National Pollutant Discharge Elimination System in the United States

National Pollutant Discharge Elimination System (NPDES) in Environmental Law

The permitting system for discharges of polluted water, established in 1972 by a major overhaul of the Clean Water Act. Except for a few exemptions specified in the statute, a permit is required for all discharges from a point source to any navigable waters of the United States. A point source, according to the law, is a “discrete conveyance” from which effluent is discharged. The definition includes more than one might think. In addition to pipes and conduits, it covers ditches, machinery, and other methods of channeling water. Navigable waters, prior to the 1972 revisions, meant waters that could be navigated by ships. However, when Congress enacted the changes, it made it clear that the term was to be interpreted as broadly as possible. Thus the term navigable waters now includes streams, wetlands, manmade waters, tributaries, storm sewers, interstate and intrastate lakes, rivers, lagoons, and even seasonal pools. The word navigable no longer limits the scope of regulation.

Regulation under the National Pollutant Discharge Elimination System

Congress had always given states the primary responsibility for determining what was necessary to protect their waters, but the result was disappointing. The states did establish water quality standards, but they had little authority to measure pollution or enforce the standards, and except in rare cases, the federal government was relegated to a support role.

The 1972 Clean Water Act moved many responsibilities from the states to the Environmental Protection Agency (EPA). The statute set goals for clean, fishable, swimmable water, but its most significant aim was total elimination of pollutant discharges to water. That goal remains in the law today. For the first time the EPA was required to establish national standards for effluents. Technology was to be the key to the limits, but the law anticipated and forced better technology as time went on. The law began with a requirement of using best practicable technology for industrial discharges and became more stringent over time, finally dictating use of best available technology. Domestic sewage plants were required to use best conventional technology.

Technology standards are commonly used in pollution control today but the terms mean little to the lay person. They simply establish the type of technology the agency is to consider when setting standards. The agency sets numerical standards based on what the technology can consistently accomplish.

As may be expected, toxic pollutants are more highly regulated than conventional pollutants. For a number of industries, the regulations specify standards they must meet if they discharge into a publicly owned treatment works instead of directly into a water body. For new sources those that have not begun construction prior to a proposal for a new regulation the EPA may require not only end of pipe treatment of wastewater, but also process or design changes to reduce the amount of wastewater that must be treated.

After the national standards are set, anyone who wants to discharge wastewater must, at a minimum, meet the standards. If a national standard for a particular pollutant does not exist, the permitting authority is required to use best professional judgment in setting the limits. The next step in the process is permitting. Based on the national standards, the EPA issues individual permits for effluent. The system applies anywhere a facility is discharging directly to a surface water; wastewater that is discharged must be treated to levels that will at least meet the national standards. Regulated facilities range from sewage treatment plants owned by municipalities to industries.

Basically, the permitting process begins with a permit application. The applicant must supply information about the type of wastewater it wishes to discharge. The permit authority, usually the state or the EPA, will ask for additional data it believes is necessary. Applications must be made at least eighteen months before the discharge is to begin.

States may, and often do, assume the responsibility for the permit program. To do so, they must develop regulations and request delegation from the EPA. Among other things, the state must have the appropriate manpower and enforcement ability to both issue permits and punish violators. However, the EPA retains authority to veto a permit application or to enforce the terms of the permit.

Contents of NPDES Permits

Permits contain the blueprint for the handling of the facility’s wastewater discharges, including limits for each regulated pollutant. Permittees must monitor their discharges and submit reports (discharge monitoring reports or DMRs) to the permitting agency. Monitoring and reporting responsibilities will be specified in the permit. The permittee must allow inspections and, in addition to standard reports, must report unusual discharges or conditions. All reports are sent to the agency, but they are also available to the public upon request. Since it is a criminal offense to file a false report, the contents are generally reliable.

The NPDES permit forms the basis of the system for regulating discharges. The EPA or state agency can review the compliance status of a particular discharger by checking the discharge reports; it can also use the reports as a basis for enforcement action. Public action groups or other interested parties can do the same thing [see citizen suit].

Permits have a relatively short lifespan: up to five years. This turnover accommodates technical progress and changes in the regulations, with the goal of eliminating pollutants always in the background. At least eighteen months before expiration, the permittee must reapply.

Storm water Permitting

Until the 1987 amendments to the Clean Water Act, one source of water pollution had been studied but not actively controlled: storm water. Storm water is a peculiar problem because it often results from random runoff instead of a specific source. Uncontrolled storm water can be a significant problem in municipal areas, carrying oil and other contaminants from streets and parking lots into waterways. Storm water associated with industrial facilities often poses an even greater risk, because it may wash toxic pollutants into the surface waters or storm sewers.

Until the 1987 amendments to the Clean Water Act, one source of water pollution had been studied but not actively controlled: storm water. Storm water is a peculiar problem because it often results from random runoff instead of a specific source. Uncontrolled storm water can be a significant problem in municipal areas, carrying oil and other contaminants from streets and parking lots into waterways. Storm water associated with industrial facilities often poses an even greater risk, because it may wash toxic pollutants into the surface waters or storm sewers.

Certain storm water discharges are now regulated by the NPDES program. The regulations focus on runoff that is likely to be contaminated. Thus, storm water that flows over an industrial facility where it may pick up pollutants is regulated, as are large municipalities with storm sewers. If a permit is required, it will be one of three types: general, group, and individual. The easiest permit to obtain is a general permit, and the group is next. Individual permits are tailored to a specific site and can be expensive to obtain.

General permits are designed to cover common activities that one permit can effectively regulate, such as controlling runoff from a large parking lot. If a facility finds that its proposed activity falls within the scope of the general permit, it may file a notice of intent to be covered by it. When it no longer needs the permit, it files a notice of termination. Similarly, a group permit for storm water discharge may be obtained if the situ
ations of two or more facilities are similar enough that they can combine their efforts. The costs of collecting data and obtaining the permit can then be shared. To effectively manage storm water, permits may require diverting it, isolating facility components that can contaminate it, and treating the storm water to meet the national standards.
Based on “Environment and the Law. A Dictionary”.