The amount of E.coli found in water supplied to Hong Kong from the Dongjiang has risen by 83 per cent in the year to March, according to monitoring data released yesterday. But the Water Supplies Department insists the water is safe for consumption after treatment to remove traces of the bacteria, which can cause intestinal disease. The department tested raw water samples taken from the Muk Wu Pumping Station at the border, the receiving point for water from the Dongjiang in Guangdong. The tests, carried out between April last year and March, revealed water quality failed to meet the national standard in China in five out of 34 categories - dissolved oxygen, biochemical oxygen, phosphorus, manganese and nitrite. It was the third year running that standards for the five categories were not met. The data was first published in 2000. The tests revealed that the amount of E.coli in 100 millilitres of water had risen from 120 units to 220 units - an increase of 83 per cent. The amount of coliform bacteria - a large group of which E.coli is one - increased by 46 per cent, from 260 units to 380 units in 100 millilitres of water. The national standard allows a maximum of 1,000 units of coliform bacteria in 100 millilitres of water, but in one case, up to 5,400 units were found. The report also published for the first time the amount of two potentially fatal parasites - cryptosporidium and giardia - found in the raw water. On average, less than one unit of each was found in 100 millilitres of water. Chief executive officer of Green Power Man Chi-sum called for more enforcement by Beijing to control pollution.