Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level

Tesfaye Soressa Kiltu

doi:doi:10.11648/j.ajasr.20251101.12

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Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level

Tesfaye Soressa Kiltu^*

Published in American Journal of Applied Scientific Research (Volume 11, Issue 1)

Received: 12 December 2024 Accepted: 31 December 2024 Published: 21 January 2025

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Abstract

This research was carried out in Mendi town to evaluate the quality of drinking water from the source to household containers. The physico-chemical parameters were analyzed using HACH HQ440d multi meter and portable digital spectrophotometer (DR/2400). Bacteriological parameters were analyzed using membrane filtration technique. The temperature measurements of the water samples were found to be between 21.8°C and 23.7°C which was higher than the WHO standard limit and the PH records were between 7.23 and 7.84 and were compliant with WHO and National standard limit. The maximum turbidity record of the water samples was 3.40 NTU all the turbidity records were in conformity with WHO and National standards. Total dissolved solids (TDS) and electrical conductivity (EC) measurements of the samples were between 122 mg/l and 133 mg/l respectively. All the TDS records were compliant with WHO and National standards. Iron concentration was found to be above the WHO and national standard limit for the samples from boreholes (0.45 to 0.53 mg/l) whereas 94.4% of the samples from reservoirs, household taps and household containers had iron concentrations compliant with the WHO and national standard limits. Manganese, nitrate, fluoride and total hardness records were 0.00-0.14 mg/l, 0.00-1.70 mg/l, 0.00-0.04 mg/l and 96.67-108 mg/l respectively and were found to be compliant with WHO and National standards. Samples from boreholes and reservoirs had Total coliforms (TC) counts of 1 CFU/100 ml to 2 CFU/100 ml with no faecal coliforms (FC) detected whereas samples from tap waters had TC counts ranging from 1 CFU/100 ml to 18 CFU/100 ml with no FC detected. Samples from household containers had FC counts ranging from 5 CFU/100 ml to 32 CFU/100 ml and FC counts ranging from 3 CFU/100 ml to 11 CFU/100 ml. All the water samples tested were positive for TC ranging from 1.00 to 32.00 CFU/100 ml. Regarding FC records, the samples from boreholes, water reservoirs and household taps were negative for FC counts whereas 25% of the samples from household containers had FC counts ranging from 3 to 11 CFU/100 ml. All the samples tested did not satisfy the World Health Organization (WHO) and National standard limits of 0 CFU/100 ml for TC counts but all the samples from boreholes, water reservoirs and household taps and 75% of the samples from household containers satisfy the WHO and National standards of 0 CFU/100 ml based on faecal Coliform (FC) counts. The detection of TC in all water samples and FC in some of the household containers samples can be attributable to lack of adequate disinfection of the water, lack of regular supervision of the system, absence of proper water management and lack of safe water storage and handling practices.

Published in	American Journal of Applied Scientific Research (Volume 11, Issue 1)
DOI	10.11648/j.ajasr.20251101.12
Page(s)	1-18
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2025. Published by Science Publishing Group

Keywords

Physico-chemical, Bacteriological, Sample, Borehole, Disinfection

1. Introduction

1.1. Background

Water is the most abundant substance in nature and vital for life activities. The major water sources for use are surface water bodies such as rivers and lakes, and underground aquifers and pore spaces down the water table

[1]

. Approximately 97% of the total water is found in oceans, which is not appropriate for drinking, and only 3% is considered as fresh water, out of which 2.97% is found as glaciers and ice caps. Only the remaining little portion, 0.03%, is obtainable as surface and ground water for human use

[2]

. Water derived from these sources is not necessarily pure since it may contain dissolved inorganic and organic substances, living organisms (viruses, bacteria, etc).

Having safe drinking water and basic sanitation is a human need and right for every man, woman and child. Studies showed that access to safe drinking water is a fundamental human need and, therefore, a basic human right

[3]

. Safe water is a precondition for health and development and a basic human right, yet it is still denied to hundreds of millions of people throughout the developing world

[4]

. People need clean water and sanitation to maintain their health and dignity. Having better water and sanitation is essential in breaking the cycle of poverty since it improves people’s health, strength to work, and ability go to school

[5]

In order to be used as healthful fluid for human consumption, water must be free from organisms that are capable of causing diseases and from minerals and organic substances that could produce adverse physiological effects

[6]

Different research results also indicate that drinking water should be aesthetically acceptable; it should be free from apparent turbidity, color, and odor and from any objectionable taste

[7]

. Drinking water should also have a reasonable temperature. Water meeting these requirements is termed as potable water. A potable water is one that is safe to drink, pleasant to taste, and usable for domestic purposes

[8]

. Worldwide, more than 80% of the human diseases are caused by unsafe water supply and inadequate sanitation practices

[9]

. It is also known that more than 88% of the global diarrheal diseases are water-borne infections caused by drinking unsafe and dirty water

[3]

. Research findings identified that, every year, more people die from the consequences of unsafe water than from all forms of violence, including war

[10]

. Deteriorating water quality threatens the global gains made in improving access to drinking water. According to UNICEF (2008), From 1990 to 2004 more than 1.2 billion people gained access to improved water sources, but not all of these new sources are necessarily safe

[11]

. Unsafe handling and storage of water compounds the problem.

The chemical contamination of water supplies, both naturally occurring and from pollution is a very serious problem that threatens the health of hundreds of millions of people. But more serious still is the microbiological contamination of drinking water supplies, especially from human faeces. Faecal contamination of drinking water is a major contributor to diarrheal disease, which kills millions of children every year

[12]

. Moreover, approximately 3.7% of deaths and disability-adjusted-life-years worldwide are attributable to unsafe water, poor sanitation and hygiene

[13]

Different researches indicate that as populations, pollution and environmental degradation increase, so will the chemical and microbiological contamination of water supplies

[11]

. This shows that, despite the worldwide efforts of delivering safe drinking water, the transmission of water-borne diseases is still a matter of major concern. Thus, drinking water quality is becoming an issue of global human health concern, principally due to water contamination with pathogens and potentially toxic chemicals. Water quality reflects the composition of water as affected by natural causes and man’s activities expressed in terms of measurable quantities and related to intended water use

[14]

. This research aims to evaluate the physico-chemical and bacteriological quality of drinking water being supplied to Mendi town.

1.2. Objectives of the Study

1.2.1. General Objective

The main objective of this study was to evaluate the quality of drinking water of Mendi town starting from source to household containers.

1.2.2. Specific Objectives

1. To determine the physico-chemical parameters of Mendi town drinking water at different points,

2. To determine the bacteriological parameters of the water samples using total Coliforms and faecal Coliforms as indicator organisms,

3. To determine the quality level of the water in relation to WHO and National drinking water standards and draw necessary conclusions and recommendations,

2. Materials and Methods

2.1. Description of the Study Area

This study was conducted in Mendi town which is found in West Wollega, Ethiopia, at a distance of about 590 Km from Addis Ababa. This town has a latitude and a longitude of 9^o48’N and 35^o6’E and an elevation of 1538 meters above sea level. Administratively, the town is divided into four local administrations (kebeles). Based on figures from CSA (Central Statistics Agency) report of 2007, Mendi town has an estimated total population of 18,020 of which 9,199 are men and 8,821 are women.

2.2. Research Design

A cross-sectional study was carried out to assess the bacteriological and physico-chemical quality of the water samples from the source, the reservoirs, the household water taps, and household containers. The minimum number of sample size recommended is one per 5,000 population for piped drinking water if the population served is between 5,000 and 100,000

[15]

Accordingly, since the population of Mendi town is 18,020 according to CSA report of 2007, the recommended number of samples to be collected from household taps will be four samples (1 sample per 5,000 populations and for household containers it will be four samples in a similar manner. However, to make the samples taken to be more representative, the sample sizes were doubled, i.e., eight samples from household taps and eight samples from household containers were collected.

Thus, water samples were collected from boreholes (n=2), water reservoirs (n=2), household water taps (n=8), household water containers (n=8) in three rounds for physico-chemical and bacteriological drinking water quality determination. The results of physico-chemical and bacteriological water quality parameters were then compared with the standards set by the WHO

[9]

and the Compulsory Ethiopian Standard of 2013 which cancels and replaces ES 261: 2001.

2.3. Sampling Frequency

A total of 20 sampling points (sites) were selected which includes two sampling sites from boreholes (water wells), two sampling sites from water reservoirs, eight sampling sites from household taps, and eight sampling sites from household containers. Samples were collected from the sampling sites following the appropriate procedures and triplicate samples were taken from all the twenty sampling sites. Accordingly, sixty (60) water samples were collected and analyzed from the twenty sampling locations in three rounds. In general, water samples were collected from boreholes, water reservoirs, household taps, and household water containers in three rounds.

2.4. Sampling Procedures and Techniques

The method of sample collection from each sampling location was according to WHO guidelines for drinking water quality assessment

[16]

and American public health association guideline

[17]

. Samples were taken from locations that are representative of the water distribution system (the sources, reservoirs, household taps and household containers). Systematic random sampling method was used to determine representative sampling points. The selected households for household container water sampling were the ones that use water from the water supply system for drinking and other domestic purposes.

For the bacteriological analysis, water samples were collected from all the selected sampling sites in pre-sterilized plastic bags and immediately tested on the site with portable bacteriological analysis equipment (ELE Paqualab 25). From each sampling point, 200 ml samples were taken for analysis. Regarding the physicochemical analysis, samples were collected in 2000 ml plastic containers which were properly washed and rinsed and immediately analyzed for each sampling site using portable physico-chemical analysis equipment (HQ440d multi and DR/2400 spectrophotometer) for all the physical and chemical parameters selected to be tested.

2.5. Methods of Sample Analysis

2.5.1. Physico-Chemical Analysis

The water samples were collected in properly washed and rinsed plastic bottles. Parameters such as PH, Temperature, Total Dissolved Solids (TDS), and Electrical Conductivity (EC) were measured on site using HACH HQ440d multi parameter portable meter or PH/Conductivity/TDS/Temperature meter having the respective electrodes to measure each of the parameters. The meter connects with smart probes that automatically recognize the testing parameter, calibration history, and method settings to minimize errors and setup time. The PH calibration of the meter was done using standard buffers of PH-4 and PH-10 prior to PH measurement and the electrodes were rinsed with distilled water from one sample to another following the instruction manual.

