The realisation of a collective sewerage network is part of a global reflection on wastewater management on the scale of the CACL’s territory. Through its multi-year work programme, the CACL organised: — Collection of the entire downtown Cayenne, but also of the main subdivisions of the city. However, the whole of the communal sanitation zoning listed in the Master Plan of Sanitation is not yet served and some districts are still subject to waste water discharges into the rainwater system, either without any treatment or after passing through a septic tank. This contributes to maintaining pollution, visual and olfactory nuisances, as well as permanent health risks. This delay in infrastructure is perfectly illustrated by the existence of many private facilities intended solely for the treatment of water from small subdivisions. A multitude of treatment units have been implemented, without overall coherence, without economy of scale, but above all without real processing efficiency. A European notice for non-compliance with the ERU directives requires the CACL to bring the treatment equipment of the City of Cayenne to the standards. By remaining consistent with its Master Plan of Sanitation, the CACL therefore wishes to continue the extension of its collection network, to areas planned for collective sanitation, with the objective of collecting