Water users who are permitted to discharge more than 750 cubic meters of wastewater in one day (water law permit §§ 8 and 9 WHG) must appoint a water protection officer (water protection officer).

Water protection officers advise water users and company employees on matters that are important for water protection. For example, they monitor compliance with regulations, the proper operation and maintenance of systems and support the water user in remedying any deficiencies identified. They work towards environmentally friendly production and inform company employees about the water pollution caused in the company and about facilities and measures to reduce it. The tasks of the water protection officer can be carried out by immission control officers (Federal Immission Control Act) or waste officers (Closed Substance Cycle and Waste Management Act) already appointed in the company. The relationship between the water user and the water pollution control officer is governed by Sections 55 to 58 of the Federal Immission Control Act (duties of the operator, right of presentation, prohibition of discrimination, protection against dismissal).

Water pollution control officers only have an advisory function; they are not representatives of the authority at the user.