Storm Water Phase II Compliance Assistance Guide

Compliance Guide Notice

The statements in this document are intended solely as guidance to aid regulated

entities in complying with the Storm Water Phase II final rule. The guidance is not a

substitute for reading the regulation and understanding all its requirements as it applies

to your facility. This guidance does not constitute rulemaking by the EPA and may not

be relied on to create a substantive or procedural right or benefit enforceable, at law or

in equity, by any person. EPA may decide to update this guide without public notice to

reflect changes in EPA’s approach to implementing Storm Water Phase II or to clarify

and update text. To determine whether EPA has revised this document and/or to

obtain copies, go to EPA’s web site at www.epa.gov/owm/sw/phase2.
1.0 Introduction

Page 1-1 Storm Water Phase II Compliance Assistance Guide

1.0 INTRODUCTION

The U.S. Environmental Protection Agency (EPA) published the regulation entitled

“National Pollutant Discharge Elimination System - Regulations for Revision of the

Water Pollution Control Program Addressing Storm Water Discharges” (Federal

Register, Volume 64, Number 235, pages 68722-68852) on December 8, 1999 as

required by Section 402(p) of the Clean Water Act (CWA). This guide explains how to

tell if you are subject to the regulation and what to do if you are required to comply.

1.1 Who should use this guide?

This new rule regulates storm water discharges from two categories: 

First, the rule covers storm water discharges to certain municipal separate

storm sewer systems (MS4s). Public entities which operate these MS4s, such

as cities, counties, States, and the Federal government, could be regulated

under this rule. MS4 operators should read section 4 for more information.

Second, the rule also covers storm water discharges from construction activity

generally disturbing between 1 and 5 acres. A construction operator could

include the site owner, developer, contractor, or subcontractor. Construction site

operators should read section 5 for more information.

The storm water Phase II final rule also provide regulatory relief for certain

industrial facilities (currently permitted under EPA’s storm water regulations) where

storm water runoff is not exposed to industrial activities. Operators of industrial facilities

interested in the no exposure exclusion should read section 6.

1.2 What Does this Guide Cover?

The purpose of this guide is to help the regulated community comply with the Storm

Water Phase II Rule. This guide answers the following basic questions:

- Why is the Storm Water Phase II Rule important?

- Am I subject to the Storm Water Phase II Rule?

- What must I do to comply with the Storm Water Phase II Rule?

After reading this introduction, you should know whether you need to use

this guide, what the guide covers, and where to get the latest information

on the regulation.
1.0 Introduction

Page 1-2 Storm Water Phase II Compliance Assistance Guide

1.3 How Do I Use this Guide?

This guide is organized into seven major sections plus three appendices.

Section 1.0 Introduces you to this guide and the Storm Water Phase II Rule. 

Describes basic types of entities regulated so you can determine if

you are affected by the rule.

Section 2.0 Provides background on why the Storm Water Phase II Rule is

needed. Topics such as the environmental impacts of storm water

and why storm water should be controlled are discussed. The

history of the NPDES Storm Water program is briefly described.

Section 3.0 Delivers an overview of the Storm Water Phase II requirements. 

The basic components of the program are described and

schedules and timelines are highlighted.

Section 4.0 Gives step-by-step procedures for operators of small MS4s to

determine if they are subject to the regulation and provides

information on how to demonstrate compliance.

Section 5.0 Gives step-by-step procedures for operators of small construction

activities to determine if they are subject to the regulation and

provides information on how to demonstrate compliance.

Section 6.0 Provides a discussion of how the Rule affects industrial facilities,

including which industrial facilities are covered, and an explanation

of the No Exposure exclusion and how to determine if you qualify.

Section 7.0 Documents the Compliance Assurance Process - Discusses how

EPA will determine compliance, what happens if you or EPA

discovers noncompliance, and the legal status of the guide.

Appendices Provides additional references and where to go for more

information on storm water.

1.4 Where Can I Get More Information on the Storm Water Phase II Rule?

Additional information on the NPDES storm water Phase II rule, including a series of

fact sheets and a full copy of the final rule, can be found on EPA’s web pages at

http://www.epa.gov/owm/sw/phase2.

Compliance assistance will be covered in Section 7 of the guide. One source for

compliance assistance and information on the rule is the Local Government

Environmental Assistance Network (LGEAN). LGEAN is one of EPA’s compliance
1.0 Introduction

Page 1-3 Storm Water Phase II Compliance Assistance Guide

assistance centers and can be found on the web at www.lgean.org or contacted by

phone at 1-877-TO-LGEAN.
2.0 Background

Page 2-1 Storm Water Phase II Compliance Assistance Guide

2.0 BACKGROUND

2.1 What are the Environmental Impacts from Storm Water Discharges?

Storm water runoff from lands modified by human activities can harm surface water

and, in turn, cause or contribute to an exceedance of water quality standards by

changing natural hydrologic patterns, accelerating natural stream flows, destroying

aquatic habitat, and elevating pollutant concentrations and loadings. Such runoff may

contain high levels of contaminants, such as sediment, suspended solids, nutrients

(phosphorus and nitrogen), heavy metals, pathogens, toxins, oxygen-demanding

substances (organic material), and

floatables (U.S. EPA. 1992.

Environmental Impacts of Storm

Water Discharges: A National

Profile. EPA 841-R-92-001. Office

of Water. Washington, DC). After

a rain, storm water runoff carries

these pollutants into nearby

streams, rivers, lakes, estuaries,

wetlands, and oceans. 

Individually and combined, these

pollutants impair water quality,

threatening designated beneficial

uses and causing habitat

alteration and destruction. 

The 1996 305(b) Report (U.S.

EPA. 1998. The National Water

Quality Inventory, 1996 Report to

Congress. EPA 841-R-97-008.

Office of Water. Washington, DC),

provides a national assessment of

water quality based on biennial

reports submitted by the States as

required under CWA section

305(b) of the CWA. In the CWA

305(b) reports, States, Tribes, and

Territories assess their individual

water quality control programs by

examining the attainment or Figure 2-1. Pollutants and Sources in Surveyed River Miles (EPA, 1998) 

After reading section 2, you should understand the environmental impacts

of storm water and the history of the storm water program, including

existing regulations to control storm water (Phase I).
2.0 Background

Page 2-2 Storm Water Phase II Compliance Assistance Guide

nonattainment of the designated

uses assigned to their rivers,

lakes, estuaries, wetlands, and

ocean shores. The 1996

Inventory indicated that

approximately 40 percent of the

Nation's assessed rivers, lakes,

and estuaries are impaired.

The 1996 Inventory also found

urban runoff/discharges from

storm sewers to be a major

source of water quality

impairment nationwide. Urban

runoff/storm sewers were found to

be a source of pollution in 13

percent of impaired rivers; 21

percent of impaired lakes, ponds,

and reservoirs; and 45 percent of

impaired estuaries (second only

to industrial discharges). See

Figures 2-1 and 2-2 for an

illustration of the pollutants and

sources of pollution for both rivers

and estuaries. In addition to

these waterbodies, urban runoff

was found to be the leading

cause of ocean impairment for

those ocean miles surveyed.

Urbanization alters the natural

infiltration capability of the land

and generates a host of pollutants

that are associated with the

activities of dense populations, Figure 2-2. Pollutants and Sources in surveyed Estuaries (EPA, 1998)

thus causing an increase in storm 

water runoff volumes and pollutant loadings in storm water discharged to receiving

waterbodies (U.S. EPA, 1992). Urban development increases the amount of

impervious surface in a watershed as farmland, forests, and meadowlands are

converted into buildings with rooftops, driveways, sidewalks, roads, and parking lots

with virtually no ability to absorb storm water. Storm water and snow-melt runoff wash

over these impervious areas, picking up pollutants along the way while gaining speed

and volume because of their inability to disperse and filter into the ground (see Figure

2-3 which illustrates the increased runoff resulting from increased impervious area). 

The resulting storm water flows are higher in volume, pollutants, and temperature than

the flows in less impervious areas, which have more natural vegetation and soil to filter

the runoff (U.S. EPA, 1997. Urbanization and Streams: Studies of Hydrologic Impacts.
2.0 Background

Page 2-3 Storm Water Phase II Compliance Assistance Guide

EPA 841-R-97-009. Office of

Water. Washington, DC).

In addition to the pollutants

picked up by storm water

runoff before it enters a storm

drain, studies have shown that

discharges from a storm drain

system often include wastes

and wastewater from nonstorm water sources, referred

to as illicit discharges. These

discharges are ‘illicit’ because

municipal storm sewer

systems are not designed to

accept, process, or discharge

such wastes. Sources of illicit discharges can include sanitary wastewater illegally

connected to the storm drain system; effluent from septic tanks; car wash, laundry, and

other industrial wastewaters; improper disposal of auto and household toxics, such as

used motor oil and pesticides; and spills from roadways.

Illicit discharges enter the system through either direct connections (e.g., wastewater

piping either mistakenly or deliberately connected to the storm drains) or indirect

connections (e.g., infiltration into the MS4 from cracked sanitary systems, spills

collected by drain outlets, and paint or used oil dumped directly into a drain). The result

is untreated discharges that contribute high levels of pollutants, including heavy metals,

toxics, oil and grease, solvents, nutrients, viruses and bacteria into receiving

waterbodies.

2.2 Summary of EPA’s Storm Water Program

In 1972, Congress amended the Federal Water Pollution Control Act (commonly

referred to as the Clean Water Act (CWA)) to prohibit the discharge of any pollutant to

waters of the United States from a point source unless the discharge is authorized by

an NPDES permit. The NPDES program is designed to track point sources and require

the implementation of the controls necessary to minimize the discharge of pollutants. 

Initial efforts to improve water quality under the NPDES program primarily focused on

reducing pollutants in industrial process wastewater and municipal sewage. These

discharge sources were easily identified as responsible for poor water quality.

As pollution control measures for industrial process wastewater and municipal

sewage were implemented and refined, it became increasingly evident that more

diffuse sources of water pollution were also significant causes of water quality

impairment. Specifically, storm water runoff was found to be a major cause of water

quality impairment.
2.0 Background

Page 2-4 Storm Water Phase II Compliance Assistance Guide

In 1987, Congress amended the CWA to require implementation, in two phases, of

a comprehensive national program for addressing storm water discharges. The first

phase of the program, commonly referred to as “Phase I,” was promulgated on

November 16, 1990 (55 FR 47990). Phase I requires NPDES permits for storm water

discharge from a large number of priority sources including medium and large municipal

separate storm sewer systems (“MS4s”) generally serving populations of 100,000 or

more and several categories of industrial activity, including construction activity that

disturbs five or more acres of land.

The Phase I permits for municipal separate storm sewer systems mostly covere

larger cities, and require them to develop a storm water management program, track

and oversee industrial facilities regulated under the NPDES storm water program,

conduct some monitoring, and submit periodic reports.

The operators of construction activities disturbing greater than 5 acres have been

required to obtain NPDES permit coverage since 1992. General permits for large

construction activity require construction operators to develop and implement a storm

water pollution prevention plan to control erosion, sediment and other wastes on the

site.

The Phase I industrial storm water program also regulates the following industrial

sectors:

- facilities subject to EPA storm water effluent guidelines, new source performance

standards, or toxic pollutant effluent standards

- heavy manufacturing facilities

- mining/oil and gas

- hazardous waste faciliites

- landfills

- recycling facilities

- steam electric power

- transportation facilities

- sewage treatment plants

- construction activity (described above), and

- light manufacturing facilities.

The second phase of the storm water program, which this guide addresses, requires

permits for storm water discharges from certain small municipal separate storm sewer

systems and construction activity generally disturbing between 1 and 5 acres. See

Figure 2-4 for a summary of the federal storm water permit requirements under Phases

I and II.
Page 2-5 Storm Water Phase II Compliance Assistance Guide

Figure 2-4. Summary of Federal Permit Requirements Under the NPDES Storm Water Program

Municipal Separate Storm Sewer Systems (MS4s) Construction Activity Industrial Activity

Requirementsin EffectNow

(Phase I)

Medium and Large MS4s (§ 122.26(d))• Storm Water Management Program:

- Public education and outreach- Public participation efforts- Illicit discharge detection and elimination program- Construction and post-construction runoff controlprogram for all construction activity (no size threshold)- BMPs to reduce pollutants from industrial, commercial,and residential areas 

• Track/oversee industrial facilities regulated under the

NPDES storm water program

• Conduct analytical and visual monitoring of MS4

discharges

• Submit periodic program assessment reports

Category (x) ConstructionActivity (5+ Acres)*CGP:

• Storm Water Pollution

Prevention Plan (SWPPP)- Site description- Description of BMPs forerosion and sediment, postconstruction storm watermanagement, and othercontrols- Self-evaluation and reporting

*Category (x) is one of the categories of"storm water discharges associated withindustrial activity." Temporarily excludedfrom permitting: Category (x) constructionactivity operated by a municipality of<100,000 (ISTEA moratorium).

Ten Categories of IndustrialActivity (Categories (i)-(ix),(xi))*

MSGP:

• SWPPP - Site evaluation -Description of appropriatestorm water managementBMPs - Self-evaluation, monitoring,  and reporting• If discharging into a medium or

large MS4, notify the MS4operator

*Temporarily excluded from permitting:Industrial activity operated by a municipality of <100,000, except for power plants, airports,and uncontrolled sanitary landfills (ISTEA

moratorium).

Requirement

s that

Will Be 

in Effect 

by 2003

(Phase II)

Regulated Small MS4s (§ 122.34 outlined here, but maychoose permit coverage under § 122.26(d) instead)• Storm Water Management Program:

- Public education and outreach- Public participation efforts- Illicit discharge detection and elimination program- Construction runoff control program for constructionactivity disturbing 1 acre or greater- Post-construction runoff control program forconstruction activity disturbing 1 acre or greater- Good housekeeping/pollution prevention for municipaloperations

• Conduct assessment of identified BMPs and measurable

goals for each minimum control measure

• Submit annual program assessment reports

Small Construction Activity (<1 and <5 Acres)

• Expected to be similar to

Category (x) ConstructionActivity requirements above

Category (x) ConstructionActivity Operated by aMunicipality of < 100,000• Same requirements as for

Category (x) ConstructionActivity above

Industrial Activity Operated bya Municipality of <100,000*

• Same requirements as for Ten

Categories of Industrial Activityabove

*Does not include: Power plants, airports, anduncontrolled sanitary landfills
3.0 Regulation Requirements

Page 3-1 Storm Water Phase II Compliance Assistance Guide

3.0 REGULATION REQUIREMENTS

3.1 What Does The Storm Water Phase II Rule Require?

This regulation can be divided into three main components, each with distinct

requirements, affecting three types of entities. These components and the

requirements for each are summarized below.

Regulated Small MS4s (see section 4.0)

A certain subset of operators of small MS4s (primarily those located in urbanized

areas) are required to implement programs and practices to control polluted storm

water runoff from the jurisdiction serviced by the MS4. The operator must design its

storm water management program to satisfy applicable CWA water quality

requirements and technology standards. The program must include the development

and implementation of best management practices (BMPs) and measurable goals for

the following six minimum measures, and include evaluation and reporting efforts:

• Public education and outreach, 

• Public participation/involvement, 

• Illicit discharge detection and elimination, 

• Construction site runoff control, 

• Post-construction runoff control, and 

• Pollution prevention/good housekeeping for municipal operations.

Two waivers from coverage are available for small MS4s brought into the program

by the Phase II regulation. 

Small Construction Activity (see section 5.0)

All construction operators disturbing more than 1 acre and less than 5 acres are

required to apply for an NPDES storm water permit for small construction activity. EPA

already regulates construction activity disturbing more than 5 acres. A construction

operator is usually the developer or landowner, but can also be the contractor or

another party responsible for the operational control of erosion and sediment control

practices on site. 

After reading section 3.0, you should understand the basic components

and requirements of the Storm Water Phase II Rule and the rule's

compliance schedule/timeline. This information is meant to serve as a

basis for understanding the details of the Rule as discussed in further

sections of this guidance.
3.0 Regulation Requirements

Page 3-2 Storm Water Phase II Compliance Assistance Guide

Unlike the requirements for regulated small MS4s, the requirements for small

construction activity (primarily activity disturbing between 1 and 5 acres of land) are not

detailed in the Phase II regulation. Rather, the requirements are left to the discretion of

the NPDES permitting authority when it develops the small construction activity permit. 

EPA expects the permit for small construction activity to be similar to the existing storm

water general permits for large construction activity regulated under the Phase I

program. EPA's existing Construction General Permit includes requirements to:

• Submit a Notice of Intent (NOI); 

• Develop and implement a Storm Water Pollution Prevention Plan (SWPPP). 

The SWPPP includes erosion and sediment controls, controls on waste at the

site, self-inspection/monitoring, and reporting efforts; and 

• Submit a Notice of Termination (NOT) when permit coverage is no longer

necessary.

Two waivers from coverage are available for small construction activity.

Industrial Activity (see section 6.0)

Eleven categories of industrial activity are regulated under Phase I of the NPDES

Storm Water Program. Under the Phase II Rule, no new categories of industrial activity

are designated into the storm water program. The Rule does, however, include a

revised no exposure exclusion that is available to all regulated categories of industrial

activity (except category (x) - large construction activity) if the facility operator can certify

that storm water runoff is not exposed to industrial activities.

Also, this regulation further extends the deadline to obtain permit coverage for those

industrial activities operated by municipalities with populations of less than 100,000 that

were temporarily exempted from permitting under the Intermodal Surface

Transportation Enforcement Act (ISTEA) of 1991. 

3.2 What Is the Phase II Rule's Compliance Schedule/Timeline?

The Phase II Final Rule was published in the Federal Register on December 8,

1999 (64 FR 68722). The following table lists milestones for EPA, the NPDES

permitting authorities, and the regulated community under this program.
3.0 Regulation Requirements

Page 3-3 Storm Water Phase II Compliance Assistance Guide

Storm Water Phase II Program Compliance Timeline

ACTIVITY DEADLINE

Conditional No Exposure Exclusion option available in States

where EPA is the NPDES permitting authority

February 7, 2000

Submission of No Exposure Certification Every 5 years

EPA issues a menu of BMPs for small MS4 programs October 2000

EPA issues a model general permit for small MS4s October 2000

EPA issues guidance on measurable goals for small MS4

programs

October 2001

NPDES permitting authority determines designation of small MS4s

located outside of an urbanized area that serve a jurisdiction with

a population of 10,000 and population density of 1,000

By December 9, 2002; or by

December 8, 2004 if apply

designation criteria on a

watershed basis under a

comprehensive watershed plan

NPDES permitting authority determines waivers for regulated

small MS4s in urbanized areas

By December 9, 2002

NPDES permitting authority issues general permits for regulated

small MS4s and small construction activity

By December 9, 2002

Operators of regulated small MS4s and small construction activity

designated by the rule must obtain permit coverage

By March 10, 2003

Operators of regulated small MS4s and small construction activity

designated by NPDES permitting authority must obtain permit

coverage

Within 180 days of notice

Temporarily exempted municipal operators of industrial activity

must obtain permit coverage (ISTEA moratorium)

By March 10, 2003

The NPDES permitting authority may phase in coverage for small

MS4s serving jurisdictions with a populations less than 10,000 on

a schedule consistent with a State watershed permitting approach 

Completion of phase-in by

March 8, 2007

The regulated small MS4s must fully implement their storm water

management programs

By the end of the first permit

term – typically a 5-year period

Re-evaluation of the Phase II small MS4 regulations by EPA By December 2012

NPDES permitting authority determination on a petition for

designation of a non-regulated storm water discharger

Within 180 days of receipt
 4.0 Regulated Small MS4s

Page 4-1 Storm Water Phase II Compliance Assistance Guide

4.0 REGULATED SMALL MS4S

4.1 MS4 DEFINITIONS

EPA’s National Pollutant Discharge Elimination System (NPDES) storm water

permitting program labels municipal separate storm sewer systems (MS4s) as either

“small,” “ medium,” or “large” for the purposes of regulation. The definitions of each are

included herein. The Phase I storm water program covers medium and large MS4s.

The Phase II storm water regulation covers a certain subset of small MS4s, known as

"regulated small" MS4s. Regulated small MS4 coverage under the rule is discussed in

section 4.2.

4.1.1 What is an "MS4"?

What constitutes a municipal separate storm sewer system (MS4) is often

misinterpreted and misunderstood. The term MS4 does not solely refer to municipallyowned storm sewer systems, but rather is a term of art with a much broader application

that can include, in addition to local jurisdictions, State departments of transportation,

universities, local sewer districts, hospitals, military bases, and prisons. An MS4 also is

not always just a system of underground pipes – it can include roads with drainage

systems, gutters, and ditches. The regulatory definition of an MS4 is provided in the

text box below.

After reading section 4.0, you should understand what an MS4 is, which

operators of MS4s are subject to the Phase II small MS4 regulations

(including who may be waived from coverage), the small MS4 permit

options, and the permit requirements for a small MS4 storm water

management program. The discussion of these elements concludes with

a step-by-step review of the process for compliance with the small MS4

program and possible funding options. Special concerns regarding

Federal and State-operated small MS4s are also addressed.
 4.0 Regulated Small MS4s

Page 4-2 Storm Water Phase II Compliance Assistance Guide

According to 40 CFR 122.26(b)(8), “municipal separate storm sewer means a conveyance or

system of conveyances (including roads with drainage systems, municipal streets, catch basins,

curbs, gutters, ditches, man-made channels, or storm drains):

(i) Owned or operated by a State, city, town, borough, county, parish, district, association,

or other public body (created by or pursuant to State law)...including special districts

under State law such as a sewer district, flood control district or drainage district, or

similar entity, or an Indian tribe or an authorized Indian tribal organization, or a

designated and approved management agency under section 208 of the Clean Water

Act that discharges into waters of the United States.

(ii) Designed or used for collecting or conveying storm water;

(iii) Which is not a combined sewer; and

(iv) Which is not part of a Publicly Owned Treatment Works 

(POTW) as defined at 40 CFR 122.2."

4.1.2 What is a "large" MS4?

A large MS4 is any MS4 located in an incorporated place or county with a

population of 250,000 or greater as of the 1990 Census. The Phase II Final Rule

revised the original large MS4 definition (found in the 1990 Phase I regulations) by

freezing it as of the 1990 Census so that no new large MS4s could be automatically

designated based on the 2000 Census, or any subsequent Census. Listings of

incorporated places and counties with populations of 250,000 or greater as of the 1990

Census are included in the revised Appendices F and H to Part 122, found in the Phase

II Final Rule.

