Suitability Of Groundwater Research Articles

Spatiotemporal variability and source apportionment of the ionic components of groundwater of a mineral-rich tribal belt in Bastar, India

This study illustrates the spatiotemporal variability pattern and source-routes of major ionic contaminants of groundwater in mineral-rich tribal belt of Bastar, India. Around 160 groundwater samples from 95 sampling sites were collected during the pre- and post-monsoon periods using a pooled study design. These samples were then chemically analyzed for pH, TDS, EC, TH, Mg2+, Ca2+, Na+, K+, HCO3−, F−, NO3−, Cl−, and SO42−. Ionic species exhibited distinct spatial variability patterns at the temporal scale of pre- and post-monsoon periods. Two source apportionment modeling techniques (PCA and PMF 5.0), based on factor analysis, were applied to investigate the source-routes of ionic components in groundwater. Three major contributing source-routes were identified for the ionic components: 1) mineral dissolution (~25%), 2) agricultural activities (30–36%), and 3) rainwater percolation (40–45%). The suitability of groundwater for irrigation purposes was also evaluated by analyzing the electrical conductivity, sodium percentage, and sodium adsorption ratio. The study will serve as an important reference for understanding groundwater chemistry and improving sustainable groundwater management planning in the tribal belt of the Bastar region.

Simultaneous comparison of modified-integrated water quality and entropy weighted indices: Implication for safe drinking water in the coastal region of Bangladesh

• A new unbiased drinking water quality index has been developed. • Using the index, groundwater of coastal region of Bangladesh was classified. • A comparative assessment was done between newly developed index and entropy index. • Most of the coastal groundwater exhibited as unsuitable for drinking purposes. • The index sensitivity is very high as it considered below- and upper threshold levels. Drinking-water sources are subjected to vulnerability due to chemical contamination and health risk in the southern coastal region of Bangladesh. Different types of water quality indices are being used to express the water quality, though most of them have both advantages and limitations. In this study, we modified and proposed an integrated water quality index by principal component analysis (PCA), and compared with the entropy theory. Spatial autocorrelation index and fuzzy GIS analysis are applied to delineate the suitability of groundwater in the study area based on randomly selected 377 groundwater samples from various depths (15–300 m). This study determined 20 water quality parameters. To avoid the bias of parameter selection, PCA was performed to reduce 12 parameters loads (TDS, EC, Ca 2+ , Mg 2+ , Na + , K + , Cl − , HCO 3 − , NO 3 − , pH, PO₄ 2− , and F − ). Unlike traditional indices, both desired and tolerable limits were considered in the modified-integrated water quality index (MIWQI). The results of entropy analysis depict NO 3 − , Cl − , and Na + as the most contributing parameters influencing the groundwater quality and much emphasis should be paid on these parameters to stop further groundwater pollution. MIWQI and Entropy water quality index (EWQI) results classify 21.22% and 42.43% of water samples as good quality for drinking, respectively. The rest 79% and 58% are classified as medium to extremely poor-quality water in the study area. A significant spatial pattern was identified for both water quality indices which were positively correlated (Moran’s I > 0). The MIWQI classification system exhibited commendable outcomes compared to EWQI due to comprehensiveness. Fuzzy GIS map revealed the spatial heterogeneity of groundwater parameters showing weak spatial dependency.

