Groundwater Quality Management Research Articles

Contamination zoning and health risk assessment of trace elements in groundwater through geostatistical modelling.

Trace elements (TEs) concentration in groundwater is a key factor for health risk assessment (HRA). To achieve high level of accuracy in HRA, the present study performed Monte Carlo simulations, sensitivity analysis and uncertainty analysis to a total of 184 (N=184) groundwater samples, collected during December 2016 from Birbhum district. TEs in samples were detected by anodic stripping voltammetry (ASV). The mean concentration of TEs were found as Fe (855.88μg/L)> Zn (204.0μg/L)> Cu(84.9μg/L)> Ni(47.31μg/L)> Pb(14.43μg/L)> Co(10.58μg/L)> Cd (7.88μg/L). It indicated serious contamination by Fe, Cd. Pb and Ni according BIS, 2012. Pollution indicators such as heavy metal pollution index (HPI) revealed that study area is heavily contaminated by these TEs. Incremental lifetime cancer risk (ILCR) value of TEs showed that Cd is the main offender for cancer risk. Average value of total hazard index (THI), was found to be 2.48. THI through ingestion pathways was found to be more risky than dermal contacts accounting for 88% and 12% health hazard respectively. The sensitivity analysis indicated ingestion rate, exposure time, and TEs concentration were the most influential parameters for all groundwater associated health hazards. The TEs affected areas were mapped through Empirical Bayesian Kriging geostatistical model and health risk prone zones were projected. The study demonstrated that Monte Carlo simulation and EBK can provide better accuracy in health risks prediction and spatial distribution analysis of contaminants in any geographical area. The TEs and their hazard zonation mapping with geostatistical modelling will be helpful for the policy makers and researchers to improve groundwater quality management practices.

The SIVI index: a comprehensive approach for investigating seawater intrusion vulnerability for island and coastal aquifers

Seawater intrusion is a major groundwater quality management issue for islands and coastal aquifers. In this paper, a new comprehensive index called the SIVI index has been proposed to assess the vulnerability of these aquifers to seawater intrusion. The index consists of eight parameters including: surface area of the aquifer affected; the intensity of intrusion; its seasonal variation; its evolution; aquifer type; the hydraulic conductivity of the aquifer; the height of groundwater levels above sea elevation; and distance of the aquifer from the coast. The SIVI index considers both the dynamic and intrinsic characteristics of the region to evaluate seawater intrusion vulnerability. The new index was applied to the Tourian aquifer located in Qeshm island in the Persian Gulf. The results show that the aquifer locally has a high vulnerability (SIVI index 0.54) to seawater intrusion as currently an area 9.5 km2 of the aquifer is in danger of being salinized. The presented SIVI classification method can be used to analyze vulnerability of aquifers and management of groundwater resources in any coastal region.

Hydrogeochemical characterisation and health hazards of fluoride enriched groundwater in diverse aquifer types

High concentration of fluoride (up to 20.9 mg/L) in groundwater with significant variation (p = 5.9E-128) among samples was reported from Birbhum district, an acknowledged fluoride endemic region in India. The groundwater samples (N = 368) were grouped based on their hydrochemical properties and aquifer geology for hydro-geochemical characterization. Friedman’s test showed p < 0.0001 confidence level which indicates that fluoride concentration among geological groups and water groups are independent. Bland-Altman plot was used to study the inter-relationships among the groups through bias value (∂) and limit of agreement (LoA). Among the geological groups, laterites and granite-gneiss groups exhibited statistically significantly difference in fluoride geochemistry; whereas the younger and older alluvium groups displayed similar characteristics. The fluoride concentration was found to be in the order Lateritic > Granite-gneiss > Older alluvium ≥ Younger alluvium. Dissolution of minerals (such as fluorite, biotite) in laterite sheeted basalt, and granite-gneiss is the main source of groundwater fluoride in the region. Fluoride concentration is also influenced by depth of water table. Hydrochemical study indicated that fluoride concentration was higher in Na–HCO3 than in Ca–SO4 and Ca–HCO3 type of groundwater. The fluoride concentration were positively correlated with Na+ and pH and negatively correlated with the Ca2+ and Mg2+ signifying linkage with halite dissolution and calcite, dolomite precipitation. Geostatistical mapping of WQI through empirical bayesian kriging (EBK) with respect to regional optimal guideline value (0.73 mg/L) classified that groundwater in some parts of the district are unfit for drinking purpose. Health survey (N = 1767) based on Dean’s criteria for dental fluorosis indicated presence of slight to moderate dental hazard. Besides, providing baseline data for management of groundwater quality in the study area, the study demonstrated the applicability of Bland-Altman analysis and empirical bayesian kriging (EBK) in delineation and interpolation of fluoride contaminated region.

