Water Environment

State

• River system

  In 1997, seven large river systems, lakes, reservoirs, underground water in some regions, and coastal waters were polluted to varying degrees. The arid and semi-arid regions in the north as well as many cities suffered from serious water shortage. The deficiency of water resources and the pollution of water systems became one of the main factors affecting the social and economic development of China.

  In 1997, the total amount of discharged wastewater was 41.6 billion tons, of which 22.7 billion tons was industrial wastewater and 18.9 billion tons was municipal wastewater. With regard to industrial wastewater, industries at the county level and above discharged 18.8 billion tons, while TVIE (Township and Villages Industrial Enterprises) discharged 3.9 billion tons. In discharged wastewater, the total amount of Chemical Oxygen Demand (COD) was 17.57 million tons, including 10.73 million tons of COD discharged with industrial wastewater and 6.84 million tons of COD discharged with municipal wastewater. As to the total amount of COD discharged with industrial wastewater, 6.66 million tons of COD was discharged by industrial enterprises at the county level and above, while 4.07 million tons of COD was discharged by TVIE's.

• Seven large river system

  The Yangtze River    The pollution in the main stream was not so serious and the water quality was basically good. 67.7% of the river sections monitored met Grade III or was better than Grade III of the Environmental Quality Standards for Surface Water. There were no river sections that went beyond Grade V standards. The most important pollution indicator was the permanganate index followed by Biologycal Oxygen Demand (BOD) and volatile phenols. Since the completion of first stage of the Three Gorges project, no obvious impacts of the project on the water quality upstream or downstream in the construction area have been found.

  The Yellow River    The yellow River was under dual pressures from both water pollution and damming. The water quality in 66.7% of the monitored river sections met Grade IV standards. Ammonia nitrogen, volatile phenols, permanganate index, and BOD were major pollution indices. In the 1970's, the river ran dry for 21 days at its longest; however, the dry period lasted 133 days in 1996 and increased sharply to 226 days in 1997.

  The Pearl River    The water quality of main stream was barely acceptable. Water quality in 62.5% of the monitored river sections was Grade III or better. Water quality at 29.2% of the river sections could meet Grade IV standards. Water quality of the rest of the sections was Grade V or worse than Grade V. The major pollution indices were ammonia nitrogen, permanganate index and total mercury.

  The Huaihe River      The water quality along the main stream of Huaihe River has shown some improvement. The most obvious improvements were along those sections that in the past years had high pollution levels. The water quality of the main stream met Grade III and Grade IV standards. The pollution in the tributaries was still serious. Among the primary tributaries, the water quality of 52% river sections exceeded Grade V. Among the secondary and tertiary tributaries, the water quality of 71% river sections exceeded Grade V. The major pollution indices were non-ionized ammonia and permanganate index.

  The Haihe and Luanhe River      The river water in this region was seriously polluted and water quality was quite poor on the whole. The water quality in 50% of the monitored river sections was Grade V or worse. The major pollution indicators were permanganate index, ammonia nitrogen, and BOD.

  Liaohe River      The water quality was quite bad on the whole and the river system was heavily polluted. The water quality in 50% of the monitored river sections exceeded Grade V. The major pollution indicators were ammonia nitrogen, total mercury, volatile phenols, BOD and permanganate index.

  The Songhuajiang River     The river quality has improved compared with that of previous years. The water quality in 70.6% of the monitored river sections met Grade IV standards. The major pollution indices were permanganate index, volatile phenols and BOD.

  Generally speaking, the water quality in the main branches of the Yangtze, Pearl and Yellow rivers was marginally acceptable. The Huaihe and Songhuajiang rivers had shown improvement. The water quality in the Haihe, Luanhe and Liaohe rivers was bad.

• Lakes and reservoirs

  Large freshwater lakes and urban lakes were moderately polluted, while the pollution of reservoirs was relatively less. Compared with previous years the pollution in Chaohu lake and Dianchi Lake has increased while that in Taihu Lake has dropped. According to pollution levels, the major lakes as ranked from high to low were: Dianchi, Chaohu (west part), Nansihu, Hongze, Taihu, Dongting, Jingbo, Bositeng, Xingkai, and Erhai, In 1997, the most significant environmental problems of lakes and reservoirs were heavy eutrophication and increase of oxygen consuming organic substances. The major pollution indicators for large freshwater and urban lakes were total phosphorous, total nitrogen, permanganate index and BOD. The major pollution indicators for large reservoirs were total phosphorous, total nitrogen and volatile phenols. Some lakes and reservoirs were found to be polluted by mercury. A few reservoirs were found to be polluted by arsenic.

• Coastal waters

  Compared to that in 1996, the pollution in coastal waters did not change much in 1997. The main pollutants were inorganic nitrogen and inorganic phosphorous. The water quality assessment showed that 18.7% of coastal waters met Grade I standards, 21.4% met Grade II, 6.5% met Grade III, and 53.4% exceeded Grade III. The coastal areas of Pearl River Estuary was still one of the most heavily polluted coastal regions. In the coastal areas, the percentage exceeding Grade I standard for sea water were: 44% for Bohai Sea, 46% for Yellow Sea, 94% for East China Sea, and 42% for South China Sea. In which, inorganic phosphorous exceeded Grade I by the ratios as follows: 16% for Bohai Sea, 47% for Yellow Sea. 81% for East China Sea, and 38% for South China Sea. Oil pollution was less serious than in 1996 with the percentage that exceeded standards being 11% for East China Sea and 12% for South China Sea. The concentration of heavy metal and COD did not exceed standards. Among four sea areas, East China Sea was most polluted, followed by Bohai Sea, the Yellow Sea and South China Sea.

  Environmental Quality Standards of Surface Water