Infamous as the cause of Japan’s first major pollution incident, the Ashio Copper Mine became one of Japan’s most productive mines during the late nineteenth century through a combination of investment, the discovery of new deposits, technological innovation, and labor reform. With the help of Siemens, a hydroelectric power plant was constructed in 1890 allowing long-standing ventilation and flooding issues to be resolved, the mine’s overreliance on firewood to be reduced, and productivity to increase. While this helped to reduce pollution within and potentially around the mines, it also aided in creating a more productive mining system, exacerbating pollution damage downstream.