4.1.3 What is a "medium" MS4?

A medium MS4 is any MS4 located in an incorporated place or county with a

population between 100,000 - 249,999 as of the 1990 Census. The Phase II Final Rule

revised the original medium MS4 definition (found in the 1990 Phase I regulations) by

freezing it as of the 1990 Census so that no new medium MS4s could be automatically

designated based on the 2000 Census, or any subsequent Census. Listings of

incorporated places and counties with populations between 100,000 - 249,999 as of the

1990 Census are included in the revised Appendices G and I to Part 122, found in the

Phase II Final Rule.

Important Note: Many MS4s in areas below 100,000 in population have been

individually brought into the Phase I program by NPDES permitting authorities. 

Such already regulated MS4s are considered Phase I MS4s and are not required

to develop a Phase II program.

4.1.4 What is a "small" MS4?
 4.0 Regulated Small MS4s

Page 4-3 Storm Water Phase II Compliance Assistance Guide

A small MS4 is any MS4 that is not already regulated under the Phase I storm water

program. Unlike the definitions of medium and large MS4s, the definition of a small

MS4: 1) is not dependant on a population threshold, and 2) includes Federally-owned

systems, such as military bases and veterans hospitals.

4.2 COVERAGE: Who Is Subject to the Phase II Final Rule?

4.2.1 Are All Small MS4s Covered by the Phase II Final Rule?

No. The universe of small MS4s is quite large since it includes every MS4 except

for the approximately 900 medium and large MS4s already regulated under the Phase I

storm water program. Only a select sub-set of small MS4s, referred to as regulated

small MS4s, are covered by the Phase II Final Rule, either through automatic

nationwide designation by the rule or designation on a case-by-case basis by the

NPDES permitting authority.

4.2.2 How Is A Small MS4 Designated as a Regulated Small MS4 under

Phase II?

A small MS4 can be designated as a regulated small MS4, and thereby be subject

to the Phase II rule, in any one of the three ways explained in the following

subsections.

4.2.2.1 Automatic Nationwide Designation by the Rule

The Phase II Final Rule requires "automatic" nationwide coverage of all operators of

small MS4s that are located within the boundaries of a Bureau of the Censusdelineated “urbanized area” (UA) based on the latest decennial Census. This doesn't

just include municipal operators of small MS4s, but also universities, highway

departments, and any other operator of a storm sewer system that is located fully or

partially within the UA. Refer to section 4.3 for more information on how to

determine if a particular small MS4 is located within a UA. 

Important Note: Only the portion of the small MS4 that is located within the UA

boundaries is regulated under Phase II. For example, if a county operates a

small MS4 that serves the whole county but only half of the MS4 falls within the

UA boundary, then the county must obtain permit coverage (and implement a

storm water management program) only for the half of the MS4 in the UA. 

Once a small MS4 is designated into the program based on the UA boundaries, it

cannot be waived from the program if in a subsequent UA calculation the small MS4 is

no longer within the UA boundaries. An automatically designated small MS4 remains

regulated unless, or until, it meets the criteria for a waiver. See section 4.4 for more

information on waivers from coverage for regulated small MS4s in urbanized areas.
 4.0 Regulated Small MS4s

Page 4-4 Storm Water Phase II Compliance Assistance Guide

An operator of a small MS4 located outside of a UA boundary may be designated as

a regulated small MS4 if the NPDES permitting authority determines that the small

MS4's discharges cause, or have the potential to cause, an adverse impact on water

quality. See sections 4.2.2.2 and 4.2.2.3 below for more information on designations by

the permitting authority.

Preamble of the Phase II Final Rule: Appendix 6

A listing of governmental entities that are located either fully or partially within a UA

according to the 1990 Census can be found in Appendix 6 to the Preamble of the

Phase II Final Rule. The list is a general geographic reference intended to help

operators of small MS4s determine whether or not they are located in a UA and,

consequently, required to comply with the regulation; it is not a list of all Phase II

regulated MS4s and it may contain errors. For example, the list does not include small

MS4 operators such as colleges and universities, Federal prison complexes, and State

highway departments located within a UA. 

4.2.2.2 Potential Designation by the NPDES Permitting Authority — Required

Evaluation of 10,000/1,000 Areas

The Phase II Final Rule requires the NPDES permitting authority to develop a set of

designation criteria and apply them, at a minimum, to all small MS4s located outside of

a UA that serve a jurisdiction with a population of at least 10,000 and a population

density of at least 1,000 people/square mile. The permitting authority is required to

evaluate such small MS4s but is not required to designate them into the program

unless they meet the designation criteria.

Recommended Designation Criteria

EPA recommends in the Phase II regulations that the NPDES permitting authority

use a balanced consideration of the following designation criteria on a watershed or

other local basis:

r Discharge to sensitive waters;

r High population density;

r High growth or growth potential;

r Contiguity to a UA;

r Significant contributor of pollutants to waters of the United States; and

r Ineffective protection of water quality concerns by other programs.

Preamble of the Phase II Final Rule: Appendix 7

A listing of governmental entities located outside of a UA that have a population of

at least 10,000 and a population density of at least 1,000 people per square mile, can

be found in Appendix 7 to the Preamble of the Phase II Final Rule. Similar to Appendix

6, the list is a geographic reference only – it is not a list of regulated entities and it may

contain errors. Operators of small MS4s located within a listed area could be

examined by their NPDES permitting authority for potential designation into the Phase II 
 4.0 Regulated Small MS4s

Page 4-5 Storm Water Phase II Compliance Assistance Guide

Physically interconnected means that one MS4 is connected to a second MS4

in such a way that it allows for direct discharges into the second system.

program. Furthermore, the NPDES permitting authority reserves the right to designate

for regulation any small MS4 that is contributing pollutants to waters of the United

States, whether or not its jurisdiction is found in Appendix 7. 

Deadline for Designation

The NPDES permitting authority is required to designate small MS4s meeting the

designation criteria by December 9, 2002, or by December 8, 2004 if a comprehensive

State watershed plan is in place and the criteria are being applied on a watershed

basis.

4.2.2.3 Potential Designation by the NPDES Permitting Authority — Physically

Interconnected

The Phase II Final Rule requires the NPDES permitting authority to designate any

small MS4 located outside of a UA that contributes substantially to the pollutant

loadings of a physically interconnected MS4 that is permitted by the NPDES storm

water program. This means the other MS4 could be a large, medium, or regulated

small MS4.

Small MS4s located right outside the boundary of an urbanized area are the ones

most likely to meet this criterion for designation and, therefore, should make an effort to

become aware of whether they discharge pollutants directly into a regulated MS4. The

sooner a small MS4 operator is prepared for potential designation and implementation

of the Phase II program, the better.

Deadline for Designation

The final rule does not set a deadline for designation of small MS4s meeting this

criterion.

4.3 URBANIZED AREAS: What Are They and How Does a Small MS4

Operator Determine If It Is Located in One?

As discussed in section 4.2, the Phase II Final Rule covers all small municipal

separate storm sewer systems (MS4s) located within an “urbanized area” (UA). Based

on the 1990 Census, there are 405 UAs in the United States that cover 2 percent of

total U.S. land area and contain approximately 63 percent of the Nation’s population. 

These numbers include Puerto Rico — the only U.S. Territory with UAs.

UAs constitute the largest and most dense areas of settlement. UA calculations

delineate boundaries around these dense areas of settlement and, in doing so, identify

the areas of concentrated development. UA designations are used for several 
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purposes in both the public and private sectors. For example, the Federal Government

has used UAs to calculate allocations for transportation funding, and some planning

agencies and development firms use UA boundaries to help ascertain current, and

predict future, growth areas.

4.3.1. What Is the Definition of an Urbanized Area (UA)?

The Bureau of the Census determines UAs by applying a detailed set of published

UA criteria (see 55 FR 42592, October 22, 1990) to the latest decennial census data. 

Although the full UA definition is complex, the Bureau of the Census’ general definition

of a UA, based on population and population density, is provided below.

UA Facts:

• The basic unit for delineating the UA boundary is the census block. Census

blocks are based on visible physical boundaries, such as the city block, when

possible, or on invisible political boundaries, when not. An urbanized area can

comprise places, counties, Federal Indian Reservations, and minor civil divisions

(MCDs - towns and townships). 

• A UA can include governmental entities of every population size: 200; 7,000;

15,000; 30,000, 200,000; or 3 million! Entities with small populations are

commonly found in the urban fringe of the UA.

• Before the time of permit issuance (by December 9, 2002), new UA calculations

based on the 2000 Census should be published. The regulated small MS4

universe then will be based on these new calculations.

4.3.2. What Does A UA Look Like?

The drawing below (see Figure 4-1) is a simplified UA illustration that demonstrates

the concept of UAs in relation to the Phase II Final Rule. This “urbanized area”

includes within its boundaries incorporated places, a portion of a Federal Indian

reservation, an entire MCD, a portion of another MCD, and portions of two counties. 

Any and all operators of small MS4s located within the boundaries of the UA are

covered under the Phase II Final Rule, regardless of political boundaries. Operators of

small MS4s located outside of the UA are subject to potential designation into the

Phase II MS4 program by the NPDES permitting authority, as explained in section 4.2.

An urbanized area (UA) is a land area comprising one or more places – central place(s) –

and the adjacent densely settled surrounding area – urban fringe – that together have a

residential population of at least 50,000 and an overall population density of at least 1,000

people per square mile. It is a calculation used by the Bureau of the Census to determine

the geographic boundaries of the most heavily developed and dense urban areas.
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1719D

County A

County B

FIR

Town B

Town A

Central Place

Incorporated Place

Federal Indian Reservation (FIR)

Unincorporated “Urbanized

Area” Portion of a Town

(MCD) or County

Urbanized Area

Town or Township as a

functioning Minor Civil Division

(MCD). An MCD is the primary

subdivision of a County.

County

Figure 4-1

4.3.3 How Can An Operator of a Regulated Small MS4 Determine If It Is

Located Within a UA?

Operators of small MS4s can determine if they are located within a UA, and

therefore covered under the Phase II storm water program, through the following two

steps:

— STEP 1 — 

Refer to a listing of incorporated places, MCDs, and counties that are

located entirely or partially within a UA. Such a listing, based on the 1990

Census and including only those entities not regulated under Phase I, can

be found in Appendix 6 to the Preamble of the Phase II Final Rule. If a

small MS4 is located in a listed incorporated place, MCD, or county, then

the operator of the small MS4 should follow step (2) below. It is important

to note that Appendix 6 is general guidance only and may contain errors. 

For this reason, even if a particular small MS4 isn't located in a listed

area, EPA recommends that the small MS4 operator follow Step 2.

— STEP 2 —

Some operators of small MS4s may find that they are located within an 
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entity listed in Appendix 6 but not know if their systems are within the

urbanized portion of the listed entity, or they are not on the list but want to

confirm their status as recommended above. In such cases, they should

contact one or more of the following institutions for more detailed

information on the location of UA boundaries:

® The State or NPDES Permitting Authority

Storm Water Coordinators: The NPDES permitting authority may be the State or

the U.S. EPA Region. The Storm Water Coordinators for each U.S. EPA Region

are listed in Section 8. These regional contacts can assist with UA information and

provide the names of State storm water contacts. 

State Data Centers: Each State’s Data Center receives listings of all entities that

are located in UAs, as well as detailed maps and electronic files of UA boundaries. 

The Bureau of the Census web site includes a list of contact names and phone

numbers for the Data Center in each State at www.census.gov/sdc/www.

State Planning/Economic/Transportation Agencies: These agencies typically

use UAs to assess current development and forecast future growth trends and,

therefore, should have detailed UA information readily available to help determine

the UA boundaries in any given area.

® County or Regional Planning Commissions/ Boards

As with State agencies, these entities are likely to have detailed UA data and maps

to help determine UA boundaries.

® The Bureau of the Census

Urbanized Areas Staff: 301 457-1099

Web Site: www.census.gov

The site provides information on purchasing UA maps and electronic files for use

with computerized mapping systems. Obtain free UA cartographic boundary files

(Arc/Info export format) for Geographical Information System (GIS) use at:

www.census.gov:80/geo/www/cob/ua.html.

UA Maps: Detailed UA maps are available for purchase with a $25 minimum order

($5 per map sheet). Each map sheet measures 36 by 42 inches. For prices and a

listing of UAs, visit www.census.gov/mp/www/geo/msgeo12.html. Order from the

Department of Commerce, Bureau of the Census (MS 1921), P.O. Box 277943,

Atlanta, GA 30384-7943 (Phone: 301 457-4100; Toll-free fax: 1-888-249-7295).

® U.S. EPA
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EPA is currently modifying a web-based geographic program called Enviromapper

for use in determining UA boundaries. This program will allow users to enter a

location (by name, zip code, or street address) and see a map that will show if the

location is within a UA boundary. EPA is committed to using Enviromapper to

create a tool that, someday, will be the only tool necessary to determine the location

of UA boundaries. Information about Enviromapper will be available at

www.epa.gov/owm/phase2.

4.3.4 How Will the Year 2000 Census Affect the Determination of Status as a

Regulated Small MS4?

The listing of incorporated places, MCDs, and counties located within UAs in the

United States and Puerto Rico, found in Appendix 6, is based on the 1990 Census. 

New listings for UAs based on the 2000 Census are scheduled to be available by

August of 2001. Once the official 2000 Census listings are published by the Bureau of

the Census, operators of small MS4s located within the revised boundaries of former

1990 UAs, or in any newly defined 2000 UAs, become regulated small MS4s and must

develop a storm water management program.

Any additional automatic designations of small MS4s based on subsequent census

years is governed by the Bureau of the Census’ definition of a UA in effect for that year

and the UA boundaries determined as a result of the definition.

Once a small MS4 is designated into the Phase II storm water program based on

the UA boundaries, it can not be waived from the program if in a subsequent UA

calculation the small MS4 is no longer within the UA boundaries. An automatically

designated small MS4 will remain regulated unless, or until, it meets the criteria for a

waiver.

4.4 WAIVERS: Which Regulated Small MS4s May Obtain a Waiver From

Coverage?

Two waiver options are available to operators of regulated small MS4s in urbanized

areas if the NPDES permitting authority determines that their discharges do not cause,

or have the potential to cause, water quality impairment. 

Important Note: The waivers are granted by the NPDES permitting

authority, the operator of the regulated small MS4 can not determine for

itself that it meets the waiver criteria. If the permitting authority is not

proactive in assessing small MS4s for potential waivers, an operator may

petition for a waiver assessment.

If a permitting authority decides to grant waivers, it is required to do so by December

9, 2002 to coincide with the expected date of the small MS4 permit issuance. The 
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TMDLs are water quality assessments that determine the source or sources of

pollutants of concern for a particular waterbody, consider the maximum amount of

pollutants the waterbody can assimilate, and then allocate to each source a set level of

pollutants that it is allowed to discharge (i.e., a “wasteload allocation”). Small MS4s

that are not given a wasteload allocation would meet the third criterion above. 

permitting authority is also required to periodically review any waivers granted to small

MS4 operators to determine whether any information required for granting the waiver

has changed. Minimally, such a review needs to be conducted once every five years. 

The waiver options are described in the following two subsections.

Deadline for Waivers

The NPDES permitting authorities are required to make their waiver determinations

by March 9, 2002 to coincide with the expected issuance of their small MS4 general

permit. If the permit authority chooses to phase in permit coverage based on a

comprehensive watershed plan (see section 4.5.2.2), then regulated small MS4s may

be waived on the same schedule. The phase-in of permit coverage and waivers is to

be completed no later than March 8, 2007. 

4.4.1 Option 1: Less than 1,000 Population in a UA

The first waiver option applies where:

(1) the jurisdiction served by the system is less than 1,000 people;

(2) the system is not contributing substantially to the pollutant loadings of a

physically interconnected regulated MS4; and

(3) if the small MS4 discharges any pollutants identified as a cause of impairment of

any water body to which it discharges, storm water controls are not needed

based on wasteload allocations that are part of an EPA approved or established 

“total maximum daily load” (TMDL) that addresses the pollutant(s) of concern. 

The third criterion of this waiver option need only be met if the small MS4 is discharging

into a impaired water body and the discharge contains a pollutant or pollutants that are

the cause of the impairment (i.e., the "pollutants of concern").

4.4.2 Option 2: Less than 10,000 Population in a UA

The second waiver option applies where:

(1) the jurisdiction served by the system is less than 10,000 people;
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Pollutants of Concern include biochemical oxygen

demand (BOD), sediment or a parameter that addresses

sediment (such as total suspended solids, turbidity or

siltation), pathogens, oil and grease, and any pollutant that

has been identified as a cause of impairment in any water

body to which the MS4 discharges. 

(2) an evaluation of all waters of the U.S. that receive a discharge from the system

shows that storm water controls are not needed based on wasteload allocations

that are part of an EPA approved or established TMDL that addresses the

pollutant(s) of concern or an equivalent analysis; and 

(3) it is determined that future discharges from the small MS4 do not have the

potential to result in exceedances of water quality standards.

This waiver option differs from the first option in that: 1) it applies to a larger jurisdiction

size (up to 10,000 rather than 1,000), 2) it requires a determination that the discharges

are not affecting the receiving water body, whether the water body is impaired or not (in

the first option an assessment is only necessary if the water body is impaired and the

MS4 is discharging a pollutant of concern), 3) the determination must be based on a

TMDL or an equivalent analysis (the first option does not allow for an equivalent

analysis), and 4) an assessment of the impacts of future discharges must be performed

(no such assessment is necessary under the first option). 

4.5 PERMITTING OPTIONS: What Permitting Choices are Available?

The Storm Water Phase II Final Rule requires operators of a particular subset of

small MS4s in urbanized areas to obtain National Pollutant Discharge Elimination

System (NPDES) permit coverage because their storm water discharges are

considered “point sources” of pollution. All point source discharges, unlike nonpoint

sources such as agricultural runoff, are required under the Clean Water Act (CWA) to

be covered by federally enforceable NPDES permits. Those MS4s already permitted

under the NPDES Phase I storm water program, even MS4s serving less than 100,000

people, are not required to be permitted under the Phase II storm water program.

NPDES storm water permits are issued by an NPDES permitting authority, which

may be an NPDES-authorized State or a U.S. EPA Region in non-authorized States. 

Once a permit application is submitted by the operator of a regulated small MS4 and a

permit is obtained, the conditions of the permit must be satisfied (i.e., development and

implementation of a storm water management program) and periodic reports must be

submitted on the status and effectiveness of the program. This section addresses the

flexible permit options the Phase II regulations allow for the regulated small MS4

operator, as well as for the permitting authority. The permit requirements are discussed

in section 4.6.
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4.5.1 For Regulated Small MS4 Operators

4.5.1.1 The Types of Permit Coverage Available

Unlike the Phase I program that requires individual permits for medium and large

MS4s, the Phase II approach allows operators of regulated small MS4s to choose from

as many as three permitting options as listed below. Each NPDES permitting authority

reserves the authority to determine, however, which options are available to the

regulated small MS4s in their jurisdiction. 

1) General Permits

# General permits are strongly encouraged by EPA. The Phase II program has

been designed specifically to accommodate a general permit approach.

# General permits prescribe one set of requirements for all applicable permittees. 

General permits are drafted by the NPDES permitting authority, then published

for public comment before being finalized and issued.

# A Notice of Intent (NOI) serves as the application for the general permit. The

regulated small MS4 operator complies with the permit application requirements

by submitting an NOI to the NPDES permitting authority that describes the storm

water management plan, including best management practices (BMPs) and

measurable goals. The operator has the flexibility to develop an individualized

storm water program that addresses the particular characteristics and needs of

its system, provided the requirements of the general permit are satisfied.

# For general permit coverage, the regulated small MS4 operator must follow the

Phase II permit application requirements (see section 4.6.2).

2) Individual Permits

# Individual permits are required for Phase I medium and large MS4s, but not

recommended by EPA for Phase II program implementation.

# Individual permits prescribe a particular set of requirements for a particular

permittee or a group of co-permittees. Individual permits require the submission

of a more comprehensive permit application than an NOI that is submitted under

a general permit. Once the permit application is received, an individual permit is

drafted by the NPDES permitting authority, then published for public comment

before being finalized and issued.

# The Phase II rule allows a regulated small MS4 to submit an individual

application for coverage under either the:
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 • Phase II MS4 regulation (see § 122.34 of the Phase II rule), or 

• Phase I MS4 regulation (see 40 CFR §122.26(d)).

3) Modification of an Existing Phase I Individual Permit – A Co-Permittee Option

with Medium and Large MS4s

# The operator of a regulated small MS4 could participate as a limited co-permittee

in a neighboring Phase I MS4’s storm water management program by seeking a

modification of the existing Phase I individual permit. As a limited co-permittee

the small MS4 operator would be responsible for compliance with the permit's

conditions applicable to its jurisdiction.

Note: A list of Phase I medium and large MS4s can be obtained from the

EPA Office of Wastewater Management (OWM) or downloaded

from the OWM web site.

# The permittee must comply with the applicable terms of the modified Phase I

individual permit rather than the minimum control measures in the Phase II Final

Rule.

4.5.1.2 Co-permittee with Another Operator of a Regulated Small MS4

Section 4.5.1.1 explained the permitting option of a modification of an existing

Phase I individual permit in order to be a co-permittee with a medium or large MS4. 

Regulated small MS4 operators may also choose to share responsibilities for meeting

the Phase II program requirements with another regulated small MS4 operator under a

general or individual permit. Those operators choosing to do so may submit jointly an

NOI or individual permit application that identifies who will implement which minimum

measures within the area served by the MS4s. 

4.5.1.3 Relying on Another Entity to Satisfy One or More of the Minimum

Control Measures

Under either a general or individual permit, the Phase II small MS4 permittee has

the option of relying on other entities that are already performing one or more of

the minimum control measures to implement the measure(s) on the permittee's behalf. 

This is only allowable where the existing control measure, or component thereof, is at

least as stringent as the Phase II rule requirements (under § 122.34(b)) and the other

entity has agreed to the arrangement. 

For example, a county may already have an illicit discharge detection and

elimination program in place and may allow an operator of a regulated small MS4 within

the county’s jurisdiction to rely on the county program instead of formulating and

implementing a new program. In such a case, the permittee would not need to 
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implement the particular measure, but would still be ultimately responsible for its

effective implementation. For this reason, EPA recommends that the permittee enter

into a legally binding agreement with the other entity. If the permittee chooses to rely

on another entity, they must note this in their permit application and subsequent

reports. 

Note: Also, the other entity does not necessarily need to be a

governmental entity. For example, a permittee could rely on a nonprofit organization that is performing public education efforts on

environmental issues to satisfy the public education and outreach

minimum measure. 

