Runoff Rundown
Winter 2008
Feature Article #2

Getting Down and Dirty with Illicit Discharges

For six days in early November, the Center had the wet, but enjoyable, task of conducting our Illicit Discharge Detection and Elimination (IDDE) training in the Jones Falls Watershed in Baltimore, MD.  Funded by the Rauch Foundation, this project will provide an opportunity to train local watershed groups, staff from Baltimore City and Baltimore County, citizens and local environmental consultants on the field and laboratory techniques used to detect illicit discharges.

Over the course of the week, field crews walked 6.5 stream miles in the Stony Run and Western Run subwatersheds to look for flowing outfalls that may indicate the presence of an illicit discharge. Of the 135 outfalls assessed, 28 were flowing! Field crews collected samples from the flowing outfalls and conducted an initial screening. Field crews looked at a number of physical indicators for each sample, including color, odor and taste (just kidding there; don’t try that at home!). Field crews then headed to the lab to conduct a chemical analysis of the samples.

Back in the lab, the Flow Chart Method presented in the IDDE Manual was used to determine the presence of contaminants. Lab crews then tested the samples for detergents, ammonia, potassium, fluoride, and E. Coli. Preliminary results showed that over 20% of the samples tested positive for sewage or washwater.  This is a considerably high number, especially when finding an actively flowing discharge in the field is often pure luck -- or, unfortunately, the sign of a much bigger problem!     

Our next step will be to focus on another Baltimore watershed - Herring Run - and further train staff and volunteers from the Herring Run Watershed Association on the IDDE methods.  Once this training is complete, volunteers will be equipped to continue discharge investigations in their respective neighborhoods. 

To learn more about the Center IDDE techniques, including the Flow Chart Method, download the IDDE Manual and its related resources here: http://www.cwp.org/IDDE/IDDE.htm

Anatomy of a Dye Tracing Scene :

1. Preparing dye for dye tracing a sewage leak

2. Dropping the dye in the sanitary line

3. Waiting for the dye to appear at the storm drain outfall to confirm the sewage leak

4. Confirmed sewage leak!