tailings dam
Technical term in mining and civil engineering; a dam used to store mining waste (tailings).
See also: 鉱滓ダム
A tailings dam failure causes serious environmental pollution.
Compound of 尾鉱 (びこう, 'tailings') and ダム ('dam'). 尾鉱 is a mining term combining 尾 ('tail') and 鉱 ('ore').