Water Quality Assessment of Kashkadarya Springs: Implications for Human Health and Water Resource Management ^†

Abstract

Direct access to good-quality drinking water in Uzbekistan is becoming a major issue. This challenge is exacerbated by growing demands, driven by population growth, industrial development, and desert land cultivation. In this regard, there is a significant need for a thorough analysis of the existing water resources. This study aims to identify the chemical composition of springs’ water in the Kashkadarya region of Uzbekistan and to assess their suitability as drinking water sources. To analyze the water quality, three springs were selected, Hazrat Bashir, Boshmanbulak, and Chillabulak, which are the most used springs by the population of this region, and the artesian waters of the city of Shakhrisabz were also included in the study. The quality of the spring water was evaluated based on the primary water quality indicators, including salt composition, heavy metals, and some essential trace elements such as iron (Fe), chromium (Cr), and selenium (Se) in the selected samples. According to the results, the spring water in Chillabulak was found to be relatively harder than the other samples, with magnesium and calcium concentrations of 28 and 390 mg/L, respectively. However, the study also revealed that the water from the other three examined samples meets sanitary norms and water quality standards, confirming their suitability for human consumption. The results can be used to develop water quality management strategies and environmental protection, as well as to inform the population about the ecological safety of regional aquatic reserves.

1. Introduction

Water is a fundamental resource for life, playing an essential role in human health, agriculture, industry, and ecosystem functions. Access to clean and safe drinking water is a fundamental human necessity. In this context, the problem of water resource availability is considered one of the most important issues of environmental protection, since water quality primarily plays a special role in the health of the population, and also affects the flora and fauna across the globe [1,2,3]. The quality of drinking water is compromised by various pollutants such as heavy metals, organic contaminants, and pathogens, posing serious threats to human health. Monitoring and improving water quality is essential for sustainable development and ensuring the well-being of populations, particularly in regions facing water scarcity and pollution challenges [4,5]. Effective water quality management requires comprehensive assessments of water sources to identify contamination levels and implement appropriate mitigation strategies [6].

Central Asia faces significant water scarcity challenges, exacerbated by climate change, population growth, and inefficient water management practices [7]. Uzbekistan, the most populous country in the region, is particularly affected, with its water resources under immense pressure due to extensive irrigation practices and industrial activities [8].

Yet in Uzbekistan, a double-landlocked nation in Central Asia, this basic need for water is increasingly at risk. The escalating water scarcity challenges in the country are due to a combination of factors. The arid climate, coupled with unsustainable agricultural practices and outdated irrigation infrastructure, has exacerbated the strain on limited water resources [9,10,11]. Apart from that, the country strongly depends on transboundary water resources from the AmuDarya and SyrDarya rivers, both experiencing reduced flows due to upstream withdrawals and climate change impacts, further compounding the problem. This scarcity not only threatens agricultural productivity, a cornerstone of the economy, but also poses risks to public health and environmental sustainability as there is also a lack of a supply of drinking water in several regions of the country [12].

The Kashkadarya region, in southern Uzbekistan, exemplifies these issues as it relies heavily on springs and artesian wells for its water supply, which are increasingly vulnerable to contamination and overuse [13,14]. Addressing water scarcity in this region requires comprehensive strategies for sustainable water management and pollution control to ensure the availability of safe drinking water for its inhabitants.

Effective water resource management in this region requires a detailed understanding of water quality, particularly regarding its chemical composition and potential health impacts. Previous studies have highlighted the importance of monitoring water quality indicators such as salt composition, heavy metals, and essential trace elements to ensure water safety and compliance with sanitary norms [15,16]. This study focuses on the water quality assessment of three heavily utilized springs in the Kashkadarya region of Uzbekistan (see Figure 1).

This study is the first to comprehensively evaluate the water quality of springs in the Kashkadarya region, where water scarcity is a pressing issue, particularly for drinking purposes. These springs serve as a critical source of water for the local population due to their accessibility and perceived purity. While studies on spring water quality in other parts of Uzbekistan exist [17], limited attention has been given to the springs in this region. Potential sources of contamination in the area include agricultural runoff, livestock activities, and natural mineral leaching, which could impact water quality. This research not only addresses these gaps, but also provides valuable insights into the quality of springs in sustaining the drinking water needs of the local communities.

