An illicit discharge is defined by U.S. EPA as “any discharge into a separate storm sewer system that is not composed entirely of storm water.” Typically, illicit discharges enter a storm sewer system either through direct connections, or indirectly from cracked sanitary sewer conveyance systems, spills collected by storm drains, or from contaminants dumped directly into a storm drain inlet.
Pollutants associated with illicit discharges include heavy metals, toxics, oil and grease, solvents, nutrients, viruses and bacteria. The following are typical examples of illicit discharges:
Sanitary wastewater
Effluent from septic tanks
Laundry wastewater
Commercial car wash discharges
Improper disposal of household or automotive toxics
Spills from roadway accidents
Under its Storm Water Management Plan, Clermont County developed a multi-faceted program to identify and eliminate illicit discharges to the storm sewer system. This program includes the following activities:
MAPPING THE STORM WATER CONVEYANCE SYSTEM – To track sources of illicit discharges, it is important to understand where storm sewers are located and how they are interconnected with each other and with ditches and streams. Clermont County is required by Ohio EPA to map all points where the storm sewer system discharges to local waterways. In order to better manage the storm system and develop a more effective illicit discharge program, the County is going above and beyond these requirements by developing a comprehensive computer-based map of the entire storm water conveyance system Click here for more information on this program.
ILLICIT DISCHARGE REGULATIONS – Clermont County recently adopted a set of regulations prohibiting illicit discharges to the storm water conveyance system as part of its Water Management and Sediment Control Regulations (Chapter 8). Click here to download the illicit discharge regulations.
ILLICIT DISCHARGE SCREENING – As of 2007, Clermont County has identified over 3000 public and private storm water discharge points. Field crews visit these outfalls looking for signs of illicit discharges, including flow during dry weather, odors, discolored or turbid water, solids and floatables, deposits or stains, and many other signs.
ILLICIT DISCHARGE SAMPLING – If a suspected illicit discharge is identified, field crews may collect a sample and have it analyzed for various pollutants. Additionally, both the Office of Environmental Quality and the Soil and Water Conservation District help by conducting stream sampling during dry weather, when the impacts from continuous illicit discharges aren’t masked by storm water runoff.
HOME SEWAGE TREATMENT SYSTEMS – Discharging septic systems (household sewage treatment systems, or HSTS) that cause violations of State Water Quality Standards are classified as illicit discharges by Ohio EPA. The Clermont General Health District conducts regular inspections of these systems. The Storm Water Department periodically helps the Health District and the Office of Environmental Quality collect and analyze samples from these systems. To ensure proper installation, operation and maintenance, the Health District conducts annual HSTS installer training sessions and frequently conducts homeowner education sessions.
EDUCATION PROGRAMS - The Storm Water Department has several educational fact sheets available that provide helpful tips on what you can do to prevent storm water pollution. The Department also presents education programs from time to time for various storm-water related issues. Check the News & Events section for upcoming programs.
HOW YOU CAN HELP – The Storm Water Department does its best to identify illicit discharges, but we can always use an extra set of eyes. If you see something other than storm water being discharged into a storm sewer, ditch or stream, please contact the Storm Water Management Department at (513) 732-7880, or send an email to storm@co.clermont.oh.us. For tips on how to identify an illicit discharge, check Clermont County’s Guide to Spotting and Reporting Illicit Discharges.