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MEMORANDUM

TO: Public Record for the NPDES Electronic Reporting Rule

EPA Docket Number EPA-HQ-OECA-2009-0274 (www.regulations.gov)

FROM: Carey A. Johnston, P.E.

USEPA/OECA/OC

ph: (202) 566 1014

johnston.carey@epa.gov

DATE: 17 November 2012

SUBJECT: Description of the NPDES Program [DCN 0005]

As authorized by the Clean Water Act, the NPDES permit program controls water 

pollution by regulating point sources that discharge pollutants into waters of the United States. 

Point sources are discrete conveyances such as pipes or man-made ditches. For example, NPDES 

permits control municipal and industrial sources of wastewater pollution. NPDES permits 

typically require monitoring and reporting, and limit a facility’s discharge of specific chemicals, 

bulk parameters, and flow to ensure the protection of water quality.

With very few exceptions (e.g., 40 CFR 122.3), point sources require NPDES permit 

authorization to discharge. The requirement for permit authorization applies to, among other 

discharges, the discharges from concentrated animal feeding operations that discharge or propose 

to discharge (40 CFR 122.23), concentrated aquatic animal production facilities (40 CFR 

122.24), aquaculture projects (40 CFR 122.25), silviculture (40 CFR 122.27), and certain storm 

water discharges (40 CFR 122.26, 122.32). NPDES permit authorization is required for 

discharges from certain municipal separate storm sewer systems (MS4s), storm water discharges 

associated with industrial activity, and storm water discharges from construction sites with 

certain acreage thresholds (40 CFR 122.26(c)). Additional storm water discharges also may be 

designated on a case-by-case basis and required to be authorized under an NPDES permit (40 

CFR 122.26(a)(9)).

In general, facilities are categorized as municipal or non-municipal (a.k.a., “industrial”). 

In addition, EPA has developed criteria to determine which of the sources should be considered 

“major” facilities. The distinction was made initially to assist EPA and states in setting priorities 

for permitting and compliance and enforcement activities. The regulations at 40 CFR 122.2 

define major facility as, “any NPDES facility or activity classified as such by the Regional 

Administrator, or in the case of approved state programs, the Regional Administrator in 

conjunction with the [s]tate Director.” All facilities that are not designated as majors are 

considered non-major facilities. Through guidance, EPA has established working definitions for 

POTW and nonmunicipal major facilities1. For POTWs, major facilities are those that have a 

design flow of one million gallons per day or greater or serve a population of 10,000 or more or 

 

1

See “Procedures for Revising the Major Permit List” <www.epa.gov/npdes/pubs/owm0364.pdf> and “Delegation 

of Updates to Major/Minor Lists” www.epa.gov/npdes/pubs/owm0142.pdf.
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cause significant water quality impacts. Non-POTW discharges are classified as major facilities 

on the basis of the number of points accumulated using the NPDES Permit Rating Work Sheet.

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The worksheet evaluates the significance of a facility using several criteria, including 

toxic pollutant potential, flow volume, and water quality factors such as impairment of the 

receiving water or proximity of the discharge to coastal waters. Historically, EPA has placed 

greater priority on major facilities, and has required authorized states to provide more 

information about the compliance status of these dischargers. Specifically, EPA policy created 

the expectation that the permitting authority enter DMR information from “major discharges” 

into one of two EPA databases (PCS or ICIS-NPDES).3

NPDES permit authorization to discharge may be provided under an individual NPDES 

permit, which is developed after a process initiated by a permit application (40 CFR 122.21), or 

under a general NPDES permit, which applies to one or more categories of dischargers (e.g., oil 

and gas extraction facilities, seafood processors). (40 CFR 122.28(a)(2)). Authorization to 

discharge under a general NPDES permit typically occurs upon submission of a “notice of 

intent” (NOI) to be authorized under the permit (40 CFR 122.28(b)(2)), though submission of a 

notice of intent is not required for certain types of discharges under certain circumstances (40 

CFR 122.28(b)(2)(v)).

