They are compact greywater treatment plants for both, single family houses and apartment buildings. Sizes of these treatment plants range from 4 to 144 PE (population equivalents). They are made of standard elements, which are conveniently combined, making them suitable for both, new buildings as well as renovation projects. With increasing prices of drinking water, water reuse is becoming ever more important. The economical and environmentally friendly technology employed in the AS-GW system is characterized by low energy consumption and independence on climatic conditions.