Client

Istanbul Water and Sewerage Corporation (ISKI)

Location

Istanbul, Turkey

Capacity

7,380,000 m³/day

City Wastewater Management, Istanbul, Türkiye

One City One Operator Model Delivering 24×7 City Wastewater Management for 16 Million Residents

The Istanbul Water and Sewerage Administration (ISKI) appointed WABAG to manage wastewater operations across the Asian and European districts of Istanbul under an integrated One City One Operator model. Serving nearly 16 million people, this project represents one of the most extensive city wastewater management assignments worldwide, ensuring uninterrupted, compliant, and energy-efficient operations across the metropolitan network.

Reliable O&M Service Covering the Entire City Wastewater Infrastructure

Under this contract, WABAG operates and maintains a city-wide network of wastewater facilities—spanning pretreatment systems, mechanical and biological treatment plants, and pumping stations. With a managed capacity of 7.38 million m³/day, the project delivers reliable O&M service across both continents of Istanbul, positioning the city as a benchmark for efficient municipal utilities.

City Wastewater Management Strengthened Through Integrated Operational Excellence

The One City One Operator framework consolidates operations of diverse assets into a unified management system. This includes 9 pretreatment plants, 51 biological wastewater treatment plants, and 64 major pumping stations. Standardized processes, advanced SCADA monitoring, and round-the-clock manned operations ensure high responsiveness and operational stability across the entire wastewater network.

Energy-Optimised Wastewater Operations with Anaerobic Digestion and Biogas Utilization

Three major WWTPs—Tuzla, Pasaköy, and Ataköy—play a central role in managing Istanbul’s wastewater load. These facilities incorporate anaerobic sludge digestion and biogas-based combined heat and power (CHP) systems to improve energy efficiency and reduce operational expenditure. The plants demonstrate Istanbul’s leadership in adopting sustainable, low-carbon wastewater solutions.

Full-Scale O&M Scope Under the One City One Operator Model

The operational scope includes:

O&M of 124 wastewater units across two continents
9 pretreatment facilities with 4,200,000 m³/day capacity
51 biological WWTPs with a combined 880,000 m³/day capacity
64 pumping stations handling 2,300,000 m³/day
Implementation of optimized process designs for efficiency and regulatory compliance

This integrated O&M ecosystem ensures unified control, consistent service quality, and improved long-term asset performance.

Treatment Processes Supporting Large-Scale Metropolitan Wastewater Loads

The city’s wastewater is treated through:

Mechanical screening and grit removal
Biological treatment using activated sludge processes
Anaerobic sludge digestion for energy recovery
Biogas utilization through CHP units at major plants
Continuous SCADA-enabled monitoring for performance stability

These systems collectively ensure safe, compliant treatment and contribute to Istanbul’s environmental health.

Impact on Public Health, Environmental Protection, and Urban Sustainability

The project significantly enhances Istanbul’s wastewater resilience by:

Preventing pollution in the Bosphorus, Marmara Sea, and major water bodies
Ensuring safe, reliable wastewater treatment across the entire city
Reducing carbon footprint through energy-efficient O&M models
Delivering long-term improvements in sanitation and public health

This One City One Operator assignment reinforces WABAG’s standing among leading wastewater management companies delivering large-scale, city-wide solutions.

A Global Benchmark in Integrated City Wastewater Management

Through its ability to operate a metropolitan wastewater system of this scale, WABAG demonstrates unmatched capability in implementing integrated O&M models for large cities. Istanbul now stands as a global reference for dependable, unified wastewater operations under a single operator framework.