Hydrochemical Evolution of the filling of the Mining Lake of As Pontes (Spain)

The old As Pontes lignite mine is located in northwest Spain, in the Galicia region. Filling of the 547 hm3 pit began at the end of January 2008 through the controlled input of surface water. The filling was completed on April 18, 2012, leading to a steady water regime. During this process, both the water input and the water stored in the pit were hydrochemically monitored. The water chemistry in the superficial area of the lake, as well as the chemical stratification, are presented.