Assessment of physiochemical parameters of the Tawi River of Jammu and Kashmir, India for drinking and agricultural purposes

Although 71% of the planet Earth is covered with water (USBR 2020; Mishra 2023), the availability of freshwater varies widely across the globe. Every living being depends on the amount of fresh water. As time goes by, the quality of water is becoming an increasingly important issue in both developed and developing nations. In addition, every nation at a different scale experiences difficulty in conserving quality drinking water, which may be affected by the rapid rise in population, random settlement of inhabitants, industrialization, and deforestation. Furthermore, modernization started corroding the environment by producing more and more waste.

In a developing country like India, access to clean drinking water is essential because water-borne diseases like diarrhea and malnutrition are the leading causes of death (Misra & Paunikar 2023; Arnold 2024). In 2014, the Government of India in association with USAID (United State Agency for International Development) jointly organized WASH (Water, Sanitation, and Hygiene) program in India to increase access to clean water and hygiene. In order to further overlook the access to clean drinking water, the Indian government in 2019 envisioned and decreed ‘Jal Jeevan Mission.’ The mission is expected to provide access to sufficient and safe drinking tap water to all households in the country by 2024 (Bassi et al. 2023; Jal Jeevan Mission 2023). In addition, with the help of the World Bank, the Indian government launched the ‘Atal Bhujal Yojana’ program and the ‘Pani Bachao Pani Kamao’ program in Punjab, respectively, to manage and conserve groundwater (World Bank Group 2023).

Despite the country having taken such important efforts, access to safe drinking water still remains challenging. About 40% of the population in India is still under defecated area with contaminated water that leads India to stand tall in the world in diarrhea-related deaths of children under 5 years of age (USAID 2020; Vatsa et al. 2023). Many other water-borne diseases such as cholera, shigellosis, poliomyelitis, typhoid, and hepatitis are still posing threats to human health. A few World Bank figures illustrate the predicament the country finds in itself: safe drinking water is unavailable to 163 million Indians, 210 million people are inaccessible to improved sanitation, and 21% of infectious diseases have a connection to contaminated water (SIWI 2018).

The deterioration of water quality not only ruins human health but also imparts significant damages on agricultural productivity. Therefore, regular water quality study and monitoring are crucial for every region. The sources of freshwater are groundwater, surface water (such as rivers, lakes, reservoirs, streams, ponds, and wetlands), rainwater, frozen and melt water, as well as desalinated water obtained through artificial processes. Among which, groundwater stands as world's largest freshwater supply and is widely utilized for agriculture, drinking, and industrial purposes. However, for under groundwater-stressed areas as in the case of Jammu City, the main source of safe drinking water is the snow-fed rivers. Rivers can be designated as important elements of nature that contribute to human development, in addition to their vital role as the surface source for drinking water (Islam et al. 2020; Patidar et al. 2024). The deterioration level of rivers is higher due to direct contributions of waste from the household, spills from industry, and intense agricultural activities (Nienhuis & Leuven 2001; Akhtar et al. 2021; Sharma et al. 2024). Due to human interventions such as industrialization, intense agricultural wastes, urbanization, wastes, and garbage from market areas, river water is being polluted. The specific parameters that are hazardous to human health are to be monitored intensively. Likewise, in order to enhance/increase the growth of agricultural productivity, it is equally essential to keep a regular track of important parameters that hamper the crops. As 80% of diseases are water-borne (WHO), it is crucial to study the water quality in order to prevent future pollution and victimization of any disease outbreaks. Hence, there are still many recent studies that basically focused on water quality and its deterioration, whether it be on surface water (Edokpayi et al. 2017; Yunus et al. 2020; Hammoumi et al. 2024) or ground water (Alao et al. 2023; Rao et al. 2024).

The Tawi River system in the Jammu City region is experiencing a sharp growth in demand for high-quality water as a result of the growing agricultural, tourism, and damping activities, in addition to an increase in population. The present study focused on determining the resultant impact of the on-going water deterioration level due to the above mentioned reasons and its suitability for drinking and irrigation purposes. The important physiochemical parameters considered in this study are pH, TDS (total dissolved solid), Ca²⁺, Mg²⁺, complete alkalinity, EC (electrical conductivity), sodium, total hardness (TH), potassium, and chlorides. However, for irrigation purpose, the targeted metrices for the quality of water include SAR (sodium adsorption rate), MH (magnesium hazard), KR (Kelly ratio), PI (permeability index), and %Na (sodium percentage).

