In recent years, the Chinese government has focused its pollution-control efforts on what are known as the "key regions," with marked achievements to its credit. The "key regions" refer to the three rivers (Huaihe, Liaohe and Haihe), the three lakes (Taihu, Dianchi and Chaohu), the major state projects (the Three Gorges Project and the South-North Water Diversion Project), the "two control's area" (sulfur dioxide control area and acid rain control area), Beijing and the Bohai Sea. -- Prevention and control of water pollution in key drainage areas. The drainage area of the above-mentioned three rivers and three lakes totals 810,000 sq km, traversing 14 provinces (municipalities) with a total population of 360 million. The State formulated and put into practice a plan for the prevention and control of water pollution in key drainage areas for the ninth and tenth Five-Year Plan periods (1996-2005), under which it set up a system to control the total amount of pollutants. Every enterprise that discharges pollutants is required to reduce its emission to a certain level, which contributes to the goal of reducing the total amount of pollutants. While improving its pollutant-discharge licensing management method, the State had established a number of key pollution-control projects. By the end of 2005, of the 2,130 water pollution prevention and control projects in key drainage areas in the Tenth Five-Year Plan, 1,378 were completed, accounting for 65 percent of the total. In the three-river, three-lake drainage area, 416 sewage treatment plants have been completed or are under construction, with a daily treating capacity of 20.93 million tons. Over 80 percent of the more than 5,000 heavy polluters in the drainage area have reached the standard discharge level. Water pollutants in this drainage area have been reduced greatly, and the trend toward deteriorating water environment is now basically under control. Water quality in certain parts of the rivers or lakes has been improved significantly. The State has spent 18.167 billion yuan constructing sewage- and garbage-treatment facilities in the Three Gorges Reservoir Area and its upper stream. It also has had solid wastes removed from the bed of the reservoir to ensure water safety. -- Prevention and control of pollution in the "two control's area." In 1998, the Chinese government approved the delimiting of the acid rain control area and sulfur dioxide control area. The "two control's area" covers a total of 1.09 million sq km, involving 175 cities or districts in 27 provinces, autonomous regions and municipalities directly under the Central Government. The State readjusted the energy structure in this area by promoting the use of clean fuel and low-sulfur coal, and prohibiting residents in big and medium cities from using coal for household stoves. Compared with 1998, the proportion of cities located within the sulfur dioxide control area that achieved the standard annual sulfur dioxide density level in 2005 rose from 32.8 percent to 45.2 percent. The proportion of cities located within the acid rain control area whose sulfur dioxide density surpassed the national third grade level declined from 15.7 percent in 1998 to 4.5 percent in 2005. -- Air pollution control in Beijing. Beijing has taken measures to control air pollution since 1998. Technologies that use clean energy or save on energy are being widely introduced. This includes the use of natural gas, electricity-powered heating, geothermal resources, and energy-saving architecture. In 2005, the amount of natural gas used in Beijing was 3.2 billion cu m, and the city's heating network provided central heating to buildings exceeding 100 million sq m in area. Management of motor vehicle emission was tightened, and environmental protection labeling was adopted for motor vehicles; those with high emission were identified with yellow labels and prohibited from using some roads. More than 300,000 old or dilapidated motor vehicles were scrapped and 2,800 public buses burning natural gas were introduced. In 2005, the national emission standard for the third phase (equivalent to the European Standard III) was adopted ahead of schedule. Standards for environmental protection on construction sites were revised and improved, and management was tightened. Supervision and inspection were strengthened for road sweeping and water spraying by machines. More than 100 enterprises in the city center that caused pollution were closed down or moved out. All shaft kiln cement production lines were closed down. Thanks to these efforts, the number of days with Grade II air quality or better in Beijing increased from 100 in 1998 to 234 in 2005. The concentration of various air pollutants all declined, and air quality improved significantly. -- Control of pollution in the Bohai Sea. In 2001, the Chinese government approved the Action Plan to Bring Back Turquoise Water to the Bohai Sea. By the end of 2005, 166 projects aimed at controlling pollution in the Bohai Sea and protecting the environment were completed, and 70 more were under construction, with the investment totaling 17.5 billion yuan. Forty-four new urban sewage treatment plants were built, with a total daily treatment capacity of 3.553 million tons. Eighteen new urban garbage treatment plants were established, with a total daily treatment capacity of more than 7,000 tons. In addition, 89 ecologically-friendly agriculture and breeding industry projects were set up, and nine ports and oil-spill response projects built, bringing under control the trend toward environmental deterioration in the Bohai Sea for the time being.