SCAST: a long-term partnership for sanitation in Tunisia

SUEZ operates Tunisia’s first public-private partnership (PPP) in the water sector on behalf of the National Sanitation Office (ONAS).

This contract, led by SCAST (SUEZ Concession Assainissement Sud Tunisien), marks a key structural milestone for the sustainable improvement of sanitation services in the governorate of Sfax, Gabès, Médenine, and Tataouine.

Since June 2024, SCAST has been responsible for the operation and maintenance (O&M) of all sanitation infrastructure, serving over 960,000 inhabitants. The scope of the project includes the rehabilitation of 13 existing Wastewater Treatment Plants (WWTP), the management of 108 pumping stations, and 1,900 km of sanitation networks.

Since June 2024, SCAST has been responsible for the operation and maintenance (O&M) of all sanitation infrastructure, serving over 960,000 inhabitants. The scope of the project includes the rehabilitation of 13 existing Wastewater Treatment Plants (WWTP), the management of 108 pumping stations, and 1,900 km of sanitation networks.

Beyond daily operations, additional works are being implemented to enable the long-term reuse of treated wastewater (REUT) for agricultural purposes, thereby fostering the territory's economic development.

The project incorporates tertiary treatment processes (UV disinfection, phosphorus removal, and nitrogen treatment) designed to preserve water quality and mitigate environmental impact, particularly on sensitive aquatic environments and local biodiversity.

This PPP demonstrates the ability of public and private stakeholders to co-create sustainable solutions tailored to local needs. SCAST is fully aligned with SUEZ’s commitments to wastewater recovery, knowledge transfer, and the circular management of resources.