Jammu City is one of the most populous cities and serves as the winter capital of the Union Territory Jammu and Kashmir, India. Tawi River is one of the central lifelines of Jammu City which bifurcate the city into two sections, i.e. separating the old and new city. It derives its origin from the Kailash Kund glacier. The catchment boundary is demarcated within the periphery of latitude 32°35′-33°5′N and longitude 74°35′-75°45′E, and cover an area of about 2,168 km² within the Indian border. The catchment elevation ranges between 400 and 4,000 m. The river traverse toward Pakistan after crossing the Indian border and joins the Chenab River; it has a length of about 141 Km. The Tawi River is considered one of the holy and sacred rivers and is also known as Surya Putri as per ancient text.

Sitlee Filtration Plant (S1) is located at Nagrota Bypass near Jammu, where many towns are along the stream vicinity of this plant. Each individual town is a viable source of pollution, spilling untreated wastes and dirt into this river. The second sampling point is Har ki Pauri (S2) which is situated near the Baghe Bahu Fort. It is considered as a modern-day temple, which was built along the banks of the Tawi River. The temple attracts a large number of devotees due to the presence of its magnificent idols of almost all gods and goddesses of Hinduism. The third sampling point for the collection of samples is Gujjar Nagar Bridge (S3). It is located just opposite to the Baghe Bahu Fort. The height of the river bed and the bridge is 90 m whereas the length is 310 m. The untreated sewage from towns like Mubarak Mandi, Pram Nagger, Bahu Fort, and Ballicharna is released into sewers that join the river later on.

A river water composition, in general, depends on the sample collection site and is a part of a dynamic medium (Montgomery & Hart 1974; Ellis & Lacey 1980). Sampling depends on several factors such as use of appropriate containers, volume of the sample, types of samples (purpose of sampling), and sampling locations. The present study cautiously followed the sampling techniques described in IS 3025 (Part 1).

As per IMD (Indian Meteorological Department), the highest rainfall in the Jammu district spanned the months of June, July, August, and September. In the present study, water samples were obtained inconsistently from three stations S1, S2, and S3 (Figure 1) starting from the period September 2019 to March 2020, for evaluation. Two liter samples were collected every month from S1, S2, and S3. The samples were collected at mid-depths using a long-handled water scooper from these three sites, as sampling too near the bank might provide erroneous or fictitious results. The polyvinyl chloride (PVC) bottles used for gathering the samples were cleaned by concentrated hydrochloric acid, left for 1 or 2 days, and then, finally, rinsed with distilled or deionized water for few times. The stopper was also used in such a way that no air was present in it.

During the time of sampling, the following tasks were taken care of: (i) tests such as pH, EC, DO, turbidity, and temperature are conducted at the site as waste water disintegrates quickly at room temperature, while the remaining tests of the samples are preserved at different bottles for laboratory analysis; (ii) the reagent bottles are handled with dry hand during the time of sampling to avoid improper outcomes; and (iii) entry of large number of floating objects are also taken care during the time of sampling. The samples collected from the sites are labeled and then shipped to a laboratory for evaluation within 24 h. The samples are shipped to the laboratory by maintaining a temperature of 4 °C through refrigeration.

In this study, around 17 critical parameters (physical and chemical) are selected for assessing the quality of drinking water. These include calcium (Ca²⁺), pH, TH, TDS, magnesium (Mg²⁺), chloride (Cl⁻), sodium (Na⁺), potassium (K⁺), DO, alkalinity, EC, color, temperature, turbidity, and taste.

