Groundwater hydrogeochemistry and non-carcinogenic health risk assessment in major river basins of Punjab, India.

The Indian Punjab state is drained by the four rivers, along with a well-connected network of canals, and is now dealing with a slew of water quality issues and problems. In this study, basin-wise hydrogeochemical modelling of 323 groundwater samples and identification of NO3- and F- enrichment pathways in aquifer systems of Punjab were studied using different plots and multivariate statistics. To evaluate the groundwater quality and human health risks, an entropy-based water quality index and Monte Carlo simulation were used, respectively. Spatial distribution of NO3- indicated that its very high values were prominent in parts of southwestern Punjab falling under LSRB, along with few pockets in eastern and northeastern Punjab falling under MSRB and GRB. High NO3- values (> 45.0 mg/L) were found in 15.0% of Ravi River Basin (RRB) groundwater samples, 22.86% of Beas River Basin (BRB), 23.52% of Middle Sutlej River Basin (MSRB), 36.9% of Lower Sutlej River Basin (LSRB), and 21.31% of Ghaggar River Basin (GRB). The spatial distribution of NO3- revealed elevated concentrations (> 100 mg/L) in the southwestern part of Punjab, particularly in LSRB and localized pockets in the eastern and northeastern areas of Punjab within MSRB and GRB. High F- concentration (> 1.5 mg/L) was observed in 15.12% and 21.31% groundwater samples of LSRB and GRB, respectively. Spatially southern parts falling under LSRB and GRB reflected high F- content (> 1.5 mg/L) in groundwater. In LSRB, evaporative and anthropogenic processes influence the groundwater quality. The results of interionic relationships and statistical analysis revealed that NO3- has anthropogenic origin and that is being aggravated by leaching, the evaporation processes, animal excreta, septic tanks and irrigation return flows in LSRB and GRB, while F- is geogenic in nature. Hazard index (HI) values in 14.63%, 22.2%, 24.6%, 49.58%, and 34.42% samples for adults and 21.95%, 27.7%, 42.0%, 72.3%, and 52.46% samples for children were higher than unity in RRB, BRB, MSRB, LSRB, and GRB, respectively. The basin-wise demarcation of various groundwater quality parameter and assessment of human health risk would be of significance for the management of water resources.

Mapping and identification of potential groundwater development zones of an alluvial aquifer in parts of Ghaggar and Upper Yamuna basins in India.

Using an integrated analytical hierarchy process, remote sensing and geographic information system techniques, the current study aims to map and identify the potential groundwater zones of Kurukshetra District of Haryana, which is located in the Ghaggar and Upper Yamuna Basins in India. This is done in the context of a significant change in the use of groundwater pattern, with respect to its continuously increasing demand due to the growing population, expansion of area under irrigation and related economic factors. The amount and quality of groundwater are anticipated to be impacted by anthropogenic activities as well as natural factors such as geomorphology, soil type, lithology and rainfall variance owing to a changing climatic scenario. The potential index of groundwater for this study was calculated by using nine important factors, including geomorphology, rainfall, soil type, depth to groundwater level, lithology, land use land cover, normalized difference vegetation index, cumulative sand thickness and elevation. The integration of multiple thematic layers was accomplished using the overlay weighted method to generate a potential groundwater zonation map and the accuracy of the resulting map was validated against a groundwater resource potential map. Statistical measures demonstrate an 82% agreement between the two maps, indicating a high level of concurrence. Accordingly, three groundwater zones of good, average and bad potential have been identified in the study area. In the current study, a process that combines weighted ranking with spatial data transformation and harmonization has been developed to obtain information for accurate decision-making. The results accruing from this research have significant ramifications for creating regional sustainable groundwater management plans.

Geographic information system-based groundwater quality assessment for drinking and irrigation purposes in transboundary aquifers of River Ravi, India.

Access to safe and clean drinking water is a basic human right, and assessment of groundwater suitability for drinking purpose imparts significant role in providing clean and suitable water for human consumption. The main objective of this study was to assess the groundwater quality status of Gurdaspur district falling along international boundary of Indo-Pak, thus serving as transboundary aquifers, for drinking and irrigation purpose based on physicochemical analysis of 111 samples using standard numerical indices and GIS techniques. Shannon's entropy theory was employed to assess the groundwater quality for human consumption as it removes the subjectivity problem and integral ambiguities of groundwater systems. The results of entropy water quality index revealed that the drinking groundwater quality was found to be in excellent, good and medium water class except 5 samples which were in poor to extremely poor water class. Piper trilinear plot revealed that the main water types were Ca2+ and Mg2+-HCO3-. Mineral saturation index indicated that carbonate minerals were oversaturated and the evaporative minerals were undersaturated. The outcomes of principal component analysis indicated that the ion exchange, weathering and agricultural practices were the dominant controlling factors in the study area. Furthermore, the results of the irrigation water quality index illustrated that 3 and 65 samples were placed in 'severe restriction' and 'high restriction' class respectively indicating irrigation water as an issue for sustainable agricultural production in agrarian dominant district. The study recommends the adaptation of remedial actions particularly in the regions where drinking and irrigational groundwater quality issues are reported to ensure clean and suitable drinking water for the inhabitants.

