Primary Water Source Research Articles

Rapid decline in extratropical Andean snow cover driven by the poleward migration of the Southern Hemisphere westerlies.

Seasonal snow in the extratropical Andes is a primary water source for major rivers supplying water for drinking, agriculture, and hydroelectric power in Central Chile. Here, we used estimates from the Moderate Resolution Imaging Spectroradiometer (MODIS) to analyze changes in snow cover extent over the period 2001-2022 in a total of 18 watersheds spanning approximately 1,100km across the Chilean Andes (27-36°S). We found that the annual snow cover extent is receding in the watersheds analyzed at an average pace of approximately 19% per decade. These alarming trends have impacted meltwater runoff, resulting in historically low river streamflows during the dry season. We examined streamflow records dating back to the early 1980s for 10 major rivers within our study area. Further comparisons with large-scale climate modes suggest that the detected decreasing trends in snow cover extent are likely driven by the poleward migration of the westerly winds associated with a positive trend in the Southern Annular Mode (SAM).

Challenges associated with access to safe water in Rhino Camp refugee settlement in Arua District, Uganda

ABSTRACT The study evaluated water access and disease prevalence in the Rhino Camp refugee settlement by mapping water sources, interviewing residents, and reviewing health centre records. Primary water sources were tanks providing 10.2 litres per person per day (l/p/d). Microbial contamination including total coliforms reaching 2.8 × 104 cfu/ml (household container – Tika), thermotolerant coliforms, and faecal enterococci were observed throughout the water supply chain, suggesting faecal contamination and posing a health risk. We attributed this to poor handling and storage related to poor sanitation in the settlement, highlighting the importance of promoting hygiene practices among refugees, particularly in the Ofua Zone, which had the highest contamination risks and the highest sanitary risk scores. Malaria and typhoid were the most prevalent diseases, with Ofua having the highest disease incidence. Water collection was mostly done by adult females and female children (34.7 and 30.3%, respectively) although water collection was generally low (<4 times a day). Boiling water was associated (p < 0.05) with the incidence of hepatitis A in Ofua. Adequate water (>20 l/p/d), water treatment, and education on hygiene practices especially for adult females are essential in lowering contamination and the incidence of diseases.

Unrevealing the water-use strategies for typical ecological restoration plants and cash crops in the Eastern Chinese Loess Plateau region

Study regionFour geomorphic types in the eastern Loess Plateau (ECLP). Study focusquantitatively study the water-use strategies of typical plants (ecological restoration plants, food crops) based on stable isotope technology. New hydrological insights for the regionSignificant spatial-temporal heterogeneity appeared in regional soil water content and stable isotopes, with more significant fluctuations in soil water isotope values appearing in the rocky mountain region. Regional tree growth (including natural and plantation forests) was mainly influenced by precipitation (35±14 %) and surface layer (0–40 cm depth) soil water (25±11 %) during April and June, whereas deep soil water gradually became the main water source (> 20 %) in autumn and winter. A. Lavandulifolia mainly uses surface soil water (> 23 %), and the proportion of deep soil water utilization has increased after September. Surface soil water (0–40 cm) was the primary water source for T. aestivum during the overwintering (> 16 %) and reviving periods (> 26 %), and Z. mays utilized the largest proportion of soil water from 0 to 20 cm depth layer during the seeding (> 60 %) and maturation stages (> 35 %). Collectively, the results of this study have important implications for sustainable vegetation protection and the optimal allocation of water resources in the arid region.

