This Code of Practice W 130 serves as a basis for the regeneration of wells and groundwater monitoring points. Ageing processes frequently compromise water well performance, adversely affecting, in turn, a well’s service life and economic mode of operation. Well operators therefore face the dual challenge of having to identify the most appropriate regeneration methods for each specific case and being able to evaluate the success of the measures taken. Eventually, a direct capacity increase will ensure the economically efficient operation of a well over the long term only when combined with sustainably successful measures. Any well regeneration measures will, therefore, depend on the nature and scope of ageing and on the constructional condition of the well as well as on groundwater protection requirements. This Code of Practice describes the current requirements on the technically safe and hygienically flawless implementation of well regeneration measures, points out the causes of and explains how to identify well ageing processes, among other things, and offers suggestions on how to delay them. It additionally describes the application options and limits of both mechanical and chemical regeneration procedures and/or methods. By applying this Code of Practice, well operators and contractors alike will be able to record and trace the results achieved by the regeneration measures and evaluate their success, from the planning to the implementation and on to the final phase.