City of Maryville
Illicit Discharge Detection and Elimination
Department of Engineering & Public Works
Stormwater Management is located at the Maryville Municipal Building (Lower Level)
400 W Broadway Avenue   |   Maryville, TN 37801   |    Phone: 865-273-3500  
Business Hours   |   8:00 a.m. - 5:00 p.m.   |   Closed 12:00 p.m. - 1 p.m. for lunch
Jana Brown, Stormwater Program Manager  |  865-273-3512  |  [email protected]
Storm Water Management Home
Illicit Discharge Detection and Elimination Program (IDDE) 
​Only stormwater is allowed in the City’s stormwater drainage system. When anything else gets intentionally or accidentally put into stormwater pipes or ditches, it is called a non-stormwater or illicit discharge. Sometimes, buildings or homes have pipes that are illegally connected to the stormwater drainage system for getting rid of waste. Others might dump their waste into these drains. 
It's against the law to put anything besides rainwater or allowed substances that are not stormwater into the storm drains.  
The City has a program to find and stop illicit discharges from entering the stormwater system. Learn more about Maryville's illicit discharge program through the links below.
  • Why Illicit Discharges are Hazardous
  • The City's Strategy for Managing Illicit Discharges
  • Allowable Non-Stormwater Discharges within the City
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NPDES Permit Section 4.2.3
Why Illicit Discharges are Hazardous
​Stormwater in Maryville can pick up pollutants as it moves through storm drains and ditches on its way to creeks and rivers. Illicit discharges are dangerous because they can pollute rivers and streams with harmful chemicals, nutrients, and bacteria that hurt both aquatic life and people:
  • Toxic Pollutants: Car fluids, diesel fuel, and other chemicals can poison large amounts of water, killing fish and other water animals.
  • Nutrients: Too much phosphorus and nitrogen can make algae grow too fast, which lowers oxygen levels and harms plants and animals that need oxygen to survive.
  • Pathogens (disease causing organism): Bacteria from animal waste or bad sewer connections can make water unsafe for swimming, wading, or eating fish. Pathogens in the water can raise the cost of our drinking water because the water treatment plant has to spend more money to make it safe to drink.
  • Eroded Soil: Loose soil can muddy the water and ruin the homes of fish and plants.
Illicit discharges can get into the stormwater system in different ways. For example, when a spill is not promptly cleaned-up, stormwater can wash the spilled substance into the stormwater system. Or people can dump pollutants, such as motor oil or unused paint, directly into storm drains or ditches without realizing these substances will end up in a local stream after it rains. Even a leaking septic or sewer system is an illicit discharge. Accidental or intentional, illicit discharges can cause many problems for our local government and local waterways.
  • Do your part to help!
The City of Maryville relies on you to prevent illicit discharges. Clean up spills promptly, make sure wastewater pipes are connected to the sanitary sewer system, fix leaky vehicles and equipment, and don’t dump anything, including grass clippings and dead animals, into storm ditches, drains, and streams. 
The City wants your help to find any illegal dumping or spills. You can look for signs like colored water, bubbles, foam, or an oily layer in a storm drain or nearby stream or lake. Bad smells or dead fish can also mean there are pollutants in the water. Finally, if you see water moving in a storm drain or ditch when it hasn't rained, that might be a sign of an illegal discharge. Outfalls (the openings of the end of pipes) and ditches should not have flow when it has not rained within the last 48 hours.
 
IF YOU SEE THESE CONDITIONS, REPORT IT!  Tell us what you saw, if there was a smell, when you saw it and where you saw it.  You can also call the City at (865) 273-3500 to report a problem.
  • City Employee Training on Illicit Discharges
In addition to citizen reporting, the City regularly trains our employees on how to recognize and report illicit discharges if they come across them during their daily duties.
NPDES Permit Section 4.2.3
Strategy for Managing Illicit Discharges 
The City’s illicit discharge detection and elimination program has a few key strategies that help the City locate, investigate and remove illegal discharges:
  • A map of the stormwater drainage system that shows all the City owned outfalls, places where water enters the City’s stormwater system (like inlets and catch basins), and flows from nearby areas that also have a permit from the State of Tennessee for stormwater management. The map shows the receiving streams for any stormwater flowing from the regulated part of the City. 
  • An ordinance that bans some types of non-stormwater discharges into the City’s stormwater drainage system.
  • Enforcement response plans that explain how the City will handle illegal discharges. These plans allow the City to take stronger actions if needed and to deal with repeat or serious violations that harm the environment.
  • A program to find, investigate, and address non-stormwater discharges, like illegal dumping, into the City’s stormwater drainage system. The program has set procedures and forms to help investigate these problems throughout the City’s regulated areas. To see the City’s illicit discharge detection and elimination plan (Click here)​​
NPDES Permit Section 4.2.3
Allowable Non-Stormwater Discharges 
​The slogan "Only Rain Down the Storm Drain" is used to remind people not to dump anything into storm drains.  However, the City does allow some types of non-stormwater discharges because the City has determined that they are not a big source of pollution. You can find this list in the City’s Stormwater Discharges Ordinance. The City reviews this list regularly. If the City finds that any of these discharges cause or may cause pollution, the City can order them stopped.