Hundreds of abandoned mines and mine waste disposal sites all over the world are waiting for restoration and soil remediation. The economic and social benefit of overexploited mining was enjoyed over the last 60–70 years without investing in proper management of environmental risks posed to the area during mining operations and its reduction afterwards. The footprints of former metal ore mining activities are the worst: lack of vegetation, drastically altered landscape, wastes piled up and left, damage to water and soil from acidic mine water and waste leachates, diffuse contaminated environment and deteriorated, destroyed ecosystem. Contaminants are derived originally from point sources which are dispersed during the years of careless abandonment, resulting in countless diffuse secondary sources polluting entire watersheds. This is a typical consequence of long-abandoned mine sites without restoration.
To reduce the environmental impact of mining, collaborative efforts are needed from a variety of stakeholders. Environmental engineering plays a key role in risk reduction, both before and after mining activities. Risk assessment and risk reduction of abandoned metal mines involve similar tasks all over the world and the innovative solutions could be largely utilized.
The problem with abandoned mines and its management was discussed in the first volume of this book series (Vaszita, 2014), the acid mine drainage formation and treatment in Chapter 7 of this volume, while risk reduction by remediation of soil contaminated from point and diffuse sources of metal-containing waste is discussed here. After a general overview of the existing technological solutions, a case study is presented about the former Hungarian zinc, lead mine in Gyöngyösoroszi, abandoned over 30 years ago.