For conductivity, the meter was calibrated using the recommended standard calibration solution range and the probe was thoroughly rinsed with distilled water from one sample to another following the HACH HQ440d User Manual instructions

[18]

. Each probe was calibrated using the recommended calibration solutions to maintain the highest level of accuracy. The probes of the instrument were immersed in the sample of the water to be tested and the measured parameters were displayed on the LCD screen of the instrument and carefully recorded. With regard to turbidity, it was analyzed colorometrically using portable digital spectrophotometer (DR/2400) following HACH instructions.

The selected chemical parameters such as Phosphate, nitrate, fluoride, total iron, and manganese were tested on the site using portable digital spectrophotometer (DR/2400) following HACH instructions

[19]

. To analyze the parameters, the appropriate reagent chemicals for each of the parameters to be tested were dissolved in 10 ml of water sample in a cylindrical cell and allowed to react. Color develops with intensity proportional to the amount of the target parameter to be measured. Each parameter has a unique maximum absorption wave length at which the spectrophotometer is adjusted. Light was allowed to pass through the sample cell so that light is absorbed at the required wave length. The amount of light absorbed is directly proportional to the concentration of absorbing compounds or parameters in the sample, so concentrations of the compounds in the solution can be determined. The results were displayed on the LCD screen as mg/l of the parameter under analysis in proportion to the amount of light absorbed at that particular wave length.

Total hardness was determined by titration using digital titrator/burette. In the total hardness test procedure, the water sample was first buffered using an organic amine and its salts to a PH of 10. An organic dye, calmagite, was added as the indicator for the test. The organic dye reacts with calcium and magnesium ions to give a red-colored complex. EDTA (ethylenediaminetetraacetic acid) was added as a titrant. The EDTA reacts with all free calcium, magnesium, barium and strontium in the sample. At the end point of the titration, when free magnesium and calcium ions are no longer available, the indicator changed from red to blue and the number of digits on the counter was recorded and multiplied by digit multiplier to calculate the concentration. Since the water supply system is not using chlorination, free residual chlorine test was not carried out.

2.5.2. Bacteriological Analysis

For bacteriological analysis of the water samples, the samples were collected from all the sample collection locations using pre-sterilized plastic bags of 200 ml volume after wearing latex gloves on hand. The samples were analyzed using membrane filtration (MF) method for bacteriological water quality to determine the presence of total Coliforms (TC) and faecal Coliforms (FC) and to determine the degree of contamination

[6, 17]

. One hundred milliliter of water sample for each test was filtered through a sterile cellulose membrane filter with a pore size of 0.45 µm to retain the indicator bacteria as specified in standard methods

[17]

The filtration apparatus was sterilized before use and re-sterilized between samples using methanol when analyzing water samples

[20]

. The cellulose membrane filter was transferred from filtration apparatus to a sterilized aluminum Petri-dish containing absorbent pad soaked with m-Coli Blue24 Broth which has been used as a medium to grow total Coliforms (TC) and feacal Coliform (FC). This media is a ready-to-use media that eliminates measuring, mixing, and autoclaving steps necessary to prepare dehydrated media. Hach’s m-ColiBlue24 Broth media helps to simultaneously detect and identify both total coliforms and Escherichia coli (E. coli). This media, m-ColiBlue24Broth, makes it easy to differentiate between Coliforms and E. col: E. coli is blue; other Coliforms are red; total Coliforms are the sum of the two.

The Petri-dish were then incubated using ELE Paqualab 25 field incubator by adjusting the temperature at 37°C and 44.5°C for the growth of total Coliforms and faecal Coliforms/E-Coli respectively for 24 hours. The filters were examined 24 hours later to count the grown colonies to determine the TC and FC in the samples. At 37°C TC/E-Coli were grown as blue colonies whereas other Coliforms were grown as red colonies and the sum of the two were the results for total Coliforms. To further determine TC/E-Coli the results were examined at 44.5°C to count the blue colonies as other Coliforms do not form colonies or grow at this temperature.

2.6. Methods of Data Analysis

A computer program was used to analyze tabulated data using Microsoft Excel version 2010 and SPSS version 20. Descriptive statistics like percentage, mean and range were used to describe the findings. Pearson’s correlation (r) values were determined using SPSS version 20 to show the correlation between different physico-chemical and bacteriological parameters. Analysis of variance (ANOVA) at 1% and 5% level of significance was also used to compare mean values of the bacteriological and physico-chemical parameters.

2.7. Validity of the Data and Quality Assurance

The quality of the analysis and the recorded data were carefully assured by the researcher. All the necessary reagents and testing equipment were made ready prior to the field work. The water samples were carefully collected and immediately tested on the site according to the standard methods. The analysis results were carefully recorded and checked. The results were then compared with WHO and national drinking water quality standards to draw conclusions and give recommendations.

3. Results and Discussion

3.1. Physico-Chemical Characteristics of the Water from Boreholes & Water Reservoirs

The physico-chemical characteristics of the water samples collected from boreholes and reservoirs are shown in Table 1.

Table 1. Mean values of physico-chemical parameters of samples from boreholes and reservoirs.

Parameter	Mean Values of Sampling Sites
Parameter	BH-1	BH-2	WR-1	WR-2	P-Value	WHO Limit	National Standard
Temp (°C)	23.67±0.09	23.70±0.06	22.43±0.18	21.87±0.09	0.000*	<15
PH	7.23±0.09	7.37±0.12	7.80±0.00	7.81±0.06	0.002*	6.5-8.5	6.5-8.5
Turbidity (NTU)	0.00±0.00	0.00±0.00	1.27±0.15	1.27±0.13	0.000*	<5	<5
TDS (mg/l)	122±0.44	133±0.44	127±0.44	127±0.60	0.000*	<600	1000
EC (μS/cm)	244.3±0.88	265.3±0.88	253.3±0.88	253.3±1.20	0.000*
Total Iron (mg/l)	0.53±0.01	0.45±0.01	0.29±0.01	0.29±0.01	0.000*	0.3	0.3
Manganese (mg/l)	0.12±0.01	0.14±0.02	0.07±0.04	0.08±0.04	0.339*	0.4	0.5
Nitrate (mg/l)	1.34±0.01	0.00±0.00	1.30±0.06	1.17±0.03	0.000*	50	50
Phosphate (mg/l)	2.70±0.06	1.50±0.29	2.37±0.09	2.20±0.06	0.004*	-	-
Fluoride (mg/l)	0.00±0.00	0.04±0.01	0.02±0.01	0.02±0.00	0.002*	<1.5	<1.5
Total Hardness (mg/l CaCO₃)	98.00±1.16	108.00±1.16	101.00±0.58	100.00±0.58	0.000*	300	300

*The mean difference is significant at the 0.01 level

BH-1, Borehole-1; BH-2, Borehole-2; WR-1, Water Reservoir-1; WR-2, Water Reser-2

3.1.1. Temperature

The temperatures of the four sampling pints (BH-1, BH-2, WR-1, and WR-2) were found to be 23.67, 23.70, 22.43 and 21.87°C for borehole-1, borehole-2, and water reservoir-1and water reservoir-2 respectively (Table 1) with the average value of 22.9°C and with significant difference amongst the mean values of the sampling points (p=0.000). There was no significant difference between the mean values of the temperature records of the two boreholes (p=0.838) since they were found almost at the same elevation and within the same location. The temperature records of the samples from the two reservoirs showed statistically significant difference (p=0.001) and this was possibly due to the difference in the exposure of the reservoirs to factors affecting temperature such as direct exposure to sun light. The results for the temperature were above the permissible limit of 15°C recommended by World Health Organization and all the temperature records of the sampling points were significantly different from WHO maximum permissible limit (p=0.000). The analysis data showed that the highest temperature of 23.70 and the lowest temperature of 21.87°C were recorded from BH-2 and WR-2 respectively (Table 1).

The climatic condition of Mendi town is responsible for the high temperature values since the elevation of Mendi town lies within the range of 1,566 m – 1,739 m a.s.l. which is approaching to the upper elevation limit of the warm semi-arid climatic zone of the country. The relatively higher temperature of the water samples from BH- 1 and BH-2 was due to the relatively low elevation of the location of the boreholes and the relatively lower temperature of the samples from WR-1 and WR-2 were due to the relatively higher elevation of the locations of the reservoirs as reservoirs were situated at higher elevations to allow flow of the water by gravity.

3.1.2. PH

The PH of the four sampling points showed PH records of 7.23, 7.37, 7.80 and 7.81 for BH-1, BH-2, WR-1 and WR-2 respectively with the average value of 7.55 with significant difference amongst the mean values of the four sampling points (p=0.002). There was no significant difference amongst the mean values of the two boreholes (p=0.273) and between the mean values of the two reservoirs (p=0.909). The PH values of the four sampling points were found to be within the permissible limits of WHO and National standard which is between 6.5-8.5

[9]

The overall PH records from all the four sampling points indicated that the water is slightly basic. The slightly higher PH values of WR-1 and WR-2 when compared to the results for BH-1 and BH-2 is due to the iron content of the water. When groundwater having iron is pumped up to the reservoirs it gets into contact with air (O2) which enters the solutions and starts the oxidation process that releases carbon dioxide (CO₂) from the groundwater to the atmosphere and when this happens, the PH values are increased

[21]

3.1.3. Turbidity

The turbidity of the water samples from the four sampling points were found to be 0 NTU for both boreholes (borehole-1 and 2) and 1.27 NTU for both samples from water reservoir-1 and water reservoir-2 with significant difference amongst the mean values of the four sampling points (p=0.000). There was no significant difference amongst the mean values of the two boreholes (p=1.000) and amongst the mean values of the two reservoirs (p=1.000).The results were found to be compliant with the standards set by WHO and ESA (Ethiopian Standards Agency for turbidity which is less than 5 NTU.

