Witterschlick is a district of the municipality of Alfter near Bonn. The Witterschlick gravel plant has belonged to the Quarzwerke Group since 2008. Quatenary sands and gravels and high-grade Tertiary silica sands and quartz gravels have been mined and processed for a good 30 years at this opencast mine, which has an area of 45 hectares (450,000 m2). On account of its quality, the ultra-pure, almost white silica sand and quartz gravel from Witterschlick is significantly more suitable than other sands or gravels for various areas of application. Through the creation of new habitats in the form of an ecologically configured landscaped lake and the planting of new forests, Quarzwerke is also comprehensively and sustainingly compensating for its temporary interference in nature at this site.