2. Materials and Methods

Spring waters were chosen as the object of the study using the example springs of rural and mid-mountain zones of the Kashkadarya region of the Republic of Uzbekistan. Monitoring the quality of water from springs makes it possible to establish changes in a timely manner, identify and promptly eliminate the causes of deterioration in the properties of the water, and eliminate adverse effects on human health [18].

The priority list of chemicals for the control of their content in water used for drinking purposes includes:

• Salt composition—mineralization, general hardness, chlorides, alkalinity.
• Trace elements—fluorine, bromine, iodine, boron, nitrates, selenium, beryllium, strontium.
• Heavy metals—cadmium, copper, zinc, nickel, chromium, cobalt, molybdenum, iron, manganese, arsenic, lead, etc.

2.1. Sampling Procedure

As for the study area and sampling locations, the study focused on spring waters from rural and mid-mountain zones of the Kashkadarya region (shown in Figure 1), in Uzbekistan. Three springs commonly used by the local population and one artesian water source were selected:

• Hazrat Bashir spring;
• Boshmanbulak spring;
• Chillabulak spring;
• Artesian water from Shakhrisabz.

Water samples were collected in Autumn (October 2023), a period characterized by moderate temperatures and high levels of organic and sedimentary material due to seasonal conditions. This timing was selected because the water temperature is typically at an average level, and the likelihood of contamination is higher, allowing for an assessment of potential worst-case scenarios for water quality.

Samples were collected using 1 L sterilized, acid-washed polyethylene bottles to avoid contamination. Prior to collection, each bottle was rinsed three times with the respective water source. Surface water samples were collected from midstream in springs at a depth of 30–50 cm to avoid surface interference. For the artesian source, water was extracted after purging the well for 10 min to ensure a representative sample. After collection, the samples were immediately preserved to prevent chemical or biological alterations and transported to the laboratory in insulated containers under controlled temperature conditions.

2.2. Quantitative Determination of Micro and Macroelements

The concentrations of both microelements and macroelements in the water samples were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This technique was chosen for its high sensitivity and precision, which are critical for assessing water quality parameters.

ICP-MS Procedure

The analysis was performed using an optical emission spectrometer with inductively coupled argon plasma. For each element, the optimal wavelength corresponding to its maximum emission was selected to ensure accurate detection. The testing sequence involved preparing the sample with a specified amount (measured in mg) and diluting it to a precise volume (measured in mL).

The ICP-MS system automatically analyzed the samples, calculating the quantitative content of each element. The results were reported in mg/kg or μg/g, along with error limits expressed as the Relative Standard Deviation (RSD) percentage.

This method provided reliable data for both trace-level (microelements) and higher-concentration (macroelements) analyses, ensuring a comprehensive evaluation of the water’s contamination levels, mineral balance, and potential scaling properties.

2.3. Ionometric Analysis

Ionometric analysis is critical in water quality assessment, as it provides precise measurements of various ions present in water, which are vital indicators of water’s chemical properties and potential contaminants. Accurate ion concentration data are essential for evaluating the water’s suitability for consumption, agricultural, and industrial use, and for monitoring environmental health.

The ionometric analysis was conducted using a PXSJ-216F ionometer (Nanbei Instrument Limited, Zhengzhou, China) at room temperature (20 °C). To ensure consistency, the water samples were equilibrated to room temperature using a thermostat before measurements. Each ion’s quantitative determination was performed using specialized electrodes designed for specific ions.

The results obtained using the ionometer are converted into concentrations through mathematical calculations. To do this, the obtained values are converted into a numerical expression in the following order, taking into account that they represent the results obtained in the inverse logarithm.

$$pX={-\log }_{10}X{-\log }_{10}X={10}^{-X}$$

(1)

The value of X is reduced to a fraction. For example, if X = 2/3,

$${10}^{{\displaystyle \frac{2}{3}}}=\sqrt[3]{{10}^2}=C (concentration)$$

(2)

3. Results and Discussion

The results of this study provide a comprehensive assessment of the water quality of springs in the Kashkadarya region. Key findings include the identification and quantification of various chemical constituents in the water samples, such as salts, trace elements, and heavy metals. The analysis also highlights the differences in ion concentrations across the different springs, offering insights into potential sources of contamination and the overall ecological state of the water sources.