NON-CARCINOGENIC RISK ASSESSMENT OF GROUNDWATER IN SOUTHERN PART OF SALEM DISTRICT IN TAMILNADU, INDIA

The main objective of this study was to evaluate the groundwater quality for domestic, agriculture use and to describe fluoride contamination in groundwater and their impacts on human health. 67 groundwater samples were collected and analyzed for major ions. Water Quality Index (WQI), Piper diagram and Gibbs diagrams were calculated to measure the suitability of groundwater for drinking purpose. The hazards index value was calculated to estimate the noncarcinogenic risk to adult (male, female) and children suggested by the United States Environmental Protection Agency (USEPA). The irrigation indices were calculated to evaluate the quality of water for irrigation purpose. Statistical methods such as principal component and hierarchical cluster analysis were used to analyses the inter-relationship of data. Hydrochemistry of the samples shows, the major ions in the order of Ca2+>Mg2+>Na+ and Cl->SO4- in the study area. WQI value of groundwater, 74.62% of sample locations are good and 25.38 % of sample locations need primary treatment for drinking purpose. The results of the hazards index show that 65.67% of the sample locations exceeds the tolerable limit for non-carcinogenic risk (greater than one) for children higher than the risk level for Male and female. Statistical report of PCA and HCA reveals that Ca-Na-HCO3-F has positive loading and TDS-EC has negative loading. The study results show that rock-water interaction and anthropogenic activities are the major factors that influence the quality of groundwater. The continuous intake of excess concentration fluoride causes bone diseases and teeth problems.

Groundwater Quality in Sidi Slimane, Morocco.

Background.Groundwater is an important source of drinking water for human and animal populations and therefore should be protected from pollution. The study area, Sidi Slimane, is in the western region of Morocco, which is a highly important agricultural area.Objectives.The aim of the present study was to assess the suitability of groundwater for drinking in the Sidi Slimane region.Methods.Twenty (20) samples were collected from different locations in the study area in 2015 in order to evaluate the quality of groundwater for human consumption. Collection, transportation and analysis of samples were performed according to the Standard Methods for the Examination of Water and Wastewater of the American Public Health Association (APHA), 2017. The major ions (cations and anions), ammonium (NH4+), pH and electrical conductivity (EC) of the groundwater samples were analyzed. Total dissolved solids (TDS) and total hardness (TH) parameters were calculated on the basis of obtained chemical data. ArcGIS program (version 10.4.1) was used in the preparation of topographic and hydrological maps of the study area.Results.Groundwater showed high concentrations of most parameters of drinking water quality according to Moroccan and international standards. Groundwater was brackish and very hard. The results showed that sodium and chloride ions were the predominant ions. Salinity was present at low depths. The majority of groundwater samples in the study area (18 out of 20) were sodium chloride type, and only 2 samples were mixed calcium-magnesiumchlorine type.Discussion.The obtained results were compared with the Moroccan standards for drinking water. The results show that 100%, 75%, 70%, 70%, 65% and 55% of groundwater samples exceeded the permissible limits for drinking water quality according to the Moroccan standard with regard to sodium, calcium, TDS, EC, chlorine, and nitrate, respectively.Conclusions.Most of the groundwater samples in the study area showed poor drinking water quality. Groundwater quality must be protected by controlling the use of pesticides, fertilizers, manure, and harmful irrigation practices.Competing Interests.The authors declare no competing financial interests

Evaluation of groundwater suitability for irrigation in the coastal aquifer of Mnasra (Gharb, Morocco)

The coastal area of the Gharb plain constitutes the only hydric resource for region in terms of domestic consumption and agricultural demand which does not cease to increase. It is a very productive and easily accessible groundwater resource, used extensively for irrigation by own pumping. This study was performed to understand the impact of groundwater quality on the crop yields and its suitability for the irrigation for 63 wells and 7 boreholes. Groundwater quality in Mnasra was studied based on different indices for irrigation. The values of SAR, Na %, MAR, SSP, PI, RSC and TDS show that most of the samples fall under good to suitable category. Piper diagram reveals three facies: sodic, calcic and magnesic chlorinated. The results indicate that the order of cation dominance is Na > Ca > Mg > K, while anion dominance is in the order Cl > HCO3> SO4. Stuyfzand's classification indicates that most of the waters analyzed are fresh with moderate alkalinity. Richard Plot indicates that groundwater in the study area is within the low salinity to low sodium hazard and medium salinity to low sodium hazard class (C2S1 and C3S1). Wilcox Plot shows groundwater to be within excellent to a good class.