The lower turbidity of the water from the water wells indicated the absence of inert clay or chalk particles in the wells and it also indicated that the water wells were well protected from the entrance of foreign materials and surface runoffs. Actually, the water wells were delineated and well protected by the Town’s Water Supply Service Office. The other reason for no turbidity of the water samples from the wells is that ground waters are most of the time clear because the turbidity has been filtered out by slow movement and infiltration of the rain water through the soil and rock formations

[22]

The slightly higher turbidity of the waters from the reservoirs when compared to the water samples from the wells can be due to the precipitation of non-soluble iron oxides as the water pumped from the source contains the soluble Fe 2+ which can easily be converted to insoluble Fe 3+ when exposed to oxygen and this increases turbidity to some extent. It can also be due to the presence of suspended, colloidal and silt materials and this is associated with lack of timely and regularly cleaning and washing of the water reservoirs. Generally, the turbidities of the samples from the sampling locations were compliant with the maximum permissible limit of WHO and National standard and make the water to be aesthetically acceptable by the consumers.

3.1.4. TDS and EC

For the samples from the four sampling points, the results showed TDS values of 122, 133, 127 and 127 mg/l for BH-1, BH-2, WR-1 and WR-2 respectively and EC values of 244.3, 265.3, 253.3 1nd 253.3 μS/cm for BH-1, BH-2, WR-1 and WR-2 respectively with significant difference amongst the mean values of the sampling points for both TDS and EC (p=0.000). There was significant difference between the mean values of TDS and EC for the two boreholes (p=0.000) and this can be attributable to the type of rock formations through which the water infiltrates. However, there was no significant difference between the mean values of TDS and EC for the two reservoirs (p=1.000) since the water pumped from both wells was conveyed to the two reservoirs that were interconnected.

The average value of TDS for the samples from the four sampling locations was 127.25 mg/l and the average value for EC was 254 μS/cm. TDS and EC values showed the same pattern from the different sampling locations and EC value increased with increasing value of TDS.

The palatability of water with a total dissolved solids (TDS) level of less than about 600 mg/l is generally considered to be good; drinking-water becomes significantly and increasingly unpalatable at TDS levels greater than about 1000 mg/l. Therefore, the TDS and EC values of the samples from the boreholes and reservoirs showed that the water is generally considered to be good for drinking and will not cause excessive scaling in water pipes, heaters, boilers and household appliances

[6]

3.1.5. Iron and Manganese

For the samples that were collected from BH-1, BH-2, WR-1 and WR-2, the tested results showed the iron concentrations of 0.53, 0.45, 0.29, and 0.29 mg/l respectively with significant difference amongst the mean values (p=0.000). There was significant difference amongst the mean values of iron for the two boreholes (p=0.000) and this can be due to the difference in the rock formations through which the water seeps down to the aquifers. The mean values of iron for the two boreholes were also significantly different from WHO and national standard (p=0.000).

The mean values of iron records for WR-1 and WR-2 showed no statistically significant difference from WHO and national standard with P-values being 0.319 and 0.502 respectively. In addition, there was no significant difference amongst the mean values of iron for the two reservoirs (p=0.784) as the water was pumped to the reservoirs that were inter-connected. The iron concentrations of the boreholes (BH-1 and BH-2) were higher than the WHO limit and the National maximum permissible limit set by ESA, which is 0.3 mg/l.

The higher concentration of iron of the water samples when compared to the WHO and a National maximum limit is attributable to the dissolving of iron when the ground water seeps through iron-bearing rock formations which are common in the area. Iron is very common in the earth, especially in Western part of Ethiopia, and water containing carbon dioxide which seeps through iron-bearing material dissolves iron to from ferrous bicarbonate, Fe (HCO₃)₂ which as a result increases the iron concentration of the ground water

[8]

The iron concentrations of the samples from WR-1 and WR-2 were lower than the iron concentration of the samples from the boreholes and were also lower than the WHO and the National maximum permissible limit of 0.3 mg/l. This is because the most dominant form of dissolved iron in the ground water is the soluble Fe⁺²which is mainly found under the PH range of 5 to 8 and when groundwater is pumped up to the surface it gets into contact with air (O₂) which enters the water and starts the oxidation process. When this happens, the soluble Fe²⁺is changed into the insoluble Fe 3+ which is precipitated as a rusty sediment or Fe (OH)₃ and this reduces the concentration of iron in the water samples from WR-1 and WR-2.

Regarding the manganese results of the water samples, the test result showed manganese concentrations of 0.12, 0.14, 0.07 and 0.08 mg/l for BH-1, BH-2, WR-1 and WR-2 respectively with no significant difference amongst the mean values of the sampling points (p=0.339). The mean values of manganese for the two boreholes did not show significant difference (p=0.631) and in the same manner the mean values of manganese records of the two reservoirs did not show significant difference (p=0.923). These results were found to be less than the WHO (2011) and ESA (2013) recommended limits of 0.4 mg/l and 0.5 mg/l respectively.

Manganese is naturally occurring in many surface water and groundwater sources, particularly in anaerobic or low oxidation conditions, and this is the most important source for drinking-water and the presence of manganese in the tested water samples is compliant with this fact. The slightly lower manganese concentrations of the water samples from WR-1 and WR-2 when compared to the samples from the boreholes (water wells) was due to the oxidation of the soluble Mn⁺² to insoluble Mn+4. As the groundwater is pumped up to the surface it gets into contact with air (O₂) which enters the water and starts the oxidation process to change the soluble Mn⁺² to the insoluble Mn⁺⁴ and thus reducing the manganese concentration detected in the water samples.

3.1.6. Nitrate

The nitrate results for the water samples from BH-1, BH-2, WR-1 and WR-2 were 1.34, 0.00, 1.30 and 1.17 mg/l respectively with statistically significant difference amongst the mean values of the sampling points (p=0.000). The nitrate records were by far lower than the WHO and ESA maximum permissible limits of 50 mg/l. There was significant difference between the mean values of the two boreholes (p=0.000). The relatively higher concentration of nitrate for BH-1 can be attributable to the consequence of leaching of nitrate from natural vegetation

[9]

. The water wells that are being used as the drinking water sources of Mendi town have ground water protection area which is delineated and being protected by the Town’s Water Supply Office and this avoids human and animal interferences and restricts any agricultural activity in the ground water wells area.

Therefore, the probability of pollution of the water wells by nitrate from agricultural activity, waste- water disposal, human and animal excreta including septic tank is highly minimized through the buffer zone that is being well protected and the nitrate test results of the samples from the sampling points confirmed this reality.

3.1.7. Phosphate

The phosphate results of the samples from boreholes and water reservoirs for this study were 2.7, 1.50, 2.37 and 2.20 mg/l for BH-1, BH-2, WR-1 and WR-2 respectively with statistically significant difference amongst the mean values of the sampling points (p=0.004). There was significant difference amongst the mean values of the two boreholes (p=0.000) but the mean values of the two reservoirs did not show significant difference (p=0.374) as the water is pumped from the two boreholes to the inter-connected reservoirs. Although there is no guideline value for phosphate content in drinking water, phosphate levels greater than 1.0 mg/l could interfere and induce coagulation in water treatment

[23]

3.1.8. Fluoride

The results of the samples from boreholes and water reservoirs for this study showed fluoride results of 0.00, 0.04, 0.02, and 0.023 mg/l for BH-1, BH-2, WR-1 and WR-2 respectively with statistically significant difference amongst the mean values of the sampling points (p=0.002). There was significant difference between the mean values of the two borehole (p=0.000) which can be due to the type of rocks through which the water infiltrates. However, the mean values for fluoride from the two reservoirs did not show significant difference (p=0.525) and were also not significantly different from the records of BH-2. The results were compliant with the WHO and ESA recommended limits of <1.5 mg/l.

In groundwater, concentrations of fluoride vary with the type of rock through which the water flows (WHO, 2011) and the result for this study showed that the type of rock through which the water for which the sample was tested seeps is almost fluoride free. There is epidemiological evidence that concentrations above 1.5 mg/l of fluoride carry an increasing risk of dental fluorosis and that progressively higher concentrations lead to increasing risks of skeletal fluorosis. Therefore, the results of the current study showed that the water being supplied to Mendi town is safe with regard to risks from fluoride.

3.1.9. Total Hardness

The results of the water samples from boreholes and reservoirs for this research showed total hardness results of 98, 108, 101 and 100 mg/l as CaCO₃ for BH-1, BH-2, WR-1 and WR-2 respectively with average value of 101.75 mg/l and with statistically significant difference amongst the mean values of the sampling points (p=0.000). The mean values of total hardness for the two boreholes showed significant difference (p=0.000) which can be attributable to the type of rock through which the water seeps. However, the mean values of total hardness records from the two reservoirs did not show significant difference (p=0.361) as the water was pumped to inter-connected reservoirs. The results were compliant with the WHO and national maximum limit of 300 mg/l.

Water with hardness of 0-50 mg/l is categorized as soft water and water with hardness of 50- 150 mg/l is classified as moderately soft water. Similarly, water having hardness measures of 150- 300 mg/l is categorized as hard water and that having hardness measure of more than 300 mg/l is categorized as very hard water. Therefore, the results of hardness measured for this study showed that the samples from boreholes and reservoirs were moderately soft water since the results were 98-101 mg/l.

Depending on the interaction of other factors, such as PH and alkalinity, water with a hardness above approximately 200 mg/l may cause scale deposition in the treatment works, distribution system and pipe work and tanks within buildings

[9]

. It will also result in high soap consumption and subsequent “scum” formation. On heating, hard waters form deposits of calcium carbonate scale. Soft water, but not necessarily cation exchange softened water, with a hardness of less than 100 mg/l may, in contrast, have a low buffering capacity and so be more corrosive for water pipes. Therefore, the results for the water samples tested during the current research showed that the water neither causes corrosion in water pipes nor scale deposition in the distribution system and tanks.

3.2. Bacteriological Quality of the Water from Boreholes & Water Reservoirs

The water samples from the two boreholes (BH-1 and BH-2) and the two reservoirs (WR-1 and WR-2) were tested to determine the presence of indicator organisms or total coliforms and faecal coliforms /E-Coli and to evaluate the bacteriological water quality status of Mendi town water sources. The results are summarized in the following table:

Table 2. Mean values of bacteriological analysis of boreholes and reservoirs samples.