A Phase II permittee also has the option to rely on another entity to satisfy all of the

permittee’s small MS4 permit obligations – but only if the other entity is a governmental

entity permitted under the NPDES storm water program. Should this option be chosen,

the permittee must note this in its NOI, but does not need to file the otherwise required

periodic reports on the status of the program. Again, it is important to note that the

permittee would remain ultimately liable under the small MS4 permit. This option is

particularly beneficial for operators that serve a low population, have limited resources

or legal authority, or are surrounded by an NPDES regulated municipality. For

example, let's assume a college campus or a veteran's hospital are operators of small

MS4s and they are located in the middle of a Phase II regulated city. Negotiating with

the city to implement the storm water management program for them in their

jurisdictions could be a cost-effective and less burdensome option than for each to

implement their own programs.

4.5.2 For the NPDES Permitting Authority

4.5.2.1 Alternative Options for Writing Permit Requirements

Two permitting options tailored to minimize duplication of effort by the regulated

small MS4 permittee can be incorporated into the general or individual permit by the

NPDES permitting authority:

1) Recognizing Another Governmental Entity's Program

The permitting authority can recognize in a small MS4 permit that another

governmental entity is responsible under an NPDES permit for implementing any or all

of the minimum control measures. In such a case, responsibility for implementation of

the measure(s) would rest with the other governmental entity, thereby relieving the

small MS4 permittee of its responsibility to implement that particular measure(s). See

Table 4-1 for examples of both this option and the following option.
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STORM WATER PHASE II RULE SMALL MS4 FLEXIBLE PERMITTING OPTIONS

Referencing a 

QUALIFYING LOCAL PROGRAM (QLP)

RECOGNIZING 

an NPDES-Regulated Entity

RELYING 

on Another Entity

CO-PERMITTEE with

an NPDES-Regulated

Entity

NPDES PERMITTING 

Responsibilities AUTHORITY

• PA assesses local, State, and Tribal NPDES and

non-NPDES programs to determine if theirrequirements are equivalent to one or more PhaseII minimum measures for regulated small MS4s

• PA chooses whether to reference a QLP in small

MS4 permit. Requires permittee to followrequirements of QLP rather than new permitrequirements.

• PA does not need to notify the administrator of the

QLP or obtain permission since referencing theQLP has no bearing/no affect on the administrator.

• PA assesses entities that are, or will

be, performing the equivalent of 1or more of the small MS4 minimummeasures under an NPDES permit.

• PA chooses whether to recognize

such an entity in a small MS4permit.

N/A N/A

SMALL MS4 OPERATOR

Responsibilities

• The operator should already be complying with

any QLP referenced in the permit.

• Compliance with the QLP is considered

compliance with the NPDES permit; thereforeoperator held liable if doesn't comply with the

QLP.

• Operator has no responsibility to

perform the measure(s) that is beingdone by the recognized entity. 

• Not held liable if the other entity

fails to perform the measureeffectively; however, PA may thenrequire the operator to implementthe measure itself.

• Operator chooses, under its own

permit, whether to rely on anotherentity to implement 1 or moreminimum measure on its behalf –can be a non-NPDES regulatedentity.

• Operator notes in NOI or indiv.

permit application that it is relyingon another entity to implement ameasure.

• Remain liable if other entity fails

to perform the measure effectively.

• Operator chooses

whether to be a copermittee with anotherregulated MS4 andsubmits a single NOI orindividual permitapplication

• The operators determine

who will do what andinclude this informationin the permit application

EXAMPLESThe QLP in the small MS4 permit could be a State program that requires MS4 operators to detect & eliminate illicit discharges into their systems. A county doing educational outreach for the whole county under a Phase I NPDES permit could be recognized, thereby relieving all small MS4s in the county from having to have their own educational outreach programs. 1. An environmental group is doing educational outreach on the impacts of storm water runoff. 2. A county is already implementing a construction runoff control program under a Phase I NPDES permit.
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2) Referencing a Qualifying Local Program

The NPDES permitting authority can include conditions in a small MS4 permit that

direct a permittee to follow the requirements of an existing qualifying local program

rather than the requirements of particular minimum control measure(s). A qualifying

local program is defined as a local, State or Tribal municipal storm water program that

imposes requirements that are equivalent to those of the Phase II MS4 minimum

measures (as found in § 122.34(b) of the rule). Unlike in Option 1 above, under this

option the permittee remains responsible for the implementation of the minimum

measure through its compliance with the qualifying local program. 

4.5.2.2. Alternative Option for Permit Coverage: Phase-in Coverage for

Regulated Small MS4s with Populations under 10,000

Permitting authorities may phase-in permit coverage for regulated small MS4s

serving jurisdictions with a population under 10,000 on a schedule consistent with a

State watershed permitting approach. Under this alternative option, the permitting

authority must develop and implement a schedule to phase-in permit coverage for

approximately 20 percent annually of all regulated small MS4s that qualify, completing

the phase-in schedule in no more than five years. In such a case, the regulated small

MS4 operators would be notified by the permitting authority concerning the operator's

deadlines for permit coverage. 

Deadlines for Phase-In 

• Permitting authorities are required to have their phase-in schedule approved by the

USEPA Regional Administrator no later than December 10, 2001.

• Under the phase-in option, all regulated small MS4s are required to have coverage

under an NPDES permit no later than March 8, 2007. 

4.6 REQUIREMENTS: What Requirements Are Regulated Small MS4s

Subject To?

A regulated small MS4 operator is required to submit a permit application and obtain

coverage under a NPDES storm water permit. Under the permit, the operator will be

required to develop and implement a storm water management program that includes

six minimum control measures, evaluation/assessment and reporting efforts, and

recordkeeping, as described herein. This section begins by highlighting the standards

an operator must meet to ensure compliance with the Phase II regulations.

4.6.1 Applicable Standards

A Phase II small MS4 operator must design a storm water management program so

that it:

® Reduces the discharge of pollutants to the “maximum extent practicable”
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(MEP); 

® Protects water quality; and

® Satisfies the appropriate water quality requirements of the Clean Water

Act.

The standard of MEP is the same standard applied to Phase I medium and large

MS4 programs. There is no regulatory definition of MEP in order to allow the permitting

authority and regulated MS4s maximum flexibility in their interpretation of it as

appropriate.

Compliance with the technical standard of MEP requires the successful

implementation of approved BMPs. The Phase II Final Rule considers narrative

effluent limitations that require the implementation of BMPs and the achievement of

measurable goals as the most appropriate form of effluent limitations to achieve the

protection of water quality, rather than requiring that storm water discharges meet

numeric effluent limitations.

EPA intends to issue Phase II NPDES permits consistent with its August 1, 1996,

Interim Permitting Approach policy, which calls for BMPs in first-round storm water

permits and expanded or better tailored BMPs in subsequent permits, where necessary,

to provide for the attainment of water quality standards. In cases where information

exists to develop more specific conditions or limitations to meet water quality standards,

these conditions or limitations should be incorporated into the storm water permit. 

Monitoring is not required under the Phase II Rule, but the NPDES permitting authority

has the discretion to require monitoring if deemed necessary.

4.6.2 Permit Application Requirements

The permit application requirements differ depending on the type of permit chosen. 

The following subsections describe the applicable requirements for each type of permit

option allowable under the Phase II regulation. 

Deadline for Submission of Permit Application

The deadline for submission of each type of permit application is the same – it must

be done no later than March 10, 2003 unless the NPDES permitting authority chooses

to phase-in permit coverage on a watershed basis and establishes other deadlines (see

section 4.5.2.2).

4.6.2.1 General Permit Under Phase II Regulations

Operators of regulated small MS4s are required to submit in their NOI the following

information:
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® Best management practices (BMPs) for each of the six minimum control

measures:

õ Public education and outreach on storm water impacts

ö Public participation/involvement

÷ Illicit discharge detection and elimination

ø Construction site storm water runoff control

Post-construction storm water management in new development/

redevelopment

 Pollution prevention/good housekeeping for municipal operations

® Measurable goals for each minimum control measure (i.e, narrative or

numeric standards used to gauge program effectiveness);

® Estimated months and years in which actions to implement each measure

will be undertaken, including interim milestones and frequency; and

® The person or persons responsible for implementing or coordinating the

storm water program.

The operator of a regulated small MS4 has the flexibility to determine the BMPs and

measurable goals, for each minimum control measure, that are most appropriate for the

system. The chosen BMPs and measurable goals, submitted in the permit application,

become the required storm water management program; however, the NPDES

permitting authority can require changes in the mix of chosen BMPs and measurable

goals if all or some of them are found to be inconsistent with the provisions of the

Phase II Final Rule. Likewise, the permittee can change its mix of BMPs if it

determines that the program is not as effective as it could be. Section 4.6.2 fully

describes the minimum control measures, including sample BMPs and measurable

goals for each, while section 4.6.3 describes the permit requirements concerning

evaluation/assessment and recordkeeping activities. 

4.6.2.2 Individual Permit Under the Phase II Regulation

For individual permit coverage under Phase II, the regulated small MS4 operator

must follow the requirements of 40 CFR § 122.21(f) and the Phase II permit application

requirements as described in section 4.6.2.1 above. The operator must also provide an

estimate of the square mileage served by the system and any additional information

requested by the NPDES permitting authority. A storm sewer map that satisfies the

requirements of § 122.34(b)(3)(i) of the Phase II rule will satisfy the map requirements

of § 122.21(f)(7).

4.6.2.3 Individual Permit Under the Phase I Regulation
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For individual permit coverage under Phase I, the regulated small MS4 operator

must follow the permit application requirements detailed at 40 CFR § 122.26(d). The

operator must submit both Part 1 and Part 2 of the application requirements in

§§ 122.26(d)(1) and (2) by March 10, 2003. The operator would not need to submit the

information required by §§ 122.26(d)(1)(ii) and (d)(2) regarding legal authority unless it

wanted the permitting authority to take that information into account when developing

the individual permit.

4.6.2.4 Modification of an Existing Phase I Individual Permit

Under this permit option, the operator of a regulated small MS4 must follow Phase I

permit application requirements in § 122.26(d), with some exclusions, rather than

Phase II permit application requirements. The operator would not need to follow the

application requirements of §§ 122.26(d)(1)(iii) and (iv) and (d)(2)(iii) – discharge

characterization. The operator may satisfy the requirements in §§ 122.26(d)(1)(v) and

(d)(2)(iv) – identification of a management program – by referring to the Phase I MS4's

storm water management program. 

EPA Recommendations 

In referencing a Phase I's MS4's storm water management program, the operator

should briefly describe how the existing plan will address discharges from the small

MS4 or would need to be supplemented in order to adequately address the small MS4

discharges. The small MS4 operator should explain their role in coordinating storm

water pollutant control activities in their MS4 service area and detail the resources

available to accomplish the plan.

If a small MS4 is considering this option, it should find out when the Phase I MS4's

permit is scheduled for renewal and become thoroughly familiar with the Phase I MS4's

permit conditions. This co-permitting approach will be most successful if both MS4s

have had thorough discussions of their storm water programs and if the small MS4

submits it’s application at the time that the Phase I MS4 is submitting its reapplication.

4.6.2 Program Requirements: The Six Minimum Control Measures

If coverage is obtained under a general permit or an individual permit under the

Phase II regulations, the operator of a regulated small MS4 is required to implement a

storm water management program that includes, at a minimum, the six minimum

control measures described in the following subsections. As you read these

subsections, keep in mind that the operator has a great deal of flexibility in determining

the best management practices they will use to accomplish each measure. The rule

allows the operators to chose the BMPs and measurable goals for each measure as

appropriate for their particular MS4 service area – as long as the chosen BMPs and

measurable goals result in effective control of pollutants in storm water runoff. 

Otherwise, the permitting authority may require changes in the chosen mix of BMPs

and measurable goals to result in a more effective program.
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4.6.2.1 Public Education and Outreach on Storm Water Impacts

Why Is Public Education and Outreach Necessary?

An informed and knowledgeable community is crucial to the success of a storm

water management program since it helps to ensure the following: 

Greater support for the program as the public gains a greater understanding of the

reasons why it is necessary and important. Public support is particularly beneficial

when operators of small MS4s attempt to institute new funding initiatives for the

program or seek volunteers to help implement the program; and

Greater compliance with the program as the public becomes aware of the personal

responsibilities expected of them and others in the community, including the

individual actions they can take to protect or improve the quality of area waters.

What Is Required?

To satisfy this minimum control measure, the operator of a regulated small MS4 must:

® Implement a public education program to distribute educational materials to

the community, or conduct equivalent outreach activities about the impacts

of storm water discharges on local waterbodies and the steps that can be

taken to reduce storm water pollution; and

® Determine the appropriate best management practices (BMPs) and

measurable goals for this minimum control measure. Some program

implementation approaches, BMPs (i.e., the program actions/activities), and

measurable goals are suggested below. 

What Are Some Guidelines for Developing and Implementing This Measure?

Three main action areas are important for successful implementation of a public

education and outreach program:

õ Forming Partnerships

Operators of regulated small MS4s are encouraged to enter into partnerships with

other governmental entities to fulfill this minimum control measure’s requirements. It

is generally more cost-effective to use an existing program, or to develop a new

regional or state-wide education program, than to have numerous operators

developing their own local programs. Operators also are encouraged to seek

assistance from non-governmental organizations (e.g., environmental, civic, and

industrial organizations), since many already have educational materials and

perform outreach activities.
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ö Using Educational Materials and Strategies

Operators of regulated small MS4s may use storm water educational information

provided by their State, Tribe, EPA Region, or environmental, public interest, or

trade organizations instead of developing their own materials. Operators should

strive to make their materials and activities relevant to local situations and issues,

and incorporate a variety of strategies to ensure maximum coverage. Some

examples include:

Brochures or fact sheets for general public and specific audiences;

Recreational guides to educate groups such as golfers, hikers, paddlers, climbers,

fishermen, and campers;

Alternative information sources, such as web sites, bumper stickers, refrigerator

magnets, posters for bus and subway stops, and restaurant placemats;

A library of educational materials for community and school groups;

Volunteer citizen educators to staff a public education task force;

Event participation with educational displays at home shows and community

festivals;

Educational programs for school-age children;

Storm drain stenciling of storm drains with messages such as “Do Not Dump -

Drains Directly to Lake;”

Storm water hotlines for information and for citizen reporting of polluters;

Economic incentives to citizens and businesses (e.g., rebates to homeowners

purchasing mulching lawnmowers or biodegradable lawn products);and

Tributary signage to increase public awareness of local water resources.

÷ Reaching Diverse Audiences

The public education program should use a mix of appropriate local strategies to

address the viewpoints and concerns of a variety of audiences and communities,

including minority and disadvantaged communities, as well as children. Printing

posters and brochures in more than one language or posting large warning signs

(e.g., cautioning against fishing or swimming) near storm sewer outfalls are methods

that can be used to reach audiences less likely to read standard materials. Directing

materials or outreach programs toward specific groups of commercial, industrial,

and institutional entities likely to have significant storm water impacts is also

recommended. For example, information could be provided to restaurants on the

effects of grease clogging storm drains and to auto garages on the effects of

dumping used oil into storm drains.

What Are Appropriate Measurable Goals?
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Measurable goals, which are required for each minimum control measure, are

intended to gauge permit compliance and program effectiveness. The measurable

goals, as well as the BMPs, should reflect the needs and characteristics of the operator

and the area served by its small MS4. Furthermore, they should be chosen using an

integrated approach that fully addresses the requirements and intent of the minimum

control measure. An integrated approach for this minimum measure could include the

following measurable goals:

Target Date Activity

1 year............ Brochures developed (bilingual, if appropriate) and distributed in water

utility bills; a storm water hotline in place; volunteer educators trained.

2 years.......... A web site created school curricula developed; storm drains stenciled.

3 years.......... A certain percentage of restaurants no longer dumping grease and other

pollutants down storm sewer drains.

4 years.......... A certain percentage reduction in litter or animal waste detected in

discharges.

4.6.2.2 Public Participation/Involvement

Why Is Public Participation and Involvement Necessary?

EPA believes that the public can provide valuable input and assistance to a

regulated small MS4's municipal storm water management program and, therefore,

suggests that the public be given opportunities to play an active role in both the

development and implementation of the program. An active and involved community is

crucial to the success of a storm water management program because it allows for:

Broader public support since citizens who participate in the development and

decision making process are partially responsible for the program and, therefore,

may be less likely to raise legal challenges to the program and more likely to take an

active role in its implementation;

Shorter implementation schedules due to fewer obstacles in the form of public

and legal challenges and increased sources in the form of citizen volunteers;

A broader base of expertise and economic benefits since the community can be

a valuable, and free, intellectual resource; and

A conduit to other programs as citizens involved in the storm water program

development process provide important cross-connections and relationships with

other community and government programs. This benefit is particularly valuable

when trying to implement a storm water program on a watershed basis, as

encouraged by EPA.

What Is Required?
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To satisfy this minimum control measure, the operator of a regulated small MS4 must:

® Comply with applicable State, Tribal, and local public notice requirements; and

® Determine the appropriate best management practices (BMPs) and measurable

goals for this minimum control measure. Possible implementation approaches,

BMPs (i.e., the program actions and activities), and measurable goals are

described below. 

What Are Some Guidelines for Developing and Implementing This Measure?

Operators of regulated small MS4s should include the public in developing,

implementing, and reviewing their storm water management programs. The public

participation process should make every effort to reach out and engage all economic

and ethnic groups. EPA recognizes that there are challenges associated with public

involvement. Nevertheless, EPA strongly believes that these challenges can be

addressed through an aggressive and inclusive program. Challenges and example

practices that can help ensure successful participation are discussed below.

Implementation Challenges

The best way to handle common notification and recruitment challenges is to know

the audience and think creatively about how to gain its attention and interest. 

Traditional methods of soliciting public input are not always successful in generating

interest, and subsequent involvement, in all sectors of the community. For example,

municipalities often rely solely on advertising in local newspapers to announce public

meetings and other opportunities for public involvement. Since there may be large

sectors of the population who do not read the local press, the audience reached may be

limited. Therefore, alternative advertising methods should be used whenever possible,

including radio or television spots, postings at bus or subway stops, announcements in

neighborhood newsletters, announcements at civic organization meetings, distribution

of flyers, mass mailings, door-to-door visits, telephone notifications, and multilingual

announcements. These efforts, of course, are tied closely to the efforts for the public

education and outreach minimum control measure.

In addition, advertising and soliciting for help could and should be targeted at

specific population sectors, including ethnic, minority, and low-income communities;

academia and educational institutions; neighborhood and community groups; outdoor

recreation groups; and business and industry. The goal is to involve a diverse crosssection of people who could offer a multitude of concerns, ideas, and connections

during the program development process.

Possible Practices (BMPs)

There are a variety of practices that could be incorporated into a public participation

and involvement program, such as:
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Public meetings/citizen panels allow citizens to discuss various viewpoints and

provide input concerning appropriate storm water management policies and BMPs;

Volunteer water quality monitoring gives citizens first-hand knowledge of the

quality of local water bodies and provides a cost-effective means of collecting water

quality data;

Volunteer educators/speakers who can conduct workshops, encourage public

participation, and staff special events;

Storm drain stenciling is an important and simple activity that concerned citizens,

especially students, can do;

Community clean-ups along local waterways, beaches, and around storm drains;

Citizen watch groups can aid local enforcement authorities in the identification of

polluters; and

“Adopt A Storm Drain” programs encourage individuals or groups to keep storm

drains free of debris and to monitor what is entering local waterways through storm

drains.

What Are Appropriate Measurable Goals?

Measurable goals, which are required for each minimum control measure, are

intended to gauge permit compliance and program effectiveness. The measurable

goals, as well as the BMPs, would greatly depend on the needs and characteristics of

the operator and the area served by its small MS4. Furthermore, they should be

chosen using an integrated approach that fully addresses the requirements and intent

of the minimum control measure. An integrated approach for this minimum measure

could include the following measurable goals:

Target Date Activity

1 year............ Notice of a public meeting in several different print media and bilingual

flyers; citizen panel established; volunteers organized to locate

outfalls/illicit discharges and stencil drains.

2 years.......... Final recommendations of the citizen panel; radio spots promoting

program and participation.

3 years.......... A certain percentage of the community participating in community cleanups.

4 years.......... Citizen watch groups established in a certain percentage of

neighborhoods; outreach to every different population sector completed.

4.6.2.3 Illicit Discharge Detection and Elimination
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Sources of

Illicit Discharges

Sanitary wastewater

Effluent from septic tanks

Car wash wastewaters

Improper oil disposal

Radiator flushing disposal

Laundry wastewaters

Spills from roadway accidents

Improper disposal of auto and

household toxics

Table 4-2

What Is An “Illicit Discharge”?

Federal regulations define an illicit discharge as “...any discharge to an MS4 that is

not composed entirely of storm water...” with some exceptions. These exceptions

include discharges from NPDES-permitted industrial sources and discharges from firefighting activities. Illicit discharges (see Table 4-2) are considered “illicit” because MS4s

are not designed to accept, process, or discharge such non-storm water wastes. It is

important to note that "illicit" does not mean "illegal." Not every illicit discharge is

necessarily a prohibited illegal discharge. 

Why Are Illicit Discharge Detection and Elimination

Efforts Necessary?

Discharges from MS4s often include wastes and

wastewater from non-storm water sources. A study

conducted in 1987 in Sacramento, California, found that

almost one-half of the water discharged from a local MS4

was not directly attributable to precipitation runoff. A

significant portion of these dry weather flows were from

illicit and/or inappropriate discharges and connections to

the MS4.

Illicit discharges enter the system through either direct

connections (e.g., wastewater piping either mistakenly or

deliberately connected to the storm drains) or indirect

connections (e.g., infiltration into the MS4 from cracked

sanitary systems, spills collected by drain outlets, or paint

or used oil dumped directly into a drain). The result is

untreated discharges that contribute high levels of pollutants, including heavy metals,

toxics, oil and grease, solvents, nutrients, viruses, and bacteria to receiving

waterbodies. Pollutant levels from these illicit discharges have been shown in EPA

studies to be high enough to significantly degrade receiving water quality and threaten

aquatic, wildlife, and human health.

What Is Required?

Recognizing the adverse effects illicit discharges can have on receiving waters, the

final rule requires an operator of a regulated small MS4 to develop and implement an

illicit discharge detection and elimination program. This program must include the

following:

® A storm sewer system map, showing the location of all outfalls and the names

and location of all waters of the United States that receive discharges from those

outfalls;
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® Through an ordinance, or other regulatory mechanism, a prohibition (to the

extent allowable under State, Tribal, or local law) on non-storm water discharges

into the MS4, and appropriate enforcement procedures and actions;

® A plan to detect and address non-storm water discharges, including illegal

dumping, into the MS4;

® The education of public employees, businesses, and the general public about

the hazards associated with illegal discharges and improper disposal of waste;

and

® The determination of appropriate best management practices (BMPs) and

measurable goals for this minimum control measure. Some program

implementation approaches, BMPs (i.e., the program actions/activities), and

measurable goals are suggested below. 