ASSESSMENT OF WATERSHED RESOURCES FOR SUSTAINABLE AGRICULTURAL DEVELOPMENT: A CASE OF DEVELOPING AN OPERATIONAL METHODOLOGY UNDER INDIAN CONDITIONS THROUGH GEOSPATIAL TECHNOLOGIES

Abstract. The watershed based integrated approach is considered as a more efficient and appropriate approach for resource appraisal and implementation of various sustainable development measures. The present study intends to demonstrate the application of geospatial technologies in preparation of comprehensive as well as an operational framework under Indian conditions to evaluate land and water resources patterns through a case study of Andipatti watershed, located in Theni district in the State of Tamil Nadu (India). The study used widely acclaimed various empirical and quantitative models to characterise the watershed and to understand the spatial pattern of potential-utilisation levels of the watershed resources. The study used mostly remotely sensed data for understanding surface characteristics and location enabled in-situ data such as soil, rainfall and groundwater data for understanding the sub-surface characteristics of the study area. All these datasets were integrated in a GIS environment to asses soil productivity, soil erosion, surface runoff, groundwater potential, groundwater quality, crop-land suitability, groundwater suitability for agriculture, determination of potential-utilisation index and to draw land use planning strategies. Since the methodology developed in the study is mostly depends on remotely sensed data, only minimal efforts are required for any agencies to prepare a similar systematic sustainable agricultural development plan.

Assessment of groundwater quality and its suitability for the inhabitants of Andrott Island, Lakshadweep

Groundwater serves as the main sources of drinking water for the Islanders. Now a days, the groundwater is contaminated due to sea water intusion and continuous anthropogenic activities. A proper understanding of the groundwater quality is important to meet the increasing demand and also for the future planning and development of the water resources. Andrott island is the largest Island in Lakshadweep having an area of 4.90 km2 with a population density of 2312 person/km2 (2011 Census). It lies in the east–west direction, between 10° 48′ and 10° 50′ N latitude and 73° 39′ and 73° 42′ E longitude. It is 293 km (158 nautical miles) away from Kochi (mainland). This paper aims to appraise the spatial distribution of groundwater quality of Andrott Island using geospatial approach. Detailed physico-chemical studies had been carried out to identify potential fresh groundwater resources and quantifying vulnerable parts of Andrott Island. BIS standard has been adopted to assess the quality of ground water at each sampling locations. 50 Samples were collected from water quality lab Andrott Island and GPS has been used to collect the sampling point locations. The statistical analysis has been performed using standard methods, by calculating correlation coefficients between different pairs of parameters. Spatial interpolation technique inverse distance weighted (IDW) has been used to estimate the spatial distribution of the groundwater parameters. The final integrated WQI map shows three priority classes such as good, poor and very poor groundwater quality zones of the study area and provides a guideline for the suitability of groundwater for domestic purposes. The result of the study estimated that 82% of pre Monsoon and 64% of post Monsoon samples fall under poor water category and the rest is categorized under good and very poor as per the WQI classification. The present study is helpful in proper planning and management of available water resources for drinking purposes.

Mapping groundwater suitability for irrigation using GIS: A Case study of Ilorin, Kwara State, Southwestern Nigeria

Agricultural water in the right quantity and desired quality is needed to drive agrarian revolution in Nigeria. Groundwater, among the forms of water in nature is strategic for Nigeria has it is easy to exploit, readily available not affected by seasonality and the largest natural storage of available freshwater on the planet. The study was aimed at evaluating and mapping irrigation water quality of groundwater system within Ilorin metropolis. Forty-four well samples were collected in triplicates over the dry and wet seasons with their locations georeferenced. The water samples were sent to the laboratory and the results were incorporated into a GIS database in the development of a water map. Six indices, Sodium Adsorption Ratio (SAR), Magnesium Adsorption Ratio (MAR), Permeability Index (PI), Residual Sodium Carbonate (RSC), Kelly’s Ratio (KR) and Soluble Sodium Percentage (SSP), were used to evaluate suitability for irrigation. The geo-spatial representation is displayed using Surfer 9 and ARC Map software. The sampling points were concentrated in the southern portion of the study area, with dense settlements and expected anthropogenic activities. The western portion of the study area within the vicinity of Moro river basin reflected general good irrigation water quality and low settlement is prime for irrigated agriculture. The geospatial representations of irrigation water quality developed guides decision makers on the use of various ground water sources within the area. In the same light, it demonstrates high efficiency of GIS in elucidating complex geospatial data through the development of quality maps.