Spatio-temporal and depth-oriented evaluation of hyporheic zone processes in headwater catchments

The hyporheic zone (HZ) is vital for nutrient cycling and overall stream ecosystem health across groundwater-surface water interfaces, with biogeochemical and physical variations influencing exchange processes. To gain a depth-oriented insight into the various hyporheic functioning, isotopic (18O and 2H) and chemical analyses, along with physical parameters, were performed in two streams named Ahna and Losse in North Hesse, Germany. Multi-level interstitial probes were installed to extract subsurface pore water samples up to 0.45 m depth. We identified three distinct HZ in Ahna upstream, downstream and Losse. The Ahna upstream HZ was a less permeable barrier with low water fluxes but reactive, while the downstream HZ was less reactive with higher permeability and vertical fluxes. The Losse HZ, remained non-reactive but well-mixed with good hydraulic circulation due to fast downward flows. Isotopic composition revealed distinctive features, indicating increased evaporation and intricate mixing with other water sources and intensified subsurface flow in Ahna downstream compared to upstream. Hydro-chemical dynamics in Ahna exposed increased ion concentrations downstream, driven by anthropogenic factors along the course. Upstream denitrification was dominant under low oxygen conditions due to the slow infiltration and low mixing rates. The primary water source for both streams and HZs was groundwater, with the potential for rainwater to serve as a secondary source. This study shows the spatial heterogeneity of HZ processes and highlights that the specific HZ conditions need to be examined locally.

High resolution concentration-discharge relationships in managed watersheds: A 30+ year analysis

Concentration-discharge (C-Q) relationships provide insight into solute transport and biogeochemical processes for watersheds. A 30+ year, high-resolution dataset from the North Appalachian Experimental Watershed (NAEW) offers an unparalleled opportunity to explore land use and land management impacts on C-Q relationships for small watersheds of varying land management histories (agricultural to forested). The NAEW was among the few hydrologic research sites where storm event runoff was sampled using proportional sampling. This method captures the concentration-discharge behavior associated with land use more effectively than instantaneous sampling, which favors rising limb or falling limb dynamics. In this study, we explore C-Q relationships by investigating baseflow and storm event flow across their total behavior. We also build a systems-understanding by comparing chemostatic behavior to soil geochemistry and land use history. Highly managed agricultural watersheds with no associated stream baseflow demonstrate near-chemostatic behavior for most solutes, while mixed use and forested watersheds with associated streams are more mutable depending on whether primary sources of water were groundwater or surface water. Using this unique high-resolution dataset, we show that concentration-discharge relationships are influenced by soil and baseflow geochemistry, pore fluid concentration, and land type/land use legacy effects.

Protecting subterranean ecosystems for the wellbeing of surface environments and humanity

Protecting subterranean ecosystems for the wellbeing of surface environments and humanity Stefano Mammola, a researcher at the Italian National Research Council and coordinator of the Biodiversa+ project ‘DarCo’, emphasizes the importance of better incorporation of subterranean biodiversity in conservation agendas. Beneath our feet lies a vast and intricate network of caves, aquifers, fissures, and other voids teeming with unique life forms crucial to both human life and the environment. Groundwaters, for instance, represent the largest unfrozen freshwater reserve, serving as the primary water source for over half of the world’s population. Despite their importance, subterranean ecosystems receive minimal attention in current biodiversity and climate change agendas – a concerning oversight that demands urgent action. (1)

Influence of tailing dust contamination in drinking water on the health status of goats in subtropical Regions

The contamination of river systems by tailing dust remains a constraint to goat productivity in communal farming systems. A cross-sectional study was conducted to investigate how resource-limited households in subtropical regions assessed the effects of tailing dust contamination in drinking water on the health status of goats. In a study conducted in the Ba-Phalaborwa Local Municipality, 200 households from two villages were randomly selected and interviewed using a questionnaire. Forty-eight percent (n = 96) of the households were located in contaminated areas, while 52% (n = 104) were from uncontaminated areas. The study found that poor water quality, caused by tailing dust contamination, as well as a high incidence of diseases, were key factors affecting goat productivity. Water contamination was most severe during the hot and cool dry seasons. It was also noted that goats rely on freshwater as their primary source of supplemental water during dry seasons. Urine colour, oedema of the eyelids, and kid survival were indicators for assessing the health status of goats. Nominal binary logistic regression revealed that water contamination was 2.96 more likely to be reported by youth compared to elderly members. Farmers who received informal education were 37 times more likely to report contamination than those who received formal education. High kid mortality as a health status indicator was 50 times less likely to be reported in uncontaminated areas. Intervention strategies for reducing the adverse health effects of tailing dust in contaminated areas should focus primarily on the health of goats during dry seasons.

