Ground water purification
Monitoring and purification: Measures to protect our reserves of drinking water. The concept of groundwater has to be distinguished from that of pit water. Groundwater too is fed by rainwater that seeps into the ground or is forced out of lakes and rivers into layers of earth that are close to the surface. It flows through subterranean cavities within these layers of earth and is kept underground by layers of rock that are impervious to water.
At the locations where our drinking water is extracted from layers of groundwater, it must meet the extremely strict criteria of various norms and specifications of water law. As a result, monitoring the groundwater in the former mining regions is also one of the perpetual obligations of RAG Aktiengesellschaft.
At former industrial sites, pollutants have often seeped into the soil and contaminated it. From the end of the 19th century to the middle of the 20th century, this was especially true of coking plants and by-product recovery plants. The pollutants included tar and aromatic hydrocarbons (PAH, benzene, toluene, xylene and phenol).
Over the decades, this pollution of the soil also led to contamination of the groundwater in some locations. Depending on the level of pollution that had been detected, the extent of the monitoring or water purification measures was coordinated with the mining authority as part of the closure plan after each mine was closed down. These processes are regulated according to numerous legal norms, such as the Federal Mining Act, the soil protection legislation, the water legislation, the pollution control legislation, the nature conservation legislation and subsidy legislation.