Salinity-Based Spatial Evaluation of Groundwater Quality for Agricultural Use

The Miandoab Plain has the largest water reserve in the province of West Azerbaijan, northwest Iran. Groundwater resources along with surface-water meet the needs of urban, industrial, and agricultural sectors, and therefore, their quality should be examined. Water quality indices are useful tools for aquifer management. In this research, the groundwater quality of the Miandoab Plain for agricultural purposes was investigated. For this purpose, the concentrations of the ions Mg2+, Ca2+, Na+, Hco3-, So42-, Cl- and the pH level were measured. The indices effective salinity and potential salinity as well as sodium adsorption ratio and electrical conductivity were analyzed to evaluate the salinity. The geostatistical analysis was performed using the GS+ software, and the zoning maps of salinity hazard were prepared using ArcGIS. To prepare the maps, EC, ES, PS, and SAR as well as Mg2+, Ca2+, Na+, Hco3-, So42, and Cl- were selected based on the semi-variogram values ​​and cross-validation technique. The Cl- map was considered as the basis for preparing the groundwater quality maps of the region. The results showed that the groundwater quality in the east of the plain is suitable, in the central part can be recommended under constant supervision, and in the west is unsuitable for agriculture. In other words, according to the geography of the plain, the recharge area is the low-risk part of the plain and the salinity hazard increases toward the discharge area. The results can pave the way for the relevant organizations to plan for the agricultural and environmental sectors.

Hydrochemical Assessment of the Irrigation Water Quality of the El-Salam Canal, Egypt

The El-Salam canal in Egypt is considered an important stream of fresh water for the agricultural sector that extends from the Nile River to Sinai, while it is subjected to several anthropogenic stresses. In this study, five-georeferenced stations (named from S1 to S5) were monitored along the El-Salam Canal before El-Sahara of the Suez Canal, via the estimation of the WQ index based on major cations and anions analysis including salinity hazard, permeability index, residual sodium carbonate, magnesium hazard, sodium percentage, sodium adsorption ratio, Kelley index, potential salinity, total hardness, and irrigation water quality index (IWQI). The sequence of average concentration of cations in water were Na+ > Ca2+ > Mg2+ > K+. The major cations constitute around 60% of the total dissolved salts. While the sequence of major anions in water were SO42− > HCO3− > Cl− > CO32−. These cations and anions showed an increasing trend from S1 (intake of the canal) to S5 (before El-Sahara) of the El-Salam Canal. Moreover, the order of heavy metals was Zn < Cd < Cr < Ni < Fe < Mn < Co < Cu < Pb. According to the US EPA (1999) guidelines, the levels of Fe and Zn in the El-Salam Canal are within the permissible limits for drinking and irrigation purposes, while Mn, Pb, Cu, Co, Ni, Cr, and Cd were detected at higher concentrations than those recommended. The value of IWQI in water samples varied from 40.26 to 114.82. The samples of S1 showed good water, the samples of region S2 (after mixing with Faraskour drainage) showed poor water quality, samples of regions S3 (after mixing with the El-Serw drain waters) and S5 (before El-Sahara) fell under the very poor water category and samples of region S4 (after mixing with the Hadous drainage) showed unsuitable water. Croplands irrigated with such water will not be exposed to any alkaline risks but will be exposed to the risk of salinity, which is more severe after mixing at the S3 and S4 sites. It is recommended to treat the drainage water before mixing with the irrigation water of El-Salam Canal to raise the suitability of irrigation water for crops, particularly for the Hadous drain.

Hydrochemical Evaluation of Groundwater in Al-Khasfa Area within Haditha, Western Iraq

The main aim of the research is to study the groundwater quality in Al-Khasfa area within Haditha district, western Iraq. To assess the groundwater, eighteen groundwater samples in the study area were collected and analyzed for major cations and anions. Results indicated that groundwater samples in the study area are between neutral and light alkaline, slightly brackish, and highly mineralized. The hydrochemical formula of the groundwater samples indicates the Ca-SO4 type dominance, except wells number 16 and 17 were of Ca-Cl water type. According to Piper diagram, the type of water is Earth-Alkaline waters. All groundwater samples are unsuitable for human drinking, industrial, and building uses, but it is suitable for livestock. For irrigation purposes, it is characterized by no Mg-harmful, good with SAR, Na%, RSC, and PI but unsuitable for salinity hazard due to very high salinity. The Water Quality Index for Euphrates aquifer in the study area in both periods are poor water for human drinking, except W-1 in dry period indicate very poor water and W-6, W-7, W-8, W-13, W-14, W-15, W-16 in wet period indicate good water.