Spatial-temporal simulation and prediction of root zone soil moisture based on Hydrus-1D and CNN-LSTM-Attention in the Yutian Oasis, Southern Xinjiang, China

Root zone soil moisture (RZSM) plays a critical role in land-atmosphere hydrological cycles and serves as the primary water source for vegetation growth. However, the correlation between RZSM and its associated variables, including surface soil moisture (SSM), often exhibit nonlinearities that are challenging to identify and quantify using conventional statistical techniques. Therefore, this study presents a CNN-LSTM-Attention (CLA) model for predicting RZSM. Owing to the scarcity of soil moisture observation data, the physical model Hydrus-1D was employed to simulate a comprehensive dataset of spatiotemporal vertical soil moisture. Meteorological data and MODIS vegetation characterization parameters were used as predictor variables for the training and validation of the CLA model. The results of the CLA model for soil moisture prediction within the root zone were significantly enhanced compared with those of the traditional LSTM and CNN-LSTM models. This was particularly notable at depth of 80–100 cm, where the coefficient of determination (R²) reached nearly 0.9298. Moreover, the RMSE was reduced by 49% and 57% compared with those of the LSTM and CNN-LSTM models, respectively. This study demonstrates that the integration of physical modeling and deep learning techniques provides a more comprehensive and accurate understanding of spatial and temporal soil moisture variations in the root zone.

Dynamic Thermomechanical Modeling of Rock‐Ice Avalanches: Understanding Flow Transitions, Water Dynamics, and Uncertainties

AbstractThe rapid melting of glaciers and thawing of permafrost in mountainous regions have heightened the danger of rock‐ice avalanches. These avalanches pose a severe threat due to their potential to transform into water‐saturated debris flows. The catastrophic event in Chamoli, India, on 7 February 2021, illustrates the devastating consequences of such processes. Developing a model capable of predicting the dynamics and extent of these events is imperative for natural hazard science and disaster mitigation. In response, we propose a depth‐averaged rock‐ice avalanche model encompassing four distinct materials: rock, ice, snow, and water. The model integrates crucial physical processes, including frictional heating, phase changes, ground material entrainment, and air‐blast hazards. Through a system of mass and momentum balance equations extended with grain flow and internal energy equations, the model captures heat exchanges and resulting phase changes as the fragmented material flows. Focusing on identifying the primary water source in the flow and testing the model on the 2021 Chamoli event, we quantify water's influence on flow dynamics and regime transitions. However, uncertainties persist in heat transfer physics and quantifying the hydro‐meteorological state of the flow path. Our thermo‐mechanical model enables the simulation of complex avalanches and identifies key flow transitions: powder cloud formation and potential debris flow transformation. The study underscores the pivotal role of water in avalanche dynamics and the challenge of accurately quantifying water content within the flow, necessitating comprehensive ground assessments for effective disaster management.

A Study the Role of Water and the Sustainable Development

Water is a crucial natural resource that serves as a primary source of water for irrigation, drinking, and industrial use in India. Despite its importance, Water resources in India are rapidly depleting due to increasing demand, climate change, and unsustainable management practices. Sustainable development, which aims to harmonize economic growth, social inclusion, and environmental sustainability, is paramount in addressing these water challenges. In this context, it is crucial to revisit the Water laws in India to ensure sustainable resource management. The current legal framework for Water in India is fragmented, outdated, and ineffective. the significance of Water has grown. Currently, private-Water resources provide about 90% of the domestic and commercial water needs as well as around 65% of the irrigation needs. However, people frequently mistakenly believe that this valuable resource is boundless and unbounded. As a result, the general public frequently overlooks crucial Water issues such its scientific management, conservation, and augmentation.

