AMBI02012,41:370-379 371 A Seven main river systems B Twenty-eight major lakes 100% 100% 80% 80% ▣Grade V plus Bnb 60% 60% ▣Grade IV-V 40% 40% Grade I-mI 200 20% 0% 0% 2000 00 2000 1008 Year Year Fig.1 Water quality in (a)seven main river basins and (b)28 major lakes (in different grades) total area of 83 400 km2 and accounting for 0.8%of the The national groundwater resources assessment in 2000- country.According to an evaluation of eutrophication in 2002 showed less than 5%of the total resources of 131 major lakes in 2000,about 50%of them were eutro- 350 thousand million m'per year suffered from serious phic (Yuan 2000).and for 75%of these lakes the eutro- pollution,so most of it could be used in agriculture and phication is getting worse.Over half of the rivers and about industry after the conventional treatment.The shallow two-thirds of the lakes in the seven river systems and 28 groundwater resources polluted by nitrate are mainly in the major lakes were assessed to be of poor quality (Grade IV North China Plan.the Northeast Plain.the Jianghan Plain and above')during 2000-2008 (Fig.1)(SEPA 2000- (in the middle reach of Yangtze River)and the Yangtze 2008).Lake eutrophication has been showing a rapidly Delta region (Zhang and Li 2004). increasing trend since 2000,with serious algal bloom crisis Projections suggest that the future nitrogen surplus from in Dianchi Lake in 2001 and in Taihu Lake in 2007(Qin crop production will increase from about 154 kg ha in et al.2007;Gao and Zhang 2010).Nitrogen concentrations 2004 to 179 kg ha in 2015,and hence the risk of non- in large rivers,especially the Yangtze and Yellow river, point source pollution will increase (Shen et al.2005). have been increasing in recent years (Li et al.2007;Yu During 2005-2008,the high-risk area for fertilizer appli- et al.2010).The estuaries and coastal water near cities are cation included five coastal provinces and three munici- seriously polluted,and the annual frequency of red tides palities in the east region and four provinces in middle has increased from 28 in 2000 to 68 in 2008 with a region.There will be three more provinces (Hainan,Anhui cumulative area of 13,738 km2(SEPA 2000-2008). and Hebei)and one municipality (Chongqing)facing high The NPS problem is not restricted to surface water risks in 2020 if current policies and trends continue bodies.The shallow groundwater in intensive vegetable (Fig.2). growing areas generally suffers from very serious nitrate pollution.A survey of 16 counties in the Yangtse Delta Pollution from Pesticides region (i.e.Jiangsu Province,Zhejiang Province and Shanghai City)found 38%of the drinking water wells had Long-term intensive application of pesticide has caused a nitrate-N content 20 mg L-(Zhang 1999).Another contamination of soil,surface water,groundwater and farm survey of 14 counties in three cities in North China(i.e. products.In the period 1950-1983,soil pollution was Beijing,Tianjin and Tangshan)found that 50%of the mainly caused by organochlorine pesticides (OCPs),with a sampling sites had nitrate-N levels>11.3 mg L-(the total consumption of 4.46 Mt of Lindane (HCH)and 0.435 Europe Union limit for drinking water)in nitrate-N con- Mt of dichlorodiphenyltrichloroethane(DDT)in 33 years tent-the highest reached 68 mg L(Zhang et al.1996). Conventional treatment for water includes physical and biological IThere are five grades in the national environmental quality treatments.The solid pollutants are removed first by sand sedimen- standards for surface water (MEP 2002).There are 24 items to tation;then the colloidal and dissolved organic pollutants (BOD. evaluate the water quality.such as pH,COD,BOD.N,P,heavy COD)are removed by biological treatment including the biological metal,petroleum,Faecal Coliform Bacteria,etc.From Grades I to IV, filter biofilm,biological dial,bio-contact oxidation and fluidized bed. the threshold value for total N is 0.2.0.5.1.0,1.5 and 2.0 mg L-, Advanced treatment is to remove the refractory organic matter, respectively.The standards also set limits for the content of different nitrogen and phosphorus by biological nutrient removal,coagulation pesticide in surface water with the highest value of 0.08 mg L-for precipitation,sand filtration,activated carbon adsorption,ion dimethoate. exchange and electrodialysis method. Royal Swedish Academy of