Chamkar Mon Water Treatment Plant

This is a project to renovate the Chamkar Mon water treatment plant, located in the heart of the Cambodian capital. After the demolition of the existing plant, a new one will be designed and built to increase the daily production capacity from 20,000 m3 to 52,000 m3.


The Chamkar Mon water treatment plant project responds to new needs arising out of the dynamic growth of Cambodia’s economy and tourism. Its goal is to develop and improve access to clean drinking water for a greater number of people in Phnom Penh, a city that is expanding every day.


The first challenge in the Chamkar Mon project is the construction of the intake, a well with a diameter of 10 m. This well, built with sheet piles along the Bassac river (a tributary of the Mekong), is affected by the swelling of the river, whose level can vary by an average of 10 m. Given the site layout, there are two options: carry out work for six months of the year, stop and continue the following year or engage in costly measures to provide a work environment that will be “dry” for the whole construction period.
The other challenge is to work on the water treatment plant in an extremely small area right in the middle of the city. For machine traffic to be smooth on the site, the construction of the different structures must be phased skilfully.
The rainy season, which lasts for three months of the year (from August to October), also adds to the complexity of the project. As underground work (earthworks, foundations and pipe-laying) is difficult – almost impossible – during this period, it has been planned for the dry season.
In addition, our geographic location in the city centre makes construction work and delivery of supplies difficult, so the logistics must be adapted accordingly.

“One of the major requirements is delivery within the time frame set by the client, that is, within 24 months. The other requirement is ensuring that the new capacity of 52,000 m3 per day is achieved when the project is finished” Benoît Chambost, project director


The project environment is a developing country and local skills are limited. Through the use of pooling and feedback from our airport projects (Phnom Penh and Siem Reap passenger terminal expansion) and the Niroth water treatment plant, VINCI Construction Grands Projets teams have become efficient in training and retaining their local staff from project to project.

Project participants

PPWSA (Phnom Penh Water Supply Authority)

Project management

Key figures

Implementation dates
October 2017 to october 2019

5,100 m3

720 tonnes

11,400 m3 (excavated materials)

Copenhagen Metro, Line M4 (Sydhavn)