Hydrogeochemical Evaluation of Groundwater Quality for Drinking and Irrigation Purposes Using Water Quality Index in Semi Arid Region of India

Groundwater is an important natural resource serving as a reliable source for drinking as well irrigation purposes worldwide. This study was aimed to evaluate the hydrochemistry of groundwater in southern Haryana. An assessment of measured physico-chemical parameters of 64 samples sites have shown that groundwater is contaminated by higher concentrations of HCO3, Na, Mg, and SO4 beyond the permissible limit of BIS standards. Water quality index (WQI) result indicates that 45.31% area has poor and very poor quality of water for drinking purposes. Irrigation groundwater suitability for the study area has been evaluated with various methods such as EC, SAR, RSC, SP, KR, MH, PI, Piper-trilinear diagram and USSL diagram. Among these parameters, SAR, RSC and PI, water samples fall in excellent and safe water quality, while SP, KR and MH imply to unsuitable and unsafe for irrigation. Piper diagram indicates that the water chemistry is dominated by Sodium and Potassium (Na+K) type, followed by mixed type. According to the USSL classification more than 85% of the samples fall under C3S1, C3S2, C4S1, C4S2 classes of irrigation water indicating very high salinity which is alarming considering the use of this water for irrigation.

Appraisal of groundwater quality for drinking and irrigation purposes in Central Telangana, India

Groundwater is only an important water resources for drinking and irrigation in the central Telangana, India. Rapid growth in the population and intensive irrigation practises has become stress on groundwater, the available groundwater are being depleted and its quality has also deteriorated. For this reason, a total of 105 groundwater samples collected from semi-arid region of central Telangana, were executed in order to evaluate its suitability for drinking and irrigation purposes. Results highlighted that most of the groundwater is suitable for drinking purposes based on pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH) as CaCO3, calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), chloride (Cl−), and sulphate (SO42−). About, 51% and 71% of groundwater samples were exceeded the maximum permissible limits of fluoride and nitrate, respectively. Therefore, it is suggested that groundwater with high fluoride and nitrate concentration water should be avoided for drinking purposes. Spatial distribution maps are generated using GIS platform and the dissimilar distribution pattern was noticed for nitrate and fluoride in the study region. Gibbs plots authenticate that the groundwater chemistry is controlled by rock-water interaction and geochemical scatter plots suggested that the silicate mineral dissolution play dominant role in the chemistry of groundwater. According to the water quality index (WQI) values, 60% and 36% of groundwater samples fall under excellent and good category for drinking purposes. The groundwater is Na+ - SO42−, deep meteoric percolation type, but most of it belong to Ca2+–Mg2+–HCO3−, Na+–HCO3− facies and few are Ca2+–Mg2+–Cl− and Na+-Cl- facies. Majority of groundwater samples exhibit that the alkaline earths (Ca2+ + Mg2+) exceed alkali cation (Na+ + K+) and strong acids (SO42− + Cl−) dominate over weak acid (HCO3−). Irrigational suitability of groundwater in the study area was also estimated through sodium adsorption ratio (SAR), sodium percentage (%Na), and residual sodium carbonate (RSC), magnesium hazard ratio (MHR), and Kelly ratio (KR) results shown that the majority of the groundwater samples were suitable for irrigation uses.