Does This Measure Need to Address All Illicit Discharges?

No. The illicit discharge detection and elimination program does not need to

address the following categories of non-storm water discharges or flows unless the

operator of the regulated small MS4 identifies them as significant contributors of

pollutants to its MS4:

® Water line flushing

® Landscape irrigation

® Diverted stream flows

® Rising ground waters

® Uncontaminated ground water

infiltration

® Uncontaminated pumped ground

water

® Discharges from potable water

sources

® Foundation drains

® Air conditioning condensation

® Irrigation water

® Springs

® Water from crawl space pumps

® Footing drains

® Lawn watering

® Individual residential car washing

® Flows from riparian habitats and

wetlands

® Dechlorinated swimming pool

discharges

® Street wash water.

What Are Some Guidelines for Developing and Implementing This Measure?

The objective of the illicit discharge detection and elimination minimum control

measure is to have regulated small MS4 operators gain a thorough awareness of their

systems. This awareness allows them to determine the types and sources of illicit

discharges entering their system, and establish the legal, technical, and educational

means needed to eliminate these discharges. Permittees could meet these objectives 
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in a variety of ways depending on their individual needs and abilities, but some general

guidance for each requirement is provided below.

The Map

The storm sewer system map is meant to demonstrate a basic awareness of the

intake and discharge areas of the system. It is needed to help determine the extent of

discharged dry weather flows, the possible sources of the dry weather flows, and the

particular waterbodies these flows may be affecting. An existing map, such as a

topographical map, on which the location of major pipes and outfalls can be clearly

presented would demonstrate such an awareness. 

EPA recommends collecting all existing information on outfall locations (e.g., review

city records, drainage maps, storm drain maps), and then conducting field surveys to

verify locations. It probably will be necessary to walk (i.e., wade through small receiving

waters or use a boat for larger waters) the streambanks and shorelines for visual

observation. More than one trip may be needed to locate all outfalls.

Legal Prohibition and Enforcement

EPA recognizes that some permittees may have limited authority under State, Tribal

or local law to establish and enforce an ordinance, or other regulatory mechanism,

prohibiting illicit discharges. In such a case, the permittee is encouraged to obtain the

necessary authority, if at all possible. Otherwise, the NPDES permitting authority

assumes responsibility for implementation of this component of the minimum measure,

yet the permittee would remain ultimately responsible for the quality of its MS4

discharge. Model ordinances, including examples of amendments to local codes or

existing ordinances, will be provided in the Phase II storm water guidance for regulated

small MS4s, which is part of EPA’s planned implementation “tool box” for the rule.

The Plan

The plan to detect and address illicit discharges is the central component of this

minimum control measure. The plan is dependant upon several factors, including the

permittee’s available resources, size of staff, and degree and character of its illicit

discharges. EPA envisions a plan similar to the one recommended for use in meeting

Michigan’s general storm water NPDES permit for small MS4s. As guidance only, the

four steps of a recommended plan are outlined below:

õ Locate Problem Areas

EPA recommends that priority areas be identified for detailed screening of the

system based on the likelihood of illicit connections (e.g., areas with older

sanitary sewer lines). Some methods that could be used to locate problem areas

include: public complaints; visual screening; water sampling from manholes and

outfalls during dry weather; and use of infrared and thermal photography.

ö Find the Source

Once a problem area or discharge is found, additional efforts usually would be
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necessary to determine the source of the problem. Some methods that could be

used to find the source of the illicit discharge include: dye-testing buildings in

problem areas; dye- or smoke-testing buildings at the time of sale; tracing the

discharge upstream in the storm sewer; employing a certification program that

shows that buildings have been checked for illicit connections; implementing an

inspection program of existing septic systems; and using video to inspect the

storm sewers.

÷ Remove/Correct Illicit Connections

Once the source is identified, the offending discharger should be notified and

directed to correct the problem. Education efforts and working with the

discharger can be effective in resolving the problem before taking legal action.

ø Document Actions Taken

As a final step, all actions taken under the plan should be documented. Doing

so would illustrate that progress is being made to eliminate illicit connections and

discharges. Documented actions should be included in the required annual

reports and include information such as: the number of outfalls screened; any

complaints received and corrected; the number of discharges and quantities of

flow eliminated; and the number of dye or smoke tests conducted.

Educational Outreach

Outreach to public employees, businesses, property owners, the general

community, and elected officials regarding ways to detect and eliminate illicit discharges

is an integral part of this minimum measure that will help gain support for the

permittee’s storm water program. Suggested educational outreach efforts include: 

• Developing informative brochures, and guidances for specific audiences (e.g., carpet cleaning businesses) and school curricula;

• Designing a program to publicize and facilitate public reporting of illicit

discharges; 

• Coordinating volunteers for locating, and visually inspecting, outfalls or to stencil storm drains; and

• Initiating recycling programs for commonly dumped wastes, such as motor oil, antifreeze, and pesticides.

What Are Appropriate Measurable Goals?

Measurable goals, which are required for each minimum control measure, are

intended to gauge permit compliance and program effectiveness. The measurable

goals, as well as the BMPs, should reflect the needs and characteristics of the operator

and the area served by its small MS4. Furthermore, they should be chosen using an

integrated approach that would fully address the requirements and intent of the

minimum control measure. An integrated approach for this minimum measure could 
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Pollutants

Commonly Discharged

From Construction Sites

Sediment

Solid and sanitary wastes

Phosphorous (fertilizer)

Nitrogen (fertilizer)

Pesticides

Oil and grease

Concrete truck washout

Construction chemicals

Construction debris

Table 4-3

include the following measurable goals:

Target Date Activity

1 year............ Sewer system map completed; recycling program for household

hazardous waste in place.

2 years.......... Ordinance in place; training for public employees completed; a certain

percentage of sources of illicit discharges determined.

3 years.......... A certain percentage of: illicit discharges detected; illicit discharges

eliminated; and households participating in quarterly household

hazardous waste special collection days.

4 years.......... Most illicit discharge sources detected and eliminated.

The educational outreach measurable goals for this minimum control measure could be

combined with the measurable goals for the Public Education and Outreach minimum

control measure.

4.6.2.4 Construction Site Storm Water Runoff Control

Why Is The Control of Construction Site Runoff Necessary?

Polluted storm water runoff from construction sites often flows to MS4s and

ultimately is discharged into local rivers and streams. Of the pollutants listed in Table 4-

3, sediment is usually the main pollutant of concern. Sediment runoff rates from

construction sites are typically 10 to 20 times greater than

those of agricultural lands, and 1,000 to 2,000 times greater

than those of forest lands. During a short period of time,

construction sites can contribute more sediment to streams

than can be deposited naturally during several decades. 

The resulting siltation, and the contribution of other

pollutants from construction sites, can cause physical,

chemical, and biological harm to our nation’s waters. For

example, excess sediment can quickly fill rivers and lakes,

requiring dredging and destroying aquatic habitats. 

What Is Required?

The Phase II Final Rule requires an operator of a

regulated small MS4 to develop, implement, and enforce a

program to reduce pollutants in storm water runoff to their

MS4 from construction activities that result in a land

disturbance of greater than or equal to one acre. The small MS4 operator is required

to:

® Have an ordinance or other regulatory mechanism requiring the implementation

of proper erosion and sediment controls, and controls for other wastes, on

applicable construction sites;
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® Have procedures for site plan review of construction plans that consider potential

water quality impacts;

® Have procedures for site inspection and enforcement of control measures;

® Have sanctions to ensure compliance (established in the ordinance or other

regulatory mechanism);

® Establish procedures for the receipt and consideration of information submitted

by the public; and

® Determine the appropriate best management practices (BMPs) and measurable

goals for this minimum control measure. Suggested BMPs (i.e., the program

actions/activities) and measurable goals are presented below.

What Are Some Guidelines for Developing and Implementing This Measure?

Further explanation and guidance for each component of a regulated small MS4's

construction program is provided below.

Regulatory Mechanism

Through the development of an ordinance or other regulatory mechanism, the small

MS4 operator needs to establish a construction program that requires controls for

polluted runoff from construction sites with a land disturbance of greater than or equal

to one acre. Because there may be limitations on regulatory legal authority, the small

MS4 operator is required to satisfy this minimum control measure only to the maximum

extent practicable and allowable under State, Tribal, or local law. If an operator is

unable to establish an enforceable construction program due to a lack of legal authority,

and is unsuccessful in trying to obtain the necessary authority, the NPDES permitting

authority would then assume responsibility. 

EPA intends to develop a model ordinance that a small MS4 operator could use as

a basis for its construction program. Alternatively, amendments to existing erosion and

sediment control programs, or other ordinances, can also provide the basis for the

program. 

Site Plan Review

The small MS4 operator is required to include in its construction program

requirements for the implementation of appropriate BMPs on construction sites to

control erosion and sediment, as well as waste at the site. To determine if a

construction site is in compliance with such provisions, the small MS4 operator should

review the site plans submitted by the construction site operator before ground is

broken. 
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Site plan review aids in compliance and enforcement efforts since it alerts the small

MS4 operator early in the process to the planned use or non-use of proper BMPs and

provides a way to track new construction activities. The tracking of sites is useful not

only for the small MS4 operator’s recordkeeping and reporting purposes, which will be

required activities under their NPDES storm water permit (see Fact Sheet 2.9), but also

for members of the public interested in ensuring that the sites are in compliance. 

Inspections and Penalties

Once construction commences, the BMPs should be in place and the small MS4

operator’s enforcement activities should begin. To ensure that the BMPs are properly

installed, the small MS4 operator is required to develop procedures for site inspection

and enforcement of control measures to deter infractions. Procedures could include

steps to identify priority sites for inspection and enforcement based on the nature and

extent of the construction activity, topography, and the characteristics of soils and

receiving water quality. Inspections give the MS4 operator an opportunity to provide

additional guidance and education, issue warnings, or assess penalties. To conserve

staff resources, one possible option for small MS4 operators could be to have these

inspections performed by the same inspector that visits the sites to check compliance

with health and safety building codes.

Information Submitted by the Public

A final requirement of the small MS4 program for construction activity is the

development of procedures for the receipt and consideration of public inquiries,

concerns, and information submitted regarding local construction activities. This

provision is intended to further reinforce the public participation component of the

regulated small MS4 storm water program and to recognize the crucial role that the

public can play in identifying instances of noncompliance.

The small MS4 operator is required only to consider the information submitted, and

may not need to follow-up and respond to every complaint or concern. Although some

form of enforcement action or reply is not required, the small MS4 operator is required

to demonstrate acknowledgment and consideration of the information submitted. A

simple tracking process in which submitted public information, both written and verbal,

is recorded and then given to the construction site inspector for possible follow-up

would suffice.

What Are Appropriate Measurable Goals?

Measurable goals, which are required for each minimum control measure, are

intended to gauge permit compliance and program effectiveness. The measurable

goals, as well as the BMPs, should reflect the needs and characteristics of the operator

and the area served by its small MS4. Furthermore, they should be chosen using an

integrated approach that fully addresses the requirements and intent of the minimum

control measure. An integrated approach for this minimum measure could include the

following measurable goals: 
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Target Date Activity

1 year............ Ordinance or other regulatory mechanism in place; procedures for

information submitted by the public in place.

2 years.......... Procedures for site inspections implemented; a certain percentage rate of

compliance achieved by construction operators.

3 years.......... Maximum compliance with ordinance; improved clarity and reduced

sedimentation of local waterbodies.

4 years.......... Increased numbers of sensitive aquatic organisms in local waterbodies.

Am I Correct in Thinking that Construction Sites Are Already Covered Under the

NPDES Storm Water Program?

Yes. EPA’s Phase I NPDES storm water program requires operators of construction

activities that disturb five or more acres to obtain a NPDES construction storm water

permit. General permit requirements include the submission of a Notice of Intent and

the development of a storm water pollution prevention plan (SWPPP). The SWPPP

must include a site description and measures and controls to prevent or minimize

pollutants in storm water discharges. The Phase II Final Rule similarly regulates

discharges from smaller construction sites disturbing equal to or greater than one acre

and less than five acres.

Even though all construction sites that disturb more than one acre are covered

nationally by an NPDES storm water permit, the construction site runoff control

minimum measure for the small MS4 program is needed to induce more localized site

regulation and enforcement efforts, and to enable operators of regulated small MS4s to

more effectively control construction site discharges into their MS4s. 

To aid operators of regulated construction sites in their efforts to comply with both

local requirements and their NPDES permit, the Phase II Final Rule includes a provision

that allows the NPDES permitting authority to reference a “qualifying State, Tribal or

local program” in the NPDES general permit for construction. This means that if a

construction site is located in an area covered by a qualifying local program, then the

construction site operator’s compliance with the local program would constitute

compliance with their NPDES permit. A regulated small MS4's storm water program for

construction could be a “qualifying program” if the MS4 operator requires a SWPPP, in

addition to the requirements summarized in this fact sheet.

The ability to reference other programs in the NPDES permit is intended to reduce

confusion between overlapping and similar requirements, while still providing for both

local and national regulatory coverage of the construction site. The provision allowing

NPDES permitting authorities to reference other programs has no impact on, or direct

relation to, the small MS4 operator’s responsibilities under the construction site runoff

control minimum measure profiled in this fact sheet.
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Is a Small MS4 Operator Required to Regulate Construction Sites that the

Permitting Authority has Waived from the NPDES Construction Program?

No. If the NPDES permitting authority waives requirements for storm water

discharges associated with small construction activity (see § 122.26(b)(15) of the Phase

II rule), the small MS4 operator is not required to develop, implement, and/or enforce a

program to reduce pollutant discharges from such sites. 

4.6.2.5 Post-construction Storm Water Management in New Development/

Redevelopment

Why Is The Control of Post-Construction Runoff Necessary?

Post-construction storm water management in areas undergoing new development

or redevelopment is necessary because runoff from these areas has been shown to

significantly effect receiving waterbodies. Many studies indicate that prior planning and

design for the minimization of pollutants in post-construction storm water discharges is

the most cost-effective approach to storm water quality management.

There are generally two forms of substantial impacts of post-construction runoff. 

The first is caused by an increase in the type and quantity of pollutants in storm water

runoff. As runoff flows over areas altered by development, it picks up harmful sediment

and chemicals such as oil and grease, pesticides, heavy metals, and nutrients (e.g.,

nitrogen and phosphorus). These pollutants often become suspended in runoff and are

carried to receiving waters, such as lakes, ponds, and streams. Once deposited, these

pollutants can enter the food chain through small aquatic life, eventually entering the

tissues of fish and humans. The second kind of post-construction runoff impact occurs

by increasing the quantity of water delivered to the waterbody during storms. Increased

impervious surfaces interrupt the natural cycle of gradual percolation of water through

vegetation and soil. Instead, water is collected from surfaces such as asphalt and

concrete and routed to drainage systems where large volumes of runoff quickly flow to

the nearest receiving water. The effects of this process include streambank scouring

and downstream flooding, which often lead to a loss of aquatic life and damage to

property.

What Is Required?

The Phase II Final Rule requires an operator of a regulated small MS4 to develop,

implement, and enforce a program to reduce pollutants in post-construction runoff to

their MS4 from new development and redevelopment projects that result in the land

disturbance of greater than or equal to 1 acre. The small MS4 operator is required to:

® Develop and implement strategies which include a combination of structural

and/or non-structural best management practices (BMPs);
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® Have an ordinance or other regulatory mechanism requiring the implementation

of post-construction runoff controls to the extent allowable under State, Tribal or

local law; 

® Ensure adequate long-term operation and maintenance of controls;

® Determine the appropriate best management practices (BMPs) and measurable

goals for this minimum control measure.

What Is Considered a “Redevelopment” Project?

The term “redevelopment” refers to alterations of a property that change the

“footprint” of a site or building in such a way that the disturbance of equal to or greater

than 1 acre of land results. The term does not include such activities as exterior

remodeling. Because redevelopment projects may have site constraints not found on

new development sites, the rule provides flexibility for implementing post-construction

controls on redevelopment sites that consider these constraints.

What Are Some Guidelines for Developing and Implementing This Measure?

This section includes some sample non-structural and structural BMPs that could be

used to satisfy the requirements of the post-construction runoff control minimum

measure. It is important to recognize that many BMPs are climate-specific, and not all

BMPs are appropriate in every geographic area. Because the requirements of this

measure are closely tied to the requirements of the construction site runoff control

minimum measure (see Fact Sheet 2.6), EPA recommends that small MS4 operators

develop and implement these two measures in tandem. Sample BMPs follow. 

® Non-Structural BMPs

• Planning and Procedures. Runoff problems can be addressed efficiently with

sound planning procedures. Master Plans, Comprehensive Plans, and zoning

ordinances can promote improved water quality by guiding the growth of a

community away from sensitive areas and by restricting certain types of growth

(industrial, for example) to areas that can support it without compromising water

quality.

• Site-Based Local Controls. These controls can include buffer strip and riparian

zone preservation, minimization of disturbance and imperviousness, and

maximization of open space.

® Structural BMPs

• Storage Practices. Storage or detention BMPs control storm water by gathering

runoff in wet ponds, dry basins, or multichamber catch basins and slowly
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releasing it to receiving waters or drainage systems. These practices both

control storm water volume and settle out particulates for pollutant removal.

• Infiltration Practices. Infiltration BMPs are designed to facilitate the percolation

of runoff through the soil to ground water, and, thereby, result in reduced storm

water quantity and reduced mobilization of pollutants. Examples include

infiltration basins/trenches, dry wells, and porous pavement.

• Vegetative Practices. Vegetative BMPs are landscaping features that, with

optimal design and good soil conditions, enhance pollutant removal,

maintain/improve natural site hydrology, promote healthier habitats, and increase

aesthetic appeal. Examples include grassy swales, filter strips, artificial

wetlands, and rain gardens.

What Are Appropriate Measurable Goals?

Measurable goals, which are required for each minimum control measure, are

intended to gauge permit compliance and program effectiveness. The measurable

goals, as well as the BMPs, should reflect needs and characteristics of the operator and

the area served by its small MS4. Furthermore, the measurable goals should be

chosen using an integrated approach that fully addresses the requirements and intent

of the minimum control measure. An integrated approach for this minimum measure

could include the following goals:

Target Date Activity

1 year............ Strategies developed that include structural and/or non-structural

BMPs.

2 years.......... Strategies codified by use of ordinance or other regulatory mechanism.

3 years.......... Reduced percent of new impervious surfaces associated with new

development projects.

4 years.......... Improved clarity and reduced sedimentation of local waterbodies.

4.6.2.6 Pollution Prevention/Good Housekeeping for Municipal Operations

Why Is Pollution Prevention/Good Housekeeping Necessary?

The Pollution Prevention/Good Housekeeping for municipal operations minimum

control measure is a key element of the small MS4 storm water management program. 

This measure requires the small MS4 operator to examine and subsequently alter own

actions to help ensure a reduction in the amount and type of pollution that (1) collects

on streets, parking lots, open spaces, and storage and vehicle maintenance areas and

is discharged into local waterways; and (2) results from actions such as environmentally

damaging land development and flood management practices or poor maintenance of

storm sewer systems.
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While this measure is meant primarily to accomplish the goal of improving or

protecting the quality of receiving waters by altering the performance of municipal or

facility operations, it also can result in a cost savings for the small MS4 operator, since

proper and timely maintenance of storm sewer systems can help avoid repair costs

from damage caused by age and neglect.

What Is Required?

Recognizing the benefits of pollution prevention practices, the rule requires an

operator of a regulated small MS4 to:

® Develop and implement an operation and maintenance program with the ultimate

goal of preventing or reducing pollutant runoff from municipal operations into the

storm sewer system;

® Include employee training on how to incorporate pollution prevention/good

housekeeping techniques into municipal operations such as park and open

space maintenance, fleet and building maintenance, new construction and land

disturbances, and storm water system maintenance. To minimize duplication of

effort and conserve resources, the MS4 operator could use training materials

that are available from EPA, their State or Tribe, or relevant organizations;

® Determine the appropriate best management practices (BMPs) and measurable

goals for this minimum control measure. Some program implementation

approaches, BMPs (i.e., the program actions/activities), and measurable goals

are suggested below.

What Are Some Guidelines for Developing and Implementing This Measure?

The intent of this control measure is to ensure that existing municipal, State or

Federal operations are performed in ways that will minimize contamination of storm

water discharges. EPA encourages the small MS4 operator to consider the following

components when developing their program for this measure:

Maintenance activities, maintenance schedules, and long-term inspection

procedures for structural and non-structural controls to reduce floatables and

other pollutants discharged from the separate storm sewers;

Controls for reducing or eliminating the discharge of pollutants from areas

such as roads and parking lots, maintenance and storage yards (including

salt/sand storage and snow disposal areas), and waste transfer stations. These

controls could include programs that promote recycling (to reduce litter),

minimize pesticide use, and ensure the proper disposal of animal waste;

Procedures for the proper disposal of waste removed from the separate 
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storm sewer systems and the areas listed in the bullet above, including dredge

spoil, accumulated sediments, floatables, and other debris; and

Ways to ensure that new flood management projects assess the impacts

on water quality and examine existing projects for incorporation of additional

water quality protection devices or practices. EPA encourages coordination with

flood control managers for the purpose of identifying and addressing

environmental impacts from such projects.

The effective performance of this control measure hinges on the proper

maintenance of the BMPs used, particularly for the first two bullets above. For

example, structural controls, such as grates on outfalls to capture floatables, typically

need regular cleaning, while non-structural controls, such as training materials and

recycling programs, need periodic updating.

What Are Appropriate Measurable Goals?

Measurable goals, which are required for each minimum control measure, are

meant to gauge permit compliance and program effectiveness. The measurable goals,

as well as the BMPs, should consider the needs and characteristics of the operator and

the area served by its small MS4. The measurable goals should be chosen using an

integrated approach that fully addresses the requirements and intent of the minimum

control measure. An integrated approach for this minimum measure could include the

following measurable goals:

Target Date Activity

1 year............ Pollution prevention plan (the new BMPs and revised procedures)

completed; employee training materials gathered or developed;

procedures in place for catch basin cleaning after each storm and

regular street sweeping.

2 years.......... Training for appropriate employees completed; recycling program fully

implemented.

3 years.......... Some pollution prevention BMPs incorporated into master plan; a certain

percentage reduction in pesticide and sand/salt use; maintenance

schedule for BMPs established.