Multi-objective Freshwater Management in Coastal Aquifers Under Uncertainty in Hydraulic Parameters

This paper proposes a novel stochastic framework for groundwater quantity and quality management in aquifers threatened by saltwater intrusion. In this methodology, a finite difference SEAWAT code is linked with an optimization model to solve density-dependent groundwater flow equations considering different patterns of pumping rates. To reduce the computational time of the simulation–optimization process especially when there are a high number of decision variables, a modular evolutionary polynomial regression (MEPR) model is developed and coupled with the optimization algorithm. The info-gap theory is utilized to evaluate the robustness of optimal scenarios incorporating the uncertainty of hydraulic conductivity (k) of the heterogeneous aquifer. For each management scenario proposed by the simulation–optimization model, values of robustness and opportuneness indices are computed based on utility functions of different agricultural sectors. The results of applying the proposed method to the Qom aquifer in Iran show that coupling MEPR model with the simulation–optimization model considering the uncertainty of the aquifer parameter k could provide a reliable management scenario with a comparatively low computational cost.

Impacts of Emerging Agricultural Practices on Groundwater Quality in Kahe Catchment, Tanzania

This paper assesses the impacts of farmers’ intensive use of agrochemicals (fertilizers and pesticides) on groundwater quality in the Kahe catchment. Samples were collected during the wet and dry seasons of the year 2018 and analyzed for the presence of agrochemicals in the water. Groundwater chemistry was dominated by magnesium-sodium-bicarbonate (Mg-Na-HCO3−). The cations levels were in the trend of Mg2+ &gt;Na+ &gt; Ca2+ &gt; K+, whereas anions were HCO3− &gt; Cl− &gt; SO42− for both seasons. The NO3− had an average value of about 18.40 ± 4.04 and 7.6 ± 1.7 mg/L in the wet and dry season, respectively. Elevated levels of nitrate, sulfate, phosphate, and ammonium were found in water samples collected near the large-scale sugarcane plantation in the catchment. For both seasons, Pb, Cd, Fe, Mn, Zn and Cu concentrations averaged approximately 0.08 ± 0.03, 0.11 ± 0.03, 0.16 ± 0.02, 0.11 ± 0.01, 0.46 ± 0.05, and 0.55 ± 0.02 mg/L, respectively. On the other hand, the concentrations were higher in shallow wells than in the deep boreholes. Pesticides’ residues were below the detection limit in all sampled groundwater. The findings from this study provide important information for intervention in groundwater quality management in Kahe Catchment, Tanzania.

Application of GIS in the Assessment of Groundwater Quality in the Yenagoa Watershed of the Niger Delta Region of Nigeria

The spatial variations in groundwater quality in parts of the Yenagoa watershed (YWS) in the Niger Delta Region of Nigeria has been investigated using Geographic Information System (GIS). An understanding of the factors responsible for groundwater vulnerability could facilitate the use of geographic information system in the control and management of groundwater quality. This study is due to the fact that the spatial distribution maps of groundwater quality in the YWS obtained by GIS modeling are not documented. The quality of groundwater accounts for the environmental and human health status of the residents in the YWS. Therefore, twenty (20) water samples obtained from shallow boreholes were analyzed for physicochemical properties. The physicochemical parameters such as pH, conductivity, total dissolved solids, sulphate, nitrate, sodium, chloride, magnesium, total hardness and iron contents were measured using standard laboratory procedure. Except for the iron content, the results obtained from the physicochemical analyses were within limits of the World Health Organization Standards for drinking water. These results were transformed into spatial distribution maps using GIS modeling and interpretation. The Index Overlay method and Inverse Distance weighted method form component parts of the GIS modeling used in the generation of the spatial distribution maps for each physicochemical parameter. These modeled results were related to the World Health Organization (WHO) Standard for drinking water. The maps generated from GIS modeling indicated zones that were suitable for groundwater extraction as opposed to zones unsuitable for groundwater extraction. In conclusion, 55% of the boreholes in the Yenagoa watershed were affected by high iron content.

