Chinanews, Beijing, Jul. 20 – The OECD released a report on China’s environmental protection effort in Beijing on Tuesday, which points out that half of Chinese cities’ drinking water sources fail to meet the required standard, and water quality in the Yangtze River, Zhu Jiang, Songhua and 4 other rivers is seriously deteriorating.OECD’s report has been approved by State Environmental Protection Administration.The report points out that the main polluted sources come from dejections, as well as industrial and chemical wastes. The Haihe, Liaohe and Huaihe rivers are under the threat of heavy pollution.