4 years.......... A certain percentage reduction in floatables discharged; a certain

compliance rate with maintenance schedules for BMPs; controls in place

for all areas of concern.

4.6.3 Program Requirements: Evaluation/Assessment & Reporting

If coverage is obtained under a general permit or an individual permit under the

Phase II regulations, the operator of a regulated small MS4 is required to comply with

the evaluation/assessment and reporting requirements summarized in this section.
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Frequency of Reports

Reports must be submitted annually during the first permit term – permit terms are

typically a 5-year period. For subsequent permit terms, reports must be submitted in

years 2 and 4 only, unless the NPDES permitting authority requests more frequent

reports. Reports do not need to be submitted if the operator of the regulated small MS4

is relying on another entity to satisfy all permit obligations (see section 4.5.1.3)

Required Report Content

The reports must include the following:

® The status of compliance with permit conditions, including an assessment

of the appropriateness of the selected BMPs and progress toward achieving

the selected measurable goals for each minimum measure;

® Results of any information collected and analyzed, including monitoring

data, if any; 

® A summary of the storm water activities planned for the next reporting cycle;

® A change in any identified best management practices or measurable goals

for any minimum measure; and

® Notice of relying on another governmental entity to satisfy some of the

permit obligations (if applicable – see section 4.5.1.3 ).

A Change in Selected BMPs

If, upon evaluation of the program, improved controls are identified as necessary,

permittees should revise their mix of BMPs to provide for a more effective program. 

Such a change, and an explanation of the change, must be noted in a report to the

NPDES permitting authority.

Recordkeeping Requirements

Records required by the NPDES permitting authority must be kept for at least 3

years and made accessible to the public at reasonable times during regular business

hours. Records need not be submitted to the NPDES permitting authority unless the

permittee is requested to do so.

4.7 SMALL MS4 PROGRAM COMPLIANCE PROCESS: What Do I Need to

Do To Comply?

Sections 4.1 through 4.6 of this guidance have provided a details on who's covered and

what's required under the Phase II regulations for regulated small MS4s. Now that you

are familiar with the Phase II program, this section walks you through the process, from

beginning to end, that an operator of a regulated small should take to comply with the

regulation. This step-by-step "walk-through" references the appropriate sections of the 
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guidance along the way as a means for understanding how the information in sections

4.1 through 4.6 fits together.

The last page of this section includes a permitting decision tree to help operators of

MS4s determine if they need an NPDES storm water permit. By starting in the upper

left hand corner, an operator can follow the decision tree to determine if they fall under

Phase I or Phase II, and if they are eligible for a waiver.

Step 1: Determine if you are an operator of an MS4 (see section 4.1.1).

Step 2: As an operator of an MS4, determine if you are an operator of a small MS4

(see section 4.1.4).

Step 3: As an operator of a small MS4, determine if you are an operator of a

regulated small MS4 (see section 4.2). You need to find out if you are:

A. Automatically designated by the rule 

 • First, determine if your system is located partially or fully within an

urbanized area (See section 4.3), 

 • Second, determine if you may qualify for a waiver (waivers are at the

discretion of the permitting authority). If you qualify for a waiver, stop

here. (See section 4.4)

B. Potentially designated by the NPDES permitting authority

 • Determine if your system, located outside of a UA, may fit the criteria

for potential designation. Since designations are at the discretion of

the permitting authority, a final determination is made by the permitting

authority and not the small MS4 operator. If designated, continue with

Step 4.

Step 4: Read Phase II Rule and guidance materials to get a sense of the permitting

options (see section 4.5 ) and program requirements (see section 4.6 ).

Step 5: Determine which neighbors are regulated as Phase I MS4s (refer to list on

the EPA web site) or Phase II MS4s (refer to Appendix 6 and maps of your

UA). This information will be used to base your decision as to whether to:

• Be a co-permittee with another regulated MS4. (See section 4.5.1.2 )

• Rely on another regulated MS4 for partial or full implementation of the

minimum measures on your behalf. (See section 4.5.1.3 )

Step 6: Determine if programs similar to one or more of the minimum measures is

already being performed by another entity. This information will be used to

decide whether you wish to rely on another entity for partial implementation

of the minimum measures on your behalf. (See section 4.5.1.3 )
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Step 7: Determine which permit option to choose (depends on which are made

available by the your NPDES permitting authority) (See section 4.5.1)

• General permit under the Phase II regulation 

• Individual permit under the Phase I or Phase II regulation

• Modification of a Phase I individual permit (Co-permittee with a large or

medium MS4)

In determine which option to choose, think about...

— If you wish to be a co-permittee and share responsibilities based on

information from Step 5

— If, instead of the co-permittee option, you wish to have own permit but

rely on another entity for implementing a measure or measures based

on information from Steps 5 & 6.

Step 8: Begin planning and development of your storm water management program

• Use menu of BMPs as a guide (provided by EPA or the permitting

authority). The EPA web site will also have references and links to

helpful guidance on every facet of a storm water management program

for MS4s.

• Meet with staff who will be responsible for implementing the storm water

management program (may be a multi-departmental team). Task them

with:

— Assessing the storm water management characteristics and needs

of the area served by the regulated small MS4.

— Determining appropriate BMPs and measurable goals

— Determining who will be responsible for what under the program

• Form a citizen advisory panel to help develop the program and give them

similar tasks as those given to the staff. 

• Meet with local Phase I and Phase II MS4 operators to discuss copermittee status or sharing of resources, such as: hiring one enforcement

inspector for multiple areas, co-sponsoring household hazardous waste

collection events, or sharing a street sweeper, recycling truck, illicit

discharge detection cameras, or any other equipment. (Note: Nothing

listed here is required by the Phase II rule -- they are only examples)

• Meet with other entities that you may rely on to implement one or more of

the minimum measures to discuss the arrangement and any legal

agreements.

Step 9: A. Under a General Permit:

1) Once a general permit is issued, read it carefully. You may not be
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required to implement every minimum measure due to the permitting

authority recognizing or referencing other similar programs (see section

4.5.2.1). For this reason, before the permit is issued (which is expected

to be no later than December 9, 2002) follow Step 8 but only do a

preliminary storm water management program until the final permit

requirements are know. Once the permit is issued, if you have chosen

this option you will need to make final decisions on the following issues

and complete the development of your storm water management plan:

• Do you want to be a co-permittee with another regulated small

MS4?

• Do you want to rely on another entity for some or all of the permit

requirements?

• Which BMPs and measurable goals will you use for each minimum

measure you will be implementing?

2) Fill out an NOI in accordance with the Phase II regulation. (See

section 4.6.2.1) 

B. Under an Individual Permit (new or modified):

If you have chosen one of the individual permit options (i.e., under Phase II,

under Phase I, or modified existing Phase I), you will need to continue

efforts in Step 8, as applicable, and complete development of your permit

application in accordance with the Phase II regulation. (See sections 4.6.2.2

through 4.6.2.4) 

Step 10: Submit your NOI under a general permit or your individual permit

application to the NPDES permitting authority by March 10, 2003; unless

your NPDES permitting authority phases-in permit coverage and

establishes alternative deadlines (see section 4.5.2.2).

Step 11: Implement your storm water management program in accordance with

applicable standards (see section 4.6.1). The Phase II rule allows you up

to five years to fully implement your program, although the exact timeframe

is at the discretion of the your NPDES permitting authority. 

Step 12: Write annual reports in your first permit term assessing the effectiveness of

BMPs and if measurable goals were met, and submit the reports to your

NPDES permitting authority. You may change the mix of BMPs originally

selected if you find that such a change is necessary to ensure a more

effective program. This step, as required in the Phase II regulations at

§ 122.34(g) and described in section 4.6.3, is not applicable if you sought

coverage under an individual permit under the Phase I regulations or under

a modification of an existing Phase I MS4 permit.
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Step 13: Be aware that you may need to take over implementation of a minimum

control measure if you are relying on another entity for its implementation

and the other entity fails to perform it effectively. This is why EPA

encourages a legally-binding agreement when choosing to rely on another

entity. Also, the permitting authority may chose to change your mix of

BMPs and measurable goals as submitted in you permit application if it

determines that your program is not effectively controlling pollutant

discharges. 

4.8 FEDERAL AND STATE-OPERATED REGULATED SMALL MS4S: Unique

Program Implementation Issues

In addition to local government jurisdictions, small MS4s include certain Federal and

State-operated MS4s. Federal facilities were not designated for regulation by the

NPDES Phase I storm water program for MS4s. The Phase II Final Rule, however,

includes the “United States” in the definition of a small MS4, thereby including Federal

MS4 operators in the NPDES Phase II storm water program. Federal and Stateoperated small MS4s can include universities, prisons, hospitals, roads (i.e.,

departments of transportation), military bases (e.g., State Army National Guard

barracks), parks, and office buildings/complexes. 

The small MS4 program, largely designed with municipally-operated small MS4s in

mind, raises a number of implementation issues for Federal and State operators of

regulated small MS4s who must obtain an NPDES permit that requires the development

and implementation of a storm water management program that includes the six

minimum control measures. This section highlights potential implementation issues

related to the minimum control measures, and then discusses the implementation

options included in the rule that may help resolve these issues.

4.8.1 What Are Some Implementation Concerns?

This section profiles the three most common implementation issues raised in the

public comments submitted regarding Federal/State implementation of the small MS4

program.

How Does the Final Rule Account for Unique Characteristics?

Federal and State small MS4s possess a number of characteristics that set them

apart from their municipal counterparts. For example, whereas municipally-operated

MS4s largely serve resident populations, many Federal or State-operated MS4s, such

as medical clinics and departments of transportation (DOTs), do not. Other types of

Federal and State MS4s, such as military bases, prisons, and State universities, serve

populations that are different from a typical municipal population. Their unique

characteristics might lead Federal or State MS4 operators to question either the need

to implement the entire suite of minimum control measures or their ability to comply fully

with their Phase II storm water permit. The flexibility within the minimum measures

allows Federal and State MS4s to develop a storm water program that comprises the 
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minimum measures in a way that makes sense for their circumstances. 

What If the Operator Lacks Legal Authority?

Three of the minimum control measures (illicit discharge detection and elimination,

and the two construction-related measures) require enforceable controls on third party

activities to ensure successful implementation of the measure. Some Federal and

State operators, however, may not have the necessary legal regulatory authority to

adopt these enforceable controls in the same manner as do local governments.

For example, a State DOT that is responsible for the portions of its roads running

through urbanized areas may not have the legal authority to impose restrictions on, and

penalties against, illicit (i.e., non-storm water) discharges into its MS4 if the source of

the discharge is outside the DOT’s right-of-way or jurisdiction. As in the case of local

governments that lack such authority, State and Federal MS4s are expected to utilize

the authority they do possess and to seek cooperative arrangements. 

How Can the Program Be Implemented in Areas Where There Are Multiple

Regulated Entities?

Since the final rule provides automatic coverage of all small MS4s within an

urbanized area, regardless of political boundaries, coverage of multiple governments

and agencies in a single area is likely. For example, a city government that operates a

small MS4 within an urbanized area must obtain permit coverage alongside the county,

State, and Federal DOTs if they all operate a portion of the roads (i.e., MS4s) in the

city. All four entities are responsible for developing a storm water management

program for their MS4s (or portions thereof) within the urbanized area. EPA

encourages State and Federal small MS4 operators to establish cooperative

agreements with cities and counties in implementing their storm water programs.

4.8.2 Are There Implementation Strategies that Help Facilitate Program

Implementation?

This section offers two hypothetical strategies for resolving the implementation

issues raised above. The best solution may include a creative combination of

strategies.

STRATEGY #1

A Focus on Choosing Appropriate BMPs

The final rule requires the permittee to choose appropriate best management

practices (BMPs) for each minimum control measure. In other words, EPA expects

Phase II permittees to tailor their storm water management plans and their BMPs to fit

the particular characteristics and needs of the permittee and the area served by its

MS4. Therefore, the Federal or State operator of a regulated storm sewer system can

take advantage of the flexibility provided by the rule to utilize the most suitable minimum

control measures for its MS4. Below is an example of tailored activities and BMPs that 
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Federal or State operators can implement for each measure:

® Public Education and Outreach. Distribute brochures and post fliers to

educate employees of a Federal hospital about the problems associated with

storm water runoff and the steps they can take to reduce pollutants in storm

water discharges. For example, employees could be advised against carelessly

discarding trash on the ground or allowing their cars to leak oil/fluids in the

parking lot.

® Public Participation/Involvement. Provide notice of storm water management

plan development and hold meetings at which employees of a Federal office

complex are encouraged to voice their ideas and opinions about the effort. 

Request volunteers to help develop the plan.

® Illicit Discharge Detection and Elimination. Develop a map of the storm

sewer system on a military base. Perform visual dry weather monitoring of any

outfalls to determine whether the storm sewer system is receiving any non-storm

water discharges from the base. If a dry weather flow is found, trace it back to

the source and stop the discharge. Should a Federal military base identify an

illicit discharge, the source of which is traced to the boundary of its system, the

Federal operator should refer the discharge to the adjoining regulated MS4 for

further action. 

® Construction Site Runoff Control. Require the implementation of erosion and

sediment controls, and control of waste, for any Federal or State DOT road

construction. The DOT would review site plans for proper controls, perform

inspections, and establish penalties in the construction contract if controls are

not implemented. If construction is done directly by the regulated DOT instead

of a private contractor, the DOT could be penalized by the NPDES permitting

authority for non-compliance with its small MS4 permit in the event that controls

are not properly implemented.

® Post-Construction Runoff Control. Require the implementation of postconstruction storm water controls for any new construction on the grounds of a

prison. This can be required as part of a construction contract, instituted as

internal policy, and considered during site plan review.

® Pollution Prevention/Good Housekeeping for Municipal Operations. Train

maintenance staff at a State university to employ pollution prevention techniques

whenever possible. For example, routinely pick up trash/litter from the university

grounds, use less salt on the parking lots and access roads in the winter,

perform any maintenance of university vehicles under shelter only, limit pesticide

use to the minimum needed, use vegetative buffer strips in the parking lots to

filter runoff, and keep dumpster lids closed.
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STRATEGY #2

Working with Other Entities

There may be instances when the Federal or State permittee has limited capabilities

to satisfy one or more of the minimum control measures. As discussed above, the

permittee may lack the proper legal authority to enforce controls (although it should try

to obtain the necessary legal authority if at all possible).

In the case of limited capabilities, the permittee can work with neighboring operators

of regulated small MS4s, preferably on a watershed basis, to form a shared storm water

management program in which each permittee is responsible for activities that are

within individual legal authorities and abilities. The final rule allows the permittee to rely

on other entities, with their permission, to implement those minimum measures that the

permittee is otherwise unable to implement. Three examples are:

® A State DOT with limited regulatory legal authority can reference a local sewer

district’s illicit detection and elimination program in its permit application,

provided the program sufficiently addresses illicit discharges into the DOT’s

storm sewer system.

® The permittee or NPDES permitting authority can reference such programs as

coastal nonpoint pollution control programs, State or local watershed programs,

State or local construction programs, and environmental education efforts by

public or private entities.

® The permittee can become a co-permittee with a neighboring Phase I MS4

through a modification of the Phase I MS4's individual permit. This may be the

most logical and preferable option for those Federal and State entities located in

close proximity to Phase I MS4s. 

Choosing to work with other governmental entities as a co-permittee, or referencing

parts of each other’s plans, can help resolve issues that may arise where multiple

regulated jurisdictions exist in the same area. Permittees can avoid duplicative efforts,

as well as territorial or regulatory disputes, by working together to implement the storm

water program.

Suggested Steps for Working with Other Entities

(1) Identify the boundaries of the urbanized area.

(2) Identify the operators of storm sewer systems or portions of the systems within the

urbanized area such as local, State, Tribal or Federal governments or other entities.

(3) In seeking permit coverage:
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Identify where another entity's program may satisfy one or more

minimum control measure. If a program has requirements that are

equivalent to a minimum control measure’s required elements, the

operator of the regulated small MS4 may reference the program in its

permit application, provided the other entity gives it permission to do

so. While such an arrangement relieves the operator from

performing the minimum measure itself, the operator remains

ultimately responsible for the measure’s effective implementation.

OR

Team with an operator of a Phase I MS4 and become a co-permittee

on its existing Phase I individual permit.

4.9 FUNDING OPTIONS

Possibly the biggest challenge for an operator of a regulated small MS4 in

implementing a storm water management program is finding funding for the program. 

Funding is needed to maintain the staff, equipment and materials necessary to develop

and implement an effective program. Adequate funding is critical to the success of the

program but attaining it can be difficult as many other important programs compete for

the same limited revenues from a general fund. Therefore, the operator of a regulated

small MS4 will need to consider alternative funding options. This section provides brief

introductions to some of the various funding options currently in use across the country. 

The following information on funding options was written by the American Public Works

Association (AWPA) as part of their Storm Water Phase II workshops: 

Debt Financing: Typically used for capital-intensive projects, local governments

can issue debt to finance storm water management programs

and facilities. Revenue bonds - or bonds that rely on ongoing

source of revenue may be used. Alternatively, a general

obligation bond can be issued which are backed by the full faith

and credit of your municipality (based on your ability to generate

revenues though taxes and other fees).

Grants and Loans: Federal, State, or Regional grant or loan funds may be available

for some elements of the storm water program, depending on

the BMP’s selected and the location. Grants and loans are

usually applicable to specific projects and not on-going

activities, such as operation and maintenance.

Users /Utility Fees: Utility services charges are rates billed to customers for

providing storm water management services. The service

charges may be flat rates, or variable rates based on classes of
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customers. Utility service charges may represent a dedicated

source of funding and an ongoing method of funding some or all

storm water management programs. 

Special Assessment: Properties can be assessed annually to fund storm water

management programs. Often, special assessments are used

to fund a special district or authority that can implement all or

portions of a region’s storm water management program. 

Local Improvement Under this type of funding system, individual properties

benefitted by storm water projects are assessed to fund the

project. Some states require special enabling legislation to

establish this type of special benefits district.

General Fund: General fund monies are used for may storm water programs. 

If storm water programs are funded from your General Fund,

the programs are at risk in each budget cycle. In addition, in

order to increase funding levels for your program, other local

government services may be affected or a general tax increase

may be required.

Inspection Fees: Plan review and inspection fees allows the community to

recover some or all of the direct cost associated with performing

design reviews for pre and post construction BMP’s.

Developer Fees: The developers construct needed facilities as a condition of

development and bear associated costs.

Alternative Fees: Instead of constructing on-site facilities to meet development

requirements, developers may be given the option of paying a

comparable fee to be used by the local government to build

regional facilities that are designed to meet the same objectives

as the developer-constructed on-site mitigation.

Connection Fees: A one time charge assessed at the time of development to

recover a proportionate share of the cost of existing facilities

and planned future facilities. The applicability depends upon

legislation in each state.

Additional Resources

• Storm Water Utilities: Innovative Financing for Storm Water Management. 1992.

U.S. EPA, Office of Policy, Planning, and Evaluation. Washington, D.C. 

• State and Local Funding of Nonpoint Source Control Programs. 1992. U.S. EPA,

Office of Water, Assessment and Watershed Protection Division. Washington, D.C. 

• Storm Water Management Utility Implementation Manual. South Carolina Land

Resources Commission, Columbia, S.C.
 4.0 Regulated Small MS4s

Page 4-48 Storm Water Phase II Compliance Assistance Guide

• Storm Water Maintenance and Financing Options (draft). 1987. State of Maryland,

Maryland Department of Natural Resources. 
 4.0 Regulated Small MS4s

Page 4-49 Storm Water Phase II Compliance Assistance Guide

MS4 Storm Water Program

Permitting Decision Tree

What is the

population of the

incorporated place or

county (unincorporated

area)?

100,000 to 249,999 250,000 or greater

The MS4 is a medium

MS4 and is required to

obtain an NPDES

storm water discharge

permit under Phase I

(deadline passed).

The MS4 is a large MS4

and is required to obtain

an NPDES storm water

discharge permit under

Phase I (deadline

passed).

Has the MS4 been

individually designated into

the NPDES Storm Water

Program by the NPDES

permitting authority prior to

Phase II?

An NPDES

storm water

discharge

permit is

required.

Is the MS4

located within an

"urbanized area"

boundary as delineated

by the Bureau of the

Census?

Does the

MS4 serve a juridiction

with a population of at least

10,000 and a population density

of at least 1,000/sq.

mile?

Does the MS4

serve a population

less than or equal

to 1,000?

Does the MS4 serve a

population less than 10,000?

The MS4 is a

small MS4 that is

not required to

obtain an NPDES

storm water

discharge permit.

The MS4 is a small MS4

required to be evaluated by the

NPDES permitting authority

and, therefore, has the

potential to be designated into

the NPDES Storm Water

Program. If designated, the

small MS4 becomes a

regulated small MS4 and is

required to obtain an NPDES

storm water discharge permit

under Phase II by March 10,

2003. See new Sections

123.35(b)(3) and (b)(4).

The MS4 is a regulated small

MS4 and is required to

obtain an NPDES storm

water discharge permit under

Phase II by March 10, 2003.

The MS4 is a regulated

small MS4 that may

potentially be waived

from the permitting

requirements by the

NPDES permitting

authority. See new

122.32(d) for the specific

waiver criteria.

The MS4 is a regulated

small MS4 that may

potentially be waived

from the permitting

requirements by the

NPDES permitting

authority. See new

122.32(e) for the specific

waiver criteria.

Yes

Yes Yes

Yes

Yes

No

No

No

No

No

1. See Appendices F, G, H, and I to Part 122 (as revised by the Phase II Final Rule) for the list of incorporated places and counties (unincorporated areas) with

a population of 100,000 or greater. If the MS4 is located in a listed entity, then the answer to this question is "Yes" and the MS4 is covered under the Phase I

MS4 program as a medium or large MS4.

Is

the MS4

located in an

incorporated place or county

(unincorporated area) with a

population

of 100,000 or

more?

No

Yes
5.0 Small Construction Activity

Page 5-1 Storm Water Phase II Compliance Assistance Guide

5.0 SMALL CONSTRUCTION ACTIVITY

 5.1 COVERAGE: Who Is Subject to the Phase II Rule?

The NPDES Storm Water Program defines construction activities as "small" and

"large" for the purposes of regulation. The Phase I storm water program covers large

construction activity. The Phase II storm water regulation covers small construction

activity. To understand who is covered under the Phase II Rule, it is necessary to

understand who is already covered under the Phase I Rule. Toward this end, this

section provides a definition of the type of construction activity covered by Phase I and

Phase II, as well as other definitions essential to understanding the construction

component of the NPDES Storm Water Program.

5.1.1 What Type of Construction Activity Is Covered Under the Phase I

Regulations?