Avaliação do perigo de contaminação das águas subterrâneas por fontes pontuais nos municípios do Vale do Taquari – RS

Avaliar o risco de contaminação dos aquíferos é uma importante ferramenta para a proteção da qualidade da água subterrânea, e como gestão para a alocação de novos empreendimentos, instalação de poços e delimitação de áreas de maior perigo. A região do Vale do Taquari apresenta 432 poços em situação de bombeamento e equipados, extraindo água principalmente para abastecimento doméstico e animal. Por isso, é fundamental mapear o perigo de contaminação da água subterrânea, que compreende a sobreposição de dois mapas, o de vulnerabilidade natural do aquífero, obtido através do método DRASTIC, e o das fontes potenciais de contaminação, classificadas de acordo com o método POSH. Os resultados demonstram que a maior representatividade no mapa de vulnerabilidade pertence ao valor moderado, com 79%, seguido por reduzido, com 16%, e elevado 5%. A multiplicação entre os mapas evidenciou que a classificação de perigo moderada corresponde a 46% da área analisada, seguida por reduzido com 38%, desprezível com 10% e por fim 6% com índice elevado, concentrado no município de Estrela. Além disso foi possível constatar que 56 poços se encontram nas zonas analisadas. Espera-se que esse trabalho seja importante para os municípios com o intuito de preservar as áreas de elevada vulnerabilidade, assim como alertar áreas com alto perigo de contaminação. E que sirva de motivação para o detalhamento do mapeamento de índices, solos e geologia da região do Vale do Taquari.

Comprehensive understanding of groundwater quality for domestic and agricultural purposes in terms of health risks in a coal mine area of the Ordos basin, north of the Chinese Loess Plateau

Assessment of groundwater quality and health risk was conducted in the Shenfu coal mine area in Ordos basin, northwestern China. Statistical analysis, Piper and Chadha diagrams were used to reveal the hydrogeochemical characteristics of groundwater via physicochemical analysis of 44 collected samples. The suitability of groundwater was assessed for domestic and irrigation purposes, and the fuzzy comprehensive method was adopted to assess the overall groundwater quality for further discussion on groundwater management. The model recommended by the USEPA was selected to estimate the non-carcinogenic risks caused by NO3−, NO2−, NH4+, F−, Fe and Mn through oral ingestion and direct dermal contact. The results revealed that the predominant hydrochemical types of groundwater were SO4∙Cl–Ca∙Mg and HCO3–Ca∙Mg types and the major cations and anions followed the orders of Ca2+ > Na+ > Mg2+ >K+ and HCO3− > SO42− > Cl−, respectively. Groundwater is generally acceptable for irrigation. However, for domestic purposes, 47.73% of the collected samples are of excellent and good quality and are suitable for direct consumption. Both adults and children face non-carcinogenic risks because of exposure to contaminants such as nitrate, nitrite and fluoride. The risk to children is higher than that to adults, which is consistent with other studies. Nitrite contributes most to the risks, followed by nitrate and fluoride. Home-use water quality improvement devices and rainwater harvesting are suggested to enhance the groundwater quality protection and management in this area. The research also indicates that health risk assessment should always accompany general water quality assessment to ensure the reliability of the water quality assessment.

