Water quality assessment of surface drinking water sources in cities and towns of China

Based on the achievements of the Safeguard Planning for Urban Drinking Water Sources in China,the water quality of surface drinking water sources is analyzed.The worst-factor assessment method is used;that is,the water quality grade of the worst factor is taken as the water quality grade of the whole water source.The water quality assessment shows that 55% of the water sources fail to reach the water quality standard and organic pollutants are the main cause.The water quality of water sources is worse in rivers than in reservoirs,and the water sources beyond the water quality standard are mainly in southern China for rivers and northern China for reservoirs.