The analysis assessed 36 lakes in the Lausitz region, in the Leipzig/Halle area, the Rhineland, Hesse and Bavaria. The assessment of ecological potential includes biological quality elements such as plankton and aquatic plants as well as traces of chemicals in the water. It was determined that 19 of the lakes have "good" or "high" ecological potential, whereas 12 others were ranked only "moderate" despite their intact biology. They are often polluted with too much mercury or endocrine disruptive tributyltin compounds. One lake had "poor" status due to excessive nutrient input. Evaluations were inconclusive for five of the lakes.
Depending on the mining technique lakes of many different kinds are formed which do not occur naturally in the regions. Older mine lakes are usually small and newer ones large, for example the Geiseltalsee (lake) in Sachsen-Anhalt, Senftenberger See in Brandenburg or Partwitzer See in Saxony, which will soon have a water surface of more than 1,000 hectares. Germany has more than 500 mine lakes. Brandenburg and Saxony will claim to be Europe's biggest region of man-made lakes by 2018.
Lignite continues to rank lowest in overall environmental performance. The most damage is caused by emissions of particulates, nitrogen dioxide and carbon dioxide, which are formed when it is fired to produce electricity. One kilowatt hour of lignite-based electricity incurs environmental damage of nearly 11 cents/kWh, compared to only 5 cents/kWh for natural gas. Solar power has the equivalent of only 1 cent/kWh and wind power an average of 0.25 cent/kWh. Despite successful landscape renewal projects, the figures clearly urge a speedy, regulated phase-out of lignite.