Evaluation of Groundwater quality and suitability for irrigation using hydro-chemical process in Bhavani taluk, Erode District, Tamilnadu, India

In most regions of the present study area, Bhavani Taluk, groundwater quality is deteriorating at an alarming rate as a result of anthropogenic activities, however, little attention was given to groundwater quality and management. This research examines the quality of groundwater in Bhavani Taluk, Tamilnadu and compares its suitability for irrigation. The Bhavani region of Erode District, Tamilnadu is the most cultivated, with a considerable use of fertilizers and pesticides. Groundwater quality for irrigation purposes was assessed during the pre-monsoon season by collecting samples from 53 different locations. Physico-chemical parameters such as pH, EC, TDS, HCO3−, CO32−, Cl−, SO42−, NO3−, Ca2+, Mg2+, Na+ and K+were measured in these groundwater samples. Irrigation quality measures such as salinity hazard, sodium hazard expressed as SAR, percentage of sodium (% Na), and permeability index (PI) were calculated to evaluate groundwater quality for agricultural irrigation. Based on the classification of Electrical conductivity (EC) most of the groundwater samples are falling under the permissible limit. As per the USSL diagram, the large majority of groundwater samples fall within the category of C3-S1 and the water is suitable for irrigation. Piper trilinear diagram interpretations were made to know the chemical type of the groundwaters. The piper diagram indicates that 50% of the groundwater sample were belongs to Mg2+, Ca2+, HCO3−, and Cl−. The groundwater samples fall under Class I category according to Doneen’s Classifications.

The Influence of Non-Engineered Municipal Landfills on Groundwater Chemistry and Quality in Bloemfontein, South Africa

This study assessed the groundwater quality around two municipal solid waste landfill sites, in the city of Bloemfontein, Free State Province, South Africa. The two landfill sites are located in two contrasting geological terrains, with both lacking some basic facilities found in a well-designed landfill. A total of eight groundwater samples were collected from pollution monitoring boreholes near the two landfill sites, with five samples representing the northern landfill site and three samples representing the southern landfill site. The samples were collected in the autumn and winter seasons to assess any possible seasonal variations. They were analysed for physicochemical (pH, electrical conductivity (EC), total dissolve solids (TDS), chemical oxygen demand (COD) and total organic carbon (TOC)) and microbiological parameters (Escherichia coli, total coliform). The results of the analysis showed that the waters from both landfills were generally dominated by Ca, Mg, SO4, and HCO3 ions. Some of the major anions and cations in the water samples were above the South African National Standard (SANS241:2015) and World Health Organisation (WHO) permissible limits for drinking water. Majority of the boreholes had total dissolved solids and electrical conductivity values exceeding the SANS 241:2015 and WHO permissible limits. Piper trilinear plots for the two landfill sites showed that Ca(Mg)HCO3 water type predominates, but Ca(Mg)SO4 and Ca(Mg)Cl were also found. These water types were further confirmed with expanded Durov diagrams, indicating that that the boreholes represented a water type that is seldom found which is undergoing ion exchange, typical of sulphate contamination. From the SAR diagrams, boreholes in the northern landfill site had a high salinity hazard with only one borehole in the southern landfill site having a high salinity hazard. The geology was found to play a significant role in the distribution of contaminants into the groundwater systems in the study area. The study concluded that the northern landfill site had a poorer water quality in comparison to the southern landfill site based on the analysed physicochemical parameters. However, the southern landfill site showed significant microbial contamination, due to the elevated amount of E. coli and total coliform concentrations. The high permeability of the weathered dolerites in the northern landfill site might have enabled the percolation of contaminants into the groundwater resulting in the poorer water quality.

