Groundwater Pollution Control Research Articles

Groundwater flow monitoring using time-lapse electrical resistivity and Self Potential data

Groundwater flow monitoring is crucial to groundwater management and pollution control. Traditional in-situ hydrological surveys monitor groundwater flow, pressure or temperature changes to infer the actual conditions of the underground, but there are characteristics of stratum destructiveness and difficult to obtain the regional variation characteristics of groundwater. Compared with geophysical methods, it has the advantages of non-destructive detection and regional quantitative interpretation, and indirect understanding of the physical properties of underground media and groundwater. In this paper, we combine the time-lapse electrical resistivity (ERT) and self-potential (SP) methods to monitor the groundwater flow. The ERT result establishes linkages between the resistivity and porewater content of the underground space, and captures the difference in resistivity through the change of underground water content. The SP method provides a direct way to predict groundwater flow according to its movement characteristics. Then, the joint resistivity and potential field are further used to estimate the soil's apparent-permeability. We carry out a real pumping experiment at a hydrological observation site to verify the proposed method. The time-lapse ERT and SP results reveal a significant increase in resistivity but a decrease in permeability during water pumping and groundwater recharge, representing the process of groundwater decline and recovery. The results also matched well with the groundwater level in-situ hydrological data. The study demonstrates that the joint ERT and SP data can provide a direct and reliable way to monitor groundwater flow or other time-lapse hydrogeological surveys in the vadose zone.

Review and prospects of groundwater pollution control in shale gas exploitation

Abstract With the successful development of shale gas in the United States, shale gas has become an effective way to solve the energy crisis. Among a series of environmental problems caused by shale gas exploitation, the most hidden and the most difficult part to control and recover is groundwater pollution in the development zone, which has been paid more and more attention by the government and the public. Starting from the shale gas exploitation process, this paper discusses the research status and problems of shale gas exploitation on groundwater pollution prevention and control from both international and domestic Chinese directions, and considers the future development of groundwater prevention and control work: to strengthen the supervision and management of wastewater treatment; to explore and evaluate shale gas resources and to plan regional water resources; to update and improve relevant environmental laws to strengthen the support for shale gas development; to make public supervision and development transparent; and to optimize the whole development process.

A study of groundwater characteristics in the Songhua River basin of China

In this paper, the representative Yinmahe and Lianhuashan areas were selected as the focus of this project. Based on investigation and sampling, we utilized previously acquired data, integrated mathematical statistics, a Piper trilinear map, proportional coefficients, and isotopic ratio comparisons. Using SPSS analysis software and PDA Based Embedded GIS technology to develop groundwater pollution analysis software, the characteristics of groundwater in the study area were mastered. Both the hardness and mineralization of groundwater in the Lianhuashan area were high. The main ions are HCO3− and Ca2+; the mass concentration levels for Mn, Fe, K+, and NO2 varied by region. There are metasilicic acid and strontium enrichment areas. The quality of groundwater improved through years of prevention and control of groundwater pollution. The groundwater in the Songhua River basin is closely connected with river water, spring water, and reservoir water and effectively supports local economic development.

Occurrence, sources and fate of pharmaceuticals and personal care products and artificial sweeteners in groundwater.

Groundwater is considered as the main source for supplying the public drinking water in many countries and regions; however, pharmaceuticals and personal care products (PPCPs) and artificial sweeteners (ASs) found in groundwater can exert harmful effects on human health and aquatic ecosystems, and therefore, they are of persistent concern. The recent data on the occurrence of a series of PPCPs (including antibiotics, excitants and lipid regulators) and ASs often detected in groundwater are reviewed, in which the PPCPs and ASs occur in groundwater at the concentration from several nanograms to several micrograms per litre. In addition, the spatio-temporal distribution characteristics of PPCPs and ASs are discussed and the main sources and possibly pollution pathways of PPCPs and ASs in groundwater are summarised and analysed. Additionally, the adsorption, migration and degradation of PPCPs and ASs in underground environments are evaluated. Due to the long residence time in groundwater, pollutants are likely to threaten the freshwater body for decades under certain conditions. Therefore, according to the current level of pollution, it is necessary to improve and enhance the supervision on PPCP and AS pollutants and prevent and control groundwater pollution.

