The upper part of the Kolpa River is still considerably affected by inappropriate municipal infrastructure. The existing cesspits constitute a great risk to the surrounding environment. The aim of this project was to prevent further deterioration and to protect the quality of water throughout the Kolpa River area up to the state border. Within this project, the following principal activities were carried out: construction of waste water treatment plant 160 PE (Kuzelj pilot project), construction and /or rehabilitation of several sewage and water distribution connections, drafting project documents, monitoring system, and information and publicity.