c][3-4]). States are further required to specify and prioritize the waters within their boundaries where technology-based standards are insufficient to meet the established water quality standards (CWA §303[d][A], 33 USC §1313[d][A]).
States must set a total maximum daily load (TMDL) for specific waterbodies. The TMDL is the maximum amount of a pollutant that a defined water segment can accept while still achieving the applicable water quality standard. In accordance with section 303(d) of the CWA (§303[d][C], 33 USC §1313[d][C]), a TMDL "shall be established at a level necessary to implement the applicable water quality standards with seasonal variations and a margin of safety which takes into account any lack of knowledge concerning the relationship between effluent limitations and water quality." States must submit a list of the prioritized waters and their applicable TMDLs to the EPA for approval (CWA §303[d], 33 USC §1313[d]). Nevertheless, states do have discretion in allocating the TMDLs among dischargers and establishing corresponding effluent limits on the facilities.
In some cases, point sources can obtain variances which provide alternatives to the national effluent controls in section 304. Among the variances in the act are the fundamentally different factors (FDF) variance (CWA §301[n], 33 USC §1311[n]; 40 CFR pt. 125 subpt. D), the §301(c) economic variance (CWA §301[c], 33 USC §1311[c]), the §301(g) water quality variance (CWA §301[g], 33 USC §1311 [g]), and the net/gross limitation (40 CFR § 122.45 [g]). The most notable of these variances is the FDF which may apply when a discharger's characteristics are fundamentally different from the sources which the EPA considered to determine the applicable technology-based standard.
Nonpoint sources are a significant contributor to water pollution. Nonpoint sources are diffuse sources of pollution created generally by land use. Nonpoint source pollution is caused, for example, by the rainfall and runoff from urban areas, mining, and agricultural sites.
Under the 1972 amendments to the act, the section 208 planning process delegates control of nonpoint source pollution to the states. This section called on state governors to designate areas with substantial water quality control problems and to select a regional planning agency to help develop section 208 plans to address nonpoint issues. This approach is not considered successful in controlling this type of pollution.
The 1987 amendments to the act, however, developed section 319 to address the nonpoint source pollution problem which was ineffectual in section 208 (CWA §319, 33 USC §1329). States are required to designate water bodies that are unable to meet water quality standards without a nonpoint source program. States must then establish nonpoint source plans for these waterbodies. The plans require best management practices regulations for different categories of sources along the waters, such as construction sites or manure storage sites. Plans must include implementation schedules and other regulatory measures and are subject to EPA approval.
Section 404 of the act requires permits for discharging dredge and fill materials into waters of the United States. The Army Corps of Engineers, generally, administers the program. However, the EPA has the authority to review section 404 permits and can veto certain permit conditions or an entire permit (CWA §334, 33 USC §1344[c]). This section is broadly applied based upon the liberal interpretation of key terms such as waters of the United States and dredge and fill materials.
Tributaries of navigable waters and wetlands are protected under section 404. Regulated activities extend well beyond dredge and fill operations. For instance, section 404 controls activities such as bridge and dam building, flood control construction activities, and dike and drainage systems.
The Army Corps of Engineers can consider several factors when making its decision to issue a section 404 permit. The corps can consider individually or cumulatively the following twelve issues:
. . . conservation, economics, aesthetics, general environmental concerns, wetlands, historic properties, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shore erosion and accretion, recreation, water supply and conservation, water quality, energy needs, safety, food and fiber production, mineral needs, considerations of property ownership and, in general, the needs and welfare of the people (33 CFR §320.4).
Section 404 also includes a review of the requirements developed under other federal environmental acts. A 404
permit application is subject to review under the NEPA,
Fish and Wildlife Coordination Act,32 CZMA, Wild and
Scenic Rivers Act,33 and the ESA.
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