Progress and experience: Water pollution control in the People’s Republic of China
Current water quality Despite the government’s efforts in strengthening institutions and measures of environmental protection, main river basins in the People’s Republic of China (PRC) have increasingly been threatened by complex water pollution problems, which have resulted in quality deterioration of both drinking and underground water, water ecosystem degradation and lake eutrophication. The growth of the economy and urban population has led to the overexploitation of water resources. Table 6.1 shows water quality observed from 411 monitoring stations in seven main watersheds in 2005. At the national level, 41.8 percent, 30.3 percent and 27.9 percent of the river water is categorized as Class 1 –3, Class 4 –5 and below Class 5, respectively.1,2 Across watershed, the water quality in Changjiang and Zhujiang are relatively better – over 70 percent of the river water is categorized as Class 1 –3, while less than 10 percent is categorized as below Class 5. Haihe has the worst water quality, with almost 57 percent of its water below Class 5. Water pollution in the country has changed from simple industrial pollution to integrated complex pollution from industry, agriculture and households. Water pollution in the PRC is increasingly characterized by compound pollution and a high organic basin pollution load which greatly exceeds the ability for
self-purification.This comes in a situationwhen infrastructureandcapacity in basin pollution prevention and management are weak and lag behind economic development. Serious water pollution has also affected rivers in the country, resulting in water ecological degradation, water quality deterioration and water shortage. Transboundary water environment is also faced with the same huge challenge in pollution control and management. Various pollutants superposition and new and toxicant presentation have also been observed. Chemical oxygen demand (COD), five-day biological oxygen demand (BOD5), ammonia nitrogen (NH3-N), total nitrogen (TN), total phosphorus (TP) and escherichia coli have alarmingly exceeded the standard and tolerableamounts.Moreover,influenceofpersistentorganicpollutants(POPs)and endocrine disrupters (EDs) is becoming serious. New pollutants, which are harmful to both human health and the safety of drinking water, have also emerged. At the same time, serious eutrophication problems are observed in lakes. In 1970s, among the 34 lakes surveyed, only 5 percent showed eutrophication problems. The percentage increased to 36 percent during 1986 and 1989, and 75 percent in 2002. In 2005, out of 28 lakes and reservoirs of national importance which are nationally monitored, only two reached water quality of Class 2. Six of the lakes and reservoirs reached water quality standard of Class 3, while three reached Class 4, and another five reached Class 5. The water quality of the remaining 12 lakes and reservoirs, or about 43 percent of the total, was below Class 5. The year 2007 was called the year of Cyanobacteria because of the outbreak of Cyanobacteria in Tai Lake, which seriously threatened the drinking water in Wuxi city. The frequent occurrence of water pollution disasters has also been noted. From 2001 to 2004, 3,988 disaster events of water pollution have been recorded, which means that nearly 1,000 events occurred each year. While the annual total economiclossinthefieldsofindustry,agricultureandhumanhealthcausedby water pollution is roughly more than RMB240 billion, or about 3 percent of the country’s gross domestic product (GDP), the economic losses due to the water pollution disasters alone was estimated at RMB286 billion in 2004, or 1.7 percent of the national GDP. In 2005, 693 water pollution disasters were recorded, which comprise nearly 50 percent of national pollution disasters during the year.