German and European standards are well established technical standards and they reflect the state of the art. Standards are a good instrument to manufacture comparable products and to distribute them on the market. Nevertheless national restrictions may hinder the free European market. This concerns also small wastewater treatment plants, which have to be in accordance with legal requirements from construction law and water law as well.
At the very moment the standard of small wastewater treatment plants consists of 7 parts. These are:
EN 12566 Small wastewater treatment systems for up to 50 PT