Investigation of quality and pollution characteristics of groundwater in the Hutuo River Alluvial Plain, North China Plain

Groundwater plays a critical role in northern China, accounting for 62 % of the total water supply in the Beijing-Tianjin-Tangshan region. Groundwater is particularly important in the North China Plain-the largest alluvial plain and one of the most densely populated regions of East Asia. The Hutuo River Plain, which is located in the western portion of the North China Plain, is essential in supplying groundwater to the entire central region of the plain. Groundwater in this region is the main source of industrial, agricultural, and drinking water and therefore directly influences daily life. In this study, 482 groundwater samples including 390 shallow groundwater samples and 92 deep groundwater samples were collected and analyzed to investigate water quality and the effects of anthropogenic activities in the Hutuo River Plain. Application of the improved fuzzy mathematics evaluation method revealed that 21.5 % of the samples exceeded the Class III water standard, and that these samples were primarily in areas containing high concentrations of industrial activity or sewage discharge, and at the same time the native hydrogeological environment is the major factor influencing distribution of most pollution components, groundwater quality in the top of the Hutuo River alluvial-proluvial fan was not very good just as the Vadose zone lithology is a little more coarse, in the leading edge of the alluvial-proluvial fan the vadose zone is mainly formed of clay with very low vertical permeability, these characteristics endow the area with good protective performance, which makes it difficult for surface pollutants to enter the aquifer. Groundwater quality in the region was primarily affected by inorganic materials including total hardness, iron, manganese, total dissolved solids, and nitrate nitrogen, the rates of exceed Class III water standard was 26.45, 17.72, 11.11, 10.58, and 8.47 %, respectively, in shallow groundwater, and 20.20, 16.34, 16.35, 14.43, 2.52 %, respectively, in deep groundwater. There are several organic materials with high detection rates including chloroform, carbon tetrachloride, carbon dichloride, and ortho-dichlorobenzene, the detection rate was 14.02, 2.12, 3.44, 2.48 %, respectively, in shallow groundwater, and there were little organic compounds detected in deep groundwater. Overall, the results indicated that the hydrogeological environment and anthropogenic activities have led to the introduction of toxic metals, nitrogen, and organic materials into groundwater in the Hutuo River Plain. These findings will be useful to future studies of the region and will facilitate the remediation and prevention of contamination in the area.