Hydrogeochemical Characteristics and Health Risk Assessment of Groundwater in Grassland Watersheds of Cold and Arid Regions in Xilinhot, China

Xilinhot City is a significant pastoral city in China where groundwater serves as the primary water source for the cold and arid pastoral regions. The formation and evolution of material components in groundwater, as well as groundwater quality, are directly linked to the health of pastoral residents. This study is based on the physical and chemical test results of 22 groundwater samples collected from the Xilinhot River Basin in Inner Mongolia. Various statistical analyses, including Piper and Chadha diagrams, as well as hydrogeochemical simulation methods, were employed to assess the hydrogeochemical characteristics and material composition sources of groundwater, evaluate groundwater quality and non-carcinogenic risks, and comprehensively discuss the impact of macro- and microelements on human health. The findings indicate that igneous rocks containing minerals such as potassium feldspar, plagioclase, and pyroxene contribute Na+, Cl−, and K+ to the groundwater, while sedimentary rocks containing minerals like dolomite and calcite supply ions such as Ca2+, Mg2+, and HCO3−. The groundwater quality is primarily classified as Class II–V, with F− and NO3− exhibiting varying hazard quotients for children and adults in the study area, though they do not pose a non-carcinogenic risk. Additionally, the enrichment of hardness, Ca2+, Mg2+, Na+, SO42−, and other indicators in localized areas exceeds the recommended values for drinking water, potentially impacting the digestive and urinary systems of the human body. There is a risk of excessive fluoride in areas where F levels exceed 1 mg/L. Furthermore, the content of beneficial micronutrients such as selenium (Se), zinc (Zn), boron (B), and germanium (Ge) is relatively low. Based on the elemental abundance characteristics and a comparative analysis of the chemical properties of groundwater across five regions of China, this comparison facilitates a discussion on the definition of healthy groundwater, particularly in relation to safe consumption in cold and arid regions. This study aims to highlight the health issues associated with drinking groundwater in the cold and arid regions of Mongolia. The findings serve as a valuable reference for efforts aimed at reducing the incidence of endemic diseases and enhancing human lifespan.

Performance analysis of an SPD integrated with a stepped pyramid solar still: experimental study

AbstractWater scarcity poses a major challenge for the next generation. Additionally, increasing agricultural and industrial activities are creating an unprecedented demand for freshwater supplies throughout Egypt. The Nile River serves as Egypt’s primary water source, accounting for 69.4% of the total water resources. Moreover, Egypt's annual share of water has decreased to approximately 500 m3 per person because of the completion of the Renaissance dam in Ethiopia and the rapid increase in population growth. Solar distillation has been presented as a long-term and promising method for producing edible drinkable water. The present research goal is to increase the daily freshwater output from a stepped pyramid solar still (SPSS) by coupling with a solar parabolic dish (SPD). The proposed system consists of a conventional pyramid solar still (CPSS) and a modified pyramid solar still (MPSS). The main components of an MPSS include an SPSS, a PV panel, an SPD with a spiral coil, a circulating pump, and an Arduino Mega Unit. The developed system was designed, fabricated, and verified from July to August 2023 at the Faculty Engineering, South Valley University. The results of the experiments indicated that the daily productivity of freshwater from MPSS was greater than that from CPSS and reached 6038 and 2612 mL/day, respectively, with an increase in the daily yield of 131%. The peak energy efficiency is 56% for the MPSS and 24% for the CPSS. The peak exergy efficiency is 4.26% for the MPSS and 3.79% for the CPSS. Additionally, the cost analysis of the suggested system revealed that the estimated cost per liter of the proposed system is 0.01635 USD/L.