Appraising the factors favouring uranium mobilization and associated health risk assessment in groundwaters of north-western India.

An attempt has been made in this study to evaluate the factors favoring the uranium mobilization into the groundwater of Northwest India using uranium isotope activity ratio (234U/238U), radon (222Rn) and environmental isotopes of water (2H, 18O and 3H). The values range from 23 - 597 µg/L for total uranium and 634-3210 Bq/m3 for radon and the corresponding annual effective dose is estimated to be 18.9-490 µSv/a and 6.2-31.5 µSv/a respectively. Uranium activity ratio (UAR) varies from 0.68 - 1.17 and maximum samples indicate secular equilibrium. Environmental isotopic data indicates that the source to groundwater is vertical percolation of rainwater in the case of shallow zone while regional flows from outcrop areas recharge the deep groundwater. A wide scatter is noticed in environmental 3H content (0.23-6.62 TU) indicating both fast and sluggish water flows. The UAR phase diagram suggests that leaching process controls the uranium mobilization into the groundwater. The correlations among UAR, uranium and Uexcess further indicate oxidative nature of leaching process. Statistical treatment of the obtained data along with available geochemical and isotope evidences suggest that source of uranium is common but the driving processes are different for shallow and deep zone. Influences of root zone CO2, oxic species from irrigation return flows and water level fluctuations are also evaluated. Low uranium, low UAR, low 3H and high 222Rn activity in deep zone suggest uranium being released from the roll front as well as transported from outcrop regions. This study highlights the application of uranium isotope ratio, radon and environmental isotopes in assessing vulnerability of alluvial aquifers towards uranium contamination.

Deciphering pollution vulnerability zones of River Yamuna in relation to existing land use land cover in Panipat, Haryana, India.

Rivers are one of the major freshwater resources, which provide water for irrigation, domestic, recreational, environmental, and industrial purposes, but they are extremely vulnerable to pollution due to discharge of untreated waste. Establishing the baseline river water quality data is important, so that monitoring changes over time, assessing impacts of particular developmental projects and setting water quality standards for the protection of the river, can be undertaken. In the present study, water quality assessment was done for a segment of Yamuna River passing through Panipat district, Haryana, India. This study is an attempt to know the impact of wastewater generated due to urban and industrial activities taking place in Panipat city and nearby areas, on River Yamuna. Furthermore, vulnerability zone of River Yamuna was delineated using CCME-WQI, NSF-WQI, and hierarchical cluster analysis (HCA). The water quality samples were further evaluated for the agricultural and industrial purposes to determine whether the water can be used for irrigation and industrial requirements. The study also considered the existing land use land cover (LULC) on left and right banks of the River Yamuna and the wastewater carrying drain. River Yamuna travels nearly a distance of ≈ 44 Kms in and around Panipat district and the results of the study indicated that nearly 13 Km stretch of River is more vulnerable to pollution. Thus, it is suggested that wastewater discharge regulation, installation of effluent treatments plants, and maintenance of environmental flow are prerequisite to protect and restore the River Yamuna.

Distribution and correlation of radon and uranium and associated hydrogeochemical processes in alluvial aquifers of northwest India.

The spatial and vertical distributions of radon and uranium are evaluated in relation to the hydrogeology, geomorphology, and hydrochemistry of southwest Punjab. Radon activity of the groundwater ranges from 580 to 3633 Bq/m3 (shallow groundwater 580 to 2438 Bq/m3 and deep groundwater 964 to 3633 Bq/m3), and uranium concentration varies from 24.4 to 253 µg/L (shallow groundwater 24.4 to 253 µg/L and deep groundwater 27.6 to 76.3 µg/L). Shallow groundwater shows higher U concentration compared with deeper ones, which can be attributed to the presence of dissolved oxygen (DO) and NO3- as oxidants and HCO3- as stabilizing agent in shallow zone. Unlike uranium, the radon activities were found to be similar in both shallow and deep groundwater. Rnexcess over secular equilibrium was used to confirm the possibility of additional sources of radon, such as secondary minerals present in the subsurface. Surface manifestations show significant influence on radon and uranium distributions in the shallow zone but not in deep zone due to limited hydraulic connectivity. Depth profiles and correlations of radon and uranium with trace elements and hydrochemical parameters indicate that groundwater exhibits different redox characteristics in shallow (younger and oxidizing) and deep zones (older and reducing). The present study provides critical information that can be helpful for planning sustainable groundwater development in this region and other similar regions without contaminating the relatively safer deep aquifers.

