Illicit Discharge Program

The IDEP (Illicit Discharge) Program

(810) 987-7253

Suspicious discharges
Failing septic systems
Strong odors
Suspicious dumpings

Anonymous 24-hour reporting

The goal of the Illicit Discharge Elimination Program (IDEP) is to identify and eliminate sources of E. coli bacteria by collecting and testing water samples from our creeks, streams, rivers, road ditches, and drains.

What is an Illicit Discharge?

An illicit discharge is the release of wastewater or pollution entering a storm drain, waterway or ditch, such as:

  • Failing septic systems
  • Illegal dumping of oil or grass clippings
  • Washing machine and dish washing water
  • Sanitary sewer connected to a storm drain system
  • Commercial or industrial chemical discharge, disposal or dumping

Why are illicit discharges a problem?

Illicit discharges contaminate our water with chemicals, diseases and bacteria that harm fish, wildlife and people. Many children like to play in small creeks and streams where many illicit discharges begin and the public swims at beaches where illicit discharges accumulate. Discharges are most problematic during and after a rainstorm commonly leading to summertime beach closures.

How is St. Clair County finding illicit discharges?

Once a suspicious problem is discovered, our Environmental Health Sanitarians take a photograph, take a GPS point, and test for E. coli. Once the source of the problem is pinpointed, the resident is notified as to what actions they need to take in order to correct the problem.

Who is responsible for correction of illicit discharges?

Responsibility for fixing illicit discharges may fall upon a city or township, the county or a resident. The St. Clair County Health Department has the responsibility and authority to ensure that corrections are made through the Environmental Health Code and the Drain Code, which make these discharges illegal.

Useful Links

See below examples of illicit discharges (failing septic systems, grass clippings, leaves, oil, etc) identified by our IDEP teams.

Laundry Suds
Grass Clippings

Septic System Maintenance

Proper Septic System Maintenance

We need your help! Be an alert observer!
Report suspicious discharges and failing septic systems. The quicker we find these problems, the more efficiently we move toward cleaner water for everyone to enjoy. Help us - help you.

(810) 987-7253 or 1-877-504-SWIM

Why should I maintain my system?
When septic systems are adequately designed, carefully installed and properly maintained, they effectively reduce or eliminate most human health and environmental threats posed by pollutants in wastewater. Routine maintenance is cheaper than emergency maintenance or repairs - and much cheaper than total system replacement.

Saves You Money
Having your septic system pumped regularly (every 3-5 years) is a bargain when you consider the cost of replacing the entire system. Failing septic systems are expensive to repair or replace and poor maintenance is often the culprit.

Protects Your Home Investment
An unusable septic system or one in disrepair will lower your property value and could pose a legal liability. To sell your home, the disposal system has to be in good working order.

Protects Your Health
The safe disposal of sewage prevents the spread of infection and disease, and protects groundwater resources. Inadequately treated sewage can be a cause of groundwater contamination, posing a significant threat to wells and drinking water.

How do I maintain my system?
Pump Frequently

Your system should be pumped every three to five years - depending on the number of persons in the household and the size of the system.

Use Water Efficiently
Using more water than the soil can absorb is the most common reason for failure. The more water a household conserves, the less water that enters the septic system. Efficient water use can improve the operation of the septic system and reduce the risk of failure.

  • Replace your existing toilets and shower heads with high-efficiency models
  • Install aerators in the kitchen and bathroom faucets
  • Repair leaky faucets and toilets
  • Run the dishwasher and clothes washer only when they are full

Watch Your Drain
What goes down your drain can have a major impact on how well your septic system works. A garbage disposal takes a lot of water to move scraps down the drain.

Once in the tank, some of the solids break down by bacterial action, but most of the grindings will have to be pumped out. Using a disposal could cause you to have your tank pumped more often. Composting is a better way to recycle kitchen scraps.

Care For Your Drainfield
Your drainfield is an important part of your septic system.
Remember to:

  • Plant only grass over and near your septic system. Roots from nearby trees or shrubs can cause damage.
  • Don’t drive or park vehicles on any part of your septic system. Doing so can compact the soil and damage the pipes.
  • Keep roof drains, water softeners, sump pumps, and storm water run-off away from the drainfield. Flooding the drainfield with excessive water slows down or stops the treatment process and can cause backups.


Where is my tank located?
You may be able to find the lids or manhole covers for your septic tank; otherwise contact the Health Department for a drawing of your septic tank and drainfield. The tank can be found by gently tapping a steel rod into the ground starting 10 feet from the point where the pipe leaves the house or by waiting for a light snowfall and observing where the snow melts first.

Should I use additives?
Many products such as solvents, yeasts, bacteria, and enzymes claim to improve septic tank performance or reduce the need for routine pumping, but have not yet been found to make a significant difference. In fact, septic tanks already contain the microbes they need for effective treatment. Periodic pumping is a much better way to ensure a safe and effective system.

How does my septic system work?
A septic system has four main components: a pipe from the home or business, a septic tank, a drainfield, and the soil. Wastewater from your toilet, bath, kitchen, and laundry flows through a pipe from your house and into the septic tank. Microbes in the soil digest or remove most contaminants from the wastewater before it eventually reaches groundwater.

The Septic Tank
A septic tank is designed to intercept, hold and partially treat solids contained in wastewater from your home. The tank is a large, buried, watertight container typically made of concrete, fiberglass, or polyethylene. It holds the wastewater long enough to allow heavy solids to settle to the bottom (forming sludge) and oil and grease to float to the surface (as scum). Solids that are not decomposed remain in the septic tank. If not removed by periodic pumping, solids will accumulate until they eventually overflow the drainfield, causing costly repairs.

Septic tanks may have one or two compartments. Two compartment tanks do a better job of settling solids and may be required for new systems. Tees or baffles are provided at the tanks inlet and outlet pipes. The inlet slows the incoming wastes and reduces disturbance of the settled sludge. The outlet keeps the solids or scum in the tank. All tanks should have accessible covers for checking the condition of the baffles and for pumping.

The Drainfield
Wastewater exits the septic tank and is discharged into the drainfield for further treatment by the soil. Generally, the drainfield has a network of perforated pipes laid in gravel-filled trenches or beds in the soil. Wastewater trickles out of the pipes, through the gravel layer, and into the soil. The size and type of drainfield depends on the estimated daily wastewater flow and soil conditions.

The soil filters effluent as it passes through the pore spaces. Microorganisms in the soil provide final treatment by removing harmful bacteria, viruses, and nutrients. After the effluent has passed into the soil, most of it percolates downward and outward, eventually reaching groundwater.