Parameters	Mean Values of Sampling Points				P-Value	WHO Limit	National Limit
Parameters	BH-1	BH-2	WR-1	WR-2	P-Value	WHO Limit	National Limit
TC (CFU/100 ml)	1.00±0.00	1.00±0.00	2.00±0.00	2.00±0.00	0.000*	0	0
FC (CFU/100 ml)	0.00±0.00	0.00±0.00	0.00±0.00	0.00±0.00	1.000*	0	0

*The mean difference is significant at the 0.01 level

TC, Total Coliforms; FC, Faecal Coliforms; CFU, Colony Forming Unit

The results of the water samples for this study showed total coliform (TC) records of 1, 1, 2 and 2 CFU/100 ml for BH-1, BH-2, WR-1 and WR-2 respectively with statistically significant difference between the mean values (p=0.000). There was no significant difference between the mean values of TC counts for both boreholes (p=1.000) and similarly the mean values of TC records from water reservoirs did not show significant difference (p=1.000). The mean values of all the samples showed significant difference from WHO and National standard for TC (p=0.000).

The presence of TC in the water samples was likely because of lack of chlorination of the water both at the wells and at the reservoirs as the water supply system is not using any type of disinfectant to disinfect the supplied water. The presence of total Coliforms in the water samples can also reveal re-growth and possible bio-film formation or contamination through ingress of foreign material, including soil or plants. This usually occurs during different maintenance works when there is no immediate well disinfection after carrying out maintenance activities. The relatively high number of TC in the reservoirs when compared to samples from boreholes was possibly due to lack of regular cleaning and disinfection of the water reservoirs and this increased the level of contamination of the water in the reservoirs as compared to the samples from the boreholes.

Faecal Coliform (FC) was not detected in all the tested water samples from boreholes and reservoirs and the results showed 0 CFU/100 ml of the samples for FC count and the result showed statistically no significant difference with WHO and National standard (p=1.000). Since total Coliform group includes both faecal and environmental species, the absence of faecal Coliforms in the water samples showed that the detected total Coliforms were of environmental species. The TC results for the water samples were not compliant with the WHO and the national standards of 0 CFU per 100 ml but the FC results were compliant with the WHO and national standard limit of 0 cfu/100 ml.

The absence of FC in the water samples showed that both the wells and the reservoirs were free from Coliforms that come from faecal matter and this makes the water microbiologically acceptable as per WHO and ESA guidelines. According to WHO, if the water sample does not contain any faecal/E-Coli count, it is in conformity with WHO guideline. According to ESA, faecl Coliforms/E-Coli must not be detectable per 100 ml of water sample tested. WHO also adds that where community water supplies are un-chlorinated (like the water supply of Mendi town), they will inevitably contain large numbers of total Coliform bacteria, which may be of limited sanitary significance

[15]

It is therefore recommended that the bacteriological classification scheme should be based on thermotolerant (faecal) Coliform bacteria or E. coli. Thus, based on the faecal coliform count of the water samples, the samples from boreholes and water reservoirs satisfied the requirements of WHO and compulsory Ethiopian standard and can be categorized as good for drinking. However, the presence of TC in the water samples needs urgent corrective measures.

Table 3. Pearson’s correlation matrix between major physico-chemical and bacteriological Parameters of samples from boreholes and reservoirs.

Parameter	Temp	PH	Turbidity	TDS	EC	Iron	Nitrate	Hardness	TC
Temp	1
PH	-0.951^*	1
Turbidity	-0.968^*	0.981^*	1
TDS	0.075	0.129	-0.064	1
EC	0.111	0.093	-0.101	0.999^**	1
Iron	0.928	-0.997^**	-0.962^*	-0.21	-0.174	1
Nitrate	-0.485	0.335	0.51	-0.887	-0.903	-0.258	1
Hardness	0.357	-0.146	-0.332	0.958^*	0.967^*	0.064	-0.965^*	1
TC	-0.968^*	0.981^*	1.000^**	-0.064	-0.101	-0.962^*	0.51	-0.332	1

* Correlation is significant at the 0.05 level (2-tailed).q

** Correlation is significant at the 0.01 level (2-tailed).

Results of Pearson’s correlation analysis were presented in table 3. From the correlation matrix it is observed that there was a strong positive correlation between TC and turbidity (r=1.000). There was also a positive correlation between TC and Nitrate (r=0.510). Microorganisms (bacteria, viruses and protozoa) are typically attached to particulates (WHO, 2011) and the positive correlations between FC and turbidity is compliant with this fact. The positive correlation between TC and PH (r=0.981) shows that coliform organisms survive more in alkaline environment than in acidic environment

[24]

On the other hand, the results of this study did not show positive correlation between TC and temperature for the samples from boreholes and reservoirs and thus the difference in the TC count for boreholes and reservoirs was mainly attributable to lack of regular washing and cleaning of the water reservoirs rather than temperature difference. The correlation matrix also showed that there is a positive correlation between EC and TDS (r=0.999) and between EC and total hardness (r=0.967). This result showed that TDS affects both the values of EC and total hardness.

3.3. Physico-Chemical Analysis of Tap Water Samples

The physico-chemical analysis results of the tap water from Mendi town water supply system were summarized in the following table:

Table 4. Mean values of Physico-chemical parameters from tap water samples.

Parameter	Mean Values of Sampling Sites								P-Value
Parameter	HHT1	HHT2	HHT3	HHT4	HHT5	HHT6	HHT7	HHT8	P-Value
Temp (°C)	22.9±0.09	23.6±0.00	22.9±0.06	23.2±0.12	22.8±0.18	22.1±0.06	22.3±0.03	23.23±0.03	0.000*
PH	7.42±0.01	7.37±0.03	7.51±0.04	7.68±0.04	7.50±0.17	7.65±0.02	7.67±0.03	7.71±0.01	0.012*
Turbidity	1.30±0.15	2.83±0.17	3.03±0.03	2.33±0.17	3.40±0.20	1.27±0.09	1.37±0.09	1.27±0.03	0.000*
TDS (mg/l)	128±0.44	129±0.44	129±0.44	126±0.44	127±0.44	129±0.17	128±0.29	128±0.29	0.002*
EC (μS/cm)	256.3±0.88	257.3±0.88	258.3±0.88	252.7±0.88	253.3±0.88	257.7±0.33	256.0±0.58	256.0±0.58	0.001*
Total Iron (mg/l)	0.23±0.02	0.26±0.01	0.27±0.01	0.27±0.01	0.35±0.01	0.25±0.01	0.24±0.01	0.23±0.01	0.000*
Mn (mg/l)	0.06±0.01	0.03±0.01	0.05±0.02	0.05±0.03	0.06±0.01	0.00±0.00	0.01±0.01	0.06±0.01	0.013*
Nitrate (mg/l)	1.07±0.07	1.30±0.06	1.50±0.15	1.17±0.09	1.70±0.10	1.13±0.03	1.03±0.03	1.10±0.06	0.000*
Phosphate (mg/l)	2.40±0.06	2.20±0.06	2.33±0.09	2.30±0.06	2.33±0.12	2.20±0.06	2.37±0.09	2.20±0.06	0.393*
Fluoride (mg/l)	0.02±0.00	0.02±0.01	0.01±0.00	0.03±0.01	0.01±0.00	0.02±0.00	0.02±0.01	0.02±0.01	0.707*
Total Hardness (mg/l CaCO₃)	99.00±0.58	99.00±1.16	98.00±0.58	98.33±0.88	97.67±0.88	98.00±0.58	99.67±0.88	98.00±0.58	0.629*

*The mean difference is significant at the 0.01 level

3.3.1. Temperature

The mean temperature records of the samples from the tap water were within the range of 22.1°C -23.6°C with the average value of 22.87°C with statistically significant difference amongst the mean values (p=0.000). There was no significant difference between the mean values of HHT-6 and HHT-7 (p>0.01) and in the same way no significant difference was observed between the mean values of HHT-1, HHT-3, HHT-4, HHT-5 and HHT-8. There was also no significant difference amongst the mean values of HHT-2, HHT-4 and HHT-8. The highest temperature was recorded at HHT-2 and the lowest was recorded at HHT-6. The mean values of temperature records for all tap water samples were found to be significantly different from WHO maximum permissible limit (p=0.000). The differences in temperatures of tap waters were possibly due to the difference in elevation and the extent to which the pipe in which the water flows is protected from sun light. Most of the temperature records for the samples from tap water were slightly higher than the temperature records of water samples from reservoirs (Table 4) and lower than the temperature records of samples from boreholes.

The relatively higher temperature records than samples from reservoirs was possibly due to the effect of elevation as the water reservoirs were located at relatively higher elevations to allow the flow of water by gravity and the lower temperature records as compared to samples from boreholes was due to the underground installation of the pipes. In general, the overall high temperature of the water being supplied to Mendi town is generally attributable to the climatic condition of the area as discussed earlier (section 4.1.1.).

The temperature records of tap water for this study were above the WHO permissible limit of <15°C and this has a negative impact on the palatability of the water. High water temperature enhances the growth of microorganisms and may increase problems related to taste, odour, colour and corrosion. Cool water is generally more palatable than warm water, and temperature will have an impact on the acceptability of a number of other inorganic constituents and chemical contaminants that may affect taste. High water temperature enhances the growth of microorganisms and may increase problems related to taste, odour, colour and corrosion

[9]

3.3.2. PH

The PH measurements of the samples from tap water were found to be within the range of 7.37-7.71 with the highest record from HHT-8 and the lowest record from HHT-2 with the average value of 7.56. There was no statistically significant difference amongst the mean values of PH for the different sampling points (p=0.012). The PH records of the tap water samples were within the WHO and national standard limits of 6.5-8.5. The PH records of the tap water samples were comparable to the PH records of the samples from boreholes and reservoirs (7.23-7.81). The results were also within the WHO and National standard limit.

3.3.3. Turbidity

The measurements of turbidity for the tap water samples showed a minimum turbidity record of 1.27 NTU (HHT-8) and a maximum turbidity record of 3.40 NTU (HHT-5) with the average value of 2.1 NTU. There was statistically significant difference amongst the mean values of the sampling points (p=0.000). There was no significant difference amongst the mean values of HHT-1, HHT-6, HHt-7 and HHT-8 and in the same way no significant difference was observed between the mean values of HHT-2, HHT-3 and HHT-5. The mean values of all the sampling points showed statistically significant difference from the mean values of the boreholes (p=0.000). On the other hand, the mean values of HHT-2, HHT-3, HHT-4 and HHT-5 showed significant difference from the mean values of samples from reservoirs (p=0.000) whereas HHT-1, HHT-6, HHT-7 and HHT-8 did not show significant difference from the mean values of the samples from reservoirs with P-values being 0.844, 0.983, 0.528 and 0.983 respectively.

