Physical and Bacterial Parameters of Well Water in Selected Rural Households of Mangaluru, Karnataka, India: A Cross-sectional Study

1. Assistant Professor, Department of Community Health Nursing, Yenepoya Nursing College, Yenepoya (Deemed to be University), Deralakatte, Mangaluru, Karnataka, India. 2. Assistant Professor, Department of Community Health Nursing, Yenepoya Nursing College, Yenepoya (Deemed to be University), Deralakatte, Mangaluru, Karnataka, India. 3. Head, Department of Community Health Nursing, Yenepoya Nursing College, Yenepoya (Deemed to be University), Deralakatte, Mangaluru, Karnataka, India.

Abstract

Introduction: Water is one of the important natural resources available for mankind for its survival. In rural Karnataka, there are 1,182,990 wells, out of which 131,305 are covered wells, and 1,051,685 are uncovered. This highlights the threat to safe and potable drinking water.

Aim: To assess the physical, chemical, and microbiological qualities of well water situated in the field practice area of Mangaluru, Karnataka, India.

Materials and Methods: A cross-sectional study was conducted in the year 2019, between July and August, in the rural area of Kinya Panchayat, Ullal Taluk, Dakshina Kannada District. This area serves as the field practice area of Yenepoya Nursing College, Yenepoya deemed to be University. This pilot project was a time-bound study, and all twenty wells available were conveniently included in the study and comprised dug and ring residential and government wells utilised by residents for drinking and domestic purposes. Water collection followed World Health Organisation (WHO) guidelines. Baseline data included the age of the wells, colour, odour, and chlorination of the well water. Chemical parameters such as pH levels and bacteriological assessments to identify the presence of Escherichia coli, H₂S, and Most Probable Number (MPN) bacterial counts were conducted using laboratory tests.

Results: The colour of all 20 (100%) well water sources met WHO standards. The water was odourless in all 20 (100%) sources. The mean age of the wells was five years. The majority, 17 (85%) of the wells, were never chlorinated. Moreover, 17 (85%) of the well water sources had a pH level of ≤7, while 3 (15%) had a pH level of >7. E. coli bacteria were present in three-fourths of the well water (17 wells, 85%). No other organisms were found during testing. Ten (50%) of the well water sources had a bacterial count of 351-550 MPN {Most Probable Number (MPN) of bacteria} per 100 mL, 7 (35%) had a count of 151-350 MPN per 100 mL, and 3 (15%) had a count of less than or equal to 150 MPN per 100 mL. The results indicate that 17 (85%) of the wells’ water was not satisfactory for potable purposes, while 3 (15%) were deemed satisfactory.

Conclusion: Water sources in the studied area were found to be contaminated, with most of the well water sources not meeting satisfactory potable standards. This underscores the importance of raising awareness, implementing routine monitoring, and conducting consistent and periodic examinations of drinking water, as well as disinfection processes, to address this issue.

Drinking water, Escherichia coli, Most probable number, Water quality

Water is one of the important natural resources crucial for mankind’s survival (1). Ensuring safe and wholesome water consumption is paramount to prevent waterborne diseases. According to the WHO factsheet on drinking water, in 2021, people were reliant on surface water, including a total of 844 million people, lacked basic drinking-water services. Globally, at least two billion people utilise a drinking water source contaminated with feces, which can lead to diseases such as diarrhoea, cholera, dysentery, typhoid, and polio (2).

At the national level, a comparative analysis between 2001 and 2011 in terms of absolute figures revealed a significant increase in tap water usage (52.5%), followed by hand pump usage (20.7%), and a substantial decrease in reliance on wells (22%) as a primary drinking water source (3). Providing safe drinking water is one of the most essential amenities that must be accessible to citizens in the modern world. Particularly in rural areas, people depend on well water due to sporadic access to tap water every two to three days (4). According to the 2011 census in India, there were 2,185,276 wells, of which 23,289,867 were uncovered (5). This statisticsunderscores the threat to safe and potable drinking water.

Groundwater serves as a crucial water source for drinking and irrigation, especially for rural residents. However, groundwater monitoring is not only costly and time-consuming but also challenging. Often, contamination can go undetected until it spreads over a wide area. Groundwater quality is evaluated based on physical, chemical, and biological parameters to establish baseline information for future water quality assessments. The present study was conducted to investigate the quality of groundwater by analysing various physical, chemical, and bacteriological characteristics in the Mangaluru district of Karnataka, India. Based on the findings of this study, researchers will be able to educate households regarding the required standards of physical, chemical, and bacterial parameters for wells and encourage them to disinfect their wells at least once a year.

