Azerbaijan has invited developers to submit expressions of interest (EoIs) for a public-private partnership (PPP) project to rehabilitate the Hovsan wastewater treatment plant (WWTP) and develop new wastewater recycling facilities.

The scheme will be Azerbaijan’s first wastewater PPP. The Asian Development Bank (ADB) is advising the government on the project.

The Hovsan WWTP is Azerbaijan’s largest wastewater treatment plant with a design capacity of 640,000 cubic metres a day (cm/d).

The project comprises two components. The first covers the rehabilitation, financing, operation and maintenance of the existing Hovsan plant to improve discharge quality and sludge management.

The second component covers the design, construction, financing, operation and maintenance of a new wastewater recycling facility with a capacity of 100,000 cm/d. The facility will supply recycled water for irrigation.

The overall project is expected to serve up to 2.5 million people in Baku.

ADB’s Office of Markets Development and PPP (OMDP) is acting as transaction adviser. Its role includes supporting project concept development and structuring, preparing and executing the competitive tender process, and assisting the government in achieving financial close.

The deadline for interested firms to submit EoIs is 21 August.

Azerbaijan has previously used the PPP model to attract private investment into large infrastructure projects, including in the water and renewable energy sectors.

The country’s first PPP tender in the water sector was for a seawater reverse osmosis desalination plant at Sumgayit Industrial Park, northwest of Baku.

As previously reported, a consortium of Saudi Arabia’s Acwa and Turkiye’s IC Ictas Insaat Sanayi ve Ticaret won the contract to develop the $400m plant, which will have a capacity of 300,000 cm/d.

In September 2025, Acwa signed agreements with the government of Azerbaijan covering a public‑private partnership agreement, a land lease, a sovereign undertaking, and a product water sale and purchase agreement. The plant has a 27.5-year project term, with early commercial operations scheduled for the second half of 2028.