Illicit Discharges & Improper Disposal

Program Overview

The City of Chattanooga Water Quality Program ensures proper identification & removal of non-stormwater discharges through the Illicit Discharge Detection & Elimination (IDDE) Program. The City implemented this on-going program in 1991 as a means of addressing significant contributors of pollutants to the City's drainage system (Municipal Separate Storm Sewer System, or MS4). The City's involvement assists in the protection of the environment, proper containment & clean-up of hazardous materials, and increases public awareness of ways to protect the environment by preventing harmful discharges and accidental spills.

IDDE Program Components

Along with everyday investigations of non-stormwater discharges, the IDDE Program includes a wide range of field activities such as:

• Field Screening

• Emergency Spill Response

• Limiting Sanitary Sewer Seepage

The combination of these tools is essential in the timely and effective detection and removal of active and potential illicit discharges into the MS4.

In order to ensure the timely and appropriate resolution to an illicit discharge it must first be properly identified. The Water Quality Program utilizes a variety of means in the tracing and identifying of these discharges. Just as there are multiple types and sources of illicit discharges, so are there tools for detecting and tracing them.

• The first of these comes in the form of training. Staff must be properly educated so as to know exactly what to look for, where to look, and which other tools to use in the tracking and identifying processes.

• The use of GIS has been proven extremely valuable. By having access to storm and sanitary sewer structures that have been previously mapped in GIS, Water Quality Staff can narrow the search for a discharge source by knowing the layout of these systems.

• Once a particular pollutant has been identified as the suspect component of a discharge, Water Quality staff members conduct necessary tests to ensure accurate identification of the source. Some of the most commonly employed tests and related suspect sources are as follows:

1. Ammonia- used when testing for sanitary defects

2. E. coli- used when testing for sanitary defects

3. Chlorine- used when testing for potable water leaks, sanitary defects, & wash water discharges

4. Phosphates – used when testing for Fertilizers

5. Detergents- used when testing for wash water discharges

6. Dye- used in the confirmation of a discharge source location

 llicit Discharge- Sources

Any non-stormwater discharge into the MS4 that contributes pollutants to receiving waters is considered an Illicit Discharge. Some examples include:

• Sanitary wastewater from compromised sanitary sewer service & main lines and septic tanks

• Laundry Wash water

• Commercial Car Wash

• Improper Disposal of Food waste (e.g. grease)

• Improper Disposal of Automotive & Household Products (e.g. oils and other fluids)

• Leaves & other yard waste dumped into an open drainage & stream channels preventing proper flow of stormwater

• Chlorinated Swimming Pool Discharges

• Unregulated Commercial & Industrial Discharges

There are, however, some exceptions. Some of these "allowable" non-stormwater discharges include:

• Water Line Flushing

• Landscape Irrigation

• Uncontaminated Pumped Groundwater

• Individual Residential Car Washing

• Discharges or Flows from Emergency Fire Fighting Activities

• Dechlorinated Swimming Pool Discharges

Chattanooga City Code

Section 31-341 of the Chattanooga City Code prohibits direct and indirect discharges into "Community Waters" or "Waters of the State". (Ordinance Number 9942, § 1, 8-31-93)

For further information on the IDDE Program, see the Standard Operating Procedure (SOP).

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