A person using a soapy cloth to wash a tire rim on the grass.

Car Washing

Make sure only rain goes down the drain

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Detergent At-home Tips Commercial Carwashes Practices for Professionals


Detergent in soapy wash water can pollute local waterways. This happens when soap and other chemicals enter a storm drain or stream when you're washing your car. You can help protect the environment by making sure this water does not go into the stormwater system.

At-home Tips

  • Direct wash water toward the lawn or a planted area. 
  • Use half the amount of soap so that the detergent breaks down faster.
  • Keep water out of the street – Wash your car on a driveway or yard. 

Mobile Carwashes

  • Use cool water and biodegradable detergents.
  • Clean vehicles on grass or gravel areas (when possible).
  • Cover nearby storm drains before washing vehicles.
  • Don't do any engine or parts cleaning.
  • Avoid acid-based wheel cleaners. 

Is a mobile carwash coming to your neighborhood? Let us know ahead of time. This will help prevent issues with wash water going into a storm drain. 

Commercial Carwashes

  • Direct soapy water from the carwash to the sanitary sewer system. Don't put wash water in the stormwater system. 
  • If a sewer connection is not available – direct wash water to collection pools or a similar method. Dispose of wash water properly in a sink.
  • Let us know if you see a mobile carwash that isn’t properly disposing wash water. They should follow the same rules as commercial carwashes.

Practices for Professionals

Do you do sanitary sewer maintenance or sidewalk/concrete repair? Follow these tips to properly dispose of wash water so that it doesn't make its way into the stormwater system. You'll protect the environment and help us meet permit requirements. 

  1. Don't use soaps or chemicals when pressure washing pavement. 
  2. Sweep surfaces before pressure washing. 
  3. Keep wash water out of storm drains and waterways. Collect all water and dispose of properly. (i.e. in a sink or drain that connects to the sewer system)
  4. Follow package instructions when disposing of chemicals and chemical waste. 
  5. Carry spill response details with you. Contact us if you can't contain the spill. (919-996-3940 or RaleighStormwater@raleighnc.gov)
  6. Wash out equipment in a designated area. (i.e. indoors or where you can use inlet protection)



Zachary Poole
Illicit Discharge Coordinator 

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