The Phase I Rule identifies eleven

categories of industrial activity in the

definition of "storm water discharge

associated with industrial activity” that

must obtain an NPDES storm water

discharge permit ( see section 6.1). 

Category (x) of this definition includes

construction activity (including clearing,

grading and excavation) that results in a

total land disturbance of 5 acres or

greater. Disturbances of less than 5

acres are also regulated under category

(x) if they are part of a "larger common

plan of development or sale" with a

planned land disturbance of 5 acres or

greater. Phase I construction activity is

commonly referred to as "large"

After reading Section 5.0, you should understand what type of construction

activity is subject to the Phase II small construction activity regulations

(including who may be waived from coverage), who is considered an

operator of small construction activity, the permit options and requirements

for small construction activity, and the interaction of the NPDES storm

water program for construction with the NPDES storm water program for

regulated MS4s. The discussion of these elements concludes with a stepby-step review of the process for compliance with the Phase II regulations

for small construction activity.

Construction activities can include road

building, construction of residential houses,

office buildings, industrial sites, or demolition. 

Land Disturbance means exposed soil due to

clearing, grading, or excavation activities. 

Larger common plan of development or sale

describes a situation in which multiple

construction activities are occurring, or will

occur, on a contiguous area. 

An operator is the person or persons that has

either operational control of construction

project plans and specifications, or day-to-day

operational control of activities necessary to

ensure compliance with storm water permit

conditions.
5.0 Small Construction Activity

Page 5-2 Storm Water Phase II Compliance Assistance Guide

construction activity. The Phase I rule requires all operators of large construction

activity to obtain an NPDES storm water discharge permit before discharging storm

water runoff to a municipal separate storm sewer system or waters of the United States.

5.1.2 What Type of Construction Activity Is Covered Under the Phase II

Regulations?

In 1992, the Ninth Circuit court remanded for further proceedings the portion of

EPA’s Phase I storm water regulation related to category (x) construction activity

(NRDC v. EPA, 966 F.2d at 1292). EPA responded to the court’s decision by

designating under Phase II storm water discharges from construction site activities that

ultimately will result in a land disturbance of equal to or greater than 1 and less

than 5 acres as “storm water discharges associated with small construction activity"

(see § 122.26(b)(15)). The Phase II rule requires all operators of small construction

activity to obtain an NPDES storm water discharge permit before discharging storm

water runoff to a municipal separate storm sewer system or waters of the United States.

Construction activities disturbing less than 1 acre are also included in Phase II of the

NPDES storm water program if they are part of a larger common plan of development

or sale with a planned disturbance of equal to or greater than 1 acre and less than 5

acres, or if they are designated by the NPDES permitting authority. The NPDES

permitting authority or EPA Region may designate construction activities disturbing less

than 1 acre based on the potential for contribution to a violation of a water quality

standard or for significant contribution of pollutants to waters of the United States.

The definition of small construction activity does not apply where the construction

operator can certify to one of two waivers – see section 5.2 for more information on

waiver options.

5.1.3 What is meant by the terms "land disturbance," "larger common plan of

development or sale," and "operator" of a construction site?

The definitions of "land disturbance," "larger common plan of development or sale,"

and "operator" of a construction site are key in understanding coverage under the

NPDES Storm Water Program for construction activity. These definitions originate from

the NPDES storm water general permit for large construction activity. 

• Land disturbance refers to exposed soil resulting from activities such as clearing,

grading and excavating. 

• Larger common plan of development or sale is a contiguous area where multiple

separate and distinct construction activities are occurring under one plan (e.g., the

operator is building on three half-acre lots in a 6-acre development). The “plan” in a

common plan of development or sale is broadly defined as any announcement or

piece of documentation (including a sign, public notice or hearing, sales pitch,
5.0 Small Construction Activity

Page 5-3 Storm Water Phase II Compliance Assistance Guide

advertisement, drawing, permit application, zoning request, computer design, etc.)

or physical demarcation (including boundary signs, lot stakes, surveyor markings,

etc.) indicating that construction activities may occur on a specific plot. 

• An operator of a construction site is the person (or persons) responsible for

obtaining coverage under an NPDES storm water permit for construction activity,

and complying with the permit requirements. An operator is the person or persons

that meet either of the following criteria: 

® Has operational control of construction project plans and specifications,

including the ability to make modifications to those plans and

specifications; or

® Has day-to-day operational control of those activities at a project which

are necessary to ensure compliance with a storm water pollution

prevention plan (SWPPP) for the site or other permit conditions (e.g., they

are authorized to direct workers at a site to carry out activities required by

the SWPPP or comply with other permit conditions). 

There may be more than one party at a site responsible for “operational control.” 

Depending on the project and the distinction between the parties’ (e.g., owner’s vs.

developer’s) responsibilities, there can either be a single party acting as a site

operator needing permit coverage or there can be two (or more) operators who may

share permit responsibilities. In cases where there are two or more operators , both

parties will need permit coverage if they choose to keep the responsibilities as

described in the above bullets separate, or they choose to separately maintain

operational control for different portions of the site, etc. In such cases both

operators should obtain permit coverage as co-permittees by co-submitting

separate Notice of Intent forms, and should share in meeting permit conditions (e.g.,

generating the storm water pollution prevention plan, performing inspections, etc.). 

The option to have one sole operator who is willing to assume complete

responsibility / liability for all permit requirements still exists and, in many cases, may

be the less overall burdensome way to comply with storm water requirements.

There are other instances where parties conduct earth disturbing activities at a site

but do not need their own permit coverage. Examples for whom this may apply

include a subcontractor who is under the supervision of the operator, or an entity

that is neither a subcontractor nor has operational control (e.g., a utility line

installer).

Additional information on the responsibilities of operators can be found in Part III.E

of EPA's NPDES Construction General Permit, published on February 17, 1998 (63

FR 7858). Part II of the fact sheet contained in the NPDES Construction General

Permit also provides answers to common questions regarding roles and

responsibilities of different parties involved on a construction site. 
5.0 Small Construction Activity

Page 5-4 Storm Water Phase II Compliance Assistance Guide

Important note: NPDES-authorized States may use a different definition of

"operator" than the one provided above.

5.2 WAIVERS: Which Small Construction Activity Sites May Obtain a Waiver

From Coverage?

Under the Phase II Rule, NPDES permitting authorities have the option of providing

a waiver from Phase II coverage and requirements to operators of small construction

activity who certify to one of two conditions:

õ 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]) would be less than 5 during the period of construction

activity.

ö A determination that storm water controls are not necessary based on either:

(A) A "total maximum daily load" (TMDL) that address the pollutant(s) of

concern for construction activities; OR

(B) For nonimpaired waters that don't require TMDLs, an equivalent analysis

that determines allocations for small construction sites for the pollutants of

concern or determines that such allocations are not needed to protect water

quality based on consideration of instream concentrations, expected growth

in pollutant concentrations from all sources, and a margin of safety.

The intent of these waiver provisions (see §§ 122.26(b)(15)(A) and(B)) is to waive

only those sites that are highly unlikely to have a negative effect on water quality. 

Therefore, before applying for a waiver, operators of small construction activity are

encouraged to consider the potential water quality impacts that may result from their

project and to carefully examine such factors as proximity to water resources and

sensitivity of receiving waters. Small construction activities disturbing less than 1 acre

that are designated by the permitting authority are not eligible for these waivers.

5.2.1 Waiver 1: The Rainfall Erosivity Factor Waiver

The Rainfall Erosivity Factor waiver is based on the potential for a construction

activity to occur in an area, or during a certain period of time, where there is low

Pollutants of concern include sediment or a parameter that

addresses sediment (such as total suspended solids, turbidity, or

siltation) and any other pollutant that has been identified as a cause

of impairment of a receiving waterbody. 
5.0 Small Construction Activity

Page 5-5 Storm Water Phase II Compliance Assistance Guide

 predicted rainfall potential and, therefore, less likelihood of causing impacts. This

waiver is time-sensitive and is dependent on when during the year a construction

activity takes place, how long it lasts, and the expected rainfall and intensity during that

time. It creates an incentive for construction site operators to build during the dry part

of the year. 

How would an operator qualify for, and certify to, this waiver?

To qualify for this waiver, the construction site operator must determine the value of

the rainfall erosivity factor (R factor) in the Revised Universal Soil Loss Equation

(RUSLE) and then certify to the permitting authority that the value of the factor is less

than 5 during the period of construction. The RUSLE is a refinement of the Universal

Soil Loss Equation (USLE), which is a method developed by the U.S. Department of

Agriculture to measure soil loss from agricultural lands at various times of the year on a

regional basis. The R factor varies based on location and time period during the year.

A construction site operator will need site-specific data to calculate the values for

rainfall erosivity using the RUSLE. The rainfall erosivity factor is determined in

accordance with Chapter 2 of Agriculture Handbook Number 703, Predicting Soil

Erosion by Water: A Guide to Conservation Planning With the Revised Universal Soil

Loss Equation (RUSLE). This handbook is no longer in print but Chapter 2 can be

obtained from EPA's web site or by contacting EPA's Water Resource Center.

5.2.1 Waiver 2: The Water Quality Waiver

The Water Quality waiver consists of: 1) a component for small construction sites

that will discharge to an impaired waterbody where total maximum daily load (TMDL)

assessments have been performed, and 2) a component for small construction sites

that will discharge to non-impaired waters where an analysis equivalent to the TMDL

assessments have been performed.

For impaired waters where technology-based controls required by NPDES permits

are not achieving State water quality standards, the CWA requires implementation of

the TMDL process. 

The TMDL process establishes the maximum amount of pollutants a

waterbody can assimilate before water quality is impaired, then requires

that this maximum level not be exceeded. A TMDL assessment

determines the source or sources of a pollutant of concern, considers the

maximum allowable level of that pollutant for the waterbody, then allocates

to each source or category of sources a set level of the pollutant that it is

allowed to discharge into the waterbody. Allocations to point sources are

called wasteload allocations.
5.0 Small Construction Activity

Page 5-6 Storm Water Phase II Compliance Assistance Guide

A TMDL is developed for each pollutant that is found to be contributing to the

impairment of a waterbody or a segment of a waterbody. To allow a waiver for

construction activities, a TMDL would need to address sediment, or a parameter that

addresses sediment such as total suspended solids, turbidity, or siltation. Additional

TMDLs addressing common pollutants from construction sites such as nitrogen,

phosphorus, and oil and grease also may be necessary to ensure water quality

protection and allow a waiver from the NPDES storm water program. More information

on TMDLs can be found at http://www.epa.gov/owow/tmdl/. 

Non-impaired waterbodies do not require TMDL assessments. However,

construction site operators that discharge to non-impaired waterbodies are still eligible

for this waiver. A construction site operator is eligible for a waiver if an analysis

equivalent to a TMDL assessment is conducted for the pollutants of concern and it is

determined through this analysis that small construction sites would not have to control

their contribution of pollutants of concern to the waterbody to protect water quality. The

analysis may also determine that allocations are not needed to protect water quality

based on consideration of variables including existing in-stream concentrations;

expected growth in pollutant contributions from all sources; and a margin of safety. In

this situation, the construction site operator also qualifies for a waiver.

How would an operator qualify for, and certify to, this waiver?

EPA expects that when TMDLs, or equivalent analyses are completed, there may be

a determination that certain classes of sources, such as small construction sites, would

not have to control their contribution of pollutants of concern to the waterbody in order

for the waterbody to be in attainment with water quality standards (i.e., these sources

were not assigned wasteload allocations). In such a case, to qualify for the Water

Quality waiver, the operator of the construction site would need to certify that its

construction activity will take place, and the storm water discharges will occur, within the

area covered either by the TMDLs or equivalent analysis. A certification form would

likely be provided by the NPDES permitting authority.

5.3 PERMIT OPTIONS

The Storm Water Phase II Rule requires operators of small construction activities to

obtain National Pollutant Discharge Elimination System (NPDES) permit coverage

because their storm water discharges are considered “point sources” of pollution. Point

source pollutant discharges, unlike nonpoint sources such as agricultural runoff, are

required under the Clean Water Act (CWA) to be covered by federally enforceable

NPDES permits. 

NPDES storm water permits are issued by an NPDES permitting authority, which

may be an NPDES-authorized State or a U.S. EPA Region in non-authorized States

(see Appendix A for a list of U.S. EPA Regions). Once a permit application is submitted

by the operator of a small construction activity, the conditions of the permit must be 
5.0 Small Construction Activity

Page 5-7 Storm Water Phase II Compliance Assistance Guide

satisfied (i.e., implementation of a storm water pollution prevention plan). This section

addresses the permit options under the Phase II regulations for operators of small

construction activity, as well as for the permitting authority. The permit requirements

are discussed in Section 5.4. 

5.3.1 For Operators of Small Construction Activity: What Types of Permit

Coverage Are Available?

Similar to the Phase I program for large construction activity, the Phase II approach

allows operators of small construction activities to choose between two permitting

options. Each NPDES permitting authority has the discretion, however, to determine

which options are available to operators of small construction activities in their

jurisdiction. 

1) General Permits

# General permits are strongly encouraged by EPA for small construction activity. 

EPA anticipates that the existing general permit for large construction activity will

serve as a model for small construction activity general permits. 

# General permits prescribe one set of requirements for all applicable permittees. 

General permits are drafted by the NPDES permitting authority, then published

for public comment before being finalized and issued.

# A Notice of Intent (NOI) serves as the application for the general permit. Under

the Phase II Rule, NPDES permitting authorities have the discretion to not

require submittal of an NOI under a general permit for small construction activity.

# Small construction operators must submit an NOI and obtain coverage under a

general permit by March 10, 2003 or an earlier date set by the permitting

authority (if this option is available). 

2) Individual Permits

# NPDES permitting authorities may deny coverage under general permits and

require operators to submit an individual NPDES permit application based on

information such as water quality data. 

# In the event that an NPDES permitting authority decides to issue an individual

construction permit for small construction activity, operators are subject to the

individual application requirements found at 40 CFR §122.26(c)(1)(ii). 

# For any discharges of storm water associated with small construction activity

identified in §122.26(b)(15) that are not authorized by a general permit, an

individual permit application must be submitted to the permitting authority by
5.0 Small Construction Activity

Page 5-8 Storm Water Phase II Compliance Assistance Guide

March 10, 2003.

5.3.2 For the NPDES Permitting Authority

5.3.2.1 Alternative Option for Writing Permit Requirements: Referencing a

Qualifying State, Tribal or Local Erosion and Sediment Control Program

Under §122.44(s) of the Phase II Rule, permitting authorities have the flexibility to

develop permit conditions that incorporate by reference qualifying State, Tribal, or local

erosion and sediment control programs into permits for large and small construction

activity. 

To be considered a qualifying State, Tribal, or local program, the program must

require construction site operators to:

• Implement appropriate erosion and sediment control BMPs; 

• Control waste such as discarded building materials, concrete truck washout,

chemicals, litter, and sanitary waste at the site that may cause adverse impacts

to water quality;

• Submit a site plan for review that incorporates consideration of potential water

quality impacts; and 

• Develop and implement a storm water pollution prevention plan (SWPPP)

containing elements similar to those required by other NPDES construction

storm water permits.

In addition to these elements, a qualifying program for large construction activities

must also include any additional requirements necessary to achieve the applicable

technology-based standards of “Best Available Technology” (BAT) and “Best

Conventional Technology” (BCT) based on the best professional judgment of the permit

writer.

Important Note: Not all the construction programs administered by

NPDES-permitted MS4s would qualify. A primary reason for this is

because NPDES-permitted MS4s are not obligated under their permit to

require construction operators to develop a SWPPP.

Should a State, Tribal, or local program include one or more, but not all, of the

elements listed above, the NPDES permitting authority can reference the program in

the permit, provided it also lists the missing element(s) as a condition in the permit. 

5.3.2.2 Permit Application: Optional Use of NOIs

Under the Phase II Rule, EPA is providing NPDES permitting authorities with the
5.0 Small Construction Activity

Page 5-9 Storm Water Phase II Compliance Assistance Guide

discretion to not require NOIs under a general permit for discharges from small

construction activity, if desired. EPA does, however, recommend the use of NOIs for

tracking permit coverage and prioritizing inspections and enforcement. This alternative

option does not apply to general permits for large construction activity. 

5.4 PERMIT REQUIREMENTS

The Phase II Rule requires operators of small construction sites, nationally, to obtain

an NPDES permit and implement practices to minimize pollutant runoff. The Phase II

Rule directs permitting authorities to develop and issue permits for small construction

activity no later than December 9, 2002. Operators of small construction activity will be

required to obtain permit coverage by March 10, 2003, or an earlier date set by the

permitting authority. However, operators may have to comply with local, State, or Tribal

construction runoff control programs (see section 4.6.2.4 for information on the Phase II

small MS4’s construction program). 

For the Phase II small construction program, EPA has taken an approach similar to

Phase I where the program requirements are not fully defined in the rule but rather in

the NPDES permit by the NPDES permitting authority. EPA recommends that the

NPDES permitting authorities use their existing Phase I NPDES construction general

permits as a guide to developing their Phase II construction permits. In doing so, the

Phase II requirements would be similar to the Phase I requirements described in

subsection 5.4.2, although the applicable standards for small construction activity are

different as outlined in subsection 5.4.1.

5.4.1 Applicable Water Quality Standards

Unlike the technology-based standards of BAT and BCT that are applicable to large

construction activity, an operator of small construction activity is required to design its

pollutant control plan so that it:

® Protects water quality (under CWA section 402(p)(6)); and

® Satisfies the appropriate water quality requirements of the CWA.

The water quality standards for large and small construction activity are different

because they were designated into the NPDES storm water program under two

separate sections of the CWA with differing standards. Practically, though, the

standard for small construction activity would be substantively the same as the standard

for large construction activity.

5.4.2 Potential Small Construction Activity Permit Requirements

EPA currently has only one type of permit available for construction activity

operators, the NPDES Construction General Permit. This permit provides coverage to
5.0 Small Construction Activity

Page 5-10 Storm Water Phase II Compliance Assistance Guide

large construction activities only. EPA expects any general permit for small

construction activity to be very similar to the CGP. To gain familiarity with the CGP, the

three main elements of the CGP are included below. 

Important note: This section on the CGP requirements is included for

informational purposes only in order to provide a sense of what the permit

requirements for small construction activity may be – these are not the

requirements for small construction activity.

5.4.2.1 Notice of Intent

A complete and accurate NOI must be submitted to the NPDES permitting authority. 

An NOI includes general information and a certification that the activity will not impact

endangered or threatened species. This certification is unique to EPA’s NOI and is not

a requirement of most NPDES-delegated State’s NOIs. 

An NOI must be postmarked at least two days prior to commencement of any work

on site (if the operator has control over plans and specifications) or two days prior to

commencement of the operator's portion of the work (if the operator has only day-today operational control).

5.4.2.2 Storm Water Pollution Prevention Plan (SWPPP)

The most important requirement of the CGP is the construction storm water pollution

prevention plan (SWPPP) that includes the appropriate BMPs to minimize the

discharge of pollutants from the site. The CGP requires at least one SWPPP for each

construction project or site. 

The construction site operator, or operators, must develop the SWPPP prior to

submitting the NOI to obtain permit coverage. Unlike the NOI and other reporting

forms, the operator(s) does not submit the SWPPP to the permitting authority. Instead,

the SWPPP remains onsite and made accessible according to the requirements

described in the CGP.

The SWPPP comprises several elements:

• Site description. This will contain a description of potential pollutant sources

and other information.

• Controls (BMPs). This part of the SWPPP must clearly describe not only the

controls, but also the timing and responsible permittee for implementing the

controls in the following categories:

r Erosion and Sediment Controls

r Storm Water Management Controls
5.0 Small Construction Activity

Page 5-11 Storm Water Phase II Compliance Assistance Guide

q Other Controls 

• Inspections. Another critical element of the SWPPP is regular inspections of

disturbed areas of the site that has not been stabilized; exposed materials

storage areas; structural controls; and vehicle entrances and exits. 

• Maintenance. The SWPPP also requires that operators perform maintenance

on the controls (BMPs) to ensure they are in effective operating condition. 

• Signatures. The SWPPP must be signed by at least one of the persons

responsible for submitting an NOI for the project. 

• Accessibility. The CGP requires the operator(s) to retain a copy of the SWPPP

at the construction site or other local location accessible to the permitting

authority.

More information on the construction SWPPP requirements can be found in the

CGP, published on February 17, 1998 (63 FR 7858, p. 7906). EPA has also issued a

construction general permit for Regions IV and VI. Contact your EPA Regional office or

State environmental agency for information on construction permits in your State. In

addition, EPA published a construction SWPPP guidance in a document entitled Storm

Water Management for Construction Activities: Developing Storm Water Pollution

Prevention Plans and Best Management Practices (EPA 832-R-92-005, September

1992). 

5.4.2.3 Notice of Termination (NOT)

A completed Notice of Termination (NOT) must be submitted to the NPDES

permitting authority within 30 days after one or more of the following conditions have

been met:

• Final stabilization has been achieved on all portions of the site for which the

permittee is responsible; 

• Another operator/permittee has assumed control over all areas of the site that have

not been finally stabilized; or

• For residential construction only: temporary stabilization of a lot has been

completed prior to transference of ownership to the homeowner, with the

homeowner being made aware of the need to perform final stabilization.

5.5 INTEGRATION OF NPDES PROGRAM FOR CONSTRUCTION WITH NPDES

PROGRAM FOR MS4S
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Page 5-12 Storm Water Phase II Compliance Assistance Guide

There is often confusion about the interaction between the NPDES Storm Water

Program for construction activity, which has been the topic of discussion in this section,

and the construction runoff control program implemented by NPDES-regulated MS4s,

which was the topic of discussion in section 4.6.2.4. 

– These are two separate and distinct construction programs.

– A construction operator is subject to requirements under BOTH programs if it

is located in an NPDES-regulated MS4’s jurisdiction.

The NPDES Storm Water Program for Construction is administered by the NPDES

permitting authority, either the State or an EPA Regional Office.

– This program requires the construction site operator to seek coverage under

an NPDES storm water discharge permit for construction. The current

permit, the Construction General Permit, requires the operator to submit an

NOI, develop a SWPPP, and comply with other applicable NPDES storm

water discharge permit requirements.

– The Construction General Permit (CGP) currently only applies to large

construction activity disturbing greater than 5 acres. Permits for small

construction activity will be issued by each NPDES permitting authority by

December 9, 2002.

The NPDES Storm Water Program for MS4s: MS4 Construction Runoff Control

Programs are administered by the MS4 operator. The MS4 operator’s NPDES storm

water discharge permit requires it to establish requirements to control storm water

discharges from construction activity and new development and redevelopment.