Identifying the impact of intensive agriculture practices on groundwater quality using GIS and multi-tracer techniques around Sangamner city, Maharashtra, India

Identifying the impact of intensive agriculture practices on groundwater quality gives an ample idea of associated hydro-chemical facies. This study deciphers the groundwater quality using physico-chemical analysis, multi-tracer and geographical information system (GIS) techniques. To investigate groundwater quality, 25 samples were collected from dug-well in May 2010 and May 2015. Physico-chemical analysis of pH, EC, TDS, Na+, K+, Ca2+, Mg2+, Cl-, HCO3 -, SO4 2-, and NO3 - carried out using American Public Health Association and integrated into AqQA and GIS software. The range of analysis increased in 2015, that is, pH (7.9–8.9), EC (910–9710 µS/cm), TDS (582–6214 mg/l), Na+ (34–850 mg/l), K+ (0.6–3.1 mg/l), Ca2+ (89–346 mg/l), Mg2+ (68–2960 mg/l), Cl- (89–1591 mg/l), HCO3 - (200–799 mg/l), SO4 2- (49–210 mg/l) and NO3 - (10–90 mg/l). Almost samples of pH, TDS, Mg2+, HCO3 - and NO3 - were above BIS standards. A present effort is an innovative approach for bids in similar hydro-geological conditions for sustainable groundwater quality management.

Nitrogen stock and leaching rates in a thick vadose zone below areas of long-term nitrogen fertilizer application in the North China Plain: A future groundwater quality threat

Nitrate in groundwater is increasing in many aquifers worldwide due to excessive use of fertilizers. However, the behavior of N-based fertilizer as it leaches through thick vadose zones is still poorly understood, and the long-term effects on groundwater quality in such settings may yet to be fully realized. In this study, deep soil cores were taken below experimental plots where N-fertilizer was applied for nearly 20 years under wheat-maize double cropping in the North China Plain (NCP). N-fertilizer application rates of zero, 400, and 600 kg N ha−1 yr−1 were applied to different plots. Water and N balances were quantified to estimate the leaching rate of NO3−-N below the root zone, and NO3−-N loss via denitrification. Transport pathways of nitrate in the vadose zone were identified using stable isotopes of water (δ18O-H2O & δ2H-H2O) and nitrate (δ18O-NO3− & δ15N-NO3−) from the sampled pore-water and groundwater. The average N transport velocity through the vadose zone ranged from 38 to 41 cm yr−1 and was relatively constant regardless of fertilizer application rate. The transport rates are significantly lower than the long-term rate of groundwater level decline (100 cm yr−1), meaning it is unlikely much of the leachate from chemical N-fertilizers (abundantly applied throughout the region since the 1970s) has entered groundwater via matrix flow. Nitrate isotopes appear to indicate that manure and septic waste (not chemical N-fertilizer) are the major sources of nitrate in groundwater to date. However, stable isotopes show that increased nitrate concentrations in groundwater may also result due to preferential flow in sand layers and/or lateral flow from headwater areas. Denitrification (particularly in the upper 4 m depth of soil) appears to have limited the flux of fertilizer-derived nitrate to some degree. However, the large N stock and generally weak denitrification potential in the deep unsaturated zone, pose a major threat to future groundwater quality. The results have major implications for groundwater quality management in the future.

Application of groundwater quality index (GWQI) and principle component analysis (PCA) to assess the groundwater quality of Pleistocene aquifer in Tan Thanh district, Ba Ria – Vung Tau province

This research applied the groundwater quality index (GWQI) and principal component analysis (PCA) for assessing pollution levels and factors effecting groundwater quality of Pleistocene aquifer in Tan Thanh district, Ba Ria – Vung Tau province. Seventeen wells were colected in April (dry season) and October (rainy season) during 5 years (2012-2017). Nine parameters of water (pH, TDS, độ cứng, Cl-, F-, NO3-, SO42-, Cu2+ và Fe2+) were collected for analyses. The results of GWQI (dry season) divided into 17 wells in dry season with groundwater quality from good to very good which occupied to 82% databases, compared to 94% of rainy season. Meanwhile, the number of wells significantly changed from poor to very poor water between two seasons. PCA demonstrated that two specific factors, interaction of chemical components in river sediments and character of aquifer and anthropogenic, affected to the quality of groundwater in this study area. These explained 65.555% (dry season) and 61.562% (rainy season) of the variances. This result is provided specific information, and the useful tools in order to deal with the complicated databases, as well as zone the groundwater quality in the study area. This further help the authorities to plan suitable strategy for groundwater quality management.

