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 July 26. 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 per cent to be safe for drinking, up from 48 per cent last year, the ministry said in a notice posted on its website.

China classifies its water supplies using six grades, with the first three grades considered safe for drinking and bathing. Another 26.4 per cent was said to be categories IV and V – fit only for use in industry and agriculture – leaving 24.3 per cent in category VI and unfit for any purpose. Despite tougher regulations over the last decade, the ministry has struggled to rein in the thousands of small paper mills, cement factories and chemical plants discharging industrial waste directly into the country’s waterways, and the overuse of fertilizers has also left large sections of China’s lakes and rivers chocking with algae.