Modelling the impact of construction waste reuse on groundwater

Your issues and needs

The construction and industrial sectors generate almost 250 million tonnes of mineral waste a year. Due to their geotechnical and environmental characteristics, some of these waste materials can be used to replace the natural raw materials used in spatial planning and road works.

In order to maintain an environmentally responsible approach, construction waste must only be reused with proper consideration for the protection of the environment, and groundwater in particular.

Our added value

Numerical modelling can simulate attenuation phenomena (dilution, dispersion, absorption and degradation) and calculate contaminant concentrations in the groundwater in the target area to be protected (e.g. a drinking water supply intake), downstream from the material reuse area.  

The simulations carried out by BRGM enable planners to assess the impact of construction-waste reuse on groundwater by taking into account the various factors that can influence the migration of pollutants:

• The numbers of the different types of structures for which the materials are to be reused;
• The meteorological context;
• The type of aquifer formations;
• The flowrate of the aquifer;
• The distance from the reuse area.

The results of these models make it possible to define the reuse values (called threshold values) of the waste generated during the construction or demolition of a building in several types of installations (foundations, paving, etc.), in order to guarantee the protection of groundwater.

These studies form an integral part of an approach that promotes the reuse and recycling of waste rather than its disposal in specific storage facilities.