Hunan province is checking tap water supplies in all counties to collect data to improve protection of the resource, Xiaoxiang Morning Post reported on Sunday.

Authorities will test for pollutant levels that surpass the national standard and find the source of the pollutants, the provincial environmental protection department said.

The department requires local bureaus to provide detailed information about reservoirs that have a first-class protection level. Information must include the sources of discharged pollutants, including exact locations, the companies’ names and details of their emissions.

The evaluation work is due to be finished by the end of June, Xiaoxiang Morning Post reported.

Other media have reported that 20,000 residents in Changshou, a town in Pingjiang county, have been refusing to drink the tap water because of fears it has been polluted by a gold mine upstream of the river, despite the government’s assurance the quality meets national standards.

The case highlights the low public confidence in local authorities, according to experts quoted by the People's Daily.