The mean values of the turbidity records in all tap water samples were found to be within the limits of the standards set by WHO and ESA that is <5 NTU. The low turbidity level of the water usually has a positive impact on the aesthetic value of the water. However, the turbidity records for the tap water samples were higher than the turbidity records of the boreholes (0 NTU for both boreholes) and most of the records for the tap water samples were slightly higher than the turbidity records of the samples from reservoirs (1.27 NTU for both reservoirs).

Turbidity in distribution systems can occur as a result of the disturbance of sediments and bio-films but is also from the ingress of dirty materials from outside the system

[9]

. Therefore, the slight increase in turbidity as it was moved from reservoirs to tap water indicated that there was a probability of ingress of foreign materials such as soil particles into the distribution networks. Especially, the relatively high turbidity records of 2.83 NTU from HHT-2, 3.03 NTU from HHT-3 and 3.40 NTU from HHT-5 were associated with the older pipelines as these samples were collected from the older pipelines and confirmed that as water pipe gets older the probability for the ingress of foreign matters such as soil particles increases. This is because as pipes get older, the fittings become looser and allow the ingress of foreign materials such as soil particles. However, all the turbidity records for the current research were within WHO and National standard limit.

3.3.4. TDS and EC

The TDS values of the samples from tap water fell within the range of 126-129 mg/l and were comparable with the TDS values of the samples from boreholes and reservoirs. As far as EC values are concerned, they also fell within the range of 252.7-258.3 μS/cm and were comparable to average values of the samples from boreholes and reservoirs. This showed that there was no probability for the entrance of foreign materials that can affect TDS and EC values in the distribution system.

The results of the current research were found to be in conformity with the WHO limit which is <600 mg/l and the National maximum permissible level which is 1000 mg/l.

3.3.5. Iron and Manganese

The iron records for the tap water samples of this research showed results of iron within the range of 0.23 to 0.35 mg/l. No significant difference was observed between the mean values of the sampling points (p>0.01) except HHT-5 which showed significant difference from all the rest samples (p=0.000). Except HHT-5, all the samples from tap water had iron concentrations that lie below WHO and ESA maximum permissible limit of 0.3 mg/l and the record for HHT-5 was significantly different from WHO and national maximum permissible limit (p=0.002). The iron concentrations records of the tap water samples were less than the iron concentration of the samples from the reservoirs except HHT-5 which had iron concentration above the samples from reservoirs. On the other hand all the samples of tap water had iron concentrations less than the concentrations for boreholes (0.53 for BH-1 and 0.45 for borehole-2).

The exceptionally higher iron concentration for HHT-5 is possibly associated with the corrosion of the pipelines that convey the water because the pipe line for HHT-5 was older and this increased the probability for corrosion which removes the internal coating of the pipe and exposes the iron part of the pipe that dissolves in the water and increases the iron concentration. As it was discussed earlier in section (4.1.5.), the decrease in iron concentrations as it was moved from the sources to the tap water is attributable to the oxidation of soluble Fe 2+ to the insoluble Fe 3+ which usually precipitates as rusty sediment.

As far as manganese concentrations were concerned, the manganese records were within the range of 0-0.06 mg/l with average value of 0.04 mg/l and with no statistically significant difference amongst the mean values (p=0.013). The average values of manganese for tap water samples were less than the average values of samples from the reservoirs and boreholes. The records of the samples from tap water showed decreasing manganese concentrations due to the further oxidation of the soluble Mn+2 to insoluble Mn+4 as discussed in section (4.1.5.). These results were found to be less than the WHO and ESA recommended limits of 0.4 mg/l and 0.5 mg/l respectively.

3.3.6. Nitrate

The nitrate records for the samples from the tap water were found to lie within the range of 1.03-1.70 mg/l and were by far less than the WHO and national maximum permissible limits with significant difference amongst the mean values of the sampling points (p=0.000). The mean values of the samples from HHT-3 (1.5 mg/l) and HHT-5 (1.7 mg/l) were significantly different from the nitrate records of the source, reservoirs and the other tap water samples (p<0.01). Household taps (HHT-3 and HHT-5) were connected to the old pipelines of the town’s water supply system and this was possibly the major cause for relative contamination of the water with nitrate as compared to the other samples. When pipeline gets older, the fittings become loose allowing the entrance of foreign materials that contribute to increase in nitrate concentration. All the samples for this research met WHO and national standard.

3.3.7. Phosphate

The phosphate records for the samples from tap water showed a minimum record of 2.20 mg/l and a maximum record of 2.4 mg/l with no significant difference amongst the mean values of the sampling points (p=0.393). The average concentrations of phosphate for tap water samples were comparable to the average concentrations of phosphate from source and reservoir water samples. Although there is no guideline value set by WHO and ESA for phosphate concentration in drinking water, the European community proposed a guideline value of 0.4 mg/l

[25]

and the recorded values were less than this guideline.

3.3.8. Fluoride

The fluoride records for the samples from tap water showed a fluoride result within a range of 0.01-0.03 mg/l with the lowest record from HHT-3 and HHT-5 and the highest record from HHT-4 and the average value being 0.019. There was no significant difference amongst the mean values of the different sampling points (p=0.707). The average result of fluoride for tap water samples was comparable to the average value of fluoride records of the samples from boreholes and water reservoirs. The records were found to be compliant with the WHO and ESA recommended limits of <1.5 mg/l.

3.3.9. Total Hardness

The records for the total hardness of the samples from tap water showed a minimum record of 97.67 mg/l (HHT-5) and a maximum record of 99.67 mg/l (HHT-7) with average value of 98.46 mg/l and with no significant difference amongst the mean values (p=0.629). The average value of total hardness for the tap water samples was comparable to the average value of total hardness for samples from boreholes and water reservoirs. The results were compliant with the WHO and national maximum limit of 300 mg/l.

3.4. Bacteriological Analysis of Tap Water Samples

Bacteriological analysis of the water samples from tap water were carried out to determine the presence of indicator organisms (TC/FC) and to evaluate the bacteriological quality of the tap water. The bacteriological analysis results of the tap water were summarized in the following table and the necessary discussion follows.

Table 5. Mean values of bacteriological parameters for tap water samples.

Parameter	Mean Values of Sampling Sites								P-Value
Parameter	HHT1	HHT2	HHT3	HHT4	HHT5	HHT6	HHT7	HHT8
TC (CFU/100 ml)	2.00±0.00	1.00±0.00	2.00±0.00	18.00±2.00	5.00±0.58	8.00±0.58	3.00±0.58	4.00±0.58	0.00**
FC (CFU/100 ml)	0.00±0.00	0.00±0.00	0.00±0.00	0.00±0.00	0.00±0.00	0.00±0.00	0.00±0.00	0.00±0.00	1.000*

*The mean difference is significant at the 0.01 level

TC-Total Coliform; FC-Faecal Coliform; HHT-Household tap

The bacteriological analysis of the tap water samples showed that all the water samples (100%) were positive for total Coliform counts ranging from 1.00 CFU/100 ml (HHT-2) to 18 CFU/100 ml (HHT-4) with the average value being 5.38 and with statistically significant difference between the mean values (p=0.000). The mean values of HHT-4, HHt-5, HHT-6 and HHT-8 were significantly different from WHO and National standard for TC (p=0.000). The rest sampling points (HHT-1, HHT-2, HHT-3, and HHT-7) had mean values of TC that did not show significant difference from WHO and National standard (p>0.01) though the results were not compliant with WHO and National standard. The mean values of TC count for HHT-4, HHT-5 and HHT-6 showed significant difference from the mean values of boreholes and reservoirs (p=0.00) whereas the mean values of TC count for HHT-1, HHT-2, HHT-3 and HHT-7 did not show significant difference from the mean TC values of boreholes and reservoirs (p>0.01).

On the other hand, FC (Faecal Coliform) was not detected in any of the tap water samples and this indicated the absence of faecal contamination in the tap water and the detected Coliforms were of environmental species. The TC count for the samples from boreholes showed 1 CFU/100 ml for both boreholes and the TC count for samples from reservoirs showed 2 CFU/100 ml for both reservoirs. Out of the tested tap water samples, 87.5% had TC count greater than the TC count for boreholes and 87.5% of the tap water samples had TC count equal to or greater than TC count for water samples from reservoirs (Table 5).

When compared to WHO and National standard limit of 0 Cfu/100 ml of TC count, 100% of the samples were not compliant with the WHO and National standard because both WHO and national standards require the absence of Coliform organisms in 100 ml of water sample (WHO, 2011; ESA, 2013). The presence of total Coliforms in the water samples can be due to re-growth and possible bio-film formation or contamination through ingress of foreign material, including soil or plants as the line extends from the reservoirs to individual household taps

[6]

Based on the faecal Coliform count of the water samples, the samples from tap water for this research satisfied the requirements of WHO and compulsory Ethiopian standard as 100% of the samples were free from FC/E-Coli. Though the samples from tap water satisfy WHO and National standards in terms of FC count, the presence of TC in the water samples needs great attention and urgent corrective measures since the presence of total Coliforms in distribution systems and stored water supplies can reveal re-growth and possible bio-film formation or contamination through ingress of foreign material, including soil or plants.

3.5. Physico-chemical and Bacteriological Quality of Water Samples from Household Containers

3.5.1. Physico-chemical Analysis

The water samples from household containers were physico-chemically and bacteriologically analyzed to determine the water quality status as it reaches household container or point of use. The physico-chemical analysis results were summarized in the following table:

Table 6. Mean values of physico-chemical parameters for samples from household containers.

