Office National de l’Assainissement (ONAS), Tunisia

What is it?

Tunisia’s national wastewater agency, with additional responsibility for protecting the water resources of the country’s population of 10.3 million people.

What has it done?

ONAS has implemented a sweeping infrastructure programme that has put Tunisia on course to meet its target of reusing 60% of its wastewater by 2016 - a doubling of the current proportion. The agency has also explored new financing avenues: two 25-year BOT WWTP contracts are a crucial element of its plans for a north-south treated effluent transfer project. To fund the programme, ONAS has mobilised funding from a variety of sources to continue the sustainable expansion of Tunisia’s wastewater infrastructure.

What makes it special?

• ONAS is spearheading the push towards greater water reuse in North Africa. Its determination to develop the water reuse sector has made it an undisputed regional pioneer.

• Significant geographical challenges have simply made ONAS raise its game. Most of Tunisia’s wastewater is produced in the populated, industrial north, but the need for treated effluent is greatest in the arid central plains. A planned north-south effluent transfer project is a solution worthy of a world-class public water agency.

• In both industrial and municipal wastewater treatment, ONAS is embracing the type of linked-up thinking that wastewater utilities elsewhere in the Maghreb would do well to replicate.