Impact of In Situ Soil in Soil-Bentonite Cutoff Wall Backfill on Compressibility and Hydraulic Conductivity

Soil-bentonite cutoff walls, consisting of excavated in situ soil and bentonite as backfills, are used extensively as vertical barriers for groundwater pollution control. Sand mixed with high-quality natural sodium bentonite (NaB) is commonly used as a research object to investigate the hydraulic and compression properties of soil-bentonite backfills. However, pure sand could rarely be found in real conditions, and natural NaB may not be available readily in some countries such as China, India, and Turkey. This paper presents a comprehensive laboratory investigation on the compressibility and hydraulic conductivity (k) of soil-bentonite backfills created by simulated in situ soil and low-quality sodium activated calcium bentonite (SACaB). The simulated in situ soils are prepared using sand-natural clay mixtures with sand to natural clay mass ratios ranging from 0.5 to 6.0, and the bentonite content (BC) in the base mixture ranges from 0 to 15%. The result indicates that BC dominates the compression index (Cc) of the backfill, and a unique relationship between void ratio at effective vertical compression stress of 1 kPa and compression index is proposed for various types of soil-bentonite backfills. An increase in either BC or clay size fraction (CF) in simulated in situ contributes to reducing k, but the impact of CF in simulated in situ soil on k tends to be insignificant for backfill with BC higher than 6%. A new characteristic parameter based on the concept of void ratio of bentonite (eb), named apparent void ratio of clay size fraction (eC), is developed for predicting soil-bentonite backfills created by in situ soils and bentonites with various contents.

The Groundwater Vulnerability Researches of Horqin District in Tongliao City Based on the AHP Method

On the basis of DRASTIC model index system, combined with the actual situation in Horqin district in Tongliao City, this paper removed the influence of the topography, added land use effects, modified the new model DRASLIC, used analytic Hierarchy Process (AHP), and calculated the new evaluation results. Groundwater management and protection decisions in Tongliao Horqin area provide a reliable basis for the application to design the groundwater monitoring network, site selection of waste landfill, evaluation and control of groundwater pollution, and provide a basis for other work. such as groundwater contamination and protection.

Geospatial Groundwater Quality Assessment and Identification of Polluted Risky Regions in Jamui District of Bihar with Special Reference to Uranium and Fluoride Concentration

Groundwater is an important source for community water needs. Geographical Information System (GIS) mapping the spatial pollution characteristics helped identifying the potential polluted risky regions in Jamui district that is covering an area of 3098 km2. It is situated between 24023’15” and 25008’30” North Latitude and 85049’30” and 86038’00” East Longitude forming a part of Phalgu-Kiul sub-basin of Ganga Basin. Water quality parameters such as pH, TDS, conductance, DO, ORP, salinity, alkalinity, hardness, calcium, magnesium, iron, uranium, carbonate, bicarbonate, fluoride, chloride, sulphate, nitrate, phosphate, etc of 91 samples were assessed as per standard protocol during pre- and post-monsoon. The results indicated that the water quality at several places in the study zone has been found contaminated with higher fluoride concentration that exceeded the permissible limit of BIS and WHO. Statistically16.48% water samples during pre-monsoon and 20.87% during post-monsoon were found seriously contaminated with fluoride concentration. However, the Uranium concentration during pre- and post-monsoon were found well within the prescribed national and international limits but at places it is in borderline and need constant monitoring. A positive correlation of fluoride with pH, total dissolved solid, electrical conductance, salinity, uranium and total alkalinity has been observed during pre-and post- monsoon. These results may provide useful information for control of groundwater pollution and its management in the area.

Application of Factor Analysis for Characterizing the Relationships between Groundwater Quality and Land Use in Taiwan’s Pingtung Plain

Although the average municipal water coverage in Taiwan is quite high, at 93.91%, only around half of the residents in the Pingtung Plain use tap water originating from the Taiwan Water Corporation to meet their needs. This means the exploitation of a substantial amount of groundwater as a source of water to meet drinking, agriculture, aquaculture, and industry requirements. Long-term groundwater quality surveys in Taiwan have revealed obvious contamination of the groundwater in several locations in the Pingtung Plain, with measured concentration levels of some groundwater quality parameters in excess of the permissible levels specified by the Taiwan Environmental Protection Administration. Clearly, establishing a sound plan for groundwater quality protection in this area is imperative for maximizing the protection of human health. The inappropriate use of hazardous chemicals and poor management of land use have allowed pollutants to permeate through unsaturated soil and ultimately reach the underlying shallow unconfined groundwater system. Thus, the quality of the water stored in shallow aquifers has been significantly affected by land use. This study is designed to characterize the relationship between groundwater quality and land use in the Pingtung Plain. This goal is achieved by the application of factor analysis to characterize the measured concentrations of 14 groundwater quality parameters sampled from 46 observation wells, the area percentages for nine land use categories in the neighborhood of these 46 observation wells, and the thicknesses of four unsaturated types of soil based on core samples obtained during the establishment of 46 observation wells. The results show that a four-factor model can explain 56% of the total variance. Factor 1 (seawater salinization), which includes the groundwater quality parameters of EC, SO42−, Cl−, Ca2+, Mg2+, Na+, and K+, shows a moderate correlation to land used for water conservation. Factor 2 (nitrate pollution), which includes the groundwater quality parameters of NO3−-N and HCO3−, shows a strong correlation to land used for fruit farming and a moderate correlation to the thickness of the gravel comprising unsaturated soil. Factor 3 (arsenic pollution), which is composed of groundwater quality parameters of total organic carbon (TOC) and As, is very weakly affected by land use. Factor 4 (reductive dissolution of Fe3+ and Mn2+), which involves Mn2+ and Fe3+, is weakly impacted by land use. Based on a geographic visualization of the scores for the four different factors and the patterns for land use, we can demarcate the areas where the groundwater in shallow unconfined aquifers is more vulnerable to being polluted by specific contaminants. We can then prioritize the areas where more intensive monitoring might be required, evaluate current land use practices, and adopt new measures to better prevent or control groundwater pollution.

Experimental Study on Dispersion of Unconfined Aquifer in a Site of Jilin City

Dispersion parameter is an important parameter for the establishment of groundwater solute transport model.The dispersion test uses sodium chloride as a tracer,which was conducted in a site in Jilin City.The standard curve comparison method was used to solve the dispersion parameters of the aquifer under the natural flow field.The test results show that under the natural flow field,the longitudinal dispersion of unconfined aquifer in Jilin City is 0.400m,and the lateral dispersion is 1.933×10-5~6.557×10-3m;while the vertical dispersion coefficient is 0.246m2d,the lateral dispersion coefficient is 1.191×10-5~4.039×10-3m2d.The above results can provide an important parameter basis for the establishment of groundwater solute transport model,the accurate prediction of temporal and spatial variation of pollutant concentration in groundwater and the formulation of groundwater pollution prevention and control scheme.

Distribution of Nitrate Content in Groundwater and Evaluation of Potential Health Risks: A Case Study of Rural Areas in Northern China.

Nitrate pollution is considered to be one of the most common environmental problems in groundwater, especially in areas affected by human mining, such as the arid region of northern China. However, the human health risk assessment of nitrate pollution in this area has not yet been carried out. In this study, groundwater samples were taken in the Selian mining area in Inner Mongolia to conduct a full analysis of water quality. On this basis, the groundwater quality, the distribution range of nitrate pollution, and human health risks were evaluated. The results show that the groundwater in the Selian mining area is neutral to alkaline, with high salinity and hardness. The concentration of nitrate ions in groundwater generally exceeds the standard, and the maximum exceeds 5.48 times the value specified in the Chinese national standard, indicating that groundwater nitrate pollution needs to be controlled urgently. Groundwater is polluted by large amounts of nitrogen fertilizer used by humans in agricultural activities. At the same time, mining activities have accelerated the severity and spread of pollution. Groundwater is not recommended for direct human life and irrigation use in the study area unless purification measures are taken. Nitrate pollution is more harmful to children through groundwater, about 1.54 times that of adults. Excess nitrate is transported into the body through drinking groundwater, so proper drinking water control will reduce the health risks of nitrate, such as centralized water supply. This study will provide a scientific basis for the rational use of groundwater and nitrate pollution control in the area.

