Adana is the fourth largest city in Turkey and is a large industrial and commercial centre with a fast growing population. It had approximately 3 million inhabitants in 2024.

Two new wastewater treatment plants (WWTP) were constructed with a loan from the European Investment Bank. In the initial phase, the Adana West WWTP was to provide full biological treatment whilst the Adana East WWTP provided primary treatment only (screening, grit and grease removal). However, during the project, a variation was issued to provide complete wastewater treatment to produce final effluent meeting international standards. The design criteria for the two plants were: