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

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.

Groundwater Pollution in Bangladesh: A Review

Bangladesh relies mainly on groundwater for irrigation and drinking purposes. Groundwater, however, continuously polluted, is a major obstacle. Nowadays, Bangladesh is moving towards industrial revolution in a considerable speed. As part of this paper's attempt to analyze the groundwater pollution scenario in Bangladesh, specifically in the past two decades, about 100 articles, conference papers, and reports published in national and international journals and books were reviewed, as well as issues concerning pollution sources, health impact assessment, and future perspectives were discussed. The groundwater is contaminated by different contaminants, such as physico-chemicals, trace metals, and microbes. Human health is at great risk from arsenic (As) contamination; it is one of the biggest threats. The cancer risk and non-cancer risk of ingesting water are increased. On the other hand, a large number of peoples were affected due to waterborne diseases governed by microbial contamination. Geophysical and anthropogenic sources, the depth of wells, and geographical factors may influence groundwater pollution. It is recommended that policy makers should address the issue immediately and precautions should be taken wherever necessary.

STATISTICAL AND MULTIVARIATE TECHNIQUES TO TRACE THE SOURCES OF GROUND WATER CONTAMINANTS AND AFFECTING FACTORS OF GROUNDWATER POLLUTION IN AN OIL AND GAS PRODUCING WETLAND IN RIVERS STATE, NIGERIA.

Background: Groundwater is an important source of drinking water for the indigenous communities of Ebocha-Obrikom. Access to safe drinking water, in particular, is critical to one's health and, by extension, one's income and well-being. Underground wells are the primary supply of drinking water in the Niger Delta, and the groundwater is not always treated before consumption. As a result, water continues to be a vital environmental component that affects both humans and other life forms. Objectives: The aims of the research is to trace the sources and affecting factors of groundwater pollution via statistical and multivariate statistical techniques. Method: The investigation made use of standard analytical procedures. All sampling, conservation, transportation and analysis followed standard procedures described in APHA (2012). To prevent degradation of the organic substances, all obtained samples were transferred to the laboratory, while keeping in an icebox. Results: The study reveals that the greater the number of principal components extracted the greater variation in geochemical composition of the ground waters. It indicated that 34 parameters were distributed into six (6) and nine (9) principal components (PCs) extracted for groundwater samples for both rainy and dry seasons, potentially suggesting the input of different pollutants from different sources. Gas flaring, mineral dissolution/precipitation and anthropogenic input are the main sources of the physicochemical indices and trace elements in the groundwater. Groundwater chemistry is predominantly regulated by natural processes such as dissolution of carbonates, silicates, and evaporates and soil leaching, followed by human activities. Climatic factors and land use types are also important in affecting groundwater chemistry. Conclusion: Greater efforts should be made to safeguard groundwater, which is hampered by geogenic and anthropogenic activities, in order to achieve sustainable groundwater development. As a result, communities are recommended to maintain a groundwater management policy to ensure long-term sustainability. The study is useful for understanding groundwater trace sources in Rivers State's Ebocha-Obrikom districts. Such understanding would enable informed mitigation or eradication of the possible detrimental health consequences of this groundwater, whether through its use as drinking water or indirectly through consumption of groundwater-irrigated crops. As a result, determining its primary probable source of pollution (MPSP) is critical since it provides a clearer and more immediate interpretation. Furthermore, the research findings can be used as a reference for groundwater pollution prevention and water resource protection in the Niger Delta region of Nigeria.

A Review on the Application of Isotopic Techniques to Trace Groundwater Pollution Sources within Developing Countries

Owing to a lack of efficient solid waste management (SWM) systems, groundwater in most developing countries is found to be contaminated and tends to pose significant environmental health risks. This review paper proffers guidelines on the application of isotopic techniques to trace groundwater pollution sources from data spanning from 2010 to 2020 within developing countries. Earlier groundwater studies in those countries were mainly focused on using hydrochemical and geophysical techniques. The limitation of these techniques is that they can only monitor the concentration of pollutants in the water bodies and possible leachate infiltration but cannot determine the specific sources of the pollution. Stable isotopes of δ18O, δ2H and δ13C can confirm leachate migration to water bodies due to methanogenesis. The high tritium in landfill leachates is useful to identify leachate percolation in groundwater. The δ15N technique has been used to distinguish between synthetic and organic nitrogen sources but its application is limited to differentiating between atmospheric vs. inorganic nitrogen sources. The use of a dual isotope of δ15N–NO3− and δ18O–NO3− is beneficial in terms of identifying various sources of nitrogen such as atmospheric and inorganic fertilizers but is yet to be used to differentiate between nitrogen pollution sources from dumpsites, sewage and animal manure. The coupling of the 11B isotope with δ15N–NO3− and δ18O–NO3− and other hydrochemical parameters has proven to be effective in distinguishing between nitrate fertilizer, animal manure, seawater contamination and sewage. Therefore, in areas affected by agricultural activities, landfill leachates, domestic or sewage effluent and seawater intrusion, it is incumbent to couple hydrochemical (Cl−, NO3−, B, DO) and isotope techniques (δ18O, 2H, δ13C, δ18O–NO3−, δ15N–NO3−, δ11B and 3H) to effectively determine pollution sources of groundwater in developing countries. The foregoing review will provide guidelines for studies that may aim to critically distinguish between seawater intrusion, dumpsites, sewage and septic leachates.

Simulation and Prediction of the Groundwater Pollution Caused by the Leakage from a Sewage Plant in an Aluminum Factory Under the Action of Ocean Tide Support

In order to predict the impact of wastewater from an aluminum plant treatment station on the groundwater environment under abnormal conditions (i.e., sewage leakage accident). Through the investigation of hydrogeological conditions, and then the permeability coefficient of the aquifer was measured through borehole injection tests. Finally, the groundwater pollution transport halo was obtained by numerical simulation based GMS software. The simulation results showed that the groundwater aquifer will be seriously polluted by COD and fluoride (F-) after the sudden sewage seepage accident. What’s more, the simulation results showed that the pollution concentration is getting higher and higher with time, which is analyzed to be caused by the small permeability of the water-bearing medium in the aquifer and the groundwater flow field was supported by seawater tide.

Groundwater Vulnerability to Pollution in Kediri City, East Java Province, Indonesia

Groundwater is a water resource that is still a mainstay for humans. The need for groundwater increases with the growth of population and the development of the industrial and agricultural sectors. The residents of Kediri City still use wells from shallow aquifers to fulfill their water needs. Shallow aquifers are prone to pollution due to the influence of shallow groundwater depths and human activities. The purpose of this study is to determine the vulnerability of groundwater pollution in Kediri City. Groundwater vulnerability was conducted by the GOD method (Groundwater Occurrence, Overlaying Lithology, and Depth of Groundwater) that consists of 3 parameters, namely the groundwater confinement, the type of overlying strata, and the depth of the groundwater level. The analysis results show that the level of groundwater vulnerability according to the GOD method in Kediri City consists of moderate and high classes. The western and the eastern part of Kediri City is classified as a high level of vulnerability. In contrast, in the middle of Kediri City, it tends to experience a moderate level of vulnerability.