Protecting the source

Heiquan Reservoir, located in Xining's Datong Hui and Tu autonomous county, serves as an important water source for people in Qinghai: it supplies water for more than one million residents.

To ensure water safety, the local government has taken a series of measures such as relocating residents near the reservoir and barring chemical vehicle traffic.

"Since 2014, the government has spent 240 million yuan ($35 million) to relocate more than 2,900 people in three villages near the reservoir," said Long Xizhou, deputy county chief of Datong. It includes surrounding facilities that may cause pollution, such as schools, restaurants and petrol stations.

Zhou Min, a chief engineer of Xining's water supply group, said the reservoir's surface water has a rating of Level II. "It's good quality. The reservoir's water quality center carries out daily, monthly and semi-annual inspections. The tests help us understand changes, so as to improve our production processes and ensure quality," Zhou noted.

China's revised Water Pollution Prevention and Control Law, which took effect in January 2018, stipulates governments above county level should publicize information on drinking water quality at least once per quarter.