Overview Description of Illicit Discharge Elimination
An illicit discharge is the introduction of polluting materials
into a pipe that drains to surface water or the dumping of polluting
material that can impact surface water. This is a broader definition
than the "classical" definition of sanitary plumbing fixtures connected
to a storm sewer. The Rouge Project found there were a number of
illicit discharges that were adversely impacting water quality.
Examples found in the Rouge River watershed include toilets connected
to storm sewers, laundry waste discharging to a drain, swimming
pool backwash water discharging to a storm sewer or situations where
polluting material can move over land to a storm sewer.
The illicit discharge elimination program (IDEP) in the Rouge River
Watershed began in 1987 when Wayne County recognized the need to
address this significant source of pollution. The program started
small and gained impetus when the Rouge Project started. The monitoring
data on the Rouge River suggested that illicit discharges were contributing
to high bacteria counts during dry weather in several parts of the
watershed. Further water quality testing found consistently high
levels of fecal coliform and E. coli bacteria upstream of locations
that had combined sewer overflows and in several locations where
there were no municipal sanitary systems. Because of the potential
threat to public health, a great deal of effort is being placed
on regulating illicit discharges.
Illicit Discharge Program in the Rouge Watershed
In a watershed as large and intensely urbanized as the Rouge River,
it is important to focus illicit connection program efforts in geographical
areas with the greatest potential to have inappropriate discharge
to storm sewers, surface waters or the ground. The target areas
in the program are named drainage service areas (DSAs) and define
the specific area serviced by an individual storm sewer. The procedure
for selecting a DSA for illicit connection investigation has been
an evolutionary process.
Criteria used to select the first target areas were based on available
water quality information, Michigan Department of Environmental
Quality (MDEQ) complaint history and generalized land use. This
process relied heavily on personal knowledge of state, county and
municipal staff. In 1989, the Southeastern Michigan Council of Governments
(SEMCOG) developed a process for prioritizing DSAs associated with
430 known outfalls within Wayne County. Criteria included: outfall
size, DSA acreage, land use, water quality information (including
complaint history), and frequency of priority businesses. The following
lists the prioritization of facilities in the screening process.
Priority I Automobile-related businesses/facilities and heavy
Priority II Printers, dry cleaners/laundries, photo processors,
utilities, paint stores, water conditioners, chemical laboratories,
construction companies, and medium-light manufacturing
Priority III Institutional facilities, private service agencies,
retail establishments, and schools
Once ranked, surveys were conducted. The surveys consist of a visual
inspection of the facility, discussion with the facility operator,
placing of dye in plumbing fixtures, flushing the dye, observing
it in sewers outside the building and reporting the findings to
The illicit discharge teams also investigate complaints of suspicious
materials reported in drains or dumped into drains. Complaint investigations
have resulted in finding both illicit and illegal discharges. The
illicit discharge teams also sample outfalls to search for illicit
discharges. A global positioning system coordinate is identified
for the outfall and samples are taken. The parameters sampled depend
on the odor and visual evaluation of the discharge.
For a more detailed description of the Wayne County IDEP see The
Do's and Don'ts on Implementing a Successful Illicit Connection
Program. See also Wayne Co. Illicit Connection
Program. For additional information on field inspection procedures
see "Illicit Connection Control Program: Field Inspection Procedures."
The methods for prioritizing facilities to be surveyed and details
of the beginning of this program are summarized in the technical
of Illicit Connection Detection Programs in Michigan, February 1996."
The IDEP Program and Storm Water Control
Since the inception of the IDEP program in the Rouge River watershed,
other requirements have been established at the federal and state
level that require such a program. One of the requirements of the
federal Phase II NPDES storm
water regulations is to develop, implement, and enforce a program
to eliminate improper connections to the storm sewer system and
other improper discharges to surface waters.
To more effectively address the issues of storm water pollution
in Michigan, the MDEQ issued a general permit. See Michigan
General Storm Water Permit for a detailed discussion of that
permit. In briefest summary, this voluntary permit establishes the
process for developing overall watershed management plans to address
the control of storm water and other sources of pollution.
The General Permit requires each permittee to develop a:
- Watershed Management Plan prepared in cooperation with others,
to resolve water quality concerns. The Plan would include: short
and long-term goals for the watershed, delineation of actions
needed to achieve the goals, estimated benefits and costs of management
options, an opportunity for all stakeholders to participate in
the process. The Watershed Management Plan is due two years after
the certificate of coverage is issued to the applicant.
- Illicit Discharge Elimination Plan (IDEP) that has the goal
of eliminating raw sewage discharges and includes addressing failing
septic systems and improper connections of sanitary sewers to
storm drains and open waterways. The IDEP is due at the time of
- Public Education Plan (PEP) designed to inform residents and
businesses what actions they should take to protect the river.
The PEP is due at the time of permit application.
- Storm Water Pollution Prevention Initiative (SWPPI) which includes
evaluation and implementation of pollution prevention and good
housekeeping practices and the evaluation and implementation of
BMPs to minimize impacts of new development and redevelopment.
The SWPPI is a subset of the Watershed Management Plan and is
due 2.5 years after the certificate of coverage is issued to the
- Monitoring and Reporting Plan including schedule for revisions
to the Watershed Management Plan
As seen in the underlined language above, a key requirement of
the General Permit is for communities to develop and implement an
effective IDEP program. MDEQ and the Rouge Project developed four
basic guidance documents for use by any community in applying for
and then implementing the General Permit. One of those four guidance
documents was Illicit
Discharge Elimination Plan Guidance (Part IV).
