Changes in groundwater flow after remediation with capping for the Upstream of Mill Tailings Pond at Ningyo-toge Environmental Engineering Center

Nishida, Nobuho; Ohara, Yoshiyuki; Kawamoto, Tsutomu

Heisei-28-Nendo Zenkoku Kozan, Seirenjo Gemba Tantosha Kaigi Shigen/Shinzozai Koenshu, p.69 - 74, 2016/06

Japan Atomic Energy Agency Ningyo-toge Environmental Engineering Center, has been conducting environmental remediation of the Ningyo-toge mine and Togo mine, after decades of mine-related activities including uranium exploration, mining and test milling were terminated, with doing safety measure, under Mining Safety law. As the one, culvert installation and multi-layered capping were performed at Upstream of Yotsugi Mill Tailings Pond to inspect about stability of multi-layered capping with checking rainwater infiltration restraint and radon dissipation inhibiting effect, from FY 2011 to FY 2012. And it was presumed possibility of amount of underground water is increased, as result of fluctuation numerical analysis for Upstream of Yotsugi Mill Tailings Pond before and after the multi-layered capping, and the water level of bowling holes around the Pond and spring water which flows from lower place of the Pond. But a culvert possesses enough drainage function and groundwater does not rise to the multi-layered capping part. Therefore, it is considered that there isn't problem to the stability of the current state of the multi-layered capping, but we will continue the monitoring of the water level of the bowling hole around the Pond, and the spring water which flows from lower place of the Pond.