Assessment of Risk and Social Impact on Groundwater Pollution by Nitrates. Implementation in the Gallocanta Groundwater Body (NE Spain)

José María Orellana-Macías,María Jesús Perles Roselló

doi:10.3390/w14020202

José María Orellana-Macías, María Jesús Perles Roselló

Open Access

https://doi.org/10.3390/w14020202

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Abstract

Groundwater is an essential resource for humans concerning freshwater supply; therefore, preserving and protecting its quality is necessary. Risk assessment, based on hazard, intrinsic vulnerability information and mapping, may be considered as a key aspect of sustainable groundwater management. An approach has been made by combining the Nitrogen Input Hazard Index and the hydrogeological parameters considered in a modified DRASTIC method. A three-level classification has been used to determine the degree of risk, and the thresholds have been established following measurable criteria related to the potential nitrate concentration in groundwater. The second part of the study focused on estimating the socioeconomic impact of groundwater pollution by relating the degree of risk and social vulnerability to groundwater pollution. The method has been tested in the Gallocanta Groundwater Body (Spain). As a result, a risk map and an impact map are provided. The risk map shows that 67% of the study area can be classified as moderate and high-risk areas, corresponding to high hazard sources located in moderate and high vulnerability zones, whereas the impact of groundwater pollution is classified as moderate in the whole groundwater body. The proposed analysis allows comparison between aquifers in different areas and the results required by water authorities to implement control and mitigation measures.

Highlights

In environmental hazards, risk is defined as the result of the interaction of a hazard, and the vulnerability of the system or element exposed, including the probability of the occurrence of the hazard phenomena [1]
Given human dependence on certain resources, people protection and security lead to the implementation of risk assessments, which comprehend the nature of the risk and determine its level [2]
When analyzing specific pollutants such as nitrates, risk assessments have to focus on agricultural lands, which are the main sources of this substance

Summary

Introduction

Risk is defined as the result of the interaction of a hazard, and the vulnerability of the system or element exposed, including the probability of the occurrence of the hazard phenomena [1]. Given human dependence on certain resources, people protection and security lead to the implementation of risk assessments, which comprehend the nature of the risk and determine its level [2]. Risk is assessed by analyzing hazard factors and the vulnerability of the elements potentially at risk, including people, assets, properties and infrastructures, and it provides the basis for implementing measures in order to ensure groundwater protection [3]. The decreasing quality status of freshwater caused by pollutants involves potential health risks to people. Many researchers and public reports have assessed the potential human health risk of several groundwater pollutants in order to establish legal thresholds and contribute to the safeguarding of human health [8,10,11,12]. In the European Union, many countries have reported nitrate groundwater pollution, Spain being the third country with the highest proportion of groundwater monitoring stations with concentrations above 50 mg L−1 (Table 1)

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