Resource and environmental risk assessment of groundwater well fields in the Beijing-Tianjin-Hebei region

Abstract

Groundwater in the Beijing-Tianjin-Hebei (BTH) region has been overdrawn for a long time, and groundwater pollution is severe. Groundwater well fields (GWFs) face resource- and environment-related pressures, and their safety is a key issue restricting regional social and economic development. We evaluated the groundwater quality and drinking suitability via the entropy-weighted water quality index and the overall health risks to adults and children with an improved model. Furthermore, the risks to GWF resources were determined based on the groundwater level and its variation. The higher Na+ and NO3− concentrations were mainly due to agricultural and industrial activities. Forty-seven GWFs approached the Class Ⅳ water standard, and 25 and 4 GWFs posed high health risks to adults and children, respectively, suggesting environmental risks. Moreover, the average annual groundwater level in the groundwater depression cone of 2 shallow and 6 deep GWFs decreased by 0.25 and 3.2 m, respectively. These GWFs were substantially threatened by groundwater resource attenuation. The groundwater level of 4 GWFs slowly declined, but a deep groundwater depression cone was not formed. However, the risk to groundwater resources remained high. The resource-related and environmental risks of GWFs in the BTH region were synchronous, but the resource-related risk was higher.