Parameter	Mean Values of Sampling Sites								P-Value
Parameter	HHC1	HHC2	HHC3	HHC4	HHC5	HHC6	HHC7	HHC8	P-Value
Temp (°C)	22.27±0.15	22.93±0.07	22.50±0.12	22.17±0.09	22.73±0.15	22.57±0.03	21.57±0.09	23.70±0.06	0.000
PH	7.32±0.07	7.42±0.01	7.81±0.02	7.63±0.03	7.84±0.02	7.55±0.07	7.62±0.01	7.57±0.09	0.000
Turbidity (NTU)	1.23±0.12	1.73±0.15	2.33±0.03	2.07±0.03	1.33±0.17	1.23±0.03	1.23±0.12	2.00±0.00	0.000
TDS (mg/l)	127±0.44	127±0.44	127±0.44	128±0.44	127±0.29	129±0.29	127±0.29	127±0.44	0.034
EC (μS/cm)	254.3±0.88	253.7±0.88	254.7±0.88	256.7±0.88	254.0±0.58	257.0±0.58	254.0±0.58	254.3±0.88	0.051
Total Iron (mg/l)	0.20±0.00	0.23±0.01	0.24±0.01	0.24±0.01	0.29±0.01	0.21±0.01	0.20±0.00	0.20±0.00	0.000
Manganese (mg/l)	0.12±0.01	0.12±0.01	0.03±0.01	0.02±0.01	0.02±0.01	0.01±0.01	0.02±0.01	0.05±0.01	0.000
Nitrate (mg/l)	1.07±0.07	1.30±0.06	1.33±0.09	1.23±0.03	1.07±0.03	1.00±0.00	1.17±0.03	1.00±0.00	0.000
Phosphate (mg/l)	2.30±0.06	2.23±0.03	2.30±0.06	2.40±0.06	2.30±0.06	2.30±0.06	2.20±0.00	2.23±0.09	0.361
Fluoride (mg/l)	0.02±0.00	0.02±0.01	0.03±0.00	0.02±0.00	0.02±0.00	0.03±0.00	0.03±0.01	0.03±0.00	0.086
Total Hardness (mg/l CaCO₃)	97.67±0.33	100.0±0.58	97.33±0.88	98.33±0.88	97.33±0.88	98.67±0.33	99.67±0.88	96.67±0.88	0.060

*The mean difference is significant at the 0.01 level

HHC-household container

(i). Temperature

The temperature records of the samples from household containers were within the range of 21.57°C to 23.7°C with the highest record from HHC-8 and the lowest from HHC-7 and with statistically significant difference amongst the mean values of the sampling points (p=0.000). The mean values of temperature records for all sampling points were significantly different from WHO maximum permissible limit (p=0.000). The mean value of HHC-8 was significantly different from the mean values all the rest sampling points (p=0.000). The average value of the temperature records from the household containers was 22.56 and this was comparable to the average temperature value of tap water samples that is 22.87. The difference in the temperature records of the water samples from different household containers can be due to the difference in storage styles of the households.

On the other hand, the overall high temperature of the water being supplied to Mendi town is generally attributable to the climatic condition of the area as discussed earlier in section (4.1.1.). In general, the temperature records of the samples from household containers for this study were above the WHO permissible limit of <15°C and this clearly has a negative impact on the palatability of the water. High water temperature enhances the growth of microorganisms and may increase problems related to taste, odour, colour and corrosion and palatability decreases as the temperature of the water increases.

(ii). pH

The pH records for the samples from household containers were found to lie between 7.32 and 7.84 with average value of 7.6 and with statistically significant difference amongst the mean values of the sampling points (p=0.000). The highest PH record was from HHC-5 for which the mean value was significantly different from all sampling points (p=0.000) except with HHC-3 (p=0.706) and the lowest pH record was from HHC-1 for which the mean value was significantly different from all the rest samples (P<0.01) except with HHC-2 (p=0.169). The difference in PH values from different household containers can be due to the storage styles and water handling practices of the households. These PH ranges were comparable to the pH range of 7.37 to 7.71 for the samples from household taps. The pH records of the samples from household containers were within the WHO and national standard limits of 6.5-8.5.

(iii). Turbidity

The turbidity results for the samples from the household containers were found to be within the range of 1.23 to 2.33 NTU with statistically significant difference amongst the mean values of the sampling points (p=0.000). The results were found to lie within the permissible limits of WHO and Ethiopian compulsory limit of <5 NTU. The difference in the turbidity records from different household containers can be due to the difference in the degree of exposure of the pipe that supplies the water to entrance of foreign materials and the difference in water storage and handling practices at the household level. The household containers turbidity results were found to be less than the turbidity record range of 1.27 to 3.4 NTU recorded for the samples from tap water. The relatively low turbidity values for most of the samples from household containers when compared to the turbidity records of the tap water can be due to the settling and precipitation of colloidal and suspended materials in the household containers as the particles get time to settle.

(iv). TDS and EC

The TDS records for the samples from household containers were within the range of 127 to 129 mg/l with statistically no significant difference amongst the mean values from different sampling points (p=0.034). The results were comparable to the TDS values of the samples from tap water that fell within the range of 126-129 mg/l and the TDS values of boreholes that fell within the range of 122-133 mg/l. The EC values for the samples from HHC were found to be within the range of 253.7 to 257 μS/cm with statistically no significant difference amongst the mean values from different sampling points (p=0.051) and were comparable to the EC values of samples from tap water that fell within the range of 252.7-258.3 μS/cm. The TDS and EC values of the samples from the household containers showed that the water is generally considered to be good for drinking and will not cause excessive scaling in heaters, boilers and household appliances.

(v). Iron and Manganese

The iron records for the samples from household containers were found to be within the range of 0.20 to 0.29 mg/l with statistically significant difference amongst the mean values of the sampling points (p=0.000). The maximum value of iron from HHC-5 was significantly different from the mean values of all the rest sampling points (p=0.000) whereas there was no significant difference between the mean values of HHC-1, HHC-2, HHC-6, HHC-7 and HHC-8 (p=0.178) and no significant difference was also observed between the mean values HHC-3 and HHC-4 (p=0.700). The difference in the iron concentrations from different household containers can be due to the corrosion status of the steel pipes that convey the water. The records from all the samples were found to be within the maximum permissible limit of 0.3 mg/l set by WHO and national standard.

The iron records for the samples from household containers showed a relatively lower iron concentration as compared to the records from the samples from tap water and the samples from boreholes and reservoirs. This confirmed that as the water containing soluble Fe²⁺ is exposed to oxygen (aerated), the oxidation process of the soluble Fe²⁺ to the insoluble Fe 3+ continues with the resulting precipitation of the insoluble iron as Fe(OH)₃ and minimizing the detectable iron in the water sample.

As far as Manganese concentrations are concerned, the records for household containers were within the range of 0.01 to 0.12 mg/l with statistically significant difference amongst the mean values of the sampling points (p=0.000). The results were found to be compliant with the WHO and national health-based guideline value. The lowest record (0.01 mg/l) was from HHC-6 which showed no significant difference with HHC-3, HHC-4, HHC-5, HHC-7 and HHC- 8 (p=0.160) and the highest records of 0.12 mg/l were from HHC-1 and HHC-2 and these mean values showed significant difference from the mean values of the rest sampling points (p=0.000).

The relatively high manganese records at HHC-1 and HHC-2 were possibly due to the type of containers in which the households store water as containers made of materials containing manganese may increase the concentration or from the cleaning materials they use to wash the containers. Manganese is used principally in the manufacture of iron and steel alloys, as an oxidant for cleaning, bleaching and disinfection (as potassium permanganate) and as an ingredient in various products.

(vi). Nitrate and Phosphate

The nitrate records for the samples from household containers were found to be between 1.00 mg/l and 1.33 mg/l with average value of 1.15 mg/l and with statistically significant difference amongst the mean values of the sampling points (p=0.000). The mean values of HHC-1, HHC-4, HHC-5, HHC-6, HHC-7 and HHC-8 did not show significant difference amongst themselves (p=0.057). The difference between the mean values of the nitrate records for the different sampling points can be due to the difference in the degree of the exposure of the pipes to entrance of foreign materials and due to the difference in water storage and handling practices at the household levels.

The results for nitrate were comparable to the 1.17 to 1.34 mg/l records for samples from boreholes and water reservoirs and 1.03 to 1.7 mg/l records for tap water samples. The results were by far lower than the WHO and national standard limit. As far as phosphate concentrations are concerned, they were found to be within the range of 2.20 to 2.40 mg/l with statistically no significant difference amongst the mean values of the sampling points (p=0.361) and were comparable to the records for the samples from tap water and samples from reservoirs and boreholes.

(vii). Fluoride and Total Hardness

The fluoride records were between 0.02 to 0.03 mg/l with statistically no significant difference amongst the mean values of the sampling points (p=0.086) and were comparable to the records for tap water samples and samples from boreholes and reservoirs. Total hardness records were found to lie between 96.67 and 100 mg/l with statistically no significant difference amongst the mean values of the sampling points (p=0.060) and were comparable with the records for samples from tap water, reservoirs and boreholes. The results were compliant with the standards set by WHO and ESA.

3.5.2. Bacteriological Quality of the Water from Household Containers

All samples from household containers (100%) were found to be positive for total Coliform with TC count of 5 CFU/100 ml to 32 CFU/100 ml with average value of 18.38 and with statistically significant difference amongst the mean values of the sampling points (p=0.000). The mean values for TC count of all the household samples were found to be significantly different from WHO and National standard limit (p=0.000). The difference in the mean values of TC records from different household samples can be due to the difference in water storage and handling practices at the household level that might result in varying degrees of contaminations and which was further aggravated due to lack of chlorination and residual chlorine in the system to protect further contamination. The TC counts of the samples from household containers (100%) were above the WHO and National limit of 0 CFU/100 ml (Table 7).

As far as faecal Coliforms were concerned, 25% of the samples from household containers were found to be positive for FC test with FC count of 3 CFU/100 ml for HHC-1 and 11 CFU/100 ml for HHC-8 and were not in conformity with WHO and national standard of 0 CFU/100 ml. On the other hand, 75% of the samples from household containers were free from FC and satisfied WHO and national standard even though they were positive for TC test (Table 7). There was statistically significant difference amongst the mean values of the sampling points when all the sampling points are considered (p=0.000). The mean values of FC for HHC-1 and HHC-8 showed significant variations from the mean values of all the rest sampling points, from WHO and National standard limits and from each other for FC (p=0.000) and this can be due to the difference in water storage and handling practices which were further aggravated by the lack of water disinfection. However, there was no significant variation amongst the mean values of HHC-2 to HHC-7 (p=1.000) for FC.

Table 7. Mean values of bacteriological parameters for household containers water samples.

