China will cap the number of tailings dams for mining projects and restrict the use of existing ones to lessen safety and environmental risks, Reuters reported March 23, citing the country's Ministry of Emergency Management.

Tailings dams are structures that mining companies commonly use to hold waste from iron ore, copper or gold mining operations. China has nearly 8,000 of these structures and is working to revise its guidelines in the wake of a fatal dam failure at Vale SA's Feijao iron ore mine in Brazil in January 2019.

The ministry called on local governments to possibly close older tailings dams should the need for newer structures arise for mines considered strategic or critical to fill a supply shortage, according to the report.

Tailings dams that have been out of commission for over three years or abandoned must be shut down within a year as part of the ministry's measures to reduce the number of active tailings dams in China.

In addition, local governments were ordered to release the details of the tailings dam within their jurisdictions through their websites or local mainstream media at the start of each year. The ministry mandated companies to enact emergency response procedures in case a dam failure occurs.

Guidelines for new tailings dams include provisions that structures should not be higher than 200 meters, not to be built within 1 kilometer of residential areas or important facilities, and should be over 3 kilometers from the Yangtze or Yellow rivers.