Hydrogeochemical characterisation and appraisal of groundwater suitability for domestic and irrigational purposes in a semi-arid region, Karnataka state, India

Hydrogeochemical investigations have been carried out in a semi-arid region of Aland taluk of Karnataka State, India. The analysis has been done to examine the quality of groundwater for drinking, domestic and irrigational purposes. In this concern, thirty-two groundwater samples were collected in pre-monsoon (April 2016) and post-monsoon season (November 2016), from the different location within the study area. These samples have been further analysed for different ions such as CO32−, HCO3−, NO3−, Ca2+, Mg2+, Na+, K+ Fe2+, SO42−, Clˉ and F− to evaluate the hydrochemical behaviour with SSP (sodium soluble percentage), SAR (sodium absorption ratio), % Na (percentage sodium), RSC (residual sodium carbonate), KR (Kelly’s ratio), PI (permeability index) and MH (magnesium hazards). These positive and negative ions have been further correlated with the maximum annual rainfall within the study area to find out the variations between these ions for the precipitation. Suitability of groundwater for drinking purposes around the catchment was not suitable except in a few places. Irrigational suitability of groundwater showed that the water is within the limit for irrigation except in a few locations. Wilcox diagram depicts that 90% of the pre-monsoon samples and 65% of the post-monsoon samples fell into excellent to good category zone. US salinity diagram explains that 71% of pre-monsoon samples belong to medium-salinity-hazard to low-sodium-content zones, whereas 50% of post-monsoon samples fall into high-salinity-hazard to low-sodium-content zone. Gibbs’s plot showed that the water–rock processes control the geochemistry of the Aland region in both monsoon seasons. Chadha’s diagram depicts that 56.25% of the groundwater samples fall under the subfield of Ca2+–Mg2+–Cl− water type with permanent hardness during pre-monsoon season, whereas 50% of groundwater samples falls under the subfield of Ca2+–Mg2+–HCO3− water type with temporary hardness during post-monsoon season.

Evaluation of River Chenab water quality with respect to its users, using different classification schemes

The Chenab River has always offered a cradle for civilizations in Punjab province of Pakistan; however, in recent times, the quality of this river has been gradually degraded due to several point and non-point pollution sources being introduced in its water. The riverine water quality was evaluated to check the suitability of water for drinking, livestock and irrigation purposes. Water samples (n = 54) were collected across the river, over a period of three years (2012–2014) and subjected to physicochemical analysis. Water quality index rating revealed that the water of River Chenab fell under the marginal category for drinking and livestock watering, due to the presence of heavy metals pollution above safe limits. Irrigation suitability parameters, such as the sodium absorption ratio (SAR), residual sodium carbonate (RSC), Na (%), Kelley's ratio (KR), magnesium hazard (MH) and the permeability index (PI) were measured, and most of the samples were within the safe limit. The piper classification of hydro-chemical parameters revealed that the alkaline-earth metals and strong acids exceed the alkali metals and weak acids, respectively. A Wilcox diagram indicated the alkali hazard was low while salinity hazard has an increasing trend. Spatiotemporal distribution of the pollutants highlighted minimal pollution until Qadirabad site (S4) which gradually keeps worsening at the downstream sites. Two factors of water quality deterioration were identified as pollution addition from the point and nonpoint sources, and diversion of the water through canals. It is inevitable to manage water quality of the Chenab River by reducing point sources pollution, through law enforcement.