A new indexing approach for evaluating heavy metal contamination in groundwater.

Three indexing methods, namely heavy metal pollution index (HPI), contamination index (Cd) and heavy metal evaluation index (HEI), are commonly used for heavy metal evaluation in groundwater. These methods have several limitations. In HPI, 14 out of 15 groundwater samples collected in the study area of Nalagarh valley, Himachal Pradesh, India qualify for drinking purposes with their values varying between 10.73 and 107.50 (critical limit = 100), while in Cd, the same number of samples (>90%) are rejected as their values (Cd = 1.31-37.87) exceed the critical limit of 3. HEI varies from 10.31 to 46.87 with a mean of 26.06, but since it does not have a defined critical limit, quality assessment depends on worker's discretion. It thus becomes very confusing as to which indexing method to use. To overcome this dilemma, a very simple indexing method called 'heavy metal contamination index (HCI)' has been developed on the basis of assigning weight to each heavy metal parameter. A new classification system with six distinct water classes of different uses too has been proposed considering the regulatory limits, human health risk and toxicity of the violator parameters. Regression analysis confirms that HCI has larger number of significantly correlated key parameters compared to the other three indices. Chemometric techniques confirm that Cr, Cu, Fe, Mn and Zn are derived from lithogenic inputs and As, Cd, Ni and Pb from anthropogenic sources. HCI when integrated with Cluster Analysis gives the best possible results in identifying factors that influence the various water classes.

Deterministic and probabilistic health risk assessment techniques to evaluate non-carcinogenic human health risk (NHHR) due to fluoride and nitrate in groundwater of Panipat, Haryana, India.

Human interferences have caused groundwater contamination in alluvial aquifers which subsequently affects the health of exposed population. In the present study, 74 groundwater samples from the semi-arid region of Panipat district, falling under Yamuna sub-basin, India was evaluated to know the potential non-carcinogenic human health risk in local adult and child population. The major objective of the present study was to know the non-carcinogenic human health risk due to intake of fluoride and nitrate contaminated water, using two different approaches: deterministic and probabilistic (Monte Carlo simulation). The values of hazard quotient (HQ) determined by deterministic as well as probabilistic approach were nearly identical. The hazard index (HI) value of 40.8% samples was above the unity in case of adults while 69.7% samples indicated HI value greater than unity for children thus indicating children are more prone to non-carcinogenic health risk than the adult population. Sensitivity analysis was performed to identify the influence of the non-carcinogenic human health risk predictor variables for the prediction of risk and concentration factor (CF) was the most influential variable. Multivariate statistical techniques were employed to know the positive and negative relationship of fluoride and nitrate with other parameters. Results of principal component analysis/factor analysis (PCA/FA) indicated that the concentration of fluoride is controlled by the presence of calcium due to their negative correlation in groundwater samples. The hierarchical agglomerative cluster analysis (HCA) also supported the outcome of PCA/FA and both indicated anthropogenic sources of fluoride and nitrate in groundwater.

Evaluation of groundwater quality and human health risks from fluoride and nitrate in semi-arid region of northern India.

Groundwater quality in the alluvial plains of Punjab has special significance and needs great attention since it is the foremost source of drinking, irrigation and industrial uses. The present research work emphasizes the integrated hydrogeochemical and chemometric statistical approaches to appraise the geochemical processes and source apportionment of the groundwater in the alluvial plains of Jalandhar district, Punjab, India. The human health risk assessment was also performed to quantify the potential non-carcinogenic impacts of nitrate and fluoride on human health through ingestion of groundwater. For this purpose, 41 groundwater samples were collected from different groundwater abstraction units and analysed for pH, electrical conductivity, total dissolved solids, total hardness, total alkalinity and major ions (Ca2+, Mg2+, Na+, K+, HCO3-, CO32-, SO42-, NO3-, F-, Cl- and PO43-) using standard protocols. Drinking water quality index and Revelle index showed that groundwater samples fall under poor to unfit water class and salinization along the south-western portion of the study region shows poor water quality. The results of the hazard index (HIingestion) show 68% and 46.34% of the groundwater samples have HI > 1 for children and adults. The non-carcinogenic health risk assessment of nitrate (NO3-) and fluoride (F-) on the local population indicated that the children are more vulnerable through direct ingestion of drinking water than adults. Piper diagram and saturation index reveal that Ca2+-Mg2+-HCO3- is the dominant hydrochemical facies and oversaturated with calcite, dolomite and aragonite minerals in the groundwater. Gibbs diagrams, chloro-alkaline indices and scatter plots show that the hydrochemistry of the groundwater is mainly governed by aquifer material interaction such as weathering of silicate, carbonate rock, halite dissolution and cation exchange process. Chemometric statistical techniques revealed that the source identification of parameters such as Ca2+, Mg2+, Na+, K+, HCO3-, CO3- and F- is originated from geogenic factors, whereas NO3-, SO42-, Cl- and PO43- are from the anthropogenic origin. Therefore, urgent and efficient measures must be taken to combat groundwater pollution and reduce human health risk in the study area.

