The National Office of Sanitation of Tunisia (ONAS) has selected SUEZ and its partners, Segor, SCET Group and BIAT1, to operate the public wastewater treatment service for the governorates of Sfax, Gabès, Medenine and Tataouine. 

The EUR200 million project involves the operation and maintenance of the infrastructure, which has a treatment capacity of 39 million m³/year thanks to 14 wastewater treatment plants, 106 pumping stations and 1900 km of pipelines for approximately 960,000 residents in the Sfax, Gabès, Medenine and Tataouine governorates, Tunisia. The project also includes the reconstruction of existing wastewater treatment plants and additional works that will allow the use of wastewater in agriculture through tertiary water treatment processes such as ultraviolet light treatment and phosphorus removal. SUEZ and its partners will use an Environmental and Social Management System (ESMS) to evaluate the contract for compliance with social and environmental obligations.

The project will prevent algae growth and lake pollution by treating the nitrogen and phosphorus contained in wastewater.
This will help protect the aquatic environment and reduce pressure on local biodiversity. Wastewater reuse and higher water quality are part of SUEZ's 2023 sustainability goals. The term of the concession is 10 years.