In some cases, mine drainage containing heavy metals (arsenic, cadmium, lead, and other metals) continues to flow out from mine mouths and accumulation sites in abandoned metal mines. The local governments that manage the abandoned mines continue to treat mine drainage water day and night. Therefore, practical and realistic measures to reduce the volume of mine drainage are required. A large amount of data on mine drainage has been accumulated for a long time at each mine. Also, several technologies have been introduced that make it possible to understand the actual hydrological water flow of mine drainage and to predict the quantitative effects of countermeasures. Under these circumstances, JOGMEC applied a surface water-groundwater coupled simulation technique to the old Matsuo Mine located in Hachimantai City, Iwate Prefecture. The simulation was used as a part of the results of the "Research and Study on Groundwater Control Technology" of the " Advanced Research and Study for Mine Drainage Treatment in Abandoned Mines Project", a project commissioned by the Ministry of Economy, Trade and Industry of Japan. It was confirmed that the existing countermeasures were efficient and effective under the limited budget. Thus, proving that it was the best practice.
