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The EPA's Storm Water Program - The Clean Water Act

The Water Pollution Control Act Prohibits The Discharge Of Pollutants Into Waterways.

40 CFR Part 122 Clean Water Act Requirements Call For NPDES Permit At Construction Sites.

Nearly 40 percent of all surveyed bodies of water in the U.S. do not meet the Environmental Protection Agency's (EPA's) water quality standards because of untreated polluted runoff that is often discharged directly into those water bodies.

This water pollution results in the destruction of fish and aquatic habitats, loss in aesthetic value and threats to public health due to contaminated food, drinking water and recreational waterways.

The 1972 Clean Water Act (CWA) prohibits the discharge of any pollutant from a point source into a U.S. body of water unless that discharge is authorized by a National Pollutant Discharge Elimination System (NPDES) permit.

A pollutant means dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials (except those regulated under the Atomic Energy Act of 1954, as amended (42 U.S.C. 2011 et seq.)), heat, wrecked or discarded equipment, rock, sand, cellar dirt and industrial, municipal, and agricultural waste discharged into water.

It does not mean:
(a) Sewage from vessels; or
(b) Water, gas, or other material which is injected into a well to facilitate production of oil or gas, or water derived in association with oil and gas production and disposed of in a well, if the well used either to facilitate production or for disposal purposes is approved by authority of the State in which the well is located, and if the State determines that the injection or disposal will not result in the degradation of ground or surface water resources.

A point source means 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. This term does not include return flows from irrigated agriculture or agricultural storm water runoff.

Waters of the United States or waters of the U.S. means:
(a) All waters which are currently used, were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters which are subject to the ebb and flow of the tide;
(b) All interstate waters, including interstate “wetlands;"
(c) All other waters such as intrastate lakes, rivers, streams (including intermittent streams), mudflats, sandflats, “wetlands," sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds the use, degradation, or destruction of which would affect or could affect interstate or foreign commerce including any such waters:

    (1) Which are or could be used by interstate or foreign travelers for recreational or other purposes;
    (2) From which fish or shellfish are or could be taken and sold in interstate or foreign commerce; or
    (3) Which are used or could be used for industrial purposes by industries in interstate commerce;
(d) All impoundments of waters otherwise defined as waters of the United States under this definition;
(e) Tributaries of waters identified in paragraphs (a) through (d) of this definition;
(f) The territorial sea; and
(g) “Wetlands" adjacent to waters (other than waters that are themselves wetlands) identified in paragraphs (a) through (f) of this definition.

Waste treatment systems, including treatment ponds or lagoons designed to meet the requirements of CWA (other than cooling ponds as defined in 40 CFR 423.11(m) which also meet the criteria of this definition) are not waters of the United States. This exclusion applies only to manmade bodies of water which neither were originally created in waters of the United States (such as disposal area in wetlands) nor resulted from the impoundment of waters of the United States. Waters of the United States do not include prior converted cropland. Notwithstanding the determination of an area's status as prior converted cropland by any other federal agency, for the purposes of the Clean Water Act, the final authority regarding Clean Water Act jurisdiction remains with EPA.

The Clean Water Act: Phase I
The CWA was amended by Congress in 1987. This amendment required the EPA to establish phased NPDES requirements for storm water discharges. The EPA published the Phase I NPDES permit application requirements for certain industries and large municipal separate storm sewer systems in 1990. More than 100,000 industrial facilities were directly affected by this requirement.

Typical industrial facilities include but are not limited to:

  • Manufacturing facilities
  • Hazardous waste treatment and storage
  • Landfills
  • Sewage treatment plants
  • Recycling facilities
  • Power plants
  • Mining operations
  • Oil and gas operations
  • Airports
  • Transportation facilities
  • Construction activities

Phase I also included the medium and large Municipal Separate Storm Sewer System (MS4). An MS4 is any municipal separate storm sewer system in an incorporated place that serves a population of over 100,000 people.

The Clean Water Act: Phase II
The EPA announced application requirements for Phase II Storm Water Program in August of 1995. Phase II required all small MS4s that discharged pollutants into a U.S. body of water to have an NPDES permit. A small MS4 is a municipal separate storm sewer system that services populations of less than 100,000. Construction activities disturbing between one and five acres must also be permitted. All Phase II regulated entities must be permitted by March of 2003.

