Illicit Discharge

What is an Illicit Discharge?

An illicit discharge is any disposal, pouring or dumping into the City’s Municipal Separate Storm Sewer System (MS4) that is not composed entirely of stormwater, except permitted discharges and firefighting related discharges. Refer to Section 7 of the City of Monroe’s Stormwater Management Ordinance Chapter (159-701),  to read a definition of Illicit Discharges.

Common examples of illicit discharges are spills of household substances such as:
     - Oil (motor oil, cooking oil & grease)
     - Paint & paint remover
     - Cleaners
     - Pesticides
     - Fertilizers
     - Pool chemicals
     - Wash water (mop buckets, car washing & power washing)
     - Construction materials (cement dust & concrete washout)

​Even if the spill occurs in dry weather, if the pollutants are not cleaned up, they can be washed into the stormwater system next time it rains.

Dumping of unwanted materials such as:
     - Trash
     - Leaves
     - Grass clippings
     - Any of the previously mentioned chemicals into storm drains, catch basins, drainage ditches or directly into waterbodies is also considered an illicit discharge.

Sources of Illicit Discharges

Illicit Discharges can enter the system through either direct connections or indirect inputs. Wastewater connections, whether intentional or inadvertent, should never be plumbed to the stormwater drainage system, but sent to the wastewater treatment plant where it can be treated before the water is released into the environment.  

Sources of indirect inputs include:
     - Cracked sanitary systems
     - Spills
     - Illegal dumping of paint and used oil
     - Mobile car washes and pressure washing services that do not collect and treat wash water before proper disposal.

As a result, illicit discharges enter the stormwater system and contribute high levels of pollutants as they flow directly into receiving creeks, streams, and lakes.

To report a suspected illicit discharge, call the Stormwater Pollution HOTLINE at (704) 282-4515 or click here to send an email. Please include the location, date, time, and description (such as, materials dumped, if known) and attach a picture of the issue if possible. Report issues immediately to prevent further pollution and contamination of our waters.


Illicit Discharge Brochure
Guide to Avoiding Illicit Discharges to Protect Water Quality

Illicit Discharge Detection and Elimination Program

Stormwater staff not only responds to tips reported to the Stormwater Pollution Hotline, but also walks streams and inspects outfalls to identify any issues. If signs of pollution are found, various methods can be used to locate the source of the discharge including visual inspections, video, smoke or dye testing and water sampling. The City issues notices of violation with remediation procedures and consequences for non-compliance with our Stormwater Management Ordinance.