Understanding the seasonal variations in access to improved water sources in Ghana: A call to action for policymakers

ABSTRACT Although studies have explored the link between seasonal change in water sources and biophysical health, there is limited evidence on the psycho-emotional impact of seasonal shifts in primary water sources in a country with two different ecological zones. The primary water source for each participating household was categorized by season, and overall changes in water sources and seasonality were explored using Fisher's exact test and Pearson chi-square test. Regarding seasonal changes, 90.3% of the study participants safely managed water sources across the seasons. Only 7.4% (45) of households switched from safely managed water sources in the dry season to limited sources in the wet season. Similarly, 2% (12) of participants switched from safely managed water sources in the dry season to unimproved water sources in the wet season. The Chi-square test indicates a significant association between emotional distress and the type of water source used in the dry (χ2 = 35.6, df = 3, p = 0.00) and wet (χ2 = 37.8, df = 3, p = 0.00) seasons. Future interventions that aim to increase access to and use of safe drinking water must consider seasonality and climate change and develop infrastructure accordingly.

Integrative genome-centric metagenomics for surface water surveillance: Elucidating microbiomes, antimicrobial resistance, and their associations

Surface water ecosystems are intimately intertwined with anthropogenic activities and have significant public health implications as primary sources of irrigation water in agricultural production. Our extensive metagenomic analysis examined 404 surface water samples from four different geological regions in Chile and Brazil, spanning irrigation canals (n = 135), rivers (n = 121), creeks (n = 74), reservoirs (n = 66), and ponds (n = 8). Overall, 50.25 % of the surface water samples contained at least one of the pathogenic or contaminant bacterial genera (Salmonella: 29.21 %; Listeria: 6.19 %; Escherichia: 35.64 %). Furthermore, a total of 1,582 antimicrobial resistance (AMR) gene clusters encoding resistance to 25 antimicrobial classes were identified, with samples from Brazil exhibiting an elevated AMR burden. Samples from stagnant water sources were characterized by dominant Cyanobacteriota populations, resulting in significantly reduced biodiversity and more uniform community compositions. A significant association between taxonomic composition and the resistome was supported by a Procrustes analysis (p < 0.001). Notably, regional signatures were observed regarding the taxonomic and resistome profiles, as samples from the same region clustered together on both ordinates. Additionally, network analysis illuminated the intricate links between taxonomy and AMR at the contig level. Our deep sequencing efforts not only mapped the microbial landscape but also expanded the genomic catalog with newly characterized metagenome-assembled genomes (MAGs), boosting the classification of reads by 12.85 %. In conclusion, this study underscores the value of metagenomic approaches in surveillance of surface waters, enhancing our understanding of microbial and AMR dynamics with far-reaching public health and ecological ramifications.

Simulation of Groundwater Potential Zone Using Geographic Information System (GIS) Through Related Factors

Groundwater is the primary water source for irrigating and drinking in dry seasons. This work was examined to assess groundwater potential area underlain by basement complex with GIS based approach of selected locations in Osogbo. The soil samples were taken and soil textural and permeability analyses were done in the laboratory. Supervised classification analysis was done on LandSAT imagery to generate Land use and a lineament map, surface analyst algorithm was applied on ASTER dam to generate elevation map. Hydraulic conductivity and overburden thickness maps were generated from the Borehole data parameters. Interpolation method was used to generate spatially spread clay, silt, sand, rainfall and hydraulic conductivity. Multi-criteria analysis was used to generate groundwater potential zone map in the study area. Specific factors were considered for groundwater potential zone. Reclassification was done on each of the considered factors and AHP model was used to assign weight to all the factors. The results of the various factors responsible for groundwater potential include lineament density 0-0.0028; sand 67.2-89.60%, silt 9.00-30.00%, clay 0.17-2.80%, permeability 0.000010-0.00002, rainfall 1304.02-1469.06mm/yr, hydraulic conductivity 0.21-0.96m/min, land use consisting of degraded forest 48.65%, riparian forest 13.05%, built up 38.29%, and water body 0.001%. However, ground water potential of the study area was assessed and classified into fair, good and very good with the coverage of 2%, 80% and 18% respectively. Conclusively, the groundwater recharge potential is very good at Ofatedo, Gbonmi and Oke-Oro locations, good at Awosuru, Gbodofon and Dagbolu locations, but fair at Mallam Tope location in Osogbo

