19th century lignite mining (Germany): Hazards from non-ideal waste sequestration

Abstract

Since the 19th Century, lignite mining and processing has left an indelible mark on the environment in East Germany, particularly around the cities of Halle and Leipzig. The European Commission in the 1990s, regarded the waste dumps and underground abandoned shafts as a major hazard and commissioned a multi-dimensional scientific team, under the title Eureka Project 674 (Advanced Mobile Analytical Laboratory or AMAL), to oversee a preliminary Environmental Impact Assessment (EIA) of the worst affected areas. Advanced mobile laboratories were built to access sites, recover complex matrices and make overall assessments of the scale of the problem, as leakage from century-old waste pits were causing hazardous environmental and health issues in the local areas.

The mobile laboratories were equipped with an inductively-coupled mass spectrometer (ICP-MS), gas-chromatography mass spectrometer (GC-MS), x-ray fluorescence (XRF) instruments and specially designed coring equipment to recover soil-gas and liquids, and other complex samples from subsurface waste pits and water basins. One of the key outcomes of the on-site surveys was the delineation of hot-spots of contamination in mine dumps (Ascheberg) and tar-pools (Schumzelteich),which over time migrated through the natural shale pit-liner into drinking water (water wells). An interpretation of the leakage anomalies suggests that the clay layer was breached over time, due to overloading of the pits and/or structural damage to the pits, which eventually permeated the environmental hinterland and aquifers. The critical choice of pit-liners in any future waste pit containment for similar chemical materials is essential to long-term sequestration of industrial wastes.