Like many other long-standing chemical companies, WACKER has some soil contamination on its site premises. In the pioneering days of chemical production, nobody was aware of the dangers posed by certain chemicals, or that some substances could remain in the ground for prolonged periods without undergoing degradation.

To remediate this legacy of contamination, WACKER has been extracting air from the soil at the Burghausen site since 1989. This predominantly removes highly volatile halogenated hydrocarbons from the soil, which are then incinerated to render them harmless. By the end of 2014, we had removed a total of 1,995 metric tons of chlorinated hydrocarbons (CHCs); the amount of contaminants removed in 2014 was 22 metric tons.

Since 2003, we have been using a groundwater stripping plant to treat an area of localized groundwater contamination east of the Burghausen site. By the end of 2014, 29 metric tons of CHCs had been removed; pollutant concentrations have been reduced to one tenth of their original levels. In order to reduce the discharge of hexachlorobutadiene (HCBD) into the tailrace, we are continuing groundwater treatment of the site’s contaminated areas. Currently, 86 kilograms of the pollutants are being removed per year. The results of our fish contaminant survey at Burghausen indicate that fish from the Salzach river are quite safe to eat.

Additionally, there is some groundwater contamination at our Nünchritz site. This predates WACKER’s takeover of the site. We have been cleaning up the groundwater there since 2009 and have been using a hydraulic process since 2013. In 2012 and 2013, we cleaned some 110,000 cubic meters of groundwater there. The project was a temporary measure that ended on schedule in 2013. We are now analyzing the results and will commence further remediation measures from 2018 on.

Siltronic’s Portland site in Oregon, USA, has developed a method of biodegrading trichloroethylene (TCE) residues in groundwater by means of microorganisms. With this method, which has been approved by the Oregon Department of Environmental Quality (ODEQ), we almost completely eliminate trichloroethylene from groundwater and thus achieve drinking water quality. The US Environmental Protection Agency (EPA) has recognized our biological method of degrading chlorinated volatile organic compounds (CVOCs) with which we eliminate 90+ percent of these substances.