oEPA
United States
Environmental Protection
Agency
Office of Water EPA 833-F-00-007
(4203) January 2000 (revised December 2005)
Fact Sheet 2.5
Storm water Phase II
Final Rule
Stormwater Phase II
Final Rule
Fact Sheet Series
Overview
1.0 - Stormwater Phase II Final
Rule: An Overview
Small MS4 Program
2.0 - Small MS4 Stormwater
Program Overview
2.1 - Who's Covered? Designation
and Waivers of Regulated Small
MS4s
2.2 - Urbanized Areas: Definition
and Description
Minimum Control Measures
2.3 - Public Education and
Outreach
2.4 - Public Participation/
Involvement
2.5 - Illicit Discharge Detection
and Elimination
2.6 - Construction Site Runoff
Control
2.7 - Post-Construction Runoff
Control
2.8 - Pollution Prevention/Good
Housekeeping
2.9 - Permitting and Reporting:
The Process and Requirements
2.10 - Federal and State-Operated
MS4s: Program Implementation
Construction Program
3.0 - Construction Program
Overview
3.1 -Construction Rainfall
Erosivity Waiver
Industrial "No Exposure"
4.0 - Conditional No Exposure
Exclusion for Industrial Activity
Illicit Discharge Detection and
Elimination Minimum Control Measure
This fact sheet profiles the Illicit Discharge Detection and Elimination minimum control
measure, one of six measures the operator of a Phase II regulated small municipal separate
storm sewer system (MS4) is required to include in its stormwater management program to
meet the conditions of its National Pollutant Discharge Elimination System (NPDES) permit.
This fact sheet outlines the Phase II Final Rule requirements and offers some general guidance
on how to satisfy them. It is important to keep in mind that the small MS4 operator has a great
deal of flexibility in choosing exactly how to satisfy the minimum control measure
requirements.
What Is An "Illicit Discharge"?
Table 1
Federal regulations define an illicit discharge
as "...any discharge to an MS4 that is not
composed entirely of stormwater..." with some
exceptions. These exceptions include discharges
from NPDES-permitted industrial sources and
discharges from fire-fighting activities. Illicit
discharges (see Table 1) are considered "illicit"
because MS4s are not designed to accept, process,
or discharge such non-stormwater wastes.
Why Are Illicit Discharge Detection and
Elimination Efforts Necessary?
Discharges from MS4s often include wastes and
wastewater from non-stormwater 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.
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
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Fact Sheet 2.5 - Illicit Discharge Detection and Elimination Minimum Control Measure
Page 2
What Is Required?
Recognizing the adverse effects illicit discharges can have
on receiving waters, the Phase II Final Rule requires an
operator of a regulated small MS4 to develop, implement and
enforce an illicit discharge detection and elimination program.
This program must include the following:
Q 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;
Q Through an ordinance, or other regulatory mechanism,
a prohibition (to the extent allowable under State,
Tribal, or local law) on non-stormwater discharges into
the MS4, and appropriate enforcement procedures and
actions;
Q A plan to detect and address non-stormwater
discharges, including illegal dumping, into the MS4;
Q The education of public employees, businesses, and
the general public about the hazards associated with
illegal discharges and improper disposal of waste; and
Q 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-stormwater discharges or flows unless the
operator of the regulated small MS4 identifies them as
significant contributors of pollutants to its MS4:
Q Water line flushing;
Q Landscape irrigation;
Q Diverted stream flows;
Q Rising ground waters;
Q Uncontaminated ground water infiltration;
Q Uncontaminated pumped ground water;
Q Discharges from potable water sources;
Q Foundation drains;
Q Air conditioning condensation;
Q Irrigation water;
Q Springs;
Q Water from crawl space pumps;
Q Footing drains;
Q Lawn watering;
Q Individual residential car washing;
Q Flows from riparian habitats and wetlands;
Q Dechlorinated swimming pool discharges; and
Q 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 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
demonstrates such 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 possible.