Nonprofit Poetry: Lewis MacAdams and the Art of Environmental Bureaucracy

Abstract Poet Lewis MacAdams is widely regarded as a founder of the movement to restore the Los Angeles River, a 51-mile concrete drainage channel that once served as the region’s primary water source. His nonprofit organization Friends of the Los Angeles River (FoLAR) began as a one-off performance art piece in 1985. Scholars in urban planning and geography have addressed FoLAR as a case study for grassroots environmentalism, but little attention has been paid to the interplay between poetry and politics in MacAdams’s work. Given that MacAdams described FoLAR as a “forty-year artwork to bring the Los Angeles River back to life,” it is worth entertaining the quixotic premise that a nonprofit could double as a conceptual artwork or performance poem. If we consider his literary efforts in conversation with his activism, the premise seems less far-fetched. In this essay, I trace MacAdams’s path from the New York School to the poets’ enclave of Bolinas, California, in the 1970s to the concrete banks of the Los Angeles River. I argue that he devised political-poetic strategies to intervene in planning bureaucracies and that FoLAR should be understood as a durational utopian experiment, pursuing transformative possibilities from within dispiriting everyday conditions.

A comprehensive analysis of water quality of open wells at Alevuru and Badagabettu-76 village of Udupi Taluk, Karnataka, India

Abstract The availability of pure water is one of the most essential requirements for all living organisms. In rural areas of Udupi, Karnataka, India, well water serves as the primary source of water for residents. Hence the objectives of the study were to find the physical and chemical characteristics of the well water sources in Udupi taluk; and to assess the suitability of the well water sources in Udupi taluk for drinking purposes by determining water quality index (WQI). Water samples (n=24) were collected from open wells from Alevuru and Badagabettu-76 villages of Udupi taluk during October 2023. Water quality parameters analyzed were pH, total dissolved solids, electrical conductivity, turbidity, total alkalinity, total hardness, dissolved oxygen, nitrate, chloride, sulphate, chemical oxygen demand and iron. The WQI revealed that the well water in majority of the sites was fit for drinking. All parameters were within the permissible limits in majority of the wells except for iron and pH.

Variations in water use strategies of Tamarix ramosissima at coppice dunes along a precipitation gradient in desert regions of northwest China.

The precipitation pattern has changed significantly in arid desert areas, yet it is not clear how the water use strategies of Tamarix ramosissima Ledeb. on coppice dunes along a natural precipitation gradient are affected. In this study, the hydrogen and oxygen isotope compositions of xylem water, soil water, precipitation, and groundwater were measured by stable isotope techniques in Huocheng, Mosuowan, and Tazhong. Additionally, the water use strategies of natural precipitation gradient were investigated in conjunction with the MixSIAR model. The results indicated that the water sources of T. ramosissima exhibited significant variation from semi-arid to hyper-arid areas. In semi-arid areas, T. ramosissima mainly absorbed shallow, shallow-middle, and middle soil water; however, T. ramosissima shifted its primary water sources to middle and deep soil water in arid areas. In hyper-arid areas, it mainly utilized deep soil water and groundwater. In contrast, the water source contribution rate of T. ramosissima exhibited relative uniformity across each layer in an arid area. Notably, in hyper-arid areas, the proportion of groundwater by T. ramosissima was significantly high, reaching 60.2%. This is due to the relatively shallow groundwater supplementing the deep soil water content in the area. In conclusion, the proportion of shallow soil water decreased by 14.7% for T. ramosissima from semi-arid to hyper-arid areas, illustrating the occurrence of a gradual shift in potential water sources utilized by T. ramosissima from shallow to deep soil water and groundwater. Therefore, T. ramosissima on coppice dunes shows flexible water use strategies in relation to precipitation and groundwater, reflecting its strong environmental adaptability. The findings hold significant implications for the conservation of water resources and vegetation restoration in arid areas.

