Almost a quarter of China’s surface water remains so polluted that it is unfit even for industrial use, while less than half of total supplies are drinkable, data from the environment watchdog showed on Monday.

Inspectors from China’s Ministry of Environmental Protection tested water samples from the country’s major rivers and lakes in the first half of the year and declared just 49.3 percent to be safe for drinking, up from 48 percent last year, the ministry said in a notice posted on its website (www.mep.gov.cn).