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. As guidance only, the four steps of a
recommended plan are outlined below:
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Fact Sheet 2.5 - Illicit Discharge Detection and Elimination Minimum Control Measure
Page 3
O 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). Methods that can locate problem areas include:
visual screening; water sampling from manholes and
outfalls during dry weather; the use of infrared and thermal
photography, cross-training field staff to detect illicit
discharges, and public complaints.
@ Find the Source
Once a problem area or discharge is found, additional
efforts usually are necessary to determine the source of the
problem. Methods that can 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.
& Document Actions Taken
As a final step, all actions taken under the plan should
be documented. This illustrates that progress is being
made to eliminate illicit connections and discharges.
Documented actions should be included in 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
The Center for Watershed Protection and Robert Pitt (2004)
researched the most cost-effective and efficient techniques
that can be employed to identify and correct inappropriate
discharges. Data from Montgomery County, Maryland, was
analyzed and it was determined that staff identify and correct
about six inappropriate discharges per year as a result of
regular screening. By contrast, over 185 inappropriate
discharges are corrected each year in Montgomery County as
a direct result of citizen complaints and calls to a storm water
compliant hotline. Public education and labeling of outfalls
and other storm drain infrastructure is an important element of
establishing a successful citizen hotline. Outreach to public
employees, businesses, property owners, the general public,
and elected officials regarding ways to detect and eliminate
illicit discharges is an integral part of this minimum measure.
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 fully addresses the requirements
and intent of the minimum control measure.
EPA has developed a Measurable Goals Guidance for Phase
II MS4s that is designed to help program managers comply
with the requirement to develop measurable goals. The
guidance presents an approach for MS4 operators to develop
measurable goals as part of their stormwater management
plan. For example, an MS4 could establish a measurable goal
of responding to all complaints received by the citizen
complaint hotline within 24 hours to minimize water quality
impacts or recurrent dumping. A complaint tracking system
could be used to log response and enforcement activity.
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 (see Fact Sheet 2.3).
Sources
Center for Watershed Protection and R. Pitt. 2004. Illicit
Discharge Detection and Elimination: A Guidance
Manual for Program Development and Technical
Assessments. Center for Watershed Protection, Ellicott
City, MD, and University of Alabama, Birmingham,
AL.
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Fact Sheet 2.5 - Illicit Discharge Detection and Elimination Minimum Control Measure
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Maryland Department of the Environment, Water
Management Administration. 1997. Dry Weather
Flow and Illicit Discharges in Maryland Storm Drain
Systems. Baltimore, Maryland.
U.S. EPA Office of Water. 1993. Investigation of
Inappropriate Pollutant Entries into Storm Drainage
Systems: A User's Guide. EPA/600/R-92/238.
Washington, D.C.
Wayne County Rouge Paver National Wet Weather
Demonstration Project. 1997. Guidance for Preparing
a Program for the Elimination of Illicit Discharges.
Wayne County, Michigan.
For Additional Information
Contacts
"^ U.S. EPA Office of Wastewater Management
http ://www. epa. gov/npdes/stormwater
Phone: 202-564-9545
"^ Your NPDES Permitting Authority. Most States and
Territories are authorized to administer the NPDES
Program, except the following, for which EPA is the
permitting authority:
Alaska
District of Columbia
Idaho
Massachusetts
New Hampshire
New Mexico
American Samoa
Guam
Johnston Atoll
Midway and Wake Islands
Northern Mariana Islands
Puerto Rico
Trust Territories
"^ A list of names and telephone numbers for each EPA
Region and State is located at http://www.epa.gov/
npdes/stormwater (click on "Contacts").
Reference Documents
"^ EPA's Stormwater Web Site
http ://www. epa. gov/npdes/stormwater
• Stormwater Phase II Final Rule Fact Sheet Series
• Stormwater Phase II Final Rule (64 FR 68722)
• National Menu of Best Management Practices for
Stormwater Phase II
• Measurable Goals Guidance for Phase II Small
MS4s
• Stormwater Case Studies
• And many others
"^ Illicit Discharge Detection and Elimination: A
Guidance Manual for Program Development and
Technical Assessments
http://www.cwp.org/idde verify.htm
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