Journal of Water Resource and Protection, 2013, 5, 653-668 Published Online July 2013 (
Contamination Levels of Some Selected Wells in
Ogbomoso South Local Government Area,
Nigeria and the Implications on Human Health
Samson O. Ojoawo*, T. Lateef Kolade
Department of Civil Engineering, Ladoke Akintola University of Technology, Ogbomoso, Nigeria
Email: *
Received April 15, 2013; revised May 22, 2013; accepted June 18, 2013
Copyright © 2013 Samson O. Ojoawo, T. Lateef Kolade. This is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is
properly cited.
Incident of water-borne diseases is becoming more rampant in developing countries in the 21st century. This paper ex-
amines the contamination levels of some selected wells in Ogbomoso South Lo cal Government Ar ea (LGA), Oyo State,
Nigeria. Methodology includes administering of structured questionnaire, field survey/sampling and laboratory analysis.
The first set of questionnaires sought information on water sources, quality, supply and treatment. These were adminis-
tered in 10 selected major locations which included: Ajegunle, Ar ink inkin, Aro wo mole, Caretake r, Esanu -Aje, I ta-O lola ,
Malete, Oke-Alapata, Ora-Gada and Sunsun. The other set which was administered in 6 randomly selected Health In-
stitutions viz: Oyo State General Hospital, Alaafia Tayo, Oore-Ofe, Bethel, Favour, and Grace Hospitals had questions
on health-related issues. Ten (10) wells were randomly selected for sampling, one in each location. Results were com-
pared with WH O’s Drink ing Water Stand ards. Qu estionnaires r evealed th at residents depended mostly on w ells for w a-
ter supply; the water quality was low; supply was irregular; quantity was inadequate and boiling was the commonest
treatment method. Health Officials established that some residents consumed improperly treated well water and there
were some incidences of water-related diseases. Laboratory analyses showed that samples from Ajegumle and Esanu-
Aje had colour values above the standard. Also, the pH was observed to vary from slightly acidic to slightly alkaline
with values ranging between 6.0 and 8.1. Only Arinkinkin and Ita-Olola areas had permissible values of total alkalinity
and Oke-Alapata had the highest chloride value of 400 mg/l while the highest nitrate concentration was at Esanu-Aje
(127.58 mg/l). Study concludes th at water supply in the area is no t fully supportiv e to health. To abate the prob lem, it is
recommended that aside boiling, each household should endeavour to coagulate, filter, soften and disinfect well water
before consumption. Also, personal hygiene within each household must always be emphasized and improved upon.
Keywords: Contamination; Wells; Water Quality; Human Health
1. Introduction
The importance of water to man cannot be over-empha-
sized. It forms about 70 per cent of our body fluids and
serves many other purposes among which are: drinking
and culinary uses, washing, bathing and laundering, wa-
tering lawns and gardens, protecting life and property
against fire, etc. People in the rural areas in absence of
potable water are exposed to the risk of water borne dis-
eases like cholera, typhoid and other environmental im-
plications [1]. There is evidence of widespread contami-
nation of water resources in many areas of Nigeria. The
Environmental Protection Agency’s National Water Qua-
lity Inventory of 1994 has identified agriculture, urban
runoff/storm water, and municipal point sources of the
largest pollutant sources for rivers, lakes, and estuaries.
Contaminants from these sources include pesticides,
metal, nitrates, solvents, and other wastes. It should how-
ever be noted that not all contamination events pose a
threat to our health [2].
Water resources normally refer to the whole of the
waters of a territory which can be used for suppo rting the
diverse needs of individuals and communities [3]. Re-
sources are all the attributes of our natural environment
that can be utilized to promote human welfare at any
place at a point in time. Resources vary in quantity, qual-
ity, mutability, renewability, reusability and availability.
*Corresponding a uthor.
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The continued availability of adequate fresh water re-
sources is a pre-requisite for sustaining life and devel-
opment. It is imperative to plan and monitor the nation’s
water resources to achieve sustainable development of
the vital resources especially in the face of changing cli-
mate. The development plan of water supply systems is
important and must account the available water as a re-
source which should be well developed planned and ex-
ploited in order to obtain maximum returns at minimum
The major sources of water pollution are sewage or
untreated faecal matter, domestic and industrial solid
waste, sullage, and industrial waste water and sediment
from soil erosion [4]. Sewage effluent and faeces when
properly treated poses minimal pollution or health prob-
lems though they require heavy financial investment but
the advantage is greater than the cost. Domestic and in-
dustrial solid wastes are found floating on rivers this
pollutes the water and constricts the water flow. This
eventually results in flooding which destroys lives and
property. Sullage and industrial wastewater often contain
significant amount of phosphate and oils and they con-
stitute significant sources of water pollution. It is unfor-
tunate that industrialization does not only increase human
comfort but also spell doom on man. In an earlier work
in South-Southern Nigeria, [5] reported that chemical
characteristics including Nitrate oil and grease and met-
als like Fe, Pb and Ni exceeded the acceptable limits in
some or most of the wells sampled and this could portend
serious health problems. This observation was more ob-
vious around the refinery and water-side areas of Warri.