Impacts of Municipal Wastewater on The Transport Characteristics of Reactive Solutes Through Agricultural Soils

ABSTRACTReliable transport parameters of agrochemicals and soluble pollutants are crucial for modeling and management of soil and groundwater quality. This study investigated impacts of municipal wastewater on the transport parameters of five heavy metal/metalloid compounds (NaAsO2, Cd(NO3)2, Pb(NO3)2, Ni(NO3)2 & ZnCl2), two pesticides (cartap & carbendazim) and an inert salt (CaCl2) in four agricultural soils of Bangladesh. Solute-breakthrough concentrations were measured in repacked soil columns with time-domain reflectometry (TDR) both before and after wastewater treatment. Transport velocity (V), dispersion coefficient (D), dispersivity (λ) and retardation factor (R) of the solutes, and pertinent soil properties were determined. Wastewater reduced bulk density (γ) of the soils (from 1.32–1.37 g/cm3 to 1.26–1.35 g/cm3) by increasing organic carbon (OC) (from 0.37%–0.84% to 0.40–0.93%), increased pore-size distribution index (n) (by 0.02 unit) and reduced soil pH (from 6.32–7.45 to 5.92–6.46). D and λ decreased while V and R increased after wastewater treatment; D decreased and R increased linearly with decreasing bulk density. The correlations of V, D, and R with n improved significantly (p < 0.05) after wastewater treatment. The correlation between λ and OC improved markedly for Ca, Pb, Ni, and cartap. The observed indicative results have practical implications in developing pedo-transfer functions for solute-transport parameters using basic soil properties, which are subject to progressive modification due to agrochemicals application and wastewater irrigation.

Effects of coal mining on the evolution of groundwater hydrogeochemistry

The mining industry, especially coal mining, may severely affect the spatial and temporal evolution of groundwater. To provide a potential model outlining the hydrogeochemical evolution of groundwater as influenced by coal mining, a multi-layer groundwater system in a coal mining area was investigated. A total of 76 groundwater samples were collected between 1964 and 2018 for hydrogeochemical analysis from boreholes, underground tunnels, and surface pits at Xinglongzhuang Coal Mine in China. Hierarchical cluster analysis and principal component analysis were used to classify four significant groundwater zones and two principal components. The results showed that mining may have caused the rock strata to sink, obstructing the path linking the Permian and lower Quaternary aquifers, and resulting in intensified ion exchange in the lower Quaternary aquifer. The concentrations of Na+ and Ca2+ in the groundwater from the lower Quaternary aquifer changed over the studied period (~54 years). The gradual increase of Na+ and decrease of Ca2+ concentration verified the action of cation exchange. The four main aquifers had relatively independent hydrogeochemistry, suggesting that the hydraulic conductivity of the natural faults is weak and the sealing properties of hydrogeological drill holes in the coal field are good. Analysis of 26 heavy metals in the mine drainage water showed that there is only minor pollution after the water has been simply treated. These data analysis methods and results could be useful in areas with long-term mining to interpret the evolution of groundwater and to promote groundwater quality management.

Geospatial Analysis of Groundwater Quality in Ludhiana, Punjab (India)

This paper presents a geospatial analysis of the groundwater quality of Ludhiana, Punjab, India. The groundwater samples were collected from 99 locations using grid based sampling procedure and analysed for parameters viz. pH, total dissolved solids (TDS), total hardness (TH), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), fluoride (F-), chloride (Cl-), nitrate (NO3-), sulphate (SO24-) and bicarbonate (HCO3-). Sampling was done during both pre-monsoon and post-monsoon periods. Water quality index (WQI) was used to represent the groundwater quality of the study area. The WQI coupled with the spatial maps indicated that merely (1%) of the total study area had good groundwater quality and the rest of the study area fell under poor, very poor and unsuitable for drinking purpose. The geographical information system (GIS) based groundwater quality mapping presented in this paper could be a potential tool for groundwater quality management.

