One of the six minimum measures of an MS4 program is Illicit Discharge Detection and Elimination (IDDE).
The goal of IDDE is to locate non-stormwater discharges – particularly chronic discharges – entering the storm drain system and to eliminate them. It is not uncommon to find that older buildings plumbed wash waters and such to a storm drain, which from there entered a stream. It’s also not uncommon to find regular washing outdoors that drains the wash water to storm drains.
Types of Innocuous Waters
There are a number of innocuous, non-stormwater discharges that may be discharged to the storm drain, but otherwise non-stormwater discharges are restricted from entering storm drains. Some of the innocuous waters are:
Air conditioning condensation
Groundwater infiltration to storm drains
Landscape irrigation or lawn watering with potable water or re-purified water
Non-commercial washing of vehicles
Other uncontaminated water source
Swimming pools (if dechlorinated)
Water line flushing or other potable water sources
Our screening activities are periodic only, and so we must rely on reports from you – citizens – and from other city staff to find non-stormwater discharges. Call us if you see wash waters being discharged into or toward storm drains at 615-848-3200.