Point source of water pollution, 1972-2017
From Ballotpedia
|
| State environmental policy |
|---|
| U.S. environmental policy |
| Endangered species policy |
| State endangered species |
| Federal land policy |
| Environmental terms |
|
Point source water pollution involves pollutants that are discharged from any identifiable, singular source, such as a pipe, ditch, drain, channel, tunnel, conduit, well, container, or vessel. By contrast, nonpoint source water pollution is caused by broadly distributed and disconnected sources of pollution, such as rain and snowmelt runoff, spills, leaks, and sediment erosion.[1]
The Clean Water Act makes it unlawful to discharge any pollutant from a point source into navigable waters without a permit. Point source water pollution is regulated under the National Pollutant Discharge Elimination System (NPDES) permit program. Regulated pollutants from point sources include wastes, soils, rocks, chemicals, bacteria, suspended solids, heavy metals, pesticides, and more.[2]
Background
The Clean Water Act established water quality standards for surface waters, programs regulating the discharge of industrial and municipal wastewater, regulation of nonpoint source water pollution (pollution with no single, identifiable source) as well as point source pollution, and federal funding for municipal sewage treatment plants.[2][3]
The 1972 amendments to the Clean Water Act created the National Pollutant Discharge Elimination System (NPDES), requiring authorization (from the relevant state or federal agency) to discharge pollutants from a point source into navigable waters. NPDES permits contain technology-based limits on discharges of pollutants from point sources known as technology-based effluent limits. These limits are based on how well a treatment method can limit pollutant levels to a certain concentration before the pollutants are discharged into a body of water. In addition to limiting pollutant discharges using the NPDES system, the act requires enforceable water quality standards to maintain overall water quality. Standards are set for bodies of water based on the water's designated use, such as industrial water supply, swimming, fishing, agricultural irrigation, and more. The act also requires that standards include the maximum concentrations of various pollutants that would inhibit a waterway's designated use. States establish water quality standards for waterways within their borders, though the EPA may disapprove and replace state standards with its own if they do not meet the act's minimum requirements.[2][4]
State governments monitor waterways to ensure that bodies of water meet standards. For waters that do not meet quality standards, states use two additional anti-pollution methods to ensure impaired water bodies ultimately meet standards. First, states will set total maximum daily loads (TMDLs), which are the maximum allowable amounts of a pollutant that may be discharged into impaired bodies of water. TMDLs are set with the goal of reducing pollution from point sources so a body of water can meet quality standards. Second, states will divide the maximum allowable amount of a pollutant discharge into an impaired water among various pollution sources.[2][5]
Types of point sources
Examples of point sources include sewage treatment plants; oil refineries; paper and pulp mills; chemical, automobile, and electronics manufacturers; and factories. Regulated pollutants from point sources include wastes, soils, rocks, chemicals, bacteria, suspended solids, heavy metals, pesticides, and more.[2]
The images below show examples of point sources:[6]
An industrial facility located along the Calumet River near Chicago, Illinois |
A sewage treatment facility |
|
See also
Footnotes
- ↑ U.S. Environmental Protection Agency, "Glossary, P," accessed November 26, 2014
- ↑ 2.0 2.1 2.2 2.3 2.4 U.S. Environmental Protection Agency, “Summary of the Clean Water Act,” accessed January 29, 2014
- ↑ U.S. Environmental Protection Agency, "NPDES Home," accessed September 23, 2014
- ↑ U.S. Environmental Protection Agency, "What are Water Quality Standards?" accessed June 28, 2017
- ↑ U.S. Government Publishing Office, "Water Quality Standards Handbook," accessed June 21, 2017
- ↑ National Oceanic and Atmospheric Administration, "Categories of Pollution: Point Source," accessed March 9, 2015