Evaluation of groundwater quality for drinking and irrigation purposes, ionic sources and land use/land cover impacts in the Kathua region of Jammu and Kashmir, India

Kathua is one of the fast-growing industrial districts of the Union Territory of Jammu and Kashmir, northern India. The primary source of water in Kathua is groundwater, which is widely used for industrial, agricultural, drinking, and building purposes. The groundwater system is changing significantly both in terms of quantity and quality in the study area due to recent industrial and infrastructural developments. Thus, 40 groundwater samples were collected from different wells in the pre-monsoon season, May 2022, and analyzed for physicochemical variables to determine the impact of geogenic and anthropogenic activities on the groundwater. The drinking groundwater quality appears to be excellent to good. Of the variables that were examined, two—TH and HCO3—had concentrations higher than the recommended limits of the BIS and WHO guidelines. Groundwater contains alkaline earth metals and weak acids, and its hydrochemistry is controlled by rock‒water interactions (silicate weathering or cation exchange and reverse-ion exchange processes). Several parameters (electrical conductivity, sodium percentage, sodium adsorption ratio, permeability index, magnesium adsorption ratio, residual sodium carbonate, and the Kelly’s ratio) were used to evaluate groundwater suitability for irrigation. The permeability index, magnesium adsorption ratio, and residual sodium carbonate indicate that the groundwater of a few samples is unsuitable for irrigation purposes. Land use/land cover (LULC) change analysis was used to determine the potential impacts of LULC changes on groundwater. Anthropogenic interventions are a major cause of LULC changes that are considerably reducing groundwater recharge zones, increasing surface runoff, and artificially polluting groundwater through domestic and industrial wastes, according to the LULC analysis conducted using satellite data for the year 2017 and 2022. Therefore, to minimize the effects of LULC on groundwater, prompt action must be taken, requiring regular monitoring of groundwater quality and LULC changes. The results of the study may be useful to the general public, farmers, and policy makers in the sustainable development and management of groundwater.

Anthropogenic Drivers of Spatial Trends in Groundwater Quality in the Upper Athi River Basin of Kenya, East Africa

Rapid urbanization and population growth in the upper Athi River basin in Kenya have increased the strain on the sub catchments water supply and sanitation situation. Due to increasing demand, inadequate supply of drinking water and lack of sanitation facilities, people in the sub-catchment are increasingly reliant on groundwater as a primary or supplementary water source. However, the use of on-site wastewater systems and agricultural pollution, mainly from runoff containing fertilizers, pesticides, herbicides, and faeces, pose a threat to groundwater in the sub catchment. Subsequently, the current study was conducted in the Thiririka sub catchment, Kiambu County, Kenya, to determine the safety of groundwater sources and to examine the factors influencing groundwater quality in the catchment area. This study assessed the influence of anthropogenic activities on the physical, chemical, and bacteriological quality of groundwater in the Upper Athi River basin of Kenya between April and June 2022. Twenty variables were analyzed and compared with water quality standards to determine hydro chemical characteristics, evidence of contamination, and suitability of groundwater. Shallow wells (SW) had higher concentrations of major ions and key parameters than boreholes (BH), such as alkalinity (7%), turbidity (96%), nitrates (92%), sulfates (48%), phosphates (93%), chlorides (77%), potassium (84%), sodium (30%) and fecal coliforms (99%) significant at p &amp;lt; 0.01. Concentrations of eleven water quality variables however were comparable in both systems. Farming, animal husbandry, and pit latrines were negatively but significantly correlated with the water quality of SW explaining substantial amounts of variation (≤ 45%) in concentrations of water quality variables. Ionic and coliform levels increased with decreasing distance and vice versa. IDW interpolation maps were generated in ArcGIS software to determine the spatial variability of groundwater quality in the basin. Anthropogenic activities such as pit latrines and animal husbandry impaired the quality of groundwater which in most cases was not potable.