Knowledge Base

An illicit discharge is any pollutant discharged to a storm sewer system that is harmful to the health or welfare of people, the environment, wildlife or surface waters. Illicit discharges include:

• Sediment washing from construction sites
• Chemical or oil spills
• Sewage from broken sewer lines or overflow from private septic systems
• Pesticides, herbicides, or wash water from paint clean-up and concrete washout

Illicit discharges could be intermittent - only occurring a few minutes per day or a few days per year, continuous - occurring almost daily, or transitory - only occurring once.

Which activities are not considered illicit discharges?

Water line flushing, residential car washing, draining dechlorinated swimming pools (left to rest for several days after treatment), firefighting, and lawn watering are not considered illicit.

To report an illicit discharge, call Rochester 311 Monday – Friday 8 a.m. to 5 p.m. or Non-Emergency Police Dispatch at (507) 328-6800 on evenings and weekends.

In your report, provide:

• Time, date and location
• Description of material
• Your contact information

The City of Rochester looks into any suspected cases of illegal dumping. It is illegal for substances other than rainwater to flow into storm drains, ditches, or natural water bodies like the Zumbro River—whether by accident or on purpose. Examples include pouring motor oil or antifreeze down a drain, dumping chemical cleaners or industrial waste, or failing to properly manage stormwater runoff at construction sites. These actions are unlawful and are regulated by the city's rules under Chapter 6-4 of the Rochester Code of Ordinances.