Source rock weathering and groundwater suitability for irrigation in Purna alluvial basin, Maharashtra, central India

Purna alluvial basin is characterized by low to high level groundwater salinity having adverse effect in a large area, however, the basin still lacks one-time data of any season regarding hydrogeochemistry and quality assessment for drinking and irrigation purposes. The present work is aimed to determine various weathering indices and estimation of groundwater quality for irrigation purpose. The interpretations are based on the study of total 158 samples, collected from dug wells (60) and bore wells (98) during both pre- and post-monsoon periods of the year 2009. The plots between Ca+Mg vs. SO4+HCO3, Na vs. Cl and Na vs. HCO3 reveal that most of the samples fall below the equiline that indicates prevalence of silicate weathering. The USSL diagram (Wilcox diagram) demonstrates higher concentration of points in the fields of C2S1 and C3S1 for both the aquifers, indicating high salinity and low to medium sodium water; however, a few sample points positioned in C3S4 and C4S4 fields indicate high salinity but medium to high sodium. The values of Na%, RSC, Kelley ratio and magnesium ratio for most of samples exhibit doubtful to unsuitable categories of groundwater for irrigation from both the aquifers during pre- and post-monsoon periods. The vast data bank generated for entire basin is significant for government and non-government organizations for future planning and management.

Groundwater Quality Assessment Using Geospatial Techniques and WQI in North East of Adama Town, Oromia Region, Ethiopia

Assessment of groundwater quality is vital for the sustainable use of the resources for domestic and agricultural purposes. In this study spatial variation of physicochemical parameters were analyzed for Northeast Adama Town. Water Quality Index (WQI) and irrigation indices were used to determine the suitability of groundwater for drinking and irrigation purposes, respectively. Further, the physical-chemical results were compared with the Ethiopian standards and the World Health Organization (WHO) standards for drinking and public health. Using GIS interpolation methods in Arc GIS 10.3.1, spatial distribution maps of pH, TDS, EC, Cl−, HCO32−, SO42−, Ca2+, Mg2+, Na+ and K+, RSC, SAR, Na% were prepared. Results indicated that except ASTU well 2, all samples are below the desirable limits of WHO. The WQI results indicated that 85% of samples and 15% of samples were in good and poor categories, respectively. Irrigation indices show that the most groundwater samples have excellent water classes, indicating that they are suitable for irrigation purposes.

Temporal Variation of Tropical Karst Groundwater Suitability for Irrigation in Gremeng Resurgence, Gunungsewu Karst Area, Indonesia

Analysis of groundwater availability for irrigation purposes pertains to not only quantity but also quality. The characteristics of groundwater quality essentially define crop productivity and determine whether or not crops can grow. This research was designed to identify the suitability of karst groundwater for irrigation temporally (in one year), with an example of Gremeng Resurgence in Gunungsewu Karst Region, Indonesia. It drew on data on electrical conductivity and several major ions, such as potassium, magnesium, sodium, and calcium, by analyzing % sodium content (Na%), Sodium Adsorption Ratio (SAR), and groundwater suitability for irrigation using the Wilcox and USSL diagrams. These analyses revealed that the water quality observed varied by seasons owing to the effects of dilution by rain and water-rock interaction in the karst region. However, this temporal variation was not substantial so that the classes of groundwater suitability only ranged between good and excellent, and the salinity hazard levels differentiated into low until medium.

Assessment of groundwater quality using GIS in Kurud block of Dhamtari district Chhattisgarh

This paper examines the quality of groundwater of Kurud block, Durg district of Chhattisgarh state, which comes under the semi-critical block with 78% groundwater development. During this study, ten groundwater samples which represent the entire block were collected during the post-monsoon period to determine its suitability for drinking and irrigation purpose. Sixteen groundwater quality parameters namely pH, EC, TDS, chloride, fluoride, calcium, magnesium, sodium, potassium, sulfate, total hardness, carbonate, bicarbonate, nitrate, manganese, and arsenic were analyzed at CGWB, NCCR Raipur. Based on the above parameter for irrigation purpose percentage sodium, Sodium absorption ratio (SAR), Residual sodium carbonate (RSC), Soluble sodium percentage (SSP) and Permeability Index (PI) were calculated. Water Quality Index (WQI) has been a useful tool for water quality monitoring programs, to evaluate the impacts of corrective measures on water quality and also useful for the suitability of groundwater for drinking purposes was also estimated. The present study block shows that 10% of samples were falling under the excellent category, 70% samples were falling under the good category and rest 20% samples were falling under the poor category as per the WQI classification. The index map provides a comprehensive picture which is easily interpretable for the decision-makers for better planning and management of water resources for drinking and irrigation purpose.

