Local industries protected by officials are responsible for the serious pollution of the Huai River, the State Environmental Protection Administration said yesterday. A two-week inspection of environmental work along the river found water quality in the main river had improved but tributaries remained heavily polluted. 'The rate of improvement has lagged behind the rate of pollution,' Pan Yue , the administration's deputy director, was quoted by Xinhua as saying in a report. 'Governments at various levels are not following set standards in managing economic activities in the Huai River valley,' Mr Pan said. 'Traditional methods of production, which have little regard for conservation of resources and cause pollution, are still commonly used.' The Huai River valley covers Anhui , Jiangsu , Shandong and Henan provinces. More than two decades of industrial development has turned the Huai into a highly polluted river thick with garbage, chemical foam and dead fish. Administration inspectors wrapped up their review recently, checking 165 industrial factories, which are rated major sources of pollution, and 30 urban water-treatment plants. They also tested water samples taken from more than 200 locations in the valley, Xinhua said. Mr Pan said the inspectors found that a third of the factories had violated environmental regulations and discharged more waste than allowed. More than half of the treatment plants were not working. The deputy director blamed industries protected by local governments for the pollution. Mr Pan said construction of urban water treatment plants had fallen behind schedule. Eighty-five approved treatment plants had not been built due to a lack of funding. Local governments were also slow in phasing out traditional industries, seen as serious polluters. Paper mills, dyeing plants, chemical factories and tanneries are still major employers and producers in the region. The Huai River also suffered from the discharge of non-industrial waste such as pesticide. Xinhua said the administration had told local governments to close 50 serious industrial polluters and step up monitoring. It will also inform the securities watchdog of any publicly listed companies that violate environmental regulations.