– Regulated small MS4s must control 1 acre and above. 

– Medium and large MS4s have no particular size thresholds that they must

control – differs among MS4s

– The specific requirements of the construction programs will vary among

MS4s. An MS4 permit typically does not specify that the MS4 operator must

require a SWPPP or that a permit application be submitted.

5.6 SMALL CONSTRUCTION ACTIVITY COMPLIANCE PROCESS: What Do I

Need To Do To Comply?

Sections 5.1 through 5.5 of this guidance have provided details on who's covered,

who may be waived, and what may be required under the Phase II regulations for small

construction activity. Now that you are familiar with the Phase II program, this section 
5.0 Small Construction Activity

Page 5-13 Storm Water Phase II Compliance Assistance Guide

walks you through the process, from beginning to end, that an operator of a small

construction activity should take to comply with the regulation. This step-by-step "walkthrough" assumes the issuance of a general permit for small construction activity that is

similar to the CGP. Remember, the general permit for small construction activity may

have different requirements, timeframes, and deadlines than what is noted here. 

Repeat the steps for each individual construction site.

The last page of this section includes a permitting decision tree to help operators of

construction activity determine if they need an NPDES storm water permit. By starting

in the upper left hand corner, an operator can follow the decision tree to determine if

they fall under Phase I, Phase II, or are eligible for a waiver.

Step 1: Determine if your construction site will discharge storm water runoff into a

MS4 (see section 4.1.1 for definition) or to waters of the United States. If so,

proceed to Step 2. If not, stop here.

Step 2: Determine if your construction site's storm water

discharge will meet the definition of a "storm water

discharge associated with small construction activity." 

If so, proceed to Step 3. If not, stop here. (See section

5.1.2)

Step 3: If your site meets the definition of small construction activity, determine if it

qualifies for a waiver from the permit requirements. If so, stop here. If not,

proceed to Step 4. (See section 5.2)

Step 4: Obtain and read the applicable storm water discharge permit for small

construction activity (or the CGP until the small construction permit has been

issued to get a sense of the upcoming permit requirements). The small

construction permit should be issued by the NPDES permitting authority by

December 9, 2002. (See section 5.4.2 for potential requirements)

Step 5: Determine which parties are considered operators and, therefore, are

responsible for complying with the requirements described in the storm water

permit for small construction activity (See section 5.1.3)

Waters of the United States include interstate 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. (Waste treatment systems,

including treatment ponds or lagoons designed to meet the

requirements of CWA are not waters of the United States.) A

complete definition can be found at 40 CFR 122.2.
5.0 Small Construction Activity

Page 5-14 Storm Water Phase II Compliance Assistance Guide

Step 6: Develop a SWPPP. (See section 5.4.2.2) 

• SWPPPs must be developed prior to submitting the NOI. 

• You do not need to submit the SWPPP to your NPDES permitting

authority, however, it should be accessible to the public. 

Step 7: Complete and submit an NOI. (See section 5.4.2.1) 

• Your NPDES permitting authority may or may not require a NOI. If so, the

Phase II regulation requires that you submit your NOI no later than March

10, 2003 (or 90 days after the NPDES permitting authority issues the

permit, whichever comes first). 

• Submit a completed NOI to your NPDES permitting authority two days

prior to beginning work at the construction site. 

Step 8: Implement the SWPPP. 

• Includes generation of inspection reports that are to be kept on-site.

Step 9: Complete and submit an NOT. (See section 5.4.2.3)

• Submit a completed NOT to your NPDES permitting authority within 30

days after one or more of the appropriate conditions have been met.
5.0 Small Construction Activity

Page 5-15 Storm Water Phase II Compliance Assistance Guide

Construction Activities Storm Water Program

Permitting Decision Tree

Does the construction

activity discharge storm

water runoff to an MS4 or

waters of the U.S.?

How many acres

will be disturbed by the

construction activity?

Greater than or equal 1

and less than 5 acres Less than 1 acre 5 or more acres

A permit is required

under Phase I.1

Is the construction activity

part of a larger common plan of

development or sale that will disturb

5 or more acres?

Is the construction

activity part of a larger

common plan of development

or sale?

No NPDES storm

water discharge

permit is required.

What is the

planned disturbance of the

larger common plan of

development or sale?

Greater than or equal to

1 and less than 5 acres Less than 1 acre 5 or more acres

"Storm water discharge associated

with small construction activity"2

Does the construction activity occur

during a negligible rainfall period where the rainfall

erosivity factor ("R" in the RUSLE) is less than 5

during the period of construction activity?3

Has a TMDL or equivalent

analysis addressing the pollutants of

concern lead to a determination that

storm water controls are not necessary

for small construction activity?4

The construction activity qualifies

for a waiver. No permit is required

but the construction operator must

certify to the waiver conditions.

An NPDES storm water discharge

permit is required under Phase II.

Yes

No

Yes

Yes

Yes

Yes

No

No

No

No

1. Construction activity disturbing, or part of a planned disturbance of, five or more acres is a "storm water discharge associated with industrial

 activity" under category (x). See 40 CFR 122.26(b)(14)(x).

2. See new 122.26(b)(15) for the definition of "storm water discharge associated with small construction activity."

3. See new 122.26(b)(15)(i)(A) for more details.

4. See new 122.26(b)(15)(i)(B) for more details.
6.0 Industrial Activity

Page 6-1 Storm Water Phase II Compliance Assistance Guide

6.0 INDUSTRIAL ACTIVITY

6.1 PHASE I INDUSTRIAL ACTIVITY: What Industrial Activities are Covered by

Phase I of EPA's Storm Water Program?

The 1990 storm water regulations for

Phase I of the federal storm water program

identify eleven categories of industrial

activities under the definition of a "storm

water discharge associated with industrial

activity" that must obtain a National

Pollutant Discharge Elimination System

(NPDES ) permit. The categories contain

industries listed either by reference to an

industry's Standard Industrial Classification

(SIC) code, or by a short narrative

description of the activity found at the

industrial site (see text box at right for more

detailed descriptions). For facilities that

match the SIC codes or description in one

of the categories, only those that have a

storm water discharge to a municipal

separate storm sewer system (MS4) or

waters of the United States are required to

seek permit coverage. The NPDES permit

requirements vary between individual and

general permits, but in general involve the

development of a storm water pollution

prevention plan based upon site

assessments, monitoring and reporting

data on storm water discharges, and

mitigating any possible effects of

discharges on endangered species and

national historic properties (for EPA issued

permits).

After reading section 6.0, you should understand the basic components

and requirements of the Phase II regulations as they affect the categories

of industrial activity covered by the Phase I regulations. Phase II revises

the original Phase I industrial no exposure exemption and also sets a new

deadline for permit coverage for the municipally-owned industrial activity

that had been temporarily exempted from storm water permit coverage.

 Storm Water Discharge 

Associated with Industrial Activity

(40 CFR 122.26(b)(14)(i) - (xi))

• Facilities subject to storm water

effluent limitation guidelines; new

source performance standards, or toxic

pollutant effluent standards under 40

CFR Subchapter N.

• "Heavy" industrial facilities with SIC

codes listed in 40 CFR

122.26(b)(14)(ii), (iii), and (vi)

• "Light" industrial facilities with SIC

codes listed in 40 CFR 122.26(b)(14)

(xi), which conduct the activities

specified in that sections.

• Hazardous waste treatment, storage, or

disposal facilities.

• Landfills, land application sites, and

open dumps that receive or have

received industrial waste.

• Steam electric power generating

facilities.

• Sewage treatment works.

• Construction activity (including

clearing, grading, and excavation)

disturbing five or more acres of land, or

less than five acres of land if it is part of

a larger common plan of development

or sale of five acre or greater.
6.0 Industrial Activity

Page 6-2 Storm Water Phase II Compliance Assistance Guide

Under the Phase I regulations, operators of facilities within category eleven (xi),

commonly referred to as “light industry,” were exempted from the definition of “storm

water discharge associated with industrial activity,” and the subsequent requirement to

obtain an NPDES permit, provided their industrial materials or activities were not

“exposed” to storm water. This Phase I no exposure exemption from permitting was

limited to those facilities identified in category (xi), and did not require category (xi)

facility operators to submit any information supporting their no exposure claim.

In 1992, the Ninth Circuit court remanded to EPA for further rulemaking the no

exposure exemption for light industry after making a determination that the limited

exemption was arbitrary and capricious. The result was a revised no exposure

exemption (now an "exclusion") as part of the Phase II regulation.

6.2 PHASE II NO EXPOSURE EXCLUSION: What is the Conditional No

Exposure Exclusion for Industrial Activity as Revised by this Regulation?

The intent of the no exposure provision is to provide a simplified method for

complying with the Clean Water Act to all industrial facilities that are entirely indoors. 

This includes facilities that are located within a large office building, or at which the only

items permanently exposed to precipitation are roofs, parking lots, vegetated areas, and

other non-industrial areas or activities.

As revised in the Phase II regulation, if a condition of No Exposure exists at a

Phase I industrial facility, then permits will not be required for storm water discharges

from these facilities. All industrial facilities that have no exposure of materials to storm

water, including the "light industrial" facilities, must submit a certification to the

permitting authority. The facility must certify that a condition of No Exposure exists at

its facility and either maintain a condition of no exposure or obtain a permit. The

following subsections discuss who is eligible for the revised no exposure exclusion, the

definition of no exposure, and the requirement to submit a written certification of no

exposure in place of a permit application. 

6.2.1 Who is Eligible to Qualify for the No Exposure Exclusion?

The Phase II Conditional No Exposure Exclusion represents a significant expansion

in the scope of the original no exposure provision in terms of eligibility. Now, 

all Phase I industrial categories with a condition of no exposure, except for construction

activity, are eligible for the no exposure exclusion. The exclusion from permitting is

available on a facility-wide basis only, not for individual outfalls

6.2.2 What is the Definition of No Exposure?

The Phase II regulatory definition of no exposure is as follows: 

No exposure means all industrial materials and activities are protected
6.0 Industrial Activity

Page 6-3 Storm Water Phase II Compliance Assistance Guide

by a storm resistant shelter to prevent exposure to rain, snow,

snowmelt, and/or runoff. Industrial materials or activities include, but

are not limited to, material handling equipment or activities, industrial

machinery, raw materials, intermediate products, by-products, final

products, or waste products. 

A storm resistant shelter is not required for the following industrial

materials and activities: 

• Drums, barrels, tanks, and similar containers that are tightly

sealed, provided those containers are not deteriorated and do

not leak. “Sealed” means banded or otherwise secured and

without operational taps or valves; 

• Adequately maintained vehicles used in materials handling; 

• Final products, other than products that would be mobilized in

storm water discharges (e.g., rock salt).

The term “storm-resistant shelter,” as used in the no exposure definition, includes

completely roofed and walled buildings or structures, as well as structures with only a

top cover but no side coverings, provided material under the structure is not otherwise

subject to any run-on and subsequent runoff of storm water. 

While the intent of the no exposure provision is to promote a condition of permanent

no exposure, certain machinery, such as trucks, may become temporarily exposed to

rain and snow while passing between buildings. Adequately maintained mobile

equipment (e.g., trucks, automobiles, forklifts, trailers, or other such general purpose

vehicles found at the industrial site that are not industrial machinery, and that are not

leaking contaminants or are not otherwise a source of industrial pollutants) also can be

exposed to precipitation or runoff. Such activities alone would not prevent a facility

from certifying to no exposure. Similarly, trucks or other vehicles awaiting maintenance

at vehicle maintenance facilities that are not leaking contaminants or are not otherwise

a source of industrial pollutants, would not be considered exposed.

EPA recognizes that there are circumstances where permanent no exposure of

industrial activities or materials is not possible and, therefore, under such conditions,

materials and activities could be sheltered with temporary covers (e.g., tarps) between

periods of permanent enclosure. The No Exposure provision does not specify every

such situation, but NPDES permitting authorities can address this issue on a case-bycase basis. 

The Phase II regulation also addresses particulate matter emissions from roof

stacks/vents. If regulated by, and in compliance with, other environmental protection

programs (i.e., air quality control programs) and not causing storm water contamination, 

they are considered not exposed. Particulate matter or visible deposits of residuals

from roof stacks and/or vents not otherwise regulated (i.e., under an air quality control

program) and evident in storm water outflow are considered “exposed.” Likewise, 
6.0 Industrial Activity

Page 6-4 Storm Water Phase II Compliance Assistance Guide

visible “track out” (i.e., pollutants carried on the tires of vehicles) or windblown raw

materials are considered “exposed.” Leaking pipes containing contaminants exposed

to storm water are deemed “exposed,” as are past sources of storm water

contamination that remain onsite. General refuse and trash, not of an industrial nature,

is not considered exposed as long as the container is completely covered and nothing

can drain out holes in the bottom, or is lost in loading onto a garbage truck. Industrial

refuse and trash that is left uncovered, however, is considered “exposed.”

6.2.3 What Do I Need To Know About Certifying to a Condition of No Exposure?

In order to obtain the Conditional No Exposure exclusion, you will have to submit

written certification that your facility meets the definition of “no exposure,” even if you

are a category (xi) facility operator. The Phase II Rule included as an appendix to the

preamble a four-page No Exposure Certification form to be used for this purpose in

areas where EPA is the NPDES permitting authority. EPA's certification form uses a

series of yes/no questions which you must answer regarding the your industrial activity. 

You may certify to no exposure if you can answer "no" to all of the questions.

Important note: EPA's No Exposure Certification form applies only in areas

where EPA is the NPDES permitting authority. Where a State is the NPDES

permitting authority, the State will issue its own form. Since most aspects of

EPA's form are also regulatory requirements as to what must be included

within a written certification of no exposure, you may expect the State forms to

be very similar to EPA's.

The Certification form serves two purposes: 1) as an aid to help you in determining

whether you have a condition of No Exposure at your facility or site, and 2) as the

necessary written certification of No Exposure, provided you are able to answer all the

questions in the negative. 

® If, after you have completed the form, you find that you answered "yes" to one or

more of the questions about possible exposure, you must make the appropriate

changes at the facility if you still wish to apply for the conditional exclusion. 

These changes must remove the particular material, process, or activity at the

facility or site from exposure to storm water. 

® If, after completing the form, you find that you were able to check "no" to every

question, you qualify for the no exposure exclusion and must sign and submit the

form to your NPDES permitting authority. 

Certification Facts:

• The certification must be completed and submitted to your permitting authority once

every 5 years, and can only be done so if the condition of no exposure continues to

exist at the facility. 

• The Certification must be provided for each facility qualifying for the no exposure
6.0 Industrial Activity

Page 6-5 Storm Water Phase II Compliance Assistance Guide

exclusion.

• The form is non-transferable. If a new operator takes over your facility, they must

complete, sign, and submit a new form to claim the no exposure exclusion when

they assume control over the operations of the facility. 

6.2.4 Are There Any Concerns Related to Water Quality Standards?

Yes. An operator certifying that its facility qualifies for the conditional no exposure

exclusion may, nonetheless, be required by the permitting authority to obtain permit

authorization. Such a requirement would follow the permitting authority’s determination

that the facility's discharge is likely to have an adverse impact on water quality.

Many efforts to achieve no exposure can employ simple good housekeeping and

contaminant cleanup activities such as moving materials and activities indoors into

existing buildings or structures. In limited cases, however, industrial operators may

make major changes at a site to achieve no exposure. These efforts may include

constructing a new building or cover to eliminate exposure or constructing structures to

prevent run-on and storm water contact with industrial materials and activities. Major

changes undertaken to achieve no exposure, however, can increase the impervious

area of the site, such as when a building is placed in a formerly vegetated area. 

Increased impervious area can lead to an increase in the volume and velocity of storm

water runoff, which, in turn, can result in a higher concentration of pollutants in the

discharge, since fewer pollutants are naturally filtered out.

The concern of increased impervious area is addressed in one of the last questions

on the Certification form, which asks, “Have you paved or roofed over a formerly

exposed, pervious area in order to qualify for the no exposure exclusion? If yes, please

indicate approximately how much area was paved or roofed over.” This question is

intended to aid the NPDES permitting authority in assessing the likelihood of such

actions interfering with water quality standards. Where this is a concern, the facility

operator and its NPDES permitting authority should take appropriate actions to ensure

that water quality standards can be achieved.

6.2.5 Industrial Program Compliance Process: What Do I Need To Do To Obtain

the No Exposure Exclusion and Comply with Applicable Requirements?

Sections 6.1 through 6.2.4. of this guidance have provided information necessary to

understand the conditional no exposure exclusion. Now that you are familiar with the

no exposure exclusion, this section walks you through the process, from beginning to

end, that an operator of industrial activity will need to take to comply with the Phase II

regulation. This step-by-step "walk-through" assumes the issuance of a no exposure

certification form that is similar to EPA's form. Remember, a State's certification form

may have different requirements and deadlines than what is noted here. Repeat the

steps for each individual facility or site.
6.0 Industrial Activity

Page 6-6 Storm Water Phase II Compliance Assistance Guide

Step 1: Determine if your industrial activity meets the definition of a "discharge

associated with industrial activity." If so, proceed to Step 2. If not, stop here.

(See section 6.1) 

• If you are a regulated industrial operator, you need to either apply for a

storm water permit, or submit a no exposure certification, in order to be in

compliance with the NPDES storm water regulations. Any storm water

permit you may currently hold becomes null and void once a completed

conditional no exposure certification form is submitted

Step 2: Obtain the no exposure certification form from your NPDES permitting

authority. Determine if your regulated industrial activity meets the definition of

" no exposure" and qualifies for the exclusion from permitting. If it does,

proceed to Step 3. If not, stop here and obtain industrial storm water permit

coverage (probably through the multi-sector general permit or similar permit).

• The conditional no exposure exclusion option is currently available only for

facilities in areas where EPA is the NPDES permitting authority. In all

other areas, where the State is the NPDES permitting authority, the facility

operators will need to wait until the State makes the option available.

Step 3: Submit the certification form to your NPDES permitting authority -- a new form

must be submitted once every 5 years.

• Be aware that even when you certify to no exposure, your NPDES

permitting authority still retains the authority to require you to apply for an

individual or general permit if it has determined that your discharge is

contributing to the violation of, or interfering with the attainment or

maintenance of, water quality standards, including designated uses.

Step 4: Submit a copy, upon request, of the certification form to the municipality in

which the facility is located.

Step 5: Allow your NPDES permitting authority or, if discharging into a municipal

separate storm sewer system, the operator of the system, to (1) inspect the

facility and (2) make such inspection reports publicly available upon request.

Step 6: Maintain a condition of no exposure. 

• The no exposure exclusion is conditional and not an outright exemption. 

Therefore, if there is a change in circumstances that causes exposure of

industrial activities or materials to storm water, the you are required to

comply immediately with all the requirements of the NPDES Storm Water

Program, including applying for and obtaining a storm water discharge

permit.
6.0 Industrial Activity

Page 6-7 Storm Water Phase II Compliance Assistance Guide

• Failure to maintain the condition of no exposure or obtain coverage under

an NPDES permit can lead to the unauthorized discharge of pollutants to

waters of the United States, resulting in penalties under the CWA. 

6.3 ISTEA MORATORIUM: How Has this Regulation Affected the MunicipallyOperated Industrial Activity Subject to the Intermodal Surface

Transportation Enforcement Act (ISTEA) Moratorium?

Provisions within ISTEA temporarily delayed the deadline for Phase I industrial

activities operated by municipalities with populations of less than 100,000 people to

obtain an NPDES storm water discharge permit. Congress delayed the permitting

deadline to allow small municipalities additional time to comply with NPDES

requirements. This moratorium on permitting did not apply to power plants, airports,

and uncontrolled sanitary landfills operated by small municipalities. 

The Phase II Rule slightly extended this temporary exemption from permitting and

set a deadline of no later than March 10, 2003 for all ISTEA-exempted municipallyoperated industrial activities to obtain NPDES permit coverage. Of course, like any

other regulated industrial activity, these municipally-operated industrial activities are

eligible to qualify for the no exposure exclusion from permitting if a condition of no

exposure exists. Municipal-operators must follow the same procedures outlined in

Section 6.2.4 in order to obtain an exclusion from permitting. 

Many of the small municipalities that will now have to obtain permit coverage for

their industrial activity will also have to obtain permit coverage for their small MS4 (see

section 4.0) and small construction activity (see section 5.0). The Phase II regulation

deadlines for industrial, small MS4, and small construction permit coverage are all the

same – no later than March 10, 2003 – to allow the NPDES permitting authority to issue

one individual permit that covers all three components if it chooses to do so. 
7.0 The Compliance Assurance Process

Page 7-1 Storm Water Phase II Compliance Assistance Guide

7.0 THE COMPLIANCE ASSURANCE PROCESS

7.1 How Will EPA Determine Compliance?

EPA employs several approaches to monitor compliance with its environmental

regulations, including both EPA-initiated and facility-initiated methods.

1. Inspections – EPA may conduct periodic inspections at facilities subject to this

regulation. Inspections may be initiated by disclosures to EPA, randomly

selecting facilities, or a variety of targeting methods. Inspections may be used,

for instance, to monitor recordkeeping requirements, visit sites where storm

water controls should be in place, and/or verify that facilities have permits.

2. Permits, Records, and Reports – Permits are not required for small

construction sites and regulated small MS4s for up to three years and 90 days

from the effective date of the final rule. After general permits are issued, the

NPDES permitting authorities intend to use the data in storm water permit

applications, construction waiver certifications, storm water pollution prevention

plans (SWPPPs), no exposure certifications, records, and reports (as required by

the Phase II regulation) to set appropriate permit conditions and track discharges

covered by a storm water permit. Compliance and enforcement authorities will

use the information to assess the regulated entity’s level of compliance. 

3. Review of No Exposure Certifications – Operators of industrial facilities that

are eligible for a no exposure exclusion from the NPDES permitting requirements

may prepare, and submit for review, a no exposure certification. NPDES

authorities will use the information contained in the certification in determining

compliance with the no exposure provisions. This information will particularly

assist in determining compliance with the no exposure certification in conjunction

with complaints from the public.

4. Self-audit and Self Disclosure – Facilities have the primary responsibility for

ensuring that they are in continuous compliance. EPA encourages the facility to

take advantage of EPA’s Audit Policy, Small Business Policy, or Small

Community Policy (these will be discussed in more detail in section 7.2). 