Assessment of groundwater vulnerability and water quality of Ngwerere sub-catchment urban aquifers in Lusaka, Zambia

The quality pressures on the aquifers in Lusaka city have increased in the past decades to a level that poses a pollution threat to drinking water sources due to human exploitations. This study is aimed at evaluation of the protection and management of groundwater quality for aquifers in Ngwerere sub-catchment, as a case study. This was achieved through the development of a vulnerability map using inherent hydrogeological and landuse data, as well as analysis of groundwater quality. The results revealed that most of the aquifers in the study area have very low protective effectiveness of the soil and rock cover, which are supposed to act as barriers against pollution. This was validated from physicochemical and microbial analyses of randomly sampled boreholes in the study area, which indicated high levels of nitrates, Escherichia coli, and total coliforms, which are above the recommended standards for drinking water. Nitrate exceeded the recommended value in one of the eight boreholes, but feacal pollution was observed in nearly all boreholes. The calculated Water Quality Index (WQI) of water in five of the eight borehole samples indicated a WQI of 1.8–13.2, which indicates that water quality was excellent. However, two of the eight boreholes had WQI exceeding 50, which indicated that water was not suitable for drinking without treatment. The analysis of Internal Factor Evaluation (IFE) and External Factor Evaluation (EFE) indicated overall weighted scores of 2.61 and 2.57, respectively. These values suggests that the legal, policies and institutional frameworks in Zambia, using the Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis revealed that the systems instituted for protection of groundwater quality are strong and well designed to meet opportunities as well as to defend against threats. However, effectiveness in the implementation is poor, which demands up-scaling of implementation strategies in order to improve sustainable groundwater management systems.

Spatial groundwater quality and potential health risks due to nitrate ingestion through drinking water: A case study in Yan’an City on the Loess Plateau of northwest China

This research was carried out to delineate the spatial distribution of shallow groundwater quality in Yan’an City, an important cultural city on the Chinese Loess Plateau, and to estimate the health risks induced by nitrate exposure in drinking water in this city. For this study, 36 shallow groundwater samples were collected from shallow pumping wells/dug wells. The entropy-weighted water quality index (EWQI) was used to evaluate the overall groundwater quality, and the spatial distribution of the groundwater quality was discussed. The potential health hazards due to nitrate intake through drinking water were also assessed. The results of the study demonstrate that the main hydrochemical facies are governed by natural processes and anthropogenic activities. Over half of the groundwater samples require treatment of different degrees before being consumed. TH, TDS, SO42–, and NO3– are the most prevalent contaminants affecting the groundwater quality in this area. Poor-quality water is prevalent in the region along the main river. Residents in almost half of the study area face noncarcinogenic health risks with children being the more susceptible group to groundwater nitrate contamination. Reducing the concentration of NO3– in drinking water by regulating excessive fertilizer application and issuing regulations supervising the domestic sewage are important to reduce the health risks. Integrated management of groundwater and surface water as well as rainwater is recommended for the groundwater quality management.

Relationship Between Aquifer Processes and Groundwater Quality: A Case of Olbanita Aquifer System, Lower Baringo Basin, Kenya Rift

A hydrogeochemical relation has been hypothesized through the analyses of physiochemical data of a fractured volcanic rock aquifer located in the Lower Baringo Basin, Kenyan Rift. Data sets included 15 individual metrics determined in 42 dry and wet season water samples obtained from 6 boreholes in the area. Aquifer evolutionary theory was postulated using sequential principal component analysis (PCA) and hierarchical cluster analysis. To eliminate the effects of scale dimensionality, PCA decomposed the variable data into 4 factors, namely, electrical conductivity, salinity, alkalinity, and carbonate equilibrium with external pH control for the dry season and salinity, carbonate equilibrium with external pH control, alkalinity, and electrical conductivity for the wet season. The main result depicted a major shift in the variability factor from electrolytic conductivity (34.8%) in the dry season to salinity (23.5%) in the wet season. Ward’s linkage cluster analysis partitioned the aquifer into 2 spatially discrete associations; the western and the eastern entities, respectively, in spite of their shared recharge area. These agglomerative scheduling validated in an integrative approach (with groundwater flow predictions using a calibrated petrophysical groundwater model for the area) linked the 4 factors to aquifer processes and 3 pathways: fault permeability, weathering processes, and water-rock interaction. Statistical approaches are, therefore, useful in the conceptualization of pollutant sources and their attenuation for effective groundwater quality management.