The pH of the water samples was measured using a pH meter tester (Model DO-35634-30 Oakton). Before taking the measurements, calibration was made with a three standard solution 4.0, 7.0, and 10.0. Readings are taken by submerging the pH meter probe in the water sample: it is held for a couple of minutes until a stabilized reading is achieved. To avoid cross contamination, the pH meter is rinsed with deionized water after each sample measurement. The conductivity of the water samples was measured using an EC meter (Model HI99301P Hanna). Calibrations of the probe were made using the standard solution. On submerging the probe in the sample, the reading was taken but on the disappearance of the stability indicator. To avoid cross contamination with the other samples, the probe was rinsed with deionized water after the measurements. The temperature was also measured using the same EC meter. The turbidity of the sample was measured using the turbidity meter (Model PCE-TUM 20). Each sample was taken and placed inside the sample holder. The reading was recorded after a stabilized reading was achieved. The DO test is carried out using the Winkler titration method at the site to avoid alternation due to atmospheric equilibrium.

The remaining test is conducted in a laboratory. The samples collected from the sites are labeled and then shipped to the laboratory for evaluation within 24 h. The samples are shipped to the laboratory by maintaining a temperature of 4 °C in a refrigerator. TS, TDS, and SS are conducted as per the stipulation IS: 3025 (Parts 16 and 17) in conformity with the method 2540 C & D of APHA standards and EPA-600/4-79-020, USEPA, method 160.1. Likewise, Ca²⁺ hardness of the water sample is conducted as per the standard IS: 3025 (Part 40) using the EDTA titrimetric method. The concentrations of Mg²⁺ in water samples are measured using the process APHA/3500/Mg/E (1995) and IS 3025(Part 46). TH of the sample is conducted using the EDTA method [IS: 3025 (Part 21)] which is based on Ca²⁺ and Mg²⁺ reaction with EDTA. The chemical parameters Na+ and K+ concentrations are estimated using a Flame Photometer [IS: 9497(1980)] and in conformity with the APHA/3500/Na/D (1995) technique. Alkalinity of the water samples is measured using potentiometric and indicator methods prescribed as in IS: 3025 (Part 23). The color and odor are measured using the spectrophotometric method of IS: 3025 (Part 4) and the method suggested in IS: 3025 (Part 5). Finally, the taste of the water sample is examined by five random observers and the findings are then articulated according to the degree of the observers' approval. The rating scale is then marked based on IS: 3025 (Part 8) specifications.

The water quality for irrigation differs based on locations, regions, and the types of sources (surface or subsurface). The major problems in irrigation water for crops are due to salinity, sodicity, and ion toxicity. Salinization is a global problem that threatens global food security and the livelihood of many farmers (SAW 2020). Due to the salinazition problem, a vast majority of farmland are lost every day, which reduces the suitable agricultural productivity. On the other hand, with the increase in population, the growing demand for food is also increasing at soar. Salinity affects the plants in two ways: one is through negative osmotic potential and the other is the salinity stress of essentials cations. Negative osmotic potential occurs due to the presence of excess amount of dissolved salts in agricultural farmland whereas salinity stress is due to the presence of unwanted ions such as sodium ions which is toxic for the crops. The presence of a large amount of makes it harder for the plant roots to absorb other positive ions such as and ⁠.

Table 2 shows the classification of suitablity of water by ranking based on the above parameters. The SAR value ranges from 0 to 6 and is assigned rank 5, representing that the quality of water is good for irrigation, whereas values >9 is assigned rank 3, representing the unsuitablity of water for irrigation. Likewise, the ranking and suitability of water for irrigation for different other parameters (MH, KR, PI, and %Na) are also assigned accordingly.

However, for irrigation purpose, the quality of water is broadly examined on the basis of the sum total score of the parameters at particular sampling sites, over time (e.g. daily, monthly, etc.). The total score ranges categorized for irrigation purpose is shown in Table 3.

Table 4

Parameters and their unit weights

Sl. no. .	Parameters .	Standard value .	Assigned weight .	Relative weight .
1	Magnesium (Mg2+)	30	3	0.088
2	Calcium (Ca2+)	75	3	0.088
3	Chloride (Cl−)	250	5	0.147
4	TDS	500	5	0.147
5	Alkalinity	200	1	0.029
6	pH	7–8.5	4	0.118
7	Sodium (Na+)	200	4	0.118
8	DO	5	3	0.088
9	Potassium (K+)	12	2	0.059
10	EC	1,000	2	0.059
11	Total hardness (TH)	300	2	0.059