Spatiotemporal evolution of groundwater nitrate nitrogen levels and potential human health risks in the Songnen Plain, Northeast China

As one of the most widespread pollutants worldwide, nitrogen has long been a concern in the environment, including groundwater. However, due to the limitations of investigations and study progress, there is still a poor understanding of groundwater nitrogen pollution and its potential effects on human health in many areas, particularly in developing countries. The spatiotemporal evolution of groundwater nitrate nitrogen levels and potential human health risks in the Songnen Plain, Northeast China were comprehensively studied based on both our own test data and available published data that were collected by us over a study period from 1995 to 2015. Groundwater nitrate nitrogen concentrations exhibited significant temporal and spatial differences: there was an increasing trend with time; and the distribution of high concentration areas expanded from the central and western areas to the east with time. The similar pattern existed in the potential health risks posed to the residents considering the two exposure pathways including drinking water and dermal contact. The effects of groundwater nitrate nitrogen on human health depend on the nitrate concentration but there were also age differences, namely, in the order of infants > children > adult females ≈ adult males, according to the hazard quotient (HQ) used in the human health risk assessment (HHRA) model. The spatiotemporal evolution of groundwater nitrate nitrogen levels and potential human health risks indicate that the issue of nitrogen pollution in groundwater in the study area is worsening and needs further attention. The drivers that increased nitrate nitrogen concentrations in the groundwater of the study area were the increased fertilizer use due to the increased cultivated land area and implementation of a land fertility policy by the local government. It should be acknowledged that the results have uncertainties that not only come from the layout of sampling points and selection of spatial interpolation methods but also come from the parameter settings in the assessment model and assumptions of drinking water scenarios. However, the conclusions still have important reference value for groundwater pollution control and management and human health risk supervision and early warning.

Analysis of groundwater pollution caused by mine leachate leakage considering natural impermeable layer

Aiming at the problem of groundwater pollution caused by mine leachate leakage, a numerical model of saturated-unsaturated groundwater is established by using FEFLOW software, and the spatial and temporal distribution of pollutants in vadose zone and aquifer is predicted, in this paper. The results show that the impervious layer of natural clay can slow down the entry of pollutants into the aquifer and reduce the impact of pollutants diffusion on the aquifer. This paper can provide some references for mine groundwater pollution prevention and control.

Wine-processing waste sludge permeable reaction barrier utilized to block a gasoline plume in a simulated aquifer.

Oil leakage from gas stations in Taiwan is commonly caused by the corrosion of oil tanks or loose pipeline joints, contaminating the soil and groundwater near the gas station. Wine-processing waste sludge (WPWS) does not contain toxic substances and has a high organic matter content. Thus, it has high affinity for methyl tert-butyl ether (MTBE) and benzene, toluene, ethylbenzene, and xylenes (BTEX), being suitable for application in preventing and controlling groundwater pollution. In this study, a permeable reaction barrier (PRB) constructed utilizing WPWS in a large water tank was designed to simulate the diffusion and blockage of gasoline plumes in an aquifer. The constructed WPWS PRB had a rectangular shape with a thickness and height of 9 and 60 cm, respectively. The depth in the aquifer was adjusted to 50 cm. MTBE was detected in the aquifer downstream of the WPWS PRB every day during the experiment; however, the maximum concentration detected was only 5.33 ppb. BTEX were only detected on 3 days during the experiment and had maximum concentrations of 1.76, 2.28, 0.34, and 0.60 ppb, which are below the water quality control standards.

Groundwater contamination risk assessment using intrinsic vulnerability, pollution loading and groundwater value: a case study in Yinchuan plain, China.

Groundwater contamination risk assessment is a useful tool for groundwater pollution prevention and control. Previous study has evaluated groundwater contamination risk at Yinchuan Plain, China, according to aquifer vulnerability. The present study enriches the assessment of contamination risk by adding pollution loading, which represents the hazard from human activities, and groundwater value, which represents the economic loss as a result of groundwater pollution. An approach that combines toxicity, release possibility, and the potential release quantity of pollutants on the ground surface was used to estimate the pollution loading. An integrated approach that considered both the in situ and extractive values was used to estimate groundwater value. In addition, a basic risk map was constructed by overlying the vulnerability and pollution loading maps showing the potential probability of pollution, while a value-weighted risk map was produced by overlying the basic risk and value map indicating the urgency of protection. The validation by specific contaminants shows the reliability of the basic risk assessment. Both the basic and value-weighted risk maps indicate a very high groundwater contamination risk in Yinchuan City, and the southern part of Yinchuan Plain exhibited a relatively high contamination risk. As a result of not only high vulnerability but also very high pollution loading and groundwater value, Yinchuan City is the most urgent area requiring groundwater protection. The produced maps provide effective information for decision-making regarding the optimization of monitoring network, preferential treatment, and allocating future potentially hazardous.