Hydrochemical Characteristics and Groundwater Quality Evaluation of Roni Area, Northwestern Nigeria

Rapid population growth rate in the study area results to an increasing demand of water for various uses. It necessitated the geoscientists to evaluate the water quality of the area for potability. Twenty (20) water samples were collected using plastic bottles and properly labelled. Atomic Absorption Spectrometry (AAS) and X-Ray Fluorescence (XRF) were used to analyse the water quality. The in-situ measured parameters of water are mostly within limit of NIS, 2007 and WHO, 2011. Cations and anions analyses revealed, they were within the range of acceptable standard, except higher concentration of Fe2+, Pb2+and Mn2+which might have resulted from acidic water of the area and weathering of silicate minerals. The cations preponderance is of the order Na+> K+ ˃Mg2+> Ca2+> while for the anions dominance are HCO3− > Cl- > SO42-. The dominant water facies are Na+-HCO3−. These facies might have sources from rock-water interaction of silicate minerals. Wilcox plot of salinity hazard of the water samples indicated that, the water of the area is good for irrigation. It can be classified, the value of electrical conductivity of 0 – 250 excellent, 250 – 750 good, 750 – 2250 doubtful and ˃ 2250 μS/cm unsuitable. Field study and petrographic analysis revealed that, the area is underlain by three (3) major rocks units which are muscovite schist, porphyritic granite, sandstone (Chad Formation) with quartzite occurring as the minor lithology. Keywords: Hydrochemical characteristics, ground water, water quality, concentration, electrical conductivity

Major Ion Chemistry and Groundwater Quality Evaluation for Irrigation

Hydrogeochemical characteristics of Groundwater analyzed in the study area of Coimbatore district by collecting 60 samples from agricultural belt. Groundwater quality for irrigation is determined by several key factors like pH, Electrical conductivity (EC), Total suspended solids (TDS). The cations such as Sodium (Na+), Potassium (K+), Calcium (Ca2+), Magnesium (Mg2+ ) and anions are Hydrocarbon (HCO3), Carbonate (CO3 -), Chlorides (Cl-)and Sulphates (SO4 2-) are tested. The irrigation water quality parameters such as Residual Sodium Carbonate (RSC), Sodium Absorption Ratio (SAR), Chloro Alkali Indices (CA I & CAII), Kelley’s Ratio (KR), Magnesium Hazard (MH), Percent sodium (%Na) and Permeability Index (PI), Soluble sodium Percent (SSP) are computed from the key factors, anions and cations. From the USSL Diagram the samples fall in C2S1, C3S1, C4S1 range. Salinity hazard is too elevated in the study area, all the samples are categorized under high to very high with the values greater than 750 μS/cm. Total dissolved solid in the study area indicated that only 2 locations are unfit for irrigation. SAR and % Na shows that there is no hazard related to irrigation watering. Magnesium hazard in the groundwater is high and indicates 51 sample out of 60 is unsuitable for irrigation. From the study it indicates the groundwater is contaminated with salt content and in most of the area it can be used for irrigation. Keywords: Groundwater, Irrigation water quality, Salinity hazard, Kelley’s ratio, Magnesium hazard

Hydrochemical and Quality Assessment of Groundwater Resources in Al-Madinah City, Western Saudi Arabia

Fifty-four groundwater samples were collected from Hamra Alasad in Al-Madinah City. The chemical and microbial characteristics of the samples were analyzed and compared with their respective standards. The results revealed that 90.7% of the samples showed higher amounts of NO3. However, 59.3% of the samples were found unfit for irrigation purposes due to a high salinity hazard. Most of the groundwater samples were highly saline, yet no sodicity hazards were anticipated as predicted by sodium adsorption ratio (SAR). Generally, the soluble cations and anions, dissolved salts, boron, and NO3− exceeded the maximum permissible limits for drinking water in most of the samples; however, Pb, Cd, As, Zn, Cu, Ni, Co, Fe, Mn, and Cr were within the permissible limits. Furthermore, 42.6%, 24.1%, 18.5%, 14.8%, 1.9%, and 37.0% of the samples were infected by a total coliforms group, fecal coliform, Escherichia coli, Staphylococcus sp., Salmonella sp., and Shigilla sp., respectively. The water quality index revealed that 3.7% of the samples were good for drinking (class II), and 9.3% were very poor (class IV). The remaining samples were unfit for drinking (class V) due to high salinity and/or microbial contamination. Durov and Piper diagrams revealed that the majority of water samples were of the calcium sulfate–chloride type. Overall, 87% of water samples were inappropriate for drinking purposes, while 77.8% were unsuitable for irrigation.