Comparison of the Soil Environment Conservation Act and the Groundwater Act in the Republic of Korea

Abstract Demand for water is steadily rising due to high population growth coupled with continuing urbanization and industrialization. Limited surface water availability makes water supplies increasingly dependent on groundwater. With growing dependence on groundwater, groundwater quality and availability are becoming an increasingly important issue. Once groundwater is contaminated, pollutants rest in the contaminated aquifer semi-permanently, requiring enormous efforts and costs for remediation, apart from the fact that it is technically impossible to restore contaminated water to its natural state. Therefore, the importance of preventing groundwater contamination cannot be overstated. In this regard, it is of paramount importance for sustainable and efficient management of groundwater resources to regulate it with clearly formulated provisions in pertinent laws and regulations. Worldwide, groundwater remediation is usually done in conjunction with soil remediation. In the Republic of Korea, too, groundwater remediation is performed mostly as part of soil remediation projects. In this study, we compare and analyze two domestic laws directly associated with groundwater remediation, namely, the Soil Environment Conservation Act and the Groundwater Act. On the basis of the analysis results, we sought strategic measures for strengthening nationwide groundwater quality management.

Spatial Variation of Ground water Quality Parameters and its Suitability for Drinking at Makutopora Aquifer, Dodoma Municipality, Tanzania.

A study was conducted to benchmark the ground water quality parameters and its spatial variation from Makutopora boreholes which are found 32 km from Dodoma town. A total of 90 samples (from both deep and shallow wells) were collected and analyzed for various quality parameters. The analysis results were interpolated using statistics and Inverse Distance Weighting tool in a Geographical Information System (GIS) environment to determine their spatial variation. The results indicated that all samples were within the permissible Tanzanian standards, except for two unused production boreholes which showed higher levels of total hardness, Electrical conductivity and total dissolved solids. However, gross pollution was found in community shallow wells of Chihanga and Veyula that showed high levels of nitrate (78-82 mg/l), Manganese (1.05 mg/l), low pH (5.98) and E. coli. (52/100 ml). It is quite clear from this study that the ground water supplied to Dodoma is still meeting the set drinking water standards in Tanzania although aquifer deterioration was noticed which demands an urgent innovative ground water management. The results obtained in this study will therefore be helpful for future monitoring and sustainable ground water quality management in the Makutopora sub basin.

Evaluation of Groundwater Quality Suitability for Drinking Purpose Using Water Quality Index Approach in Yarmouk Basin, Jordan

Groundwater quality is an issue of national concern in Jordan since it is the main water source for drinking, agriculture and industrial purposes. In this context, an attempt has been made to determine the suitability of groundwater in the Yarmouk Basin in Jordan for drinking purposes using the weighted arithmetic water quality index approach with the respect to the Jordanian standards for drinking water. Groundwater quality records from 15 sampling stations spread across Yarmouk Basin during 2008- 2015 are used. Seven physical and chemical parameters are selected to calculate the water quality index. These parameters are pH, total dissolved solids, total hardness, sulfates (SO4 −2 ), chlorides (Cl− ), nitrates (NO3 − ), and sodium (Na+ ). The relationship between the selected groundwater quality parameters is evaluated using the correlation coefficient. A strong relationship is found between several parameters such as Cl− with Na+ , total dissolved solids with Na+ , Cl− , TH and SO4 −2 and total hardness with SO4 −2. A moderate relationship is found between SO4 −2 with Na+ , TH with Cl− and Na+ , SO4 −2 with Cl− , Cl− with NO3 − and NO3 − with Na+ . Also, the mean concentration values of the physical and chemical parameters are almost below the maximum allowable level based on Jordanian standards for drinking except for two sampling locations. According to water quality index scale classification, the groundwater quality of the studied locations is in the excellent to poor water range with computed mean water quality index values range from 26.3 to 107.93. Out of 15 studied locations, ten locations are classified in the ‘Excellent water’ class, four locations as a “Good water” class, one as a “Poor water” class. None of the studied locations are classified in the “Very poor water” class and “Water unsuitable for drinking purpose” class. Temporal variations and spatial distribution of groundwater quality in Yarmouk Basin based on WQI are also evaluated. The WQI spatial distribution map clearly showed the best locations for drinking water in the Yarmouk Basin. Water quality indices are used to provide theoretical support to water managers and policymakers for proper actions on groundwater quality management