Car Washing/Detailing

Did you know, mobile car washing is subject to the same code requirements as stationary car washing? Permanent, stationary car washes are required by Lake Oswego City Code to connect and discharge their wastewater to the public sewer system. Mobile car washes are not allowed to dump wastewater into the stormwater system through manholes and catch basins.

Why is it important to discharge wastewater into the sewer system vs storm system?

Wastewater from car washes often contains chemicals that are harmful to biological organisms in creeks, streams and lakes, and this wastewater can contribute to poor water quality, biodiversity loss, and public health irritants. This is especially true when wastewater is discharged into public stormwater systems, because unlike water in the sewer system, water in the public stormwater system is not treated before it enters waterways.

Are there fines involved?

Discharging wastewater into the public stormwater system, such as catch basins, or manholes, are explicitly prohibited by Lake Oswego City Code (38.25.150), and can result in businesses being fined for an illicit discharge each time it occurs. Please explore alternatives for disposing of wastewater to help protect our vital water bodies and public stormwater infrastructure.

What alternatives are there to avoid using the stormwater system?

To prevent wastewater from entering public stormwater systems, contain wastewater by using absorbent socks to surround vehicles that are being washed or store wastewater in storage containers to be disposed of at an approved location.

Additional Resources

• For more information, please call the Engineering Department on (503) 635-0270 
• For more information on wastewater disposal, contact the Tryon Creek Wastewater Treatment Plant at 503-823-2320 or here
• Lake Oswego Stormwater Management Manual
• Lake Oswego Municipal Code