Material and Methods

A cross-sectional study was conducted in the Kinya rural area of Mangaluru Taluka, Dakshina Kannada District, Karnataka, India, between July and August 2019. The aim of this investigation was to assess the physical, chemical, and microbiological qualities of wells and well water in the field practice area of Mangaluru, Karnataka. This pilot project was a time-bound study, and all wells available in the study area were conveniently included, totaling twenty wells from rural areas. Ethical clearance was obtained from the Yenepoya Ethics Committee- 1, YEC: 1/224/2019, protocol number 2019/153. Informed consent was obtained from each respondent before data collection commenced.

Inclusion criteria: The dug and ring residential and government wells used by residents for drinking and domestic purposes.

Exclusion criteria: The locked households, bore wells, step wells, dry wells, and those who declined to participate in the study.

Procedure

Municipal water sources or water from stored containers were not included in the analysis. All wells within the 12 square km area were selected for the study. Confidentiality was maintained by not using names and keeping questionnaires anonymous. All well owners consented to be part of the study and allowed for water collection from their respective wells.

Method of testing/analysis of water: The microbial quality of the water samples was assessed based on WHO guidelines (6). The testing of the water samples was conducted according to standard operating procedures (7) in the pre-analytical, analytical, and post-analytical phases. As a quality control measure, duplicate sample testing was performed.

In the pre-analytical phase, clean, heat-sterilised bottles with a capacity of 500 mL were used for water collection. A suitable length of string was attached to the sampling bottle (7). The bottle was opened and lowered into the well, ensuring complete immersion in the water without touching the sides of the well or disturbing any sediment. After filling the bottle, it was removed by rewinding the string. The colour and odour of the water were noted and documented by two researchers from the team. Approximately, 20-30 mL of water was discarded to create sufficient airspace for shaking before analysis to achieve a homogeneous dispersion of the bacteria. Following collection, the bottles were labeled with complete details, including the water source, sample site, address, date and time of collection, and delivered (within 2 hours) to the laboratory in a light-proof insulated box containing ice packs.

The analytical phase began when the specimens were logged into the laboratory for diagnostic and testing procedures. The water samples were processed using the multiple fermentation tube method to determine the presumptive MPN of coliforms based on standard methods (8). Suspensions from positive tubes were sub-cultured on MacConkey agar and incubated at 37°C for 24-48 hours. The resulting colonies were identified following standard operating procedures (9). The culture media underwent sterility and performance evaluations before inoculation of the samples (10),(11). To ensure accurate results, all aspects of the laboratories operations were optimised to maintain reliability. Capturing high-quality images of agar plates required costly commercial apparatus, which was not utilised.

The post-analytical phase is the final phase, involving the reporting of the final results. All these steps and precautions were implemented at the water testing laboratory in Mangaluru, Karnataka, India.

The collected data and reports were analysed using descriptive statistics and are presented in frequency and percentages.

Results

The water from all 20 (100%) wells was colourless, meeting the WHO standards. The water was odourless in all 20 (100%) sources. Information regarding the age of the well and chlorination practices was collected to gain an understanding of the maintenance and condition of the wells. Among the wells, 10 (50%) were over five years old, 40% were between three to five years old, and 10% were between zero to two years old. Additionally, 17 (85%) of the wells had never been chlorinated. Most of the well water (85%) had a pH level ≤7, while 3 (15%) of the well water samples had a pH level >7.

Escherichia coli bacteria were present in the majority of the well water samples, with 17 (85%) of the wells testing positive for its presence. No other organisms, such as Salmonella, Staphylococcus, Enterococcus, or Vibrio parahaemolyticus, were found during testing.

(Table/Fig 1) indicates that 10 (50%) of the well water samples had a 351-550 MPN (MPN of bacteria) count per 100 mL, 7 (35%) had a 151-350 MPN count per 100 mL of water, and 3 (15%) had a ≤150 MPN count per 100 mL of water.

(Table/Fig 2) indicates that 17 (85%) of the well waters were not satisfactory for potable purposes.

Discussion

Natural water is never completely pure. During precipitation, water passes over and through the ground, acquiring a wide variety of dissolved or suspended impurities that profoundly affect its usefulness (12). Understanding the three types of water quality parameters-physical, chemical, and biological is when wanting to treat water and remove the many contaminants that can be found in water. In the present study, the physical parameters of the wells and well water included the age of the wells, chlorination of the wells, colour, and odour of the water. The results showed that the mean age of the wells was five years, and the majority (85%) of the wells were never chlorinated. The colour of all 20 (100%) samples of well water met WHO standards, and the water was odourless in all 20 (100%) sources.

