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Overview Description of Illicit Discharge Elimination Program

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 manufacturing

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 owner.

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 memorandum, "Summary 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 permit application.
  • 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 applicant.
  • 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 area.

Community Activities
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 Information."

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 hazardous waste.

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:

  • 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.

Overview Description of Illicit Discharge Elimination Program

Last Updated: 5/22/02

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The Rouge River National Wet Weather Demonstration Project is funded, in part, by the United States Environmental Protection Agency (EPA) Grants #XP995743-01, -02, -03, -04, -05, -06, -07 and C-264000-01.