A car wash is a facility for cleaning vehicles, ranging from automated tunnel washes at petrol stations to hand car washes on industrial estates and forecourts. Across Greater London, hand car washes operate widely on disused petrol forecourts and warehouse sites. Drainage characteristics include wash bay drainage to a silt trap and oil interceptor before discharge to the foul sewer under trade effluent consent from Thames Water. Common issues include silt-saturated traps requiring frequent emptying, detergent foaming entering surface water drains in unauthorised setups, and operators without trade effluent consent. Modern recirculating wash systems reduce water consumption and discharge volumes. Operators should hold valid trade effluent consent, arrange routine silt trap and interceptor servicing, and ensure detergent products comply with consent conditions on biodegradability and pH.
Car wash
Vehicle washing facility with detergent and silt loads to drain, often via interceptor.
