The Engineering & Consulting expertise of Veolia, alongside Suez Consulting and DevConsultants Limited (DevCon), has been selected by Chittagong Water Supply and Sewerage Authority (WASA) to deliver design review and construction supervision for the North Kattoli sewerage scheme in Bangladesh, financed by the French Development Agency (AFD).
Context and challenges
Chattogram, also known as Chittagong, is Bangladesh's second-largest city and its main port. Home to more than 3 million people, it still has no centralised sewage collection system. In the North Kattoli catchment alone - 260,000 residents today, projected to reach 380,000 by 2050 - households depend on septic tanks and pit latrines, while greywater and much of the wastewater discharge directly into open drains and canals. Combined with an undersized drainage network and recurrent flooding, often worsened by solid waste blocking drains, these conditions pose serious public health and environmental risks.
Project scope
To address these challenges, our teams will review the design and supervise construction of:
- an interceptor tunnel (5 km at a depth of 10 m) to transport wastewater to the treatment plant using microtunnelling techniques to minimise social impact and the need for land acquisition;
- more than 90 km of sewer mains (DN 200 to DN 1200) and over 8,100 household connections, delivered at no cost to residents;
- a conventional activated sludge WWTP with a treatment capacity of 50,000 m³/day, that will keep over 32 tonnes of COD and 17 tonnes of BOD5 out of the environment every day.
Expected impacts
Across its lifetime, the North Kattoli sewerage scheme is expected to avoid close to 2.5 million tonnes of CO2 equivalent, a 70% reduction against the current baseline. By 2050 it will bring safe and inclusive sanitation to the entire catchment population - 85% through the network, 15% through faecal sludge management - cutting the burden of waterborne diseases, and the pollution of surface and underground water resources.