3.1. Results of Quantitative Determination of Micro- and Macroelements

The key elements analyzed in this study include lithium (Li), boron (B), sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), barium (Ba), chromium (Cr), iron (Fe), nickel (Ni), strontium (Sr), molybdenum (Mo), selenium (Se), bromine (Br), and iodine (I). The analysis of water samples from the selected springs indicated relatively stable water quality that largely meets sanitary standards and regulations (SanPin 2.1.4.1175-02).

The data in

Table 1. Concentration data from elemental analysis of spring waters.

	Concentration, mg/dm3
	Li 10−3	B 10−3	Na	Mg	K	Ca 102	Ba 10−3	Cr 10−3	Fe 10−2	Ni 10−3	Sr	Mo 10−4	Se 10−2	Br 10−2	I 10−3
MPV	70	500	200	50	12	75	700	50	30	20	4	70	1	1	10
Shakhrisabz city	1.8	3.3	3.7	17	0.72	2.8	6.1	3.2	2.4	2.5	0.24	9.8	0.5	4	2.3
Boshmanbulak	3.6	9	15	16	1.6	2.7	8.4	2.2	2.1	1.5	0.76	2.4	0.5	5.9	4.1
Hazrat Bashir	6.1	4.9	7.4	12	0.6	2.2	6	2.5	1.8	2.1	0.36	1.2	0.5	3.9	3.3
Chillabulak	8.3	2.9	8.4	28	2.5	3.9	15	3.1	2	3.5	0.71	5.8	0.83	4.9	2

MPV—maximum permissible values based on [19,20].

provide a detailed comparison of the elemental concentrations in the water samples from four different locations in the Kashkadarya region: Shakhrisabz, Boshmanbulak, Hazrat Bashir, and Chillabulak.

The elemental analysis of the water samples from Kashkadarya’s springs indicates that the water quality is generally within safe drinking limits for most analyzed elements. The high calcium and magnesium concentrations in Chillabulak suggest harder water, which, while not harmful, may require treatment for certain domestic uses. The consistent levels of trace elements like chromium, iron, and selenium across all samples highlight the natural geochemical stability of the region’s water sources.

However, the variations in sodium and potassium levels among the samples point to differing geological or anthropogenic influences on these water sources. The elevated sodium levels in Boshmanbulak may suggest contamination from agricultural runoff or natural salt deposits.

3.2. Ionometric Analysis Results

As mentioned previously, ionometric analysis is key to water quality assessment. It precisely measures ions, revealing water’s chemistry and potential contaminants. Based on the presented ionometric analysis data obtained using the PXSJ-216 F ionometer at room temperature, we can interpret the results and conduct a discussion. The ionometric analysis provided in

Table 2. Comparative study of ion concentrations in water samples from different regions and their impact on the environment.

Water Samples	Conc. NH4+ Ions, mol/L	Conc. Cl− Ions, mol/L	Conc. NO3− Ions, mol/L	Conc. Ag+ Ions, mol/L
MPV	9.3 × 10−3	7 × 10−3	8.1 × 10−4	8.1 × 10−7
Shakhrisabz city	8.22 × 10−5	9.33 × 10−5	2.29 × 10−4	0.2285
Boshmanbulak	6.93 × 10−5	6.91 × 10−5	5.23 × 10−5	0.2490
Hazrat Bashir	5.08 × 10−5	1.5 × 10−5	2.81 × 10−5	0.1148
Chillabulak	5.12 × 10−4	2.23 × 10−5	2.6 × 10−5	0.0988

reveals distinct differences in the concentration of key ions across the water samples from different regions.