Soil NO3− storage from oasis development in deserts: Implications for the prevention and control of groundwater pollution

AbstractThe sources and storage of soil NO3− in the western Tengger Desert, Northwest China, were explored using water chemistry analysis and stable isotope techniques. In line with the expansion and development of oases, part of the desert has been transformed into cultivated land and artificial forest land. The mean soil NO3− contents found in areas of cultivated land and artificial forest were 123.06 mg kg−1 and 1.26 mg kg−1, far higher and slightly lower than the background desert soil values, respectively. The δ15N‐NO3− and δ18O‐NO3− values in cultivated soils ranged from 1.00 to 11.81 ‰, and from −1.85 to 8.99 ‰, respectively, and the mean mNO3−/Cl− value in cultivated soils was 2.3. These figures would appear to demonstrate that the rapid increase in the nitrate content in soils is principally due to the use of nitrogen fertilizer. Such increases in soil NO3− storage is likely to promote the leaching of nitrogen into the groundwater where coarsely textured soils exist, the pollution of water sources used for irrigation water, and extreme precipitation events. The δ15N‐NO3− and δ18O‐NO3− values in groundwater ranged from 3.72 to 6.54 ‰, and from −0.19 to 12.06 ‰, respectively, mainly reflecting the nitrification of soil nitrogen. These values appeared similar to those measured in the soil water in adjacent areas of cultivated land and vegetated desert, indicating that the groundwater has been affected by both natural and artificial NO3−. Artificial afforestation of desert regions would therefore seem to be a useful way of reducing the threat posed by anthropogenic sources to the circulation of NO3−‐N within arid regions, as well as promoting wind sheltering and sand fixation. This study explored the NO3− storage and groundwater quality responses to oasis development in arid areas in an attempt to provide effective information for local agricultural organizations and agricultural nitrogen management models.

Future liasing of the lockdown during COVID-19 pandemic: The dawn is expected at hand from the darkest hour

The lockdown during COVID-19 pandemic has converted the world into new experimental laboratories, which may reveal temporal or spatial comparative analysis data. However, some startling information is gathered in terms of reduced premature mortality cases associated with air and water quality improvement, enhanced e-learning on a broader platform, work from home, and successful e-health. The decline in vehicular density on roads and congestion leads to reduced energy consumption and associated greenhouse gases (GHG) and other pollutants emission. The lockdown has also been identified as a possible emergency measure to combat severe air pollution episodes. Similarly, industrial pollution has been recognized as one of the primary causes of water resource pollution and would, therefore, bring change in policy vis-à-vis groundwater pollution control. Our findings suggest that the results of successful e-learning and work from home would be a permanent shift from conventional modes in the near future due to a drastic reduction in socio-economic cost. Our critical analysis also highlights that with such temporary lockdown measures acute/chronic ill-effects of anthropogenic perturbations on planet earth can be effectively estimated through sociocultural, socioeconomical and socio-political/sociotechnological nexus.

Study on the influence mechanism of underground mineral element Fe(II) on Cr(VI) transformation under subsurface and groundwater interaction zones

BackgroundWith the acceleration of urbanization, heavy metal contamination in subsurface water and groundwater is becoming more and more serious, and the interaction between surface water and underground water is an important factor that cannot be ignored. Based on the change of oxygen content in surface water and groundwater environment, this research mainly studied the influencing factors and mechanism of underground mineral element Fe(II) on the morphological transformation of heavy metal Cr(VI) under the condition of surface–groundwater interaction, and simulates the interaction process of subsurface–groundwater by changing the dissolved oxygen content in the redox reaction system of dissolved Fe(II) and Cr(VI). The influence mechanism of pH, Fe(II):Cr(VI), groundwater hardness ion and humic acid on the morphological transformation of Cr(VI) was investigated.ResultsThe results showed that the content of DO did affect the conversion of Cr(VI) by Fe(II). pH had a great influence on the redox reaction: while pH = 3–5, the reaction rate of Fe(II) and Cr(VI) and the removal rate of Cr(VI) decreased with the increase of pH; while pH = 6–8, the reaction rate and the removal of Cr(VI) increased with the increase of pH. When Fe(II):Cr(VI) = 3:1, the reaction of Fe(II) and Cr(VI) is affected by DO; when Fe(II):Cr(VI) is 1:1, 2:1, 4:1 and 5:1, DO has no obvious effect on the reaction. Groundwater hardness ions can greatly promote the redox reaction. When humic acid exists in the reaction system, the Fe(III) formed by the oxidation of Fe(II) by Cr(VI) will once again be converted into soluble Fe(II), the reduction of humic acid further promotes the redox reaction between Fe(II) and Cr(VI), and promotes the conversion of Cr(VI) by Fe(II) more effectively. Moreover, the higher the concentration of humic acid, the higher the removal rate of Cr(VI).ConclusionsThe research results have practical guiding significance for groundwater contamination prediction, pollution control and remediation, integrated water resources management and the construction of sponge city in China.

