Only Rain down the Drain

Storm Drainage System:
Ever wonder where the rain water runs off to when it storms?  Rain that washes over the streets, lawns and parking lots flow directly in to the Stanislaus River, to the San Joaquin River, through the Delta, and eventually into the ocean.  This water is never cleaned and can pollute our surface waters with things like pet waste, litter, used oil, fertilizers, metals, soil and other potentially toxic substances.

So, who’s responsible for making sure the water our community depends on is clean?

We all are.  And here’s the best part, it doesn’t require a lot of effort – just common sense.  The following are some areas that we all can pitch in prevent pollution in our community and truly only send rain down the drain.


An illicit discharge is an unlawful act of disposing, dumping, spilling, emitting, or other discharge of any substance other than storm water into the storm water drainage system. The storm water drainage system includes streets, ditches, catch basins, yard inlets, culverts, and rivers.

Below are some examples of illicit discharges:

  • Paint being poured into or near the storm drainage system
  • Changing oil or antifreeze over or near a storm drainage system
  • Washing vehicles or equipment where the runoff could drain into the storm drainage system
  • Washing dumpster pads and allowing the runoff to drain into the storm drainage system

What information should be reported when calling in an illicit discharge to the Water Pollution Hotline (209) 599-2108 (Business hours) (209) 599-2102 (After hours)?

  1. What time did you see the discharge? It is important that illicit discharges are reported immediately so the person(s) responsible can be found and the discharge can be cleaned up and corrected as soon as possible. We want to respond as quickly as possible to prevent pollution to our environment.
  2. Where did you see the discharge? Please give us an address, intersection, business name, or landmark to help us quickly find the illicit discharge.
  3. What do you think the discharge is?
    Please let us know if you think it was a paint spill, oil spill, sewer leak, or another type of illicit discharge.
  4. Was there a business involved? Please tell us the name of the business involved to help us eliminate the discharge as quickly as possible and provide enforcement action when needed.

There are some exceptions to the Illicit Discharge Ordinance (§13.14.070)

Below are examples of exceptions:

  • Air conditioning condensate
  • Firefighting runoff
  • Dechlorinated swimming pool discharges
  • Groundwater discharges from sump pumps

Remember, exception flows are only considered allowable if they are not transporting or comingling with a pollutant source!


An illicit connection is an unlawful connection from the sanitary sewer system into the storm water drainage system or directly into lakes and streams.

Below are some examples of Illicit Connections:

  • Floor drains from inside a building going into the storm drain system instead of the sanitary sewer system
  • Providing a washing machine connection into a ditch or storm drain structure instead of the sanitary sewer system
  • Installing a new plumbing line from a toilet into a storm water drainage structure instead of the sanitary sewer system


Illegal dumping into storm drains is a huge problem. Used motor oil, discarded food, trash and other debris are just some of the items routinely dumped into storm drains throughout the city. Curbside catch basins are the entry points of the storm drain system, which eventually discharges out into the river. Additionally, catch basins filled with debris can create unhealthy conditions in residential neighborhoods by becoming a breeding ground for pests and disease.

Residents are encouraged to report illegal dumping by calling the Water Pollution Hotline (209) 599-2108 (Business hours) (209) 599-2102 (After hours).

I have some paint, paint thinner, chemicals, batteries at home that I need to dispose of. How do I do it? 

The San Joaquin County Household Hazardous Waste Collection Center can accept these items and more.  Please visit their website to see a full list of accepted items and operating hours.

Fundraising Car Washes and Commercial Mobile Cleaning Pollution Prevention

Wash water from fundraising car washes and mobile cleaning / pressure washing activities produces runoff which carries pollutants such as oils, metals, sediment, and detergents into our community’s storm water conveyance system and eventually into our local waterways.  In efforts to reduce discharges from these activities the following pollution prevention practices should be followed:

·      Consider running the fundraiser through a commercial carwash.  Some regional professional car wash businesses have developed programs to allow non-profit groups to fundraise using carwash vouchers instead of the traditional organized car wash.  These programs have been proven to be more successful and safer than traditional parking lot car washes. 

Perform washing on gravel, grass or other permeable surfaces.

·      Select a location where wash water will not flow offsite or enter a nearby storm drain.

·      Pump soapy water from washing activities into a sanitary sewer drain.

·      If pumping into a sanitary sewer drain is not feasible, pump wash water onto grass or landscaping to provide filtration.

·      Use only hoses with nozzles that automatically turn off when unattended.

·      Use only biodegradable soaps.

·      Do not dump excess water on the driveway, in the gutter, or down the storm drain.

·      Mobile cleaning and pressure washing businesses should block off storm drains and recapture water from washing activities.

City of Ripon | All Rights Reserved | Powered by CivicLive | © 2023 Civiclive.