Frequently Asked Questions

What is the National Pollutant Discharge Elimination System (NPDES) Storm Water Program?
Polluted storm water runoff is a leading cause of impairment to the nearly 40 percent of surveyed U.S. water bodies which do not meet water quality standards. Over land or via storm sewer systems, polluted runoff is discharged, often untreated, directly into local water bodies. When left uncontrolled, this water pollution can result in the destruction of fish, wildlife, and aquatic life habitats; a loss in aesthetic value; and threats to public health due to contaminated food, drinking water supplies, and recreational waterways.

Mandated by Congress under the Clean Water Act, the NPDES Storm Water Program is a comprehensive two-phased national program for addressing the non-agricultural sources of storm water discharges, which adversely affect the quality of our nation's waters. The Program uses the National Pollutant Discharge Elimination System (NPDES) permitting mechanism to require the implementation of controls designed to prevent harmful pollutants from being washed by storm water runoff into local water bodies.

What is required of regulated entities under the NPDES Storm Water Program?
The regulated entities must obtain coverage under an NPDES storm water permit and implement storm water pollution prevention plans (SWPPPs) or storm water management programs (both using best management practices (BMPs)) that effectively reduce or prevent the discharge of pollutants into receiving waters.

Who should entities regulated under the NPDES Storm Water Program contact to obtain permi coverage?
Regulated entities should contact their NPDES permitting authority, which will be either their state or EPA Regional Office, depending on the type of entity and its location. For regulated entities located in areas where EPA is the NPDES permitting authority, all information and forms needed to obtain permit coverage are available through EPA's web site (see Storm Water Discharges from Construction Activities).

How can I get a copy of the Storm Water Phase II Final Rule?
The Storm Water Phase II Final Rule was published in the Federal Register on December 8, 1999. It is available electronically here. A limited number of paper copies can be obtained from EPA's Water Resource Center at (202) 260-7786 or center.water-resource@epa.gov.

Who is regulated under the Storm Water Phase II Final Rule?
The rule automatically regulates two classes of storm water dischargers on a nationwide basis, one of which is operators of construction activities that disturb equal to or greater than 1 and less than 5 acres of land. However, additional small construction sites (disturbing less than 1 acre of land), along with other sources which are a significant contributor of pollutants to streams, rivers, etc., may be brought into the NPDES Storm Water Program by the state regulatory agency.

The rule also excludes from the NPDES program storm water discharges from industrial facilities that have "no exposure" of industrial activities or materials to storm water. This exclusion does require facilities to complete, sign, and submit a no exposure certification to the permitting authority once every five years.

When will I need to get a permit under the Storm Water Phase II regulations?
Operators of Phase II regulated small construction activities are required to apply for NPDES permit coverage by March 10, 2003. The agency that issues your NPDES permit could set an earlier deadline for permit coverage.

How does a storm water permitted construction operator terminate coverage?
A Notice of Termination (NOT) for Industrial Activity (which includes construction and is the same form for all three of EPA's CGPs) must be submitted to EPA's NOI Processing Center (address identified on the NOT form) in order to terminate coverage. A permittee may submit an NOT when:

If a construction operation disturbing five or more acres is owned by a small municipality (a population of less than 100,000 people) but operated by a private contractor, is the activity regulated?
No. If the construction activity is either owned or operated by a municipality with a population of less than 100,000 it would not be required to obtain a storm water permit during Phase I of the storm water program. Some state permitting authorities may require that an application be submitted.

What waivers are available for Storm Water Phase II construction activity?
Under the Storm Water Phase II Rule, NPDES permitting authorities have the option of providing a waiver from the requirements to operators of "small" construction activity who could certify to one of two conditions:

  1. Low predicted rainfall potential (i.e., activity occurs during a negligible rainfall period), where the rainfall erosivity factor ("R" in the Revised Universal Soil Loss Equation (RUSLE)) is less than 5 during the period of construction activity.
  2. A determination that storm water controls are not necessary based on either: (A) Total Maximum Daily Load (TMDL) approved or established by EPA that addresses the pollutant(s) of concern for construction activities; or (B) For non-impaired waters that do not require TMDLs, an equivalent analysis that determines allocations for small construction sites for the pollutant(s) of concern or that determines that such allocations are not needed to protect water quality based on consideration of existing in-stream concentrations, expected growth in pollutant contributions from all sources, and a margin of safety.
Note: Waivers are not available for any construction activity disturbing 5 acres or greater, or less than 5 acres if part of a common plan of development or sale (or if designated for permit coverage by the NPDES permitting authority).

See Storm Water Phase II Final Rule-Small Construction Program Overview (Fact Sheet 3.0) and Storm Water Phase II Final Rule-Low Rainfall Erosivity Waiver (Fact Sheet 3.1) for more information.

Who must seek permit Coverage Under an EPA construction General Permit?
See Storm Water Phase II Final Rule-Small Construction Program Overview (Fact Sheet 3.0) for more information on both the small and large construction programs.

Do clearing, grading, and excavation activities at oil and gas extraction operations require an NPDES permit for associated storm water discharges

EPA responded to a letter addressed to Christine Todd Whitman regarding the applicability of the NPDES storm water permitting program to these types of discharges from oil and gas exploration sites. A copy of the Office of Water's response is provided here. It is EPA's interpretation that these types of discharges do require permit coverage and are not subject to the statutory exclusion for "oil and gas exploration, production, processing, or treatment operations or transmission facilities."


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