Bakheng Water Treatment Plant

This design-build contract covers the construction of a drinking water treatment plant and transfer pipelines. The supply system will ultimately provide drinking water to more than 1.5 million people living in the north-east of Phnom Penh.


The north-east of Phnom Penh, where the Bakheng district is located, is experiencing strong urban expansion.
The plant is co-funded by the French Development Agency, the European Investment Bank and the Phnom Penh water authority, and will improve the water supply in this area and ultimately deliver a 60% increase in the drinking water supply capacity of the capital, which will host the South East Asian Games in May 2023. By the end of Phase 1, the plant should be operational to provide drinking water to the more than 750,000 inhabitants of the area. By the end of Phase 2, its capacity will be doubled.

Technical Overview

Raw water will be taken from the Mekong River via an intake comprising a pumping station that will pump the water through two pipes to the treatment plant.
The first project phase involves the construction of an initial treatment line with a capacity of 195,000 m3 per day, the water intake from the Mekong with a capacity of 390,000 m3 per day, and two pipes 1.4 metres in diameter and 1.5 km in length to convey the water from the Mekong to the treatment plant. A 2-metre diameter pipeline 7.8 km long (including a 630-metre river crossing which will be created with a micro-TBM) will provide the now-drinkable water to more than 750,000 inhabitants of the capital.
The second phase of the project involves doubling the plant’s treatment capacity to 390,000 m3 per day. It will ultimately supply one and a half million people with drinking water.
The project includes earthworks and soil treatment, civil engineering design of the structures, installation of the equipment, the supply of power to the equipment and automation of the whole system.

« This project will act as a major calling card due to its size. In the water sector, customers generally require builders to have experience in making structures that are at least half the size of the structure to be built. This project will therefore give us access to almost all the treatment plant projects being built in the world today.» Olivier Faussat, Operations Director of the hydraulic sector for the Asia zone.


The project will provide work for more than 1,000 local workers and management staff at peak activity. It also presents an environmental challenge. The sand, which is used in large quantities for the backfill, is transported by barge and then pumped for one kilometre through passages dug under the road to the construction site (instead of being transported by truck). Training in eco-driving has been introduced, car-pooling encouraged and presence sensors installed in the offices and outdoor areas to minimise lighting. Construction materials will be reused to make infrastructure such as road signs, and materials from demolition will be used for temporary backfill. The concrete left at the bottom of the tanks after pouring will be used to prefabricate items such as guardrails. Organic waste will be composted to improve the vegetable garden being developed for the project, rainwater will be harvested and biofiltered using a bamboo pipe system, etc.

Project participants

Client :
PPWSA (Phnom Penh Water Supply Authority)

Key Figures

Execution dates:
from March 2020 to 2024

Treatment capacity of the station:
390,000 m³ / day

Population served by the station (in the long term):
1.5 million inhabitants

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