In addition to this document, to aid in determining whether it is in compliance, the

facility might use a document currently being developed by EPA entitled

“Protocol for Conducting Environmental Compliance Audits under the Storm 

After reading section 7, you should understand how EPA will determine

compliance, what happens if you or the EPA discovers noncompliance,

and where to go for compliance assistance information.
7.0 The Compliance Assurance Process

Page 7-2 Storm Water Phase II Compliance Assistance Guide

Water Program.” This protocol, which is a part of a set containing other statutespecific audit protocols, is a tool to assist and encourage businesses and

organizations to perform environmental audits and disclose violations in

accordance with EPA’s Audit Policy. The protocol provides guidance on key

requirements, defines regulatory terms, gives an overview of the federal laws

affecting a particular environmental management area, and includes a checklist

for review of the facility. EPA anticipates making the document available for

public use in summer 2000. To see a sample of protocols that have been

completed under other statutes (RCRA, EPCRA, CERCLA), visit the Internet

site: http://es.epa.gov/oeca/ccsmd/profile.html.

7.2 If I Discover a Violation, How Can I Work With The Agency to Correct It?

EPA promotes environmental compliance by providing incentives. By participating

in compliance assistance programs or voluntarily disclosing violations and promptly

correcting violations, businesses may get penalty waivers or reductions. EPA has three

policies that potentially apply to entities regulated by the Storm Water Phase II Rule. 

These policies do not apply if an enforcement action has already been initiated.

Audit Policy. The first of these policies is “Incentives for Self-Policing: Discovery,

Disclosure, Correction and Prevention of Violations” (60 FR 66706), known as the

“Audit Policy”. EPA initiated this policy to provide entities of all sizes with incentives to

voluntarily discover and promptly disclose and correct violations of environmental

regulations. For a more detailed description of the Audit Policy, visit the Internet site at: 

www.epa.gov/oeca/polguid/polyguid1.html.

Small Business Policy. EPA’s “Policy on Compliance Incentives for Small

Business” was developed to help small businesses with 100 or fewer employees

achieve environmental compliance by creating benefits for businesses that make a

good faith effort to comply with environmental regulations before a government agency

discovers a violation or otherwise takes an enforcement action. The Policy currently

provides incentives, such as penalty waivers or penalty reduction, for businesses that

participate in on-site compliance assistance programs or conduct environmental audits

to discover, disclose, and correct violations. The Policy is presently being modified to

broaden when and how a small business can take advantage of the Policy. Revisions

are expected in spring of 2000. Please see www.epa.gov/oeca/polguid or contact

Ginger Gotliffe (202-564-7072) for more information. 

Small Community Policy. The “Policy on Flexible State Enforcement Responses

to Small Community Violations” (November, 1995) promotes alternative strategies for

communities to achieve environmental and economic goals. States are encouraged to

use multimedia compliance assistance and prioritize compliance issues to address

specific needs of their small communities. As long as states work within the parameters

of the Policy, EPA will generally defer to their decision to waive part or all of the penalty

for a small community’s environmental violations. This approach allows small 
7.0 The Compliance Assurance Process

Page 7-3 Storm Water Phase II Compliance Assistance Guide

communities to apply their limited resources to fixing their environmental problems,

rather than to paying penalties. The policy applies to communities generally comprised

of fewer than 2,500 residents. In the context of the Storm Water Phase II Rule, small

MS4s that are not eligible for waivers from their regulatory requirements would be most

likely to take advantage of this policy. For a more detailed description of the Small

Communities Policy, visit the Internet sites: www.epa.gov/oeca/scpolcy.html or

www.epa.gov/oeca/ccsmd/mun.html.

7.3 Where Can I Go for Compliance Assistance on the Storm Water Phase II

Rule?

The permitting authority is the leading source for information on the Storm Water

Phase II Rule. EPA is also developing a "tool box" to assist States, Tribes,

municipalities, and other parties involved in the Phase II program. This tool box will

facilitate implementation of the storm water program in an effective and cost-efficient

manner. The tool box is available on EPA’s web page at

http://www.epa.gov’owm/sw/phase2 and consists of the following eight major

components:

- Fact Sheets

- Guidance Documents

- Menu of BMPs

- Training and Outreach Efforts

- Information Clearinghouse

- Technical Research

- Support for Demonstration Projects

- Compliance Monitoring/Assistance Tools

In addition, EPA provides widely available compliance assistance through the

establishment of national compliance assistance centers, in partnership with industry,

academic institutions, and other federal and state agencies. Centers have been

established that provide services for several industries that contain many small

businesses. Compliance assistance centers offer a range of communications services,

including Web sites, e-mail groups, fax-back systems, and telephone assistance lines. 

Each Center is targeted to a specific sector and explains relevant federal environmental

regulations. For instance, local governments can use the services of the Local

Government Environmental Assistance Network (LGEAN). LGEAN is a “first-stop shop”

providing environmental management, planning, and regulatory information for local

government elected and appointed officials, managers, and staff. It provides 24-hour

access to regulatory and pollution prevention information, message boards, regulatory

updates, grants and information, and more. It is a good source for compliance

assistance information on the Storm Water Phase II Rule. 

For more information on EPA’s compliance assistance centers, please contact

Tracy Back (202-564-7076). You can access all the centers through

www.epa.gov/oeca/mcfac.html or individually at:
7.0 The Compliance Assurance Process

Page 7-4 Storm Water Phase II Compliance Assistance Guide

EPA’s Compliance Assistance Centers

Center Phone Web Address

Local Government Environmental Assistance

Network (LGEAN)

1-877-TO-LGEAN www.lgean.org

National Metal Finishing Resource Center 1-800-AT-NMFRC www.nmfrc.org

Printers’ National Environmental Assistance

Center

1-888-USPNEAC www.pneac.org

CCAR-Greenlink (the Automotive

Compliance Information Assistance Center)

1-888-GRN-LINK www.ccar-greenlink.org

National Agriculture Compliance Assistance

Center

1-888-663-2155 www.epa.gov/oeca/ag

Printed Wiring Board Resource Center 1-734-995-4911 www.pwbrc.org

ChemAlliance 1-800-672-6048 www.chemalliance.org

Transportation Environmental Resource

Center

1-888-459-0656 www.transource.org

Paints and Coatings Resource Center 1-800-286-6372 www.paintcenter.org
7.0 The Compliance Assurance Process

Page 7-5 Storm Water Phase II Compliance Assistance Guide

7.4 If the Agency Discovers a Violation, What Might Be Its Response?

To maximize compliance, EPA implements a balanced program of compliance

assistance, compliance incentives, and traditional law enforcement. EPA knows that

small businesses which must comply with complicated new statutes or rules often want

to do the right thing, but may lack the requisite knowledge, resources, or skills. 

Compliance assistance information and technical advice helps small businesses to

understand and meet their environmental obligations. Compliance incentives, such as

our Small Business Policy, encourage persons to voluntarily discover, disclose, and

correct violations before they are identified by the government. EPA’s strong law

enforcement program protects all of us by targeting persons who neither comply nor

cooperate to address their problems. 

EPA uses a variety of methods to determine whether regulated

entities are complying, including inspecting facilities, reviewing

records and reports, and responding to citizen complaints. If we

learn an entity is violating the law, EPA (or a State, if the program is

delegated) may file an enforcement action seeking penalties of up to

$27,500, per violation, per day. While the statutory maximum penalty is currently

$27,500, it may be increased periodically based on inflation in accordance with the

Debt Collection Improvement Act of 1996. The proposed penalty in a given case will

depend on many factors, including the number, length, and severity of the violations,

the economic benefit obtained by the violator, and its ability to pay. EPA has polices in

place to ensure penalties are calculated fairly. These policies are available to the

public. In addition, any company charged with a violation has the right to contest EPA’s

allegations and proposed penalty before an impartial judge or jury.

EPA recognizes that we can achieve the greatest possible protection by

encouraging businesses and organizations to work with us to discover, disclose, and

correct violations. That is why we have issued Audit, Small Business, and Small

Community policies to eliminate or reduce penalties for small and large entities which

cooperate with EPA to address compliance problems. To help the regulated

community in understanding their requirements for compliance with the rule, EPA 

provides compliance assistance through its regional offices, Office of Enforcement and

Compliance Assurance at Headquarters, and national compliance assistance centers

partners.
Appendix A

Page A-1 Storm Water Phase II Compliance Assistance Guide

ABBREVIATIONS:

BAT Best Available Technology Economically Achievable (applies to

non-conventional and toxic pollutants)

BCT Best Conventional Pollutant Control Technology (applies to conventional

pollutants)

BMP Best Management Practice

BPJ Best Professional Judgment

BPT Best Practicable Control Technology Currently Available (generally applies to

conventional pollutants and some metals)

CFR Code of Federal Regulations

CGP Construction General Permit

COD Chemical Oxygen Demand

CSO Combined Sewer Overflow

CWA Clean Water Act (formerly referred to as the Federal Water Pollution Control

Act or Federal Water Pollution Control Act Amendments of 1972)

CZARA Coastal Zone Act Reauthorization Amendments 

D.O. Dissolved Oxygen

DMR Discharge Monitoring Report

ELG Effluent Limitations Guidelines

EPA Environmental Protection Agency

FR Federal Register

MEP Maximum Extent Practicable

MS4 Municipal Separate Storm Sewer System

MSGP Multi Sector General Permit

NOI Notice of Intent

NOT Notice of Termination

NOV Notice of Violation

NPDES National Pollutant Discharge Elimination System

NPS Non-point Source

O&M Operation and Maintenance

OW Office of Water

OWM Office of Wastewater Management

PA Permitting Authority

POTW Publicly Owned Treatment Works

SIC Standard Industrial Classification

SWPPP Storm Water Pollution Prevention Plan

TMDL Total Maximum Daily Load

TSS Total Suspended Solids

UA Urbanized Area
Appendix A

Page A-2 Storm Water Phase II Compliance Assistance Guide

DEFINITIONS:

Best Available Treatment(BAT)/Best Control Technology (BCT): A level of

technology based on the very best (state of the art) control and treatment measures

that have been developed or are capable of being developed and that are economically

achievable within the appropriate industrial category.

Best Management Practices (BMPs): Activities or structural improvements that help

reduce the quantity and improve the quality of storm water runoff. BMPs include

treatment requirements, operating procedures, and practices to control site runoff,

spillage or leaks, sludge or waste disposal, or drainage from raw material storage.

Category (xi) facilities: Specific facilities classified as light industry with equipment or

materials exposed to storm water. 

Clean Water Act (Water Quality Act): (formerly the Federal Water Pollution Control

Act or Federal Water Pollution Control Act Amendments of 1972). Public law 92-500;

33 U.S.C. 1251 et seq.; legislation which provides statutory authority for the NPDES

program. Also know as the Federal Water Pollution Control Act.

Conveyance: The process of water moving from one place to another.

Discharge: The volume of water (and suspended sediment if surface water) that

passes a given location within a given period of time.

Erosion: When land is diminished or worn away due to wind, water, or glacial ice. Often

the eroded debris (silt or sediment) becomes a pollutant via storm water runoff. Erosion

occurs naturally but can be intensified by land clearing activities such as farming,

development, road-building, and timber harvesting.

Excavation: The process of removing earth, stone, or other materials from land.

General Permit: A permit issued under the NPDES program to cover a certain class or

category of storm water discharges. These permits reduce the administrative burden of

permitting storm water discharges.

Grading: The cutting and/or filling of the land surface to a desired slope or elevation.

Illicit Connection: Any discharge to a municipal separate storm sewer that is not

composed entirely of storm water and is not authorized by an NPDES permit, with some

exceptions (e.g., discharges due to fire fighting activities).

Industrial Activity: Any activity which is directly related to manufacturing, processing or

raw materials storage areas at an industrial plant.

Large Municipal Separate Storm Sewer System (MS4): An MS4 located in an

incorporated place or county with a population of 250,000 or more, as determined by
Appendix A

Page A-3 Storm Water Phase II Compliance Assistance Guide

the latest U.S. Census

Light Manufacturing Facilities: Described under Category (xi) of the definition of

"storm water discharges associated with industrial activity." [40 CFR 122.26(b)(14)(xi)]

Under the Phase I NPDES Storm Water Program, these facilities were eligible for

exemption from storm water permitting requirements if certain areas and activities were

not exposed to storm water. As a result of the Phase II Final Rule, these facilities must

now certify to a condition of no exposure.

Maximum Extent Practicable (MEP): A standard for water quality that applies to all

MS4 operators regulated under the NPDES Storm Water Program. Since no precise

definition of MEP exists, it allows for maximum flexibility on the part of MS4 operators

as they develop and implement their programs.

Medium Municipal Separate Storm Sewer System (MS4): MS4 located in an

incorporated place or county with a population of 100,000 or more but less than

250,000, as determined by the latest U.S. Census.

Municipal Separate Storm Sewer System (MS4): A publically-owned conveyance or

system of conveyances that discharges to waters of the U.S. and is designed or used

for collecting or conveying storm water, is not a combined sewer, and is not part of a

publicly-owned treatment works (POTW).

Multi-Sector General Permit (MSGP): An NPDES permit that regulates storm water

discharges from eleven categories of industrial activities. 

No exposure: All industrial materials or activities are protected by a storm resistant

shelter to prevent exposure to rain, snow, snowmelt, and/or runoff. Industrial materials

or activities include, but are not limited to, material handling equipment or activities,

industrial machinery, raw materials, intermediate products, by-products, final products,

or waste products. Material handling activities include the storage, loading and

unloading, transportation, or conveyance of any raw material, intermediate product, final

product or waste product.

Non-authorized States: any State that does not have the authority to regulate the

NPDES Storm Water Program. 

Non-point Source (NPS) Pollutants: Pollutants from many diffuse sources. NPS

pollution is caused by rainfall or snowmelt moving over and through the ground. As the

runoff moves, it picks up and carries away natural and human-made pollutants, finally

depositing them into lakes, rivers, wetlands, coastal waters, and even our underground

sources of drinking water.

Notice of Intent (NOI): An application to notify the permitting authority of a facility's

intention to be covered by a general permit; exempts a facility from having to submit an

individual or group application.
Appendix A

Page A-4 Storm Water Phase II Compliance Assistance Guide

NPDES: "National Pollutant Discharge Elimination System" the name of the surface

water quality program authorized by Congress as part of the 1987 Clean Water Act.

This is EPA's program to control the discharge of pollutants to waters of the United

States (see 40 CFR 122.2).

O&M Expenditures: The operating and maintenance costs associated with the

continual workings of a project.

Outfall: The point where wastewater or drainage discharges from a sewer pipe, ditch,

or other conveyance to a receiving body of water.

Permitting Authority (PA): The NPDES-authorized state agency or EPA regional office

that administers the NPDES Storm Water Program. PAs issue permits, provide

compliance assistance, and inspect and enforce the program.

Physically interconnected MS4: This means that one MS4 is connected to a second

MS4 in such a way that it allows for direct discharges into the second system.

Point Source Pollutant: Pollutants from a single, identifiable source such as a factory

or refinery.

Pollutant Loading: The total quantity of pollutants in storm water runoff.

Qualifying local program: A local, State or Tribal municipal storm water management

program that imposes, at a minimum, the relevant requirements of one or more of the

minimum control measures includes in 122.34(b).

Regulated MS4: Any MS4 covered by the NPDES Storm Water Program (regulated

small, medium, or large MS4s).

Retrofit: The modification of storm water management systems through the

construction and/or enhancement of wet ponds, wetland plantings, or other BMPs

designed to improve water quality

Runoff: Drainage or flood discharge that leaves an area as surface flow or as pipeline

flow. Has reached a channel or pipeline by either surface or sub-surface routes.

Sanitary Sewer: A system of underground pipes that carries sanitary waste or process

wastewater to a treatment plant.

Sediment: Soil, sand, and minerals washed from land into water, usually after rain.

Sediment can destroy fish-nesting areas, clog animal habitats, and cloud waters so that

sunlight does not reach aquatic plants.

Sheet flow: The portion of precipitation that moves initially as overland flow in very

shallow depths before eventually reaching a stream channel.
Appendix A

Page A-5 Storm Water Phase II Compliance Assistance Guide

Site Plan: A graphical representation of a layout of buildings and facilities on a parcel of

land.

Site Runoff: Any drainage or flood discharge that is released from a specified area.

Small Municipal Separate Storm Sewer System (MS4): Any MS4 that is not

regulated under Phase I of the NPDES Storm Water Program and Federally-owned

MS4s.

Stakeholder: An entity that holds a special interest in an issue or program -- such as

the storm water program -- since it is or may be affected by it.

Standard Industrial Classification (SIC) Code: A four digit number which is used to

identify various types of industries.

Storm Drain: A slotted opening leading to an underground pipe or an open ditch for

carrying surface runoff.

Storm Water: Precipitation that accumulates in natural and/or constructed storage and

storm water systems during and immediately following a storm event. 

Storm Water Management: Functions associated with planning, designing,

constructing, maintaining, financing, and regulating the facilities (both constructed and

natural) that collect, store, control, and/or convey storm water.

Storm Water Pollution Prevention Plan (SWPPP): A plan to describe a process

whereby a facility thoroughly evaluates potential pollutant sources at a site and selects

and implements appropriate measures designed to prevent or control the discharge of

pollutants in storm water runoff.

Surface Water: Water that remains on the surface of the ground, including rivers,

lakes, reservoirs, streams, wetlands, impoundments, seas, estuaries, etc.

Total Maximum Daily Load (TMDL): The maximum amount of pollutants which can

released into a water body without adversely affecting the water quality. 

Tool Box: A term to describe the activities and materials that EPA plans to

perform/produce to facilitate implementation of the storm water program in an effective

and cost-efficient manner. The eight components include: 1)fact sheets; 2) guidance

documents; 3) menu of BMPs; 4) compliance assistance; 5) information clearing house;

6) training and outreach efforts; 7) technical research; and 8) support for demonstration

projects.

Urbanized Area (UA): A Bureau of the Census determination of a central place (or

places) and the adjacent densely settled surrounding territory that together have a

minimum residential population of 50,000 people and a minimum average density of

1,000 people/square mile. This is a simplified definition of a UA, the full definition is

very complex.
Appendix A

Page A-6 Storm Water Phase II Compliance Assistance Guide

Urban Runoff: Storm water from urban areas, which tends to contain heavy

concentrations of pollutants from urban activities.

Watershed: That geographical area which drains to a specified point on a water

course, usually a confluence of streams or rivers (also known as drainage area,

catchment, or river basin).

Wet Weather Flows: Water entering storm drains during rainstorms/wet weather

events.
Appendix B

Page B-1 Storm Water Phase II Compliance Assistance Guide

EPA Regional Offices

Region 1 (CT, MA, ME, NH, RI, VT) Region 6 (AR, LA, NM, OK, TX)

Environmental Protection Agency Environmental Protection Agency

1 Congress St. Suite 1100 Fountain Place 12th Floor, Suite

Boston, MA 02114-2023 1200

http://www.epa.gov/region01/ 1445 Ross Avenue

Phone: (617) 918-1111 Dallas, TX 75202-2733

Fax: (617) 565-3660 http://www.epa.gov/region06/

Toll free within Region 1: (888) Phone: (214) 665-2200

372-7341 Fax: (214) 665-7113

Toll free within Region 6: (800)

Region 2 (NJ, NY, PR, VI) 887-6063

Environmental Protection Agency

290 Broadway Region 7 (IA, KS, MO, NE)

New York, NY 10007-1866 Environmental Protection Agency

http://www.epa.gov/region02/ 901 North 5th Street

Phone: (212) 637-3000 Kansas City, KS 66101

Fax: (212) 637-3526 http://www.epa.gov/region07/

Phone: (913) 551-7003

Region 3 (DC, DE, MD, PA, VA, WV) Toll free: (800) 223-0425

Environmental Protection Agency

1650 Arch Street Region 8 (CO, MT, ND, SD, UT, WY)

Philadelphia, PA 19103-2029 Environmental Protection Agency

http://www.epa.gov/region03/ 999 18th Street Suite 500

Phone: (215) 814-5000 Denver, CO 80202-2466

Fax: (215) 814-5103 http://www.epa.gov/region08/

Toll free: (800) 438-2474 Phone: (303) 312-6312

Email: r3public@epa.gov Fax: (303) 312-6339

Toll free: (800) 227-8917

Region 4 (AL, FL, GA, KY, MS, NC, Email: r8eisc@epa.gov

SC, TN)

Environmental Protection Agency Region 9 (AZ, CA, HI, NV)

Atlanta Federal Center Environmental Protection Agency

61 Forsyth Street, SW 75 Hawthorne Street

Atlanta, GA 30303-3104 San Francisco, CA 94105

http://www.epa.gov/region04/ http://www.epa.gov/region09/

Phone: (404) 562-9900 Phone: (415) 744-1305

Fax: (404) 562-8174 Fax: (415) 744-2499

Toll free: (800) 241-1754 Email: r9.info@epa.gov

Region 5 (IL, IN, MI, MN, OH, WI) Region 10 (AK, ID, OR, WA)

Environmental Protection Agency Environmental Protection Agency

77 West Jackson Boulevard 1200 Sixth Avenue

Chicago, IL 60604-3507 Seattle, WA 98101

http://www.epa.gov/region5/ http://www.epa.gov/region10/

Phone: (312) 353-2000 Phone: (206) 553-1200

Fax: (312) 353-4135 Fax: (206) 553-0149

Toll free within Region 5: (800) Toll free: (800) 424-4372

621-8431
Appendix C

Page C-1 Storm Water Phase II Compliance Assistance Guide

References

Storm Water Phase II Final Rule (64 FR 68722) published December 8, 1999.

http://www.epa.gov/owm/sw/phase2

Storm Water Phase II Final Rule Fact Sheet Series, January 2000

A series of 15 fact sheets breaking the final rule into separate parts.

http://www.epa.gov/owm/sw/phase2

USEPA. 1999. Report to Congress on the Phase II Storm Water Regulations. EPA

833-R-99-001. U.S. Environmental Protection Agency, Office of Water, Washington,

DC.

U.S. EPA. Office of Water. 1993. Investigation of Inappropriate Pollutant Entries into

Storm Drain Systems: A User’s Guide. EPA/600/R-92/238. Washington, DC.

USEPA. 1992. Storm Water Management for Construction Activities: Developing

Pollution Prevention Plans and Best Management Practices. EPA 832-R-92-005. U.S.

Environmental Protection Agency, Office of Water, Washington, DC. 

USEPA. 1992. Storm Water Management For Industrial Activities: Developing Pollution

Prevention Plans And Best Management Practices. EPA 832-R-92-006. U.S.

Environmental Protection Agency, Office of Water, Washington, DC. 

American Society of Civil Egineers. 1999. National Stormwater Best Management

Practices BMPs Database. <http://www.asce.org/peta/tech/nsbd01.html>.

American Public Works Association. 2000. Designing and Implementing an Effective

Storm Water Management Program. <http://www.apwa.net>