NPDES permits may be issued by EPA or by a state, territory, or tribe authorized by EPA 

to implement the NPDES program. Currently, 46 states and the Virgin Islands have been 

approved by EPA to administer the NPDES program as well as the general permits program; no 

tribe is currently approved to administer the NPDES program. States may also receive 

authorization from EPA to administer the pretreatment program and the biosolids program, two 

NPDES subprograms. In addition, states may receive approval to regulate federal facilities. 

Currently, 36 states have been approved by EPA to administer the pretreatment program, 8 states 

have been approved by EPA to administer the biosolids program, and 42 states and the Virgin 

Islands have been approved by EPA to regulate federal facilities.

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 EPA administers the NPDES 

program in states, territories, and tribes that have not applied for or received approval to 

implement the program. Under CWA § 402(a)(3), the NPDES permit program administered by

EPA is subject to the same terms, conditions, and requirements as apply to a state permit 

program under CWA § 402(b).

In the early years of the NPDES program, EPA and the states focused on reducing 

pollutants from specified large municipal and industrial point sources, also known as major 

facilities. In order to support development of appropriate permit limits and conditions, issuance 

of effective permits, compliance monitoring, and appropriate enforcement actions, EPA 

developed measures to track, on a nationwide basis, the information necessary to measure, 

evaluate and report on these efforts. Over the last twenty-five years, these efforts to establish 

 

2

See www.epa.gov/npdes/pubs/owm0116.pdf.

3

See (see DCN 0023 and 0007 - Permit Compliance System (PCS) Policy Statement and ICIS Addendum to the 

Appendix of the 1985 Permit Compliance System Statement)

4

See EPA’s website (http://cfpub.epa.gov/npdes/statestats.cfm) for the most current listing of NPDES program 

authorization.
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significant pollutant controls have resulted in important pollutant discharge reductions from 

traditional major sources.

Although large municipal and industrial point sources continue to be significant sources 

of pollution, analysis has shown that smaller point sources also contribute significant amounts of 

pollutants to our nation's waters. Nonmajor facilities are generally smaller sources and are often 

regulated under general permits rather than individual permits. In many cases, nonmajor facilities

use pollutant control measures based on operational activities rather than on implementation of 

pollutant control technologies, which are measured with numeric effluent limits on pollutant 

discharges. The universe of nonmajor dischargers is very large compared to the number of major 

dischargers. The universe of nonmajor dischargers also includes some large volume discharges 

that had not previously been regulated with the same types of individual permits used to regulate 

discharges from major facilities.

EPA is moving toward evaluating water pollution issues on a watershed basis, as it has 

become clear that the nonmajor municipal and industrial dischargers and storm water dischargers 

in violation may have significant impacts individually or collectively in specific watersheds. The 

most recent state reports submitted under CWA § 305(b) and compiled by EPA in the National 

Water Quality Inventory Reports indicate the growing significance and link between these 

nonmajor sources and impairments in water quality, particularly from precipitation-induced or 

"wet weather" point sources of pollutants.5These sources include discharges of storm water 

associated with industrial activity including construction, discharges from concentrated animal 

feeding operations (CAFOs), and overflows from combined sewer systems (CSSs) and sanitary

sewer systems (SSSs). Under Section 305(b) of the CWA, states have consistently reported wet 

weather point sources as contributors of water quality impairment to U.S. surface waters. Storm 

water discharges may include a variety of pollutants, such as sediment, oil and grease, chemicals, 

nutrients, metals, and bacteria. Discharges from CAFOs often include nutrients, organic matter, 

pathogens, and trace metals. Overflows from combined and separate sanitary sewer systems 

pose a significant threat to public health and the environment due to high concentrations of 

bacteria from fecal contamination, as well as disease-causing pathogens. The pollution controls 

for wet weather sources are often best management practices (BMPs) rather than traditional endof-pipe controls. These wet weather sources are high priorities for EPA’s enforcement and 

compliance program and have been for over a decade. 

 

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http://water.epa.gov/lawsregs/guidance/cwa/305b/index.cfm