Use a commercial car wash. The wash water is recycled and eventually sent to a sanitary sewer where it is treated.
Waterless car washing is a new method that's quickly becoming popular in drought stricken regions such as the American southeast and southwest. These products are sprayed onto the car, they coat the dirt particles, and are wiped of with a soft cloth. The car is sparkling clean and there are no scratches in the paint.
Sell car wash vouchers. The Puget Sound Car Wash Association can provide car wash coupons printed with your organization’s name. There are over 30 different car wash locations from Tacoma to Stanwood that accept the tickets. You can raise money all year around, instead of just the summer.