introduction | protecting threatened species | safeguarding biodiversity | improving water quality | enhancing the landscape | managing the archaeological heritage | restoring land for recreation | reducing neighbourhood noise | blending into the landscape | informing the community | creating nature reserves | conserving geological heritage | reducing environmental impacts

Improving Water Quality

BACKGROUND

Supplies of drinking water in major urban areas are generally closely monitored in order to avoid periodic shortages and to assess pollution risks. Water areas which appear in sand and gravel pits after extraction turn out to be potential reserves of drinking water.

ACTION

A number of sand and gravel pits in activity are used as drinking water tanks by local authorities. For example, the site of Bougrières, near the Lillion (1,4 Million m3/year), is occasionally exploited by the city of Rennes. As technical equipment used for extraction is mainly electric, water pollution risks are very limited.

In the site of Saint Caprais near Toulouse, scientific studies have shown that extraction activities contributed to the reduction of nitrate in water. This natural denitrification represents a major advantage, especially in farming areas with a high level of nitrogen.

At the site of Millery near Lyon, the improvement of water quality led to a change in the rehabilitation plan, so that this potentiality could be taken into account. These solutions are implemented under the control of the competent authorities such as DRIRE (Direction Régionale de l'Industrie, de la Recherche et de l'Environnement) and DDASS (Direction Régionale des Affaires Sanitaires et Sociales).

RESULTS

In Saint-Caprais, water reserves are used two months a year when the supply canal is dried. This represents approximately 1500 m3/day. The site of Bougrières represents a reserve of 6 million m3 of nitrate-free water. Lafarge has demonstrated the compatibility of its activities with the environment, as well as its positive contribution to improve water quality in two major French urban cities.

introduction | protecting threatened species | safeguarding biodiversity | improving water quality | enhancing the landscape | managing the archaeological heritage | restoring land for recreation | reducing neighbourhood noise | blending into the landscape | informing the community | creating nature reserves | conserving geological heritage | reducing environmental impacts