Site groundwater pollution risk assessment based on the protection of sensitive receptors

Abstract

Groundwater pollution risk assessment is an effective tool for preventing and controlling groundwater pollution. The study on groundwater pollution risk assessment can serve as a basis for the management of groundwater contaminated sites. The present risk assessments often ignore the spatial variability of pollution within the site and the susceptibility of receptor. This paper proposes a new site groundwater pollution risk index system that can be used for pollution sites with a variety of features. The index system considers the spatial distribution of pollutant at the site and nearby receptors. Based on the four aspects of pollution load, vadose zone vulnerability, aquifer vulnerability, and receptor susceptibility, this paper conducted index screening and weight calculation using the analytical hierarchy process. A site groundwater pollution risk assessment index system was constructed, and the risk was divided into four levels: low, medium, higher, and high. Using the constructed risk index system, the spatial risk distribution of a hexavalent chromium site in Henan Province was studied. The results show that the site was at a medium risk level, with the highest risk at the chrome slag heaps and the southeastern of the buried chrome slag. The potential loss of surrounding receptors and the pollution load are the main causes of groundwater contamination risk at the site. Single parameter sensitivity analysis shows that the effective weights of each index are in line with the theoretical weights, indicating the rationality of the constructed site groundwater pollution risk assessment system, which can be applied to other sites with characteristic pollutants.

Keywords

• site
• risk assessment
• receptor susceptibility
• pollution characteristics
• sensitivity analysis