Parameter	Mean Values of Sampling Sites								P-Value
Parameter	HHC1	HHC2	HHC3	HHC4	HHC5	HHC6	HHC7	HHC8	P-Value
TC (CFU/100 ml)	12.00±1.16	5.00±0.58	22.00±1.16	20.00±1.16	13.00±0.58	15.00±0.58	28.00±2.00	32.00±1.16	*0.000
FC (CFU/100 ml)	3.00±0.58	0.00±0.00	0.00±0.00	0.00±0.00	0.00±0.00	0.00±0.00	0.00±0.00	11.00±0.58	*0.000

*The mean difference is significant at the 0.05 level

TC-Total Coliform; FC-Faecal Coliform; HHC-Household container

The results of bacteriological analysis for samples from household containers showed that the water used for domestic purposes including drinking in the study area was of poor quality micro-biologically and the contamination is partly due to poor water management practices and poor sanitation facilities and partly due to lack of disinfection of the water. Contamination of water often occurs during the transportation of water to the home and in the home itself

[4]

. Such contamination is linked to hygiene awareness and practices of water bearers and family members and, in some cases, to the availability of appropriate receptacles and utensils (e.g., closed water jars and long-handled ladles).

The overall bacteriological analysis for the study area showed that there was increasing bacteriological water quality deterioration from the source to the reservoirs and then towards tap water and household containers.The water quality deterioration was more serious at the household containers (point of use) and this is an indicator for poor water management and storage practices at the household level in the study area.

In some cases (HHC-1 and HHC-8), the samples were found to be positive for FC and this indicated that the existing poor water storage practices have further contributed to faecal contamination of the water in the household containers. For instance, for HHC-8, during sample collection it was observed that there were animal production practices with poor waste disposal in the compound of the household from where the sample was taken and this shows that unless proper waste management practices are available and water is properly protected, there is a probability for household water to be exposed to contamination by animal and human faeces. The result also indicated that there were variations among the different households regarding TC and FC counts of the samples.

4. Conclusions and Recommendations

4.1. Conclusions

Physico-chemical parameters such as PH, turbidity, TDS, manganese, fluoride, nitrate and total hardness were tested for the samples from boreholes, water reservoirs, household taps and household containers and were found to be compliant with the WHO and National drinking water standards. The temperature record was above the WHO limit of <15°C for all of the water samples tested (21.87 to 23.7°C) and it is attributable to the climatic condition of the area and it will have negative impact on the palatability of the water and will enhance the growth of microorganisms and may increase problems related to taste, odor, color and corrosion.

Iron concentration was found to be above the WHO and national standard limit for the samples from boreholes (0.45 to 0.53 mg/l) whereas 94.4% of the samples from reservoirs, household taps and household containers had iron concentrations compliant with the WHO and national standard limits. The reduction in the iron concentration as we moved from the source to the reservoirs and the distribution systems was due to the oxidation of the soluble Fe 2+ to the insoluble Fe 3+. Only one sample from the household tap had iron concentrations above WHO and National standard limit and this was attributable to the corrosion of the steel pipe that conveys the water. In general, the current research showed that the tested water was physico-chemically potable except for temperature for all samples and iron concentration for the borehole samples.

All the water samples tested were positive for TC ranging from 1.00 to 32.00 CFU/100 ml and the TC count increased from the source to the reservoirs and then to the household taps and household containers and indicated the increasing degree of contamination from the source to the point of use. The lowest TC count of 1 CFU/100 ml was recorded for the sample taken from the borehole and the highest TC count of 32 CFU/100 ml was recorded for the sample taken from household container.

Regarding FC records, the samples from boreholes, water reservoirs and household taps were negative for FC counts whereas 25% of the samples from household containers had FC counts ranging from 3 to 11 CFU/100 ml. All the samples tested did not satisfy the WHO and National standard limit for TC counts of 0 CFU/100 ml but all the samples from boreholes, water reservoirs and household taps and 75% of the samples from household containers satisfy the WHO and National standards based on faecal Coliform (FC) counts of 0 CFU/100 ml. The most interesting point is all the samples from boreholes, reservoirs and household taps were negative for FC test and this showed the absence of faecal contamination and the identified TC were of environmental species attributable to the contamination of the water with soil particles and plant materials. The detection of TC in all water samples and FC in some of the household containers samples is partly due to lack of any type of disinfection of the water supplied to the town and partly due to lack of regular supervision of the system, absence of proper water management and lack of safe water storage and handling practices.

4.2. Recommendations

The following recommendations are drawn based on the findings of the current research:

As the iron concentration of the source (boreholes) is above the WHO and National standard limit, it may create problems of rusty sediment accumulation in the reservoirs due to the process of oxidation which may require regular cleaning of the reservoir. Iron concentration of the water can also affect the aesthetic acceptability of the water if it does not get time for oxidation prior to supplying to the users. Therefore, it is recommended that a kind of aeration and filtration structure should be incorporated into the town’s water supply system to remove iron by aeration/oxidation and filtration prior to supplying to the community.

The presence of TC in all water samples and FC in some household water containers is partly due to lack of water disinfection by using disinfectants such as chlorine. Therefore, it is recommended that regular disinfection of the water wells especially after carrying out maintenance works, regular cleaning and disinfection of the water reservoirs and regular disinfection of the distribution pipelines are very important and need to be practiced urgently to minimize the problems.

Lack of regular supervision of the water supply system specially the pipelines expose to the problems of foreign materials ingress that contributes to water contamination. Therefore, carrying out regular supervision of the distribution systems and maintaining leaky pipes timely, and replacing older pipe lines that contribute to water contamination and high iron concentration as a result of corrosion are highly recommended.

The increasing TC and FC count in household water samples indicates the poor water management and water handling practices of the community. Therefore, adequate awareness must be created for the beneficiaries on how to safely store and handle drinking water at the household level and on proper waste disposal and environmental sanitation. All concerned parties such as health offices should collaborate with the town’s Water Supply Office to arrange and provide hygiene and sanitation education to the user community so that the awareness level of the people will increase and the problems will be reduced.

Regular drinking water quality assessment from the source, reservoirs, distribution system and household containers based on basic or essential physicco-chemical and bacteriological parameters and necessary sanitary inspection activities should be carried out by the concerned bodies to ensure that the water is safe for drinking.

The present work is limited to selected water quality parameters and sampling frequency and thus year-round sampling and analysis of additional water quality parameters should be undertaken.

Abbreviations

APHA	American Public Health Association
BH	Borehole
CAWST	Centre for Affordable Water and Sanitation Technology
CFU	Colony Forming Unit
E-Coli	Escherichia Coli
EC	Electrical Conductivity
EPAI	Environmental Protection Agency of Ireland
ESA	Ethiopian Standards Agency
FC	Faecal Coliforms
FDRE	Federal Democratic Republic of Ethiopia
HHC	Household Container
HHT	Household Tap
MoH	Ministry of Health
MoWR	Ministry of Water Resources
NPC	National Planning Commission
NTU	Nephelometric Turbidity Unit
OECD	Organization for Economic Cooperation and Development
SPSS	Statistical Package for Social Sciences
TID	Technical Information Document
UNEP	United Nations Environmental Program
UNESCO	United Nations Educational, Scientific and Cultural Organization
UNICEF	United Nations Children's Fund
USDA	United States Department of Agriculture
USEPA	United States Environmental Protection Agency
WHO	World Health Organization
WR	Water Reservoir
WSTB	Water Science and Technology Board

Author Contributions

Tesfaye Soressa Kiltu is the sole author. The author read and approved the final manuscript.

Conflicts of Interest

The author declares no conflicts of interest.

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Kiltu, T. S. (2025). Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level. American Journal of Applied Scientific Research, 11(1), 1-18. https://doi.org/10.11648/j.ajasr.20251101.12

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Kiltu, T. S. Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level. Am. J. Appl. Sci. Res. 2025, 11(1), 1-18. doi: 10.11648/j.ajasr.20251101.12

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Kiltu TS. Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level. Am J Appl Sci Res. 2025;11(1):1-18. doi: 10.11648/j.ajasr.20251101.12

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@article{10.11648/j.ajasr.20251101.12,
  author = {Tesfaye Soressa Kiltu},
  title = {Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level
},
  journal = {American Journal of Applied Scientific Research},
  volume = {11},
  number = {1},
  pages = {1-18},
  doi = {10.11648/j.ajasr.20251101.12},
  url = {https://doi.org/10.11648/j.ajasr.20251101.12},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajasr.20251101.12},
  abstract = {This research was carried out in Mendi town to evaluate the quality of drinking water from the source to household containers. The physico-chemical parameters were analyzed using HACH HQ440d multi meter and portable digital spectrophotometer (DR/2400). Bacteriological parameters were analyzed using membrane filtration technique. The temperature measurements of the water samples were found to be between 21.8°C and 23.7°C which was higher than the WHO standard limit and the PH records were between 7.23 and 7.84 and were compliant with WHO and National standard limit. The maximum turbidity record of the water samples was 3.40 NTU all the turbidity records were in conformity with WHO and National standards. Total dissolved solids (TDS) and electrical conductivity (EC) measurements of the samples were between 122 mg/l and 133 mg/l respectively. All the TDS records were compliant with WHO and National standards. Iron concentration was found to be above the WHO and national standard limit for the samples from boreholes (0.45 to 0.53 mg/l) whereas 94.4% of the samples from reservoirs, household taps and household containers had iron concentrations compliant with the WHO and national standard limits. Manganese, nitrate, fluoride and total hardness records were 0.00-0.14 mg/l, 0.00-1.70 mg/l, 0.00-0.04 mg/l and 96.67-108 mg/l respectively and were found to be compliant with WHO and National standards. Samples from boreholes and reservoirs had Total coliforms (TC) counts of 1 CFU/100 ml to 2 CFU/100 ml with no faecal coliforms (FC) detected whereas samples from tap waters had TC counts ranging from 1 CFU/100 ml to 18 CFU/100 ml with no FC detected. Samples from household containers had FC counts ranging from 5 CFU/100 ml to 32 CFU/100 ml and FC counts ranging from 3 CFU/100 ml to 11 CFU/100 ml. All the water samples tested were positive for TC ranging from 1.00 to 32.00 CFU/100 ml. Regarding FC records, the samples from boreholes, water reservoirs and household taps were negative for FC counts whereas 25% of the samples from household containers had FC counts ranging from 3 to 11 CFU/100 ml. All the samples tested did not satisfy the World Health Organization (WHO) and National standard limits of 0 CFU/100 ml for TC counts but all the samples from boreholes, water reservoirs and household taps and 75% of the samples from household containers satisfy the WHO and National standards of 0 CFU/100 ml based on faecal Coliform (FC) counts. The detection of TC in all water samples and FC in some of the household containers samples can be attributable to lack of adequate disinfection of the water, lack of regular supervision of the system, absence of proper water management and lack of safe water storage and handling practices.
},
 year = {2025}
}