Colour and odour matched with an earlier study on the assessment of groundwater quality for potability in South-west Karnataka, India (13). Smelly water indicates contamination with organic substances, such as protein. The smell of rancid water is usually caused by algae, fungi, and so on (14). In this study, it was found that the water was odourless. Some of the primary odour sources are hydrogen sulfide and organic compounds produced by anaerobic decomposition. Smell, taste, and colour can be parameters that indicate water is in a polluted condition (15). The finding of acceptable colour and odour could have resulted in the majority of wells not being chlorinated and wrongly considered fit for use by the community.

The pH measurement reflects the acidity or alkalinity of the water sources, which can produce sour or alkaline tastes. In this study, most of the well water (85%) had a pH level of ≤7, while 17% of the well water had a pH level >7. Another study conducted in Mangaluru found that the pH ranged between 6.5-8.5 (16). Yet another study on the physical, chemical, and bacteriological quality of two water sources revealed pH values ranging from a minimum of 7.06 to a maximum of 8.08. This situation is favourable for intense microbial proliferation. The parameter fell within the permissible limit (6.5-8.5), indicating that the water quality can be considered safe for domestic and agricultural uses (17).

Assessing the bacteriological quality of drinking water is a crucial parameter to consider in water quality monitoring. The prevalence of pathogens in drinking water indicates potential sources of human and animal waste. The presence of Escherichia coli (E. coli) in water strongly indicates recent sewage or animal waste (fecal) contamination. The presence of E. coli in 85% of the wells in the current study is significantly higher compared to another study from Mangaluru, which showed that the majority (92.5%) of water sources were contaminated with coliforms (10). Yet another study reported that all water samples tested positive for E. coli (18). This is consistent with a study carried out on E. coli contamination of water for human consumption and its associated factors in Peru, which found that approximately 1 in 4 households had E. coli in their water supplies for human consumption at the time of sampling (19).

This study found that 10 (50%) of the well water samples had a 351-550 MPN of bacteria count per 100 mL, 7 (35%) had a 151-350 MPN count per 100 mL of water, and 3 (15%) had a ≤150 MPN count per 100 mL of water. It indicates that 85% of the wells’ water was not satisfactory for potable purposes, while 15% were satisfactory for potable purposes (13). The MPN of E. coli was also similar to the coliform count (20). Similar results were obtained in a study conducted in South-west Coastal India, where out of 100 water samples, eighty samples tested positive for the growth of E. coli, and a total of 105 coliform isolates were grown in culture (21). The MPN numbers were noted to be >100 for over 50% of all the samples (n=56), thus making the water unsatisfactory for drinking purposes (20).

The study has significant implications in the public health domain, considering the fact that the district is economically and educationally advanced compared to other regions of the state and country. The selected study setting, although rural, is closer to the township of Ullar Taluka headquarters and has a potable water supply by the panchayat for each household. It is surprising to note that despite having free water connections provided by the panchayat, people still use well water for drinking and cooking purposes, while tap water is used for other domestic purposes. This necessitates public health educational interventions on a large scale so that people can change their attitudes and practices and accept safe water sources. Community-level workers and health professionals need to identify the concerns of the community regarding tap water and ensure the treatment of well water with chlorination as per prescribed standards. Well waters needs to be periodically tested following standard guidelines.

Limitation(s)

The study has limited generalizability as it covered a small specified community area covering 12 sq km with a population of 2000-2400. This study highlights only the E. coli contamination of well water in rural areas. More extensive, larger studies are needed to find the sources and exposure of fecal contamination and to identify effective interventions.

Conclusion

Although most households in this rural study area use well water for their daily needs and many of them share the wells, it is surprising to note that although all the well water was colourless and odourless as per standards of potable drinking water, 85% of water samples are contaminated with E. coli and not potable for use. Routine monitoring, consistent and periodic examination of drinking water, and disinfection processes should be done to solve this problem and thereby prevent outbreaks of diseases. Community health professionals, including nurses, have a key role in creating awareness to decrease the occurrence of waterborne diseases.

Acknowledgement

The authors acknowledge the contribution of households of the rural area of Mangaluru.

DOI and Others

DOI: 10.7860/JCDR/2024/69793.19653

Date of Submission: Jan 26, 2024
Date of Peer Review: Feb 24, 2024
Date of Acceptance: May 07, 2024
Date of Publishing: Jul 01, 2024

AUTHOR DECLARATION:
• Financial or Other Competing Interests: None
• Was Ethics Committee Approval obtained for this study? Yes
• Was informed consent obtained from the subjects involved in the study? Yes
• For any images presented appropriate consent has been obtained from the subjects. NA

PLAGIARISM CHECKING METHODS:
• Plagiarism X-checker: Jan 26, 2024
• Manual Googling: Feb 26, 2024
• iThenticate Software: May 06, 2024 (11%)

ETYMOLOGY: Author Origin

EMENDATIONS: 7