Almost a quarter of purified drinking water tested by China’s top safety watchdog was substandard, with many products found to contain excessive levels of bacteria, the official Shanghai Daily newspaper said on Monday. The China Food and Drug Administration (CFDA) found excessive bacteria in purified water products from China’s biggest drinks maker Wahaha Group, as well as C’estbon Beverage Co Ltd and Danone SA’s Robust brand, the newspaper said. The CFDA checked 2,088 batches of purified drinking water and found that 23 percent were substandard, the Shanghai Daily said. Most failed the tests for excessive levels of bacteria. The findings underline the challenge of controlling supply chains in China. Food health scares are common in China — in 2008 there was a deadly dairy milk contamination whereby industrial chemical melamine killed six infants and made many thousands sick.