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TY  - JOUR
T1  - Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level

AU  - Tesfaye Soressa Kiltu
Y1  - 2025/01/21
PY  - 2025
N1  - https://doi.org/10.11648/j.ajasr.20251101.12
DO  - 10.11648/j.ajasr.20251101.12
T2  - American Journal of Applied Scientific Research
JF  - American Journal of Applied Scientific Research
JO  - American Journal of Applied Scientific Research
SP  - 1
EP  - 18
PB  - Science Publishing Group
SN  - 2471-9730
UR  - https://doi.org/10.11648/j.ajasr.20251101.12
AB  - This research was carried out in Mendi town to evaluate the quality of drinking water from the source to household containers. The physico-chemical parameters were analyzed using HACH HQ440d multi meter and portable digital spectrophotometer (DR/2400). Bacteriological parameters were analyzed using membrane filtration technique. The temperature measurements of the water samples were found to be between 21.8°C and 23.7°C which was higher than the WHO standard limit and the PH records were between 7.23 and 7.84 and were compliant with WHO and National standard limit. The maximum turbidity record of the water samples was 3.40 NTU all the turbidity records were in conformity with WHO and National standards. Total dissolved solids (TDS) and electrical conductivity (EC) measurements of the samples were between 122 mg/l and 133 mg/l respectively. All the TDS records were compliant with WHO and National standards. Iron concentration was found to be above the WHO and national standard limit for the samples from boreholes (0.45 to 0.53 mg/l) whereas 94.4% of the samples from reservoirs, household taps and household containers had iron concentrations compliant with the WHO and national standard limits. Manganese, nitrate, fluoride and total hardness records were 0.00-0.14 mg/l, 0.00-1.70 mg/l, 0.00-0.04 mg/l and 96.67-108 mg/l respectively and were found to be compliant with WHO and National standards. Samples from boreholes and reservoirs had Total coliforms (TC) counts of 1 CFU/100 ml to 2 CFU/100 ml with no faecal coliforms (FC) detected whereas samples from tap waters had TC counts ranging from 1 CFU/100 ml to 18 CFU/100 ml with no FC detected. Samples from household containers had FC counts ranging from 5 CFU/100 ml to 32 CFU/100 ml and FC counts ranging from 3 CFU/100 ml to 11 CFU/100 ml. All the water samples tested were positive for TC ranging from 1.00 to 32.00 CFU/100 ml. Regarding FC records, the samples from boreholes, water reservoirs and household taps were negative for FC counts whereas 25% of the samples from household containers had FC counts ranging from 3 to 11 CFU/100 ml. All the samples tested did not satisfy the World Health Organization (WHO) and National standard limits of 0 CFU/100 ml for TC counts but all the samples from boreholes, water reservoirs and household taps and 75% of the samples from household containers satisfy the WHO and National standards of 0 CFU/100 ml based on faecal Coliform (FC) counts. The detection of TC in all water samples and FC in some of the household containers samples can be attributable to lack of adequate disinfection of the water, lack of regular supervision of the system, absence of proper water management and lack of safe water storage and handling practices.

VL  - 11
IS  - 1
ER  -

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Tesfaye Soressa Kiltu

Oromia Water and Energy Bureau, Addis Ababa, Ethiopia

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http://orcid.org/0009-0008-1724-0904

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Kiltu, T. S. (2025). Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level. American Journal of Applied Scientific Research, 11(1), 1-18. https://doi.org/10.11648/j.ajasr.20251101.12

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Kiltu, T. S. Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level. Am. J. Appl. Sci. Res. 2025, 11(1), 1-18. doi: 10.11648/j.ajasr.20251101.12

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AMA Style

Kiltu TS. Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level. Am J Appl Sci Res. 2025;11(1):1-18. doi: 10.11648/j.ajasr.20251101.12

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@article{10.11648/j.ajasr.20251101.12,
  author = {Tesfaye Soressa Kiltu},
  title = {Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level
},
  journal = {American Journal of Applied Scientific Research},
  volume = {11},
  number = {1},
  pages = {1-18},
  doi = {10.11648/j.ajasr.20251101.12},
  url = {https://doi.org/10.11648/j.ajasr.20251101.12},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajasr.20251101.12},
  abstract = {This research was carried out in Mendi town to evaluate the quality of drinking water from the source to household containers. The physico-chemical parameters were analyzed using HACH HQ440d multi meter and portable digital spectrophotometer (DR/2400). Bacteriological parameters were analyzed using membrane filtration technique. The temperature measurements of the water samples were found to be between 21.8°C and 23.7°C which was higher than the WHO standard limit and the PH records were between 7.23 and 7.84 and were compliant with WHO and National standard limit. The maximum turbidity record of the water samples was 3.40 NTU all the turbidity records were in conformity with WHO and National standards. Total dissolved solids (TDS) and electrical conductivity (EC) measurements of the samples were between 122 mg/l and 133 mg/l respectively. All the TDS records were compliant with WHO and National standards. Iron concentration was found to be above the WHO and national standard limit for the samples from boreholes (0.45 to 0.53 mg/l) whereas 94.4% of the samples from reservoirs, household taps and household containers had iron concentrations compliant with the WHO and national standard limits. Manganese, nitrate, fluoride and total hardness records were 0.00-0.14 mg/l, 0.00-1.70 mg/l, 0.00-0.04 mg/l and 96.67-108 mg/l respectively and were found to be compliant with WHO and National standards. Samples from boreholes and reservoirs had Total coliforms (TC) counts of 1 CFU/100 ml to 2 CFU/100 ml with no faecal coliforms (FC) detected whereas samples from tap waters had TC counts ranging from 1 CFU/100 ml to 18 CFU/100 ml with no FC detected. Samples from household containers had FC counts ranging from 5 CFU/100 ml to 32 CFU/100 ml and FC counts ranging from 3 CFU/100 ml to 11 CFU/100 ml. All the water samples tested were positive for TC ranging from 1.00 to 32.00 CFU/100 ml. Regarding FC records, the samples from boreholes, water reservoirs and household taps were negative for FC counts whereas 25% of the samples from household containers had FC counts ranging from 3 to 11 CFU/100 ml. All the samples tested did not satisfy the World Health Organization (WHO) and National standard limits of 0 CFU/100 ml for TC counts but all the samples from boreholes, water reservoirs and household taps and 75% of the samples from household containers satisfy the WHO and National standards of 0 CFU/100 ml based on faecal Coliform (FC) counts. The detection of TC in all water samples and FC in some of the household containers samples can be attributable to lack of adequate disinfection of the water, lack of regular supervision of the system, absence of proper water management and lack of safe water storage and handling practices.
},
 year = {2025}
}

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TY  - JOUR
T1  - Assessment of Physico-chemical and Bacteriological Quality of Drinking Water from Source to Household Level

AU  - Tesfaye Soressa Kiltu
Y1  - 2025/01/21
PY  - 2025
N1  - https://doi.org/10.11648/j.ajasr.20251101.12
DO  - 10.11648/j.ajasr.20251101.12
T2  - American Journal of Applied Scientific Research
JF  - American Journal of Applied Scientific Research
JO  - American Journal of Applied Scientific Research
SP  - 1
EP  - 18
PB  - Science Publishing Group
SN  - 2471-9730
UR  - https://doi.org/10.11648/j.ajasr.20251101.12
AB  - This research was carried out in Mendi town to evaluate the quality of drinking water from the source to household containers. The physico-chemical parameters were analyzed using HACH HQ440d multi meter and portable digital spectrophotometer (DR/2400). Bacteriological parameters were analyzed using membrane filtration technique. The temperature measurements of the water samples were found to be between 21.8°C and 23.7°C which was higher than the WHO standard limit and the PH records were between 7.23 and 7.84 and were compliant with WHO and National standard limit. The maximum turbidity record of the water samples was 3.40 NTU all the turbidity records were in conformity with WHO and National standards. Total dissolved solids (TDS) and electrical conductivity (EC) measurements of the samples were between 122 mg/l and 133 mg/l respectively. All the TDS records were compliant with WHO and National standards. Iron concentration was found to be above the WHO and national standard limit for the samples from boreholes (0.45 to 0.53 mg/l) whereas 94.4% of the samples from reservoirs, household taps and household containers had iron concentrations compliant with the WHO and national standard limits. Manganese, nitrate, fluoride and total hardness records were 0.00-0.14 mg/l, 0.00-1.70 mg/l, 0.00-0.04 mg/l and 96.67-108 mg/l respectively and were found to be compliant with WHO and National standards. Samples from boreholes and reservoirs had Total coliforms (TC) counts of 1 CFU/100 ml to 2 CFU/100 ml with no faecal coliforms (FC) detected whereas samples from tap waters had TC counts ranging from 1 CFU/100 ml to 18 CFU/100 ml with no FC detected. Samples from household containers had FC counts ranging from 5 CFU/100 ml to 32 CFU/100 ml and FC counts ranging from 3 CFU/100 ml to 11 CFU/100 ml. All the water samples tested were positive for TC ranging from 1.00 to 32.00 CFU/100 ml. Regarding FC records, the samples from boreholes, water reservoirs and household taps were negative for FC counts whereas 25% of the samples from household containers had FC counts ranging from 3 to 11 CFU/100 ml. All the samples tested did not satisfy the World Health Organization (WHO) and National standard limits of 0 CFU/100 ml for TC counts but all the samples from boreholes, water reservoirs and household taps and 75% of the samples from household containers satisfy the WHO and National standards of 0 CFU/100 ml based on faecal Coliform (FC) counts. The detection of TC in all water samples and FC in some of the household containers samples can be attributable to lack of adequate disinfection of the water, lack of regular supervision of the system, absence of proper water management and lack of safe water storage and handling practices.

VL  - 11
IS  - 1
ER  -

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