Groundwater nitrate pollution risk assessment of the groundwater source field based on the integrated numerical simulations in the unsaturated zone and saturated aquifer

Groundwater pollution risk assessment in the groundwater source field (GSF) is crucial to ensure groundwater quality safety. A systematic method of assessing groundwater pollution in the GSF was established by combining the numerical models of groundwater flow and solute transport in the vadose zone and aquifer. It is featured by revealing the paramount fate of contaminant from the surface to receptor “well (wells)” via the pathway of vadose zone and aquifers. The method was verified in the phreatic and semi-confined aquifers of a vital GSF, Beijing-Tianjin-Hebei region (BTHR) in China. Nitrate was selected as the model pollutant. The results indicated that the groundwater pollution risk of the phreatic aquifer was dominated by the mediate level (45.27%), and that the second semi-confined aquifer was mainly ranked as relatively low (30.29%) and mediate (38.17%) levels. The groundwater pollution risk maps of the two aquifers were similar. The high and relatively high risk areas were affected by the high intensities of groundwater pollution sources (GPSIs) or short distances from the pollution sources to the pumping well. The low and relatively low risk areas were controlled by low GPSIs and adequate attenuation and denitrification of nitrate in the aquifer. The groundwater pollution risk in the semi-confined aquifer was lower than that in the phreatic aquifer. The groundwater pollution risk mapping provides a valuable scientific reference for the groundwater pollution prevention and control with the focus on the “pollution source” and “groundwater source field”. The proposed method can be further applied to the protections of the GSFs in the BTHR.

Optimal Buffer Zone for the Control of Groundwater Pollution from Agricultural Activities

We consider an optimal control model of groundwater pollution due to agricultural activities, the objective of the optimal manager being the optimization of the trade-off between the fertilizer use and the cleaning costs. The size of a buffer zone defined around the water production sites for limiting pollution effects may also be chosen by the manager. The spread of the pollution from crops to captation wells is modeled using a convection–diffusion–reaction equation. The main hydrogeological features of the dynamics are taken into account: the process is convection-dominated, dispersion effects are included, generic nonlinear reaction terms are considered. The existence and the uniqueness of the optimal solution is proven. Using asymptotic analysis, we then rigorously prove that a one-dimensional static model can be substituted to the full dynamic 3D model for the long time study of the optimal solution. We prove that this new optimal control problem is also well-posed. All these theoretical results are used for characterizing the optimal buffer zone.

Assessment and validation of confined aquifer vulnerability based on the VEBHAT method: a case study in Heilongjiang Province, northeastern China

Groundwater vulnerability assessment is an effective tool for groundwater pollution prevention and control. However, very few methods are available to address the vulnerability assessment of confined aquifers, though the risk of confined aquifer pollution has been increasing. This paper describes a method that integrates the vulnerability of the unconfined aquifer (V), extraction rate (E), aquitard thickness (Bt), head difference between unconfined and confined aquifers (H), aquitard media (At), and transmissivity of the confined aquifer (Tc), i.e., VEBHAT, to assess the vulnerability of confined aquifers. Hydraulic connections between the unconfined and confined aquifers, the vulnerability of unconfined aquifers, and the properties of confined aquifers were explicitly considered in this method. Moreover, the FO-TOPSIS method was used, which integrates fuzzy set theory (FST), along with an optimization model of multi-objective programming (OMP) and the classical TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) method, to determine the weights of assessment factors, and to reduce subjectivity of the weight assignment. To illustrate the applicability and reliability of the VEBHAT and FO-TOPSIS methods, they were applied to assess the vulnerability of confined aquifers in Zhaoyuan County, Heilongjiang Province, northeastern China. The Pearson correlation coefficient between the ammonium concentration data and the vulnerability assessment values was used to verify the validity of the methods. The results showed that the VEBHAT method and FO-TOPSIS method could be used to effectively assess the vulnerability of confined aquifers.