Groundwater quality assessment and health risks from nitrate contamination in the Heilongdong Spring Basin, a typical headwater basin of the North China Plain.

Groundwater quality assessment is crucial to the sustainable utilization of global groundwater resources. This study examined the current groundwater quality circumstance and the associated health risks from nitrate contamination for different age groups in the Heilongdong Spring Basin, a typical headwater basin of the North China Plain. A total of 39 groundwater samples were collected, and major ions were measured during the two field investigations (December 2017, August 2018). Results showed that most of groundwater chemical parameters were below the World Health Organization standards with a few exceptions. Anthropogenic sources and aquifer heterogeneity were jointly responsible for nitrate pollution in more than half of water samples. For drinking purpose, the groundwater was excellent or good in the western and southeastern regions where groundwater recharge and discharge mainly occur. However, the poor water quality samples were observed in the central and northern parts of the study area, which may be attributed to the slow or stagnant flow in the transitional zone. Additionally, the farmland irrigated with such groundwater will not be exposed to sodium or magnesium hazard but will suffer from the potential salinity hazard. The health risk for different age groups in the study area varied significantly, generally in the order of infants > children > adult females > adult males. The findings of this work provide valuable information for decision-makers to formulate sustainable strategies for groundwater resources development in these headwater basins of the North China Plain.