(48)The urban wastewater collection and treatment sector is specific, operating as a captive market, with public and small enterprises being connected to the collecting system without being able to choose their operators. It is therefore important to ensure public access to operators’ key performance indicators, such as the level of treatment achieved, the costs of treatment, the energy used and produced, and the related GHG emissions and carbon footprint. In order to make the public more aware of the implications of urban wastewater treatment, key information on the annual wastewater collection and treatment costs for each household should be provided, at least in agglomerations above 10 000 p.e., and preferably above 1 000 p.e., in an easily accessible manner, for instance on the invoices, while other detailed information should be accessible in a user-friendly format online, on a website of the operator or the competent authority.