Leaks on the rise at China's mining waste dumps

China has seen a "marked increase" in environmental emergencies involving tailings ponds, according to the country's top environmental watchdog, underscoring the difficulties authorities face in regulating these mineral waste dumps.

Tailings ponds are used to store the waste generated in the process of separating minerals from rocks. Chinese mining companies built thousands of such dumpsites amid the country's mining boom. While regulators focused on curbing potential safety risks, the efforts of local environmental watchdogs to prevent pollution spills have been lacking, according to industry experts. If a ponds leaks, the tailings, which often include toxic chemicals and heavy metals, can contaminate water supplies and pose a serious threat to people's health and the surrounding environment.