Reuse of treated water and sludge treatment in Mindelo

Contracting entity:
LuxDev / Câmara Municipal de S. Vicente (S. Vicente City Council)
Funded: LuxDev – Luxemburg Development Cooperation Agency – Bureau Cabo Verde

Project description

The main objective of the Consultancy Service is to determine the necessary interventions to rehabilitate the Mindelo wastewater drainage system and the Ribeira da Vinha WWTP, in order to guarantee the safe re-use of the treated wastewater, in particular in agricultural irrigation, and to ensure proper sludge treatment. Among other interventions, the following are considered to be necessary:

• The improvement of the overall performance of the WWTP, by emptying the sludge from the anaerobic lagoons and creating conditions for efficient drying in drying beds and, by designing a complementary treatment of the final treated wastewater (microscreening and disinfection), for safe re-use in the irrigation (without restrictions neither of culture nor of irrigation mode – in terms of microbiological parameters).
• The specific rehabilitation of Mindelo drainage system, if it is economically feasible to reduce and control the salinity of the incoming flow to the WWTP (and of the sludge), allowing a less restricted use of treated wastewater for irrigation. Other solutions and guidelines may need to be addressed to minimize salinity, if at all possible.
• The analysis of the characteristics of the Antulo Industrial WWTP and the quality of its final effluent, which is discharged directly into the drainage network of Mindelo. Antulo is a fish processing industry, which may contribute to the high salinity of the flow.
• The extension of the Lazareto’s domestic rising main line to the “old” WWTP line.
• The design of infiltration basins, or similar, to avoid uncontrolled discharges of the “new” WWTP line in the soil.