Wastewater Treatment System

In 2014, VINCI Construction Grands Projets signed its first contract in the Dominican Republic with the Instituto Nacional de Aguas Potables y Alcantarillados (INAPA). The goal was to design and build a wastewater treatment system in the cities of Monte Cristi, Neiba, Azua, San Jose de Ocoa, San Cristóbal, and Villa Vasquez. This design-construction project, covering 6 cities, consists of the design of 400 km of sewerage systems, 10 pumping stations, 5 lagoon water treatment systems and 1 activated sludge water treatment system. The project also includes the installation of a 54-km sewerage system, the construction of three pumping stations (270, 170 and 11 m3/hour) and a lagoon water treatment system. In Villa Vasquez, it involves constructing a 36-km sewerage system, one pumping station (270 m3/hour) and a lagoon water treatment system. In San Cristóbal, the project consists of the construction of an activated sludge water treatment system. Finally, with the assistance of WMI (VINCI Construction Grands Projets subsidiary), we have the task of establishing a technical diagnosis for drinking water supply.


This project is part of the Dominican government’s cholera-eradication program. Since 2010, with more than 33,000 cases and nearly 500 deaths, cholera has become a major issue for the country. Wastewater treatment is more than just a local issue – it is a public health issue. Arriving in the Dominican Republic in 2009 for a call for tenders for drinking water supply, we understood that the client, the Instituto Nacional de Aguas Potables y Alcantarillados (INAPA), needed technical backing and financing. So, we approached the French Finance Ministry for a loan application. Given the capital nature of the project, the construction site could benefit from French assistance through the developing country reserve funds.
The pilot project was rolled out in six cities across the country located between 30 minutes and three and a half hours from the capital of Santo Domingo.


In the majority of cities with sufficient space, water treatment plants are natural lagoons, except in San Cristóbal, near Santo Domingo, where the activated sludge process was selected. Lagooning is a natural wastewater treatment technique based on the principle of recreating stabilisation ponds through which wastewater flows before being discharged into the natural environment. The activated sludge process is a biological wastewater treatment technique based on the principle of introducing a bacterial floc, which when subjected to mechanical mixing, allows a high-quality effluent to be produced (the bacteria “eat” the pollutants and transform them into sludge).
Where the technical diagnosis of drinking water supply is concerned, it consists in understanding how the system, of which nearly 90% of losses are due to leaks, bad management, and a lack of modern infrastructure, works. With WMI, we were able to offer technical solutions to improve the performance of network infrastructure, investigate and seal leaks, and control energy billing.
The technical training of staff and the client was a constant concern. Water treatment is a new field in the country, which is why we implemented the Skill Up program to train subcontractor installation teams. To dig natural lagoons and install geomembranes, we relied on the expertise of VINCI Construction Terrassement.
The geographical management of the worksite, spread out across several cities, also presents another challenge for the sharing of information between the central offices in Santo Domingo (where the client is based) and various sites to put in place a common system, encourage best practices, and foster harmonious working relationships at project sites.

The hydraulic division is first and foremost a distinctive business line. We are present in all the stages of the water cycle from catchment to storage to effluent treatment, including irrigation, water treatment, storage, transfer, and distribution. It is a booming sector due to the increase in water treatment demands and weak competition due to the complexity of the process.


These facilities address pressing human concerns: the project has not only a public health goal, but also aims to reduce the environmental impact of sewage. The work encompasses sustainable development criteria, particularly through ease of operation, respect for the environment, and quality of the water treatment process. Accordingly, the treatment systems in Monte Cristi and Villa Vásquez are totally gravity-based and the few energy needs are covered by photovoltaic panels. This new project confirms not only our know-how in international hydraulic engineering, but also our expertise in environmentally friendly solutions.
Even today, only a quarter of the world’s population has limited access to drinking water, even no access, and half of the world’s population lacks an adequate sewerage system. This project also responds to authorities’ pressing need for wastewater treatment in the face of cholera and other waterborne diseases.
Finally, we can hope to continue having a major impact on global public health because the rise in demand for hydraulic infrastructure and services is estimated to be more than 50% over the next 30 years, which makes water management an attractive sector for the Group.

Project participants

Instituto Nacional de Aguas Potables y Alcantarillados

Key figures

Implementation dates
February 2014 to July 2018

90 km

Treatment plants

Pumping stations

Specific connection
7 850


“The country has fallen behind in terms of infrastructure development. Water supply and sanitation coverage are still very inadequate. This project will serve as a reference for the rest of the island, which must meet the challenge of water control and sanitation if it wants to achieve its tourism development ambitions in the next years.”

Thibault de Certaines, project director

Wastewater treatment plant