Foundry environment - Water

The public's expectations in terms of sustainable development are growing all the time, and many of them are aware of the serious deterioration in the state of the environment over the last few decades. This growing sensitivity to the quality of the water they drink and bathe in in summer has resulted in increasing regulatory demands.

French and European foundries have made enormous strides over the last twenty years to reduce their water bills and comply with national and European Union regulations. Foundries using the sand casting process use very little water, and cooling systems are increasingly closed-circuit. Only pressure die-casting plants, which have to cool permanent molds, generate discharges that require treatment before discharge into the natural environment or public sewage system.

The new foundry BREF will lead to the setting of Europe-wide limit values for many chemicals and metals, which should avoid the distortion of competition that occurred between countries with the 2004 BREF.

The Water Framework Directive (WFD) established a framework for a comprehensive EU water policy. Its objectives are to improve the quality of surface, ground and marine water in Europe, promote its sustainable use, protect the environment and mitigate the effects of disasters such as floods and droughts. In France, these plans are known as SDAGEs (Schémas directeurs d'aménagement et de gestion des eaux).

This article sets out the specific regulations that apply to aqueous discharges from foundries, in particular for heavy metals, hazardous substances and priority substances, whose concentrations and flows must be reduced in bodies of water.

This document also presents some of the results of R&D work carried out by CTIF (Centre technique des industries de la fonderie) with companies in the sector. The objectives were to evaluate technologies for treating wastewater in pressure diecasting and to draw up a guide to best practices for preventing untimely water pollution.

A glossary and table of acronyms are provided at the end of the article.