Regulated small MS4s and construction sites must design programs to reduce their discharge to the “maximum extent practicable," protect water quality and satisfy the water quality requirements of the CWA.
The Phase II rule also defines the storm water management program as a program comprised of the following six “Best Management Practices" or BMPs:
  • Public education and outreach
  • Public participation and involvement
  • Illicit discharge detection and elimination
  • Construction site runoff control
  • Post-construction runoff control
  • Pollution prevention and good housekeeping
Phase II Construction programs require operators of Phase II small construction sites to obtain an NPDES permit if the operators are discharging pollutants from a point source to waters of the United States. The NPDES permit contains limits on what you can discharge, monitoring and reporting requirements and other provisions to ensure that the discharge does not hurt water quality or people's health. These regulated entities must implement stormwater pollution protection programs or stormwater management programs using best management practices to effectively reduce the discharge of pollutants into receiving waters. There may also be additional state, tribal or local construction runoff control programs required in certain areas.

The EPA has recommended that the NPDES permitting authorities use their existing Phase I large construction permits as a guide in developing the Phase II permits. Although the specific NPDES permitting authority may have different requirements, the Phase II permits will typically consist of three main components:

1. Submission of Notice of Intent. This Notice of Intent will include general information on the site and what is going to be done at the site.

2. Stormwater Pollution Prevention Plan (SWPPP). Almost all NPDES permitting authorities are going to require a type of SWPPP that will detail how you are going to control the runoff.

3. Notice of Termination. Once the project is completed or is taken over by another operator a notice of termination would be submitted.

The NPDES Permit

An NPDES permit will specify the acceptable level of a pollutant in a discharge. Acceptable levels are determined by the State or Federal EPA.

NPDES permits are issued by states that have obtained approval from the EPA or through the EPA Regions in states without approval. The permits require the facility to sample its discharges and report to the regulatory agency the results.

Federal laws provide the EPA with various methods of taking enforcement against permit violators. These enforcements include correcting violations, monetary fines, and civil and criminal actions against willful violators.

The facility monitoring reports are public documents that are available to the general public. If any member of the general public finds a facility violating its NPDES permit, legal action can be taken.

The CWA limits the lengths of NPDES permits to five years. The permits can be renewed at any time after the permit holder applies. Most NPDES permits include the following:

  • A site map showing topography and/or drainage areas and site characteristics
  • An estimate of the total surface drained by each outfall
  • A description of significant materials exposed to rainfall
  • Information on significant leaks and spills in the last three years

It also includes quantitative testing data for the following parameters:
  • Any pollutant limited in an effluent guideline to which the facility is subject
  • Any pollutant listed in the facility's NPDES permit for process wastewater
  • Oil and grease, pH, BOD, COD, TSS, total phosphorus, nitrate plus nitrite nitrogen, and total Kjeldahl nitrogen
  • Certain pollutants known to be in the discharge

Sources For More Information

40 CFR Part 122
Clean Water Act

Stormwater Phase II — Small Construction Program Overview (pdf)
or consult with an attorney.

Questions & Answers

Q. How does the regulatory agency determine the discharge limits of the NPDES permit?

A. Each year, the state must submit a Water Quality Management plan to the Regional Administrator. The WQM is a comprehensive plan which describes the state of the water quality and a listing of the point sources contributing to the pollution. Through a series of calculations, the State determines the discharge limits.

Q. Do I need an NPDES Permit?

A. It depends on where you discharge pollutants. If you discharge from a point source into waters of the United States, you need an NPDES permit. If you discharge pollutants into a municipal sanitary sewer system, you do not need an NPDES permit, but you should ask the municipality about their permit requirements. If you discharge pollutants into a municipal storm sewer system, you may need a permit depending on what you discharge. You should ask the NPDES permitting authority.

Q. Where do I apply for a NPDES Permit?

A. NPDES permits are issued by states that have obtained EPA approval to issue permits or by EPA Regions in states without such approval. The following map illustrates the states with full, partial, and no NPDES Authority. This file in PDF format provides the status of states NPDES Programs.

Please Note: The information contained in this publication is intended for general information purposes only. This publication is not a substitute for review of the applicable government regulations and standards, and should not be construed as legal advice or opinion. Readers with specific questions should refer to the cited regulation or consult with an attorney.

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