Sl. no. .	Parameters .	Standard value .	Assigned weight .	Relative weight .
1	Magnesium (Mg2+)	30	3	0.088
2	Calcium (Ca2+)	75	3	0.088
3	Chloride (Cl−)	250	5	0.147
4	TDS	500	5	0.147
5	Alkalinity	200	1	0.029
6	pH	7–8.5	4	0.118
7	Sodium (Na+)	200	4	0.118
8	DO	5	3	0.088
9	Potassium (K+)	12	2	0.059
10	EC	1,000	2	0.059
11	Total hardness (TH)	300	2	0.059

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The entire framework considers the accumulation of complex information to assess the spatial and temporal changes of different parameters. It is, therefore, important to reconfigure and convert large amount of information into a single number using special techniques. So, in order to accomplish it, WQI and multivariate statistical analysis (MSA) were used. XLSTAT 18.0 software is used for all arithmetic and mathematical calculations. Three acute points S1, S2, and S3 along the Tawi River in Jammu City of Jammu district, were analyzed based on the physicochemical parameters mentioned in sub-sections 3.2 and 3.3 to determine the WQI. The descriptive statistical information of the physicochemical parameters for the sample period from September 2019 to March 2020 is shown in Table 5. The CV values provide information about the dispersion level of the variables during the evaluation period. It is observed that the CV values have good consistency with lower values, indicating better accuracy of the estimate.

Table 6 shows the Pearson's correlation matrix of these variables. SS (suspended solids) have a positive correlation with Ca²⁺, Na⁺, Mg²⁺, EC, and TH, and a negative correlation with Cl⁻ and DO. The positive correlation with inorganic salts (Ca²⁺, Na⁺, Mg²⁺) indicates that the contribution of SS is due to more contribution of these ions. The other possible causes may be waste discharge and soil erosion due to natural and human interventions, and stone quarries in the unabated zones along the Tawi River. Therefore, reflection is seen in the TH level, i.e. 0.9220 corresponding to SS. On the other hand, a negative but significant correlation of SS with Cl⁻ and DO indicates that such an impurity level decreases DO, as it strongly depends on the fresh water flow (Mitchell et al. 1999). Likewise, TDS has a positive correlation with TS and EC and a signification correlation with Na⁺ and K⁺, but has a low and negative correlation with alkalinity, Cl⁻, and DO.

Table 8 shows the total score obtained for the parameters MH, KR, SAR, %Na, and PI during the evaluation period (in month), i.e. starting from September 2019 to March 2020. With reference to Table 3 and the obtained values in Table 8, it can be concluded that the categorization of the Tawi River water falls under good category, i.e. it ranges between 21 and 25.

The result of the present study is limited to the current study period only (i.e. 2019–2020) which may vary onward and/or afterward.

The results obtained from physicochemical analysis and qualitative metrics for irrigation indicate that the parameters are within the safe limits. However, turbidity is found to be above the admissible limits as when compared to the national standard and WHO guidelines. It is observed that the average turbidity level during the evaluation period is 42.98 NTU (Table 5), which indicates the sign of pollution in water. The acceptable limit for turbidity is 10 NTU as per IS:10500(2012) and USEPA (United States Environmental Protection Agency) which also conformed the WHO guidelines. This rise in turbidity may be due to the contribution of fine sand particles, as well as silt and fine particles from stone quarries in unabated zones along the river reaches, which designates the existence of turbidity. On the other hand, during the evaluation period, the irrigation WQI value falls within a good classification threshold. Overall, the findings show that the quality of the Tawi River is suitable for irrigation and livestock. However, it is highly adviced to continue monitoring the important water quality parameters.

In future, other improved methodologies may be employed for WQI quantification. Additional research can be conducted on biological parameters and other parameters not included in this study. Furthermore, this study might be extended, particularly to look into how water pollution varies with time and seasons.

The authors wish to acknowledge Indian Meteorological Department, Jammu for making the data available. We are also thankful to the Department of Civil Engineering, National institute of Technology, Hamirpur and Department of Civil Engineering, National institute of Technology, Patna for providing research facilities.

The authors declare that no funding was received during the preparation of the manuscript.

Conceptualization, data collection, and preparation of first draft of the original manuscript were done by J.T. and S.S.. Analysis and interpretation of results, supervision, technical guidance, and help to shape the research and manuscript were performed by J.T.

All relevant data are included in the paper or its Supplementary Information.

The authors declare there is no conflict.