Communes with fewer than 3,000 inhabitants and public establishments for inter-communal cooperation, no member commune of which has more than 3,000 inhabitants, may draw up a single budget for drinking water and wastewater services if the two services are subject to the same rules for liability to value added tax and if they are managed in the same way.
The budget and the invoices issued must show the breakdown between operations relating to drinking water distribution and those relating to wastewater treatment.