A study on the role of hydrogeology on the distribution of uranium in alluvial aquifers of northwest India.

A study was undertaken to decipher the uranium distribution in relation to a number of hydrogeological factors in groundwater of southwest Punjab. Existing geological information for the region suggests that the shallow alluvial aquifer extends up to 50-70 m below ground level (bgl) and is in turn underlain by a deeper aquifer which extends to a depth of 250 m bgl. The presence of clayey units limits the vertical mixing of groundwater between the shallow and deep aquifers. Water level data (averaged over 5 years period) indicates that the south and southwestern regions of the study area have shallow water levels (3-5 m bgl) while the north and northeast regions have deep water levels (20-28 m bgl). This difference in water levels is found to be increasing with time. Higher concentrations of uranium occur in the central, southern, and southwestern parts of the study area where the water table occurs at shallow depth. Groundwater in the northern and northeastern parts of the study area shows U concentration within permissible levels for potable use (< 30 µg/L) while the highest concentration of U (341 µg/L) was found in the central part of the study area. Seasonal variation in dissolved U concentration is found to be statistically significant. The observed increases in U concentrations during the post-monsoon season are due to the addition of bicarbonate from the root zone as well as increased dissolved oxygen, nitrate, and sulphate concentration (oxic condition) in the groundwater while the decrease in U concentration is attributed to quick recharge by precipitation through sand dunes and contribution of surface water. Deeper groundwater does not show much seasonal variation in dissolved U concentration. Correlation between U and other hydrochemical parameters was evaluated. Cluster analysis of the data also indicates the oxidative mobilization of U from the sediments. Based on the lithological, hydrogeological, and dissolved U data, a schematic map is prepared depicting the various factors affecting the U distribution in alluvial aquifers, which can also be applied to other regions of similar hydrogeological setup. Graphical abstract ᅟ.

Data on fluoride contamination in potable water in alluvial plains of district Panipat, Haryana, India.

This data set reveals the fluoride concentration level of an alluvial aquifer of Panipat district Haryana India. The whole district of Panipat relies on groundwater for its agricultural, industrial and domestic purposes. Fluoride concentration in the study area varied from 0.5 mg/L to 5.95 mg/L with an average of 1.6 mg/L. 42.9% of the groundwater samples have shown higher fluoride concentration in groundwater than the permissible level prescribed by World Health Organisation and Bureau of Indian Standards. The spatial distribution map of fluoride has interestingly shown contrast between western and eastern parts of the region. Higher fluoride concentration (1.00-5.95 mg/L) in groundwater is witnessed in western half whereas the eastern half had comparatively lower concentration of fluoride ranging from 0.5 mg/L to 3.0 mg/L with maximum area having concentrations up to 1.5 mg/L. Major part 52.23% of Panipat district has shown high fluoride concentration in groundwater than the permissible level. It is further suggested that prolonged intake of groundwater with fluoride concentration higher than the permissible levels may cause dental or skeletal fluorosis in the locals.

Isotope investigation on groundwater recharge and dynamics in shallow and deep alluvial aquifers of southwest Punjab.

Groundwater samples collected from the alluvial aquifers of southwest Punjab, both shallow and deep zones were measured for environmental tritium (3H) and stable isotopes (2H and 18O) to evaluate the source of recharge and aquifer dynamics. The shallow groundwater shows wide variation in isotopic signature (δ18O: -11.3 to -5.0‰) reflecting multiple sources of recharge. The average isotopic signature of shallow groundwaters (δ18O: -6.73 ± 1.03‰) is similar to that of local precipitation (-6.98 ± 1.66‰) indicating local precipitation contributes to a large extent compared to other sources. Other sources have isotopically distinct signatures due to either high altitude recharge (canal sources) or evaporative enrichment (irrigation return flow). Deep groundwater shows relatively depleted isotopic signature (δ18O: -8.6‰) and doesn't show any evaporation effect as compared to shallow zone indicating recharge from precipitation occurring at relatively higher altitudes. Environmental tritium indicates that both shallow (3H: 5 - 10 T.U.) and deeper zone (3H: 1.5 - 2.5 T.U.) groundwaters are modern. In general the inter-aquifer connections seem to be unlikely except a few places. Environmental isotope data suggests that shallow groundwater is dynamic, local and prone to changes in land use patterns while deep zone water is derived from distant sources, less dynamic and not impacted by surface manifestations. A conceptual groundwater flow diagram is presented.