For additional information on the implementation of the General
Storm Water Permit and its role in developing and implementing watershed
management plans, see Overview
Description of Watershed Management for the Rouge River.
A number of communities in the Rouge Watershed have developed and
are implementing their illicit discharge elimination programs. Two
example plans can be viewed by clicking on Canton
Community Illicit Discharge Elimination Plan or the Illicit
Connection & Discharge Plan for Bloomfield Township.
Representatives of the Rouge Project have developed numerous technical
reports concerning illicit discharges as well as onsite sewage disposal
systems. Click on Illicit
Discharges/Onsite Sewage Disposal Systems to view those reports.
Click on Illicit Discharge Elimination
Training Program to view Wayne County's IDEP training program.
For additional and more detailed information on Rouge Project's
IDEP program, go to Rouge Project Presentations
on the Illicit Discharge Elimination Program and Illicit
Discharge Elimination Program Reports.
Results of IDEP Program in the Rouge Watershed
The following are a summary of the results (October 1987 through
December 2001) found by Wayne County through its IDEP:
4,887 facilities have been surveyed
376 facilities have been found to have illicit discharges
1,243 illicit discharges have been found. (A facility often has
more then one illicit discharge)
The types of illicit discharges Wayne County has found historically
are summarized in the pie chart below.
The most common violations found were caused by past building practices.
Floor drains were allowed to discharge to the storm system in the
1940s, 50s and 60s. A majority of these floor drains only receive
flow when the floors were washed. It is also important to point
out that 219 or 30 percent of the violations were sinks and toilets,
discharging contaminated water. An unusual finding was the horse
washing/washing machine category. This discovery was made at a horse
race track that stables 600 horses. Each horse was washed once per
day (80 to 110 gallons of water per each horse). The facility had
98 concrete pads scattered throughout the stable area for washing
horses. Each pad also had a washing machine used to wash horse blankets.
The discharge from these pads went to a county drain.
Illicit connections can also be the result of new construction
or renovations. For example, a brand new 54-room motel was found
to have its entire sanitary system retreating to a storm sewer.
A large supermarket in a strip mall was closed and the space was
divided into a hardware store and meat market. The meat market space
contained the cooler and facilities (restrooms, lunchroom). New
restrooms and a lunchroom had to be constructed for the hardware
store. Construction crews broke through the concrete floor and found
a horizontal drainpipe and tied all of the plumbing fixtures into
it. Unfortunately, this line was a lead from the storm water roof
conductor in the center of the building to the storm sewer in the
alley. These are the types of violations that may happen infrequently,
but may have a significant localized impact on the river.
Significant quantities of pollution have been eliminated through
the IDEP program.
Wayne County IDEP Services
Within a given geographic area, multiple agencies (e.g., county,
local unit of government, transportation agencies, etc.) typically
have obligations and authority to manage illicit discharge elimination
efforts. This effort requires a partnership between the County,
local government, and other agencies that own, operate, or control
discharges within a given geographic area. A key goal of Wayne County
IDEP is to facilitate partnerships with other local agencies and
to provide coordinated, comprehensive, and cost-effective Illicit
Discharge Elimination Services to reduce illegal and improper discharges
to rivers, lakes and streams in Wayne County. Detailed on the Wayne
County Web site are the variety of illicit discharge elimination
services and activities currently performed by Wayne County including
a list of services available to communities and others for a fee.
Wayne County has made available these services to assist in finding
illicit connections and in helping communities with their Illicit
Discharge Elimination Plans that are part of communities' general
storm water permit. Services offered are:
- Illicit discharge elimination training
- 24 Hour Hot Line to report environmental concerns
- Coordinated complaint response
- Response to emergency spills
- Identification/reporting of suspicious discharges
- Outfall inspections/surveys
- Advanced investigations
- Failing onsite sewage disposal investigations. This service
is focused on correcting a failing OSDS that has been reported.
Services that WCDOE will provide for a fee are:
- Inspection of all outfalls in a community, including identifying
the outfall with global positioning system, photographs, samples
of discharges and reporting results.
- Advanced investigations of suspected illicit discharges. This
service will track a discharge to the source.
- Investigation of individual buildings for illicit discharges.
- Finding a specific failing OSDS where one is suspected in an
A requirement of the Michigan General Storm Water Discharge Permit
is that the community develop an Illicit Discharge Elimination Program
and submit it with their application. Over 45 communities in the
Rouge River watershed have submitted storm water permit applications
and have begun to implement their illicit discharge elimination
programs. The plans were required to be implemented when the certificate
of coverage was issued by MDEQ.
Most communities have also established a complaint line for calling
in suspicious discharges.
Information about some community programs can be found on the Rouge
River Web site under "Local Community
One significant program that most communities are conducting to
prevent illicit discharges is a household hazardous waste disposal
program. The program provides for safe disposal of hazardous household
chemicals. The Rouge River Web site has information about household
Results of the IDEP
The IDEP being implemented by the three counties and the communities
in the Rouge Watershed is resulting in the elimination of numerous
sources of water pollution to the waterway. This is having a major
positive impact on the water quality as well as the aesthetic quality.
The program has demonstrated several things including:
Overview Description of Illicit Discharge Elimination Program
- methods that are successful in finding illicit discharges
- methods that have not been successful in finding illicit discharges
- types of businesses most likely to have an illicit discharge
- tests that can be used to determine if there is an illicit discharge
and where the discharge might have originated.