Spatial assessment and appraisal of groundwater suitability for drinking consumption in Andasa watershed using water quality index (WQI) and GIS techniques: Blue Nile Basin, Northwestern Ethiopia

This study aimed to evaluate the overall groundwater hydrogeochemical evolution and suitability for drinking in Andasa watershed (Northwestern Ethiopia). To achieve this, analyses of hydrogeochemic...

Hydrogeochemistry and Usability of Groundwater at the Tista River Basin in Northern Bangladesh

Objectives: A study on groundwater of Lalmonirhat Sadar Upazila, Bangladesh has been conducted to explore the groundwater hydrochemistry and suitability for potable water and agricultural uses. Methods/statistical analysis: During the dry season, fifty groundwater samples were collected from different shallow tube wells adjacent to Tista River, Bangladesh. Water samples were analysed according to the standard procedures. We calculated some parameters required for assessing irrigation water quality. The correlation matrix, hierarchical cluster analysis (HCA), and principal component analysis (PCA) were used for better understanding of groundwater chemistry and categorizing the water samples. Findings: The Ca2+–Mg2+–CO3 2−–HCO3 − was the dominant water type, and carbonate weathering was the main hydro geochemical process in the study area. The contributions of ion exchange and reverse ion exchange were almost equal. Groundwater characteristics were influenced by precipitation and not affected by seawater intrusion. The results of all the measured and calculated parameters clearly indicated the suitability of all ground water samples for irrigation. Based on all analysed parameters including hardness, all waters were suitable for drinking and domestic uses. Applications: The groundwater of the study area might be suitable for irrigation, drinking and domestic uses until the waters are otherwise polluted. Keywords: Hydrogeochemistry, Groundwater, Irrigation, Drinking, Bangladesh

Application of Water Quality Index (WQI) and Regression Analysis of Groundwater in Budigumma Village, Anantapur District, Andhra Pradesh

The research work is aimed at assessing the subsurface or groundwater suitability for human use or consumption depends upon the calculated water quality index values, correlation coefficient and regression analysis. The water quality index (WQI) is main important tool to calculate the characteristics of drinking water quality in rural, urban and industrial area. Different parameters which is measured and determination of the water quality index for selecting parameters. Further to study the correlation and regression method in this research work. Totally fifteen groundwater samples were collected from the Budigumma Village Anantapur district in the state Andhra Pradesh in India. Nine water quality parameters has been considered for the computation of water quality index such as pH, total dissolved solid (TDS), total hardness (TH), calcium (Ca), magnesium (Mg), nitrates (NO3), chlorides (Cl ), sulphates (SO4), fluorides (F ). The World Health Organization (WHO) has been assessed to the suitability of groundwater for drinking purposes or other uses for public and determining of WQI. This WQI index values ranged from 97.78 to 108.37. The study shows that 87% area comes under the poor category of drinking purposes and the remaining 13% comes under as good water for drinking purposes as per the WQI classification. The correlation and regression analysis gives as an outstanding device for the calculation of different parameter values within realistic degree of precision. The subsistence of strong correlation or relationship between the total hardness and magnesium is determined. The analysis of selected parameters revealed that proper treatment before use or consumption and protected from more contamination.

