Key environmental issues in relation to car washes are emissions to water and air, noise and generation of waste. Wastewater discharges contain substances from used cleaning agents, the road surface and from the car itself, and neighboursneighbors of car washes may be disturbed by unpleasant odoursodors and noise. This report provides an overview of the car wash industry in the Nordic countries and environmental impacts associated with car washes. Different systems for wastewater treatment are thoroughly described and information about associated investment costs is given. Risk factors related to discharges are listed and measures for minimizing risks. Advice is given regarding operation and maintenance. Recommendations are also included for wastewater treatment in relation to different sizes of car washes. The purpose of this report is to provide the industry, environmental authorities and consultants with a guide to the state-of-the-art of techniques that can be applied to reduce environmental impacts caused by car washes. The report was financed by the Nordic Council of Ministers' Working Group on Products and Waste through the Nordic Working Group on Best Available Techniques.