The elevated NH₄⁺ concentration in Chillabulak presented in Table 2 suggests possible contamination from organic waste or fertilizers, which may require intervention to prevent further pollution and to ensure that the water remains safe for consumption. Apart from that, while the chloride concentrations are generally within acceptable limits, they indicate the presence of salts, which could be naturally occurring or result from agricultural or industrial activities. These levels should be monitored to ensure that they do not rise to problematic levels. In terms of the Shakhrisabz artesian water, the presence of nitrate and silver could be due to agricultural activities and industrial discharge, which should be thoroughly monitored to keep their level under control. Below in

Table 3. Electrochemical analysis of ion activity in water samples from different regions.

Water Samples	pHH3-1-01 Results Electrode (NH4+ion)	MPC, mg/dm3	pCl−-1-01 Electrode Results (Cl− ion)	MPC, mg/dm3	pNO3−-1-01 Electrode Results (NO3− ion)	MPC, mg/dm3	pAg+-1-01 Electrode Results (Ag+ ion)	MPC, mg/dm3
Shakhrisabz city	4.085	-	4.03	350	3.64	45KP+	−0.641	-
Boshmanbulak	4.159		4.16		4.281		−0.603
Hazrat Bashir	4.294		4.823		4.551		−0.94
Chillabulak	3.29		4.651		4.584		−1.005

MPC—maximum permissible value.

, electrochemical analysis of ion activity in water samples from different regions is provided.

NH₄⁺, Cl⁻, NO₃⁻, and Ag⁺ ions exhibited different concentration levels in the water samples from different places (Shakhrisabz, Boshmanbulak, Hazrat Bashir, and Chillabulak). For NH₄⁺, the highest activity was found in samples from Hazrat Bashir, while for Cl⁻ and NO₃⁻, the highest values were found in Chillabulak. Concentrations of Ag⁺ showed negative activity compared to other ions, with the low value for Chillabulak being particularly notable.

The differences in ion activity can be associated with many factors, including the geochemical features of the area, anthropogenic impacts, and the degree of protection of the water sources. For example, elevated NH₄⁺ levels may indicate sewage or agricultural fertilizer intrusion, while high nitrate (NO₃⁻) levels are often associated with agricultural runoff.

Ag⁺ activity values require additional analysis as they may indicate the presence of complexing agents that may affect the accuracy of the electrode measurements. This may also indicate the peculiarities of the methodology for converting the measurement results.

It is also necessary to consider the maximum permissible concentration for each ion in order to assess the potential risks to human health and the environment. A comparison between the obtained values and the maximum permissible concentration will allow us to determine which sources are within normal limits and where measures are required to improve water quality.

The data suggest that most springs in the Kashkadarya region comply with established sanitary standards, making them suitable for drinking purposes. Elevated levels of certain ions like NH₄⁺ and NO₃⁻ highlight the need for continuous monitoring to prevent potential health risks. The differences in ion activity across various springs can be attributed to geochemical characteristics and anthropogenic influences. These findings are essential for developing effective water management strategies and for informing local populations and authorities about the safety of their water resources.

Overall, these studies can be used to develop strategies for monitoring and improving water quality in the studied regions, as well as to inform the population and local authorities about the current state of water resources.

4. Conclusions and Future Work

In this study, the chemical composition of spring water in Uzbekistan’s Kashkadarya region was examined to assess its suitability for drinking. The most used springs in the selected regions (Hazrat Bashir, Boshmanbulak, and Chillabulak) and Shakhrisabz’s artesian waters were comparatively analyzed.

In conclusion, the water quality in the examined springs of the Kashkadarya region is largely within acceptable limits, confirming their suitability for human consumption. Future work should focus on regular monitoring and implementing measures to mitigate potential contamination sources, thereby ensuring the continued safety and sustainability of these vital water resources. Further studies could also explore the impact of seasonal variations on water quality and expand the analysis to include more springs across the region.

Also, the results of the study can be used for the further monitoring and improvement of water quality in springs, as well as for informing the population and developing recommendations for the use and protection of water resources in the region. Compliance with environmental standards and the regular monitoring of the condition of spring waters are necessary to maintain their quality at the proper level, which is important both for public health and for maintaining the ecological balance in the study areas.