Groundwater suitability for drinking and agriculture purposes using irrigation water quality index and multivariate analysis: case of Sidi Bouzid aquifer, central Tunisia

The Sidi Bouzid region is one of the main centers of agricultural production in Tunisia, especially for vegetable crops (18% of national production), arboriculture (13% of almond production and 10% of olive oil), and milk production (125 million liters in 2012 around 12% of national production) [PREDD (Plan Regional d’Environnement et de Developpement Durable du gouvernorat de Sidi Bouzid), 2014]. Therefore, the groundwater quality of Sidi Bouzid aquifer was studied to evaluate the quality of the hydrochemical parameters to determine its suitability for both agricultural and drinking purposes. Thirty groundwater samples were collected and analyzed. The obtained results showed that the groundwater contains high values of dissolved ions dominated by SO4, Mg and Ca. Gypsum, anhydrite and halite dissolution, as well as direct and reverse ion exchange are the main processes of chemical evolution in the Sidi Bouzid aquifer. Multivariate statistical techniques, such as PCA and HCA, helped to focus on the hidden yet important variables and understand their roles in affecting the groundwater quality. Compared to the World Health Organization (Guidelines for drinking water quality, 3rd edn, vol 1. Recommendations. WHO, Geneva, 2008) and National Water Exploitation and Distribution Company SO.N.E.D.E (NT.09.14) guidelines for drinking water, results showed that the concentrations of major and trace elements were within the admissible concentration rate. Chemical indices such as the percentage of sodium (Na%), sodium adsorption ratio (SAR), Kelly’s ratio, and permeability index (PI) showed that more than 70% of the analyzed samples can be used for irrigation. The irrigation water quality index (IWQI) classes vary from severe (SR) to moderate restriction (MR). The visualization of the IWQI distributions, using GIS software, shows that the moderate restriction class (MR) is the dominant class.

Multi-criteria approach to water quality and health risk assessments in a rural agricultural province, southeast Nigeria

This paper assessed the quality and suitability of groundwater from hand-dug wells in Ikem agricultural province, Nigeria for human consumption and irrigation purposes. pH measurements revealed that the groundwater is slightly acidic. The trend of the cations concentrations is Ca2+ > Mg2+ > K+ > Na+ whereas that for anions is Cl− > PO42− > NO3− > HCO3– > SO42−. It was observed that the concentrations of all the ions were below their respective standard maximum allowable limits for drinking water. Similarly, all the analyzed heavy metals were also found within their respective acceptable limits. Heavy metal pollution index, heavy metal evaluation index, and contamination index confirmed that all the samples are excellent and safe drinking waters. However, water quality index placed the groundwater quality in good category, and therefore relatively suitable for drinking and domestic uses. Health hazard index revealed that, for adults, 64% of the samples pose low chronic risk while 36% predispose their consumers to medium chronic risk. However, for children, 94% of the samples pose medium chronic risk while only 4% predispose them to high chronic risk due to trace elements ingestion. Carcinogenic risk assessment due to Pb enrichment showed that all the samples pose negligible cancer risks to the consumers. All the irrigation water quality indices, except permeability index and potential salinity, classified the samples as suitable water for irrigation purposes.

Hydrogeochemical assessment and suitability of groundwater in a typical Mediterranean coastal area: A case study of the Marathon basin, NE Attica, Greece

This study aims to determine the major factors controlling the qualitative characteristics of groundwater and examine the drinking and irrigation suitability in the Marathon basin, NE Attica, Greece. In this frame, a total of 25 groundwater samples were collected from irrigation wells during October 2014. The dominant ions are Cl− for anions and Ca2+ for cations in the study area. Elevated concentrations of Cl− and Na+ were observed near the coastline indicating a zone of seawater intrusion (SWI). The groundwater quality in the coastal alluvial aquifer system of the Marathon basin is affected by several factors such as water-rock/soil interaction, SWI, reverse ion exchange, and intense agricultural activities. Saturation index (SI) of carbonate (calcite, aragonite, dolomite), sulfate (gypsum, anhydrite), and halide (halite, sylvite) mineral phases were calculated using PHREEQC geochemical software. Carbonate minerals are present in the unsaturated zone (UZ), possibly increasing Ca2+, Mg2+ and HCO3– concentrations when they are dissolved, whereas sulfate and halide minerals are minor or absent in the host rock. The water suitability assessment showed that the groundwater resources are chemical or qualitatively unsuitable for drinking purposes due to the SWI regime and the NO3− pollution, whereas they are suitable for agricultural uses according to various indices (SAR, %Na, RSC, and PI).