Sciences 2012 www.kva.se/en ②Springertotal area of 83 400 km2 and accounting for 0.8% of the country. According to an evaluation of eutrophication in 131 major lakes in 2000, about 50% of them were eutro￾phic (Yuan 2000), and for 75% of these lakes the eutro￾phication is getting worse. Over half of the rivers and about two-thirds of the lakes in the seven river systems and 28 major lakes were assessed to be of poor quality (Grade IV and above1 ) during 2000-2008 (Fig. 1) (SEPA 2000- 2008). Lake eutrophication has been showing a rapidly increasing trend since 2000, with serious algal bloom crisis in Dianchi Lake in 2001 and in Taihu Lake in 2007 (Qin et al. 2007; Gao and Zhang 2010). Nitrogen concentrations in large rivers, especially the Yangtze and Yellow river, have been increasing in recent years (Li et al. 2007; Yu et al. 2010). The estuaries and coastal water near cities are seriously polluted, and the annual frequency of red tides has increased from 28 in 2000 to 68 in 2008 with a cumulative area of 13,738 km2 (SEPA 2000-2008). The NPS problem is not restricted to surface water bodies. The shallow groundwater in intensive vegetable growing areas generally suffers from very serious nitrate pollution. A survey of 16 counties in the Yangtse Delta region (i.e. Jiangsu Province, Zhejiang Province and Shanghai City) found 38% of the drinking water wells had a nitrate–N content[20 mg L-1 (Zhang 1999). Another survey of 14 counties in three cities in North China (i.e. Beijing, Tianjin and Tangshan) found that 50% of the sampling sites had nitrate–N levels[11.3 mg L-1 (the Europe Union limit for drinking water) in nitrate–N con￾tent—the highest reached 68 mg L-1 (Zhang et al. 1996). The national groundwater resources assessment in 2000- 2002 showed less than 5% of the total resources of 350 thousand million m3 per year suffered from serious pollution, so most of it could be used in agriculture and industry after the conventional treatment.2 The shallow groundwater resources polluted by nitrate are mainly in the North China Plan, the Northeast Plain, the Jianghan Plain (in the middle reach of Yangtze River) and the Yangtze Delta region (Zhang and Li 2004). Projections suggest that the future nitrogen surplus from crop production will increase from about 154 kg ha-1 in 2004 to 179 kg ha-1 in 2015, and hence the risk of non￾point source pollution will increase (Shen et al. 2005). During 2005-2008, the high-risk area for fertilizer appli￾cation included five coastal provinces and three munici￾palities in the east region and four provinces in middle region. There will be three more provinces (Hainan, Anhui and Hebei) and one municipality (Chongqing) facing high risks in 2020 if current policies and trends continue (Fig. 2). Pollution from Pesticides Long-term intensive application of pesticide has caused contamination of soil, surface water, groundwater and farm products. In the period 1950-1983, soil pollution was mainly caused by organochlorine pesticides (OCPs), with a total consumption of 4.46 Mt of Lindane (HCH) and 0.435 Mt of dichlorodiphenyltrichloroethane (DDT) in 33 years Fig. 1 Water quality in (a) seven main river basins and (b) 28 major lakes (% in different grades) 1 There are five grades in the national environmental quality standards for surface water (MEP 2002). There are 24 items to evaluate the water quality, such as pH, COD, BOD, N, P, heavy metal, petroleum, Faecal Coliform Bacteria, etc. From Grades I to IV, the threshold value for total N is 0.2, 0.5, 1.0, 1.5 and 2.0 mg L-1 , respectively. The standards also set limits for the content of different pesticide in surface water with the highest value of 0.08 mg L-1 for dimethoate. 2 Conventional treatment for water includes physical and biological treatments. The solid pollutants are removed first by sand sedimen￾tation; then the colloidal and dissolved organic pollutants (BOD, COD) are removed by biological treatment including the biological filter biofilm, biological dial, bio-contact oxidation and fluidized bed. Advanced treatment is to remove the refractory organic matter, nitrogen and phosphorus by biological nutrient removal, coagulation precipitation, sand filtration, activated carbon adsorption, ion exchange and electrodialysis method. AMBIO 2012, 41:370–379 371 Royal Swedish Academy of Sciences 2012 www.kva.se/en 123