Sediment of soil erosion is another source of pollution
especially in the place where agriculture is being prac-
ticed. In sloppy areas it is easy by gravitational force for
liquid to spread to a wide expanse area of land.
When a contaminant first enters the soil it will travel
down vertically gravity until contact with groundwater.
At this point it will begin to floor primarily in a horizon-
tal direction. The contaminants will then spread out
three-dimensionally like smoke from a chimney and is
called a plume. Groundwater does not exhibit turbulent
flows as found in surface water. The flow is defined by
gravity, pressure and friction. It is much more constant
than surface water. An aquifer can flow at a fraction of an
much per day up to few of reducing contaminants in
drinking water by controlling it at the source. Preven-
tative measures such as modification of tilling methods
and run-off, control in agriculture, the use of lined catch-
ment ponds for treatment of wastes, and double lined
underground storage tanks can greatly reduce contamina-
tion of drinking water sources [2].
Wells are one of the oldest sources of water. In many
rural areas, wells are the only reliable water sources
while in most cases; well water is a safe and dependable
option, in rare instances where contamination has oc-
curred. A well can be contaminated by disease-producing
pathogens and leachates from disposal of hazardous
household wastes [6]. The level of contaminant in drink-
ing water is sometimes high enough to cause acute (im-
mediate) health effects such as nausea, lung irritation,
skin rash, vomiting, dizziness, and even death. And more
so, contaminants are more likely to cause chronic health
effects occurring long after repeated exposure to small
amount of a chemical. Examples of chronic health effects
include cancer, liver and kidney damage, disorder and
damage of the nervous system, damage to the immune
system and birth defects [7]. Evidence relating chronic
health effects to specific drinking water contaminants is
limited. In the absence of exact scientific information,
scientists predict the likely adverse effects of chemicals
in drinking water using human data from clinical reports
and epidemiological studies, and laboratory animal stud-
ies. Radon is a radioactive contaminant that results from
the decay of uranium in soils and rocks. It is usually
more of a health concern when it enters a home as a gas
than when it occurs in water supplies. Radon in air is
associated with the possibility of contaminant in drinking
water. Water supplies once considered to be pure may
have various contaminants, often from natural sources
these are usually at levels below those considered to be
Water systems can be sensitive barometers of the
health of the planet. Decreased fresh water supply has
encumbered world food harvest, destroyed precious
aquatic habitats and threatened biodiversity. WHO in
1985 estimated that 80% of all sickness and diseases in
the world are attributable to unhygienic water. Water
borne diseases are among the leading causes of death in
many developing countries 10% of their productive time
because of diseases related to poor and contaminated
water programmes. Water from any sources must suit the
purpose for which it is intended. Good quality water is
water that is safe to use. Water intended for drinking
must be free from pathogenic organisms. The chemical
and physical qualities must also be suitable. Water must
not contain any dissolved or suspended materials that are
injurious to health of that would give an unpleasant taste.
Physically safe water must be at suitable temperature and
not have objectionable colour or cloudiness [8]. The
quality of water according to [10] comprises considera-
tion of many different factors. Information on and control
of water quality is of great importance for a wide range
of purpose including water supply, public health, agri-
cultural and indu s trial u ses.
As a result of human activities especially in urban ar-
eas toxic materials discharged into the environment have
affected the quality of water and rendered it unsafe. Good
management of waste from households industries and
Copyright © 2013 SciRes. JWARP
automobiles will safe-guard water contamination by im-
proving its quality. Dissolved gases in water such as car-
bon-dioxide (CO2) methane (CH4) and Hydrogen Sul-
phide, for example at concentration greater than 1 mg/l are
unfit for human consumption [9]. The World Health Or-
ganization has set standards fo r water quality. This serves
as a basis for approval of results of chemical analysis of
in terms of suitability of water for various intended uses.
A recent one is those established for drinking water in
Geneva 2011. To date there is considerable controversy
with regard to the specific organic constituents that
should be included in drinking water standards and con-
centration limits that should be established. For example
total dissolved solids, Sulphate and Chloride consump-
tion by humans thought water having concentration
above WHO 2011 limits is not generally harmful [10].
Most often water when it is related to health laid more
emphasis on the water chemistry this may be due to the
fact that the world around us is made up of chemicals. In
the bid to improve water quality disinfect water or our
immediate environment and improvement in quality of
living has resulted to introduction of toxic chemicals
directly and indirectly to water available for our uses.
Lead, Arsenic and Mercury are known to be harmful to
humans even in small account. Also excessive Nitrates
(N-NO3) cause metheno-globinemia in infants at a range
more than 15 - 25 mg/l, it can affect livestock as well and
can result in certain form of cancer [11]. Uses of chemi-
cal to disinfect water require skill and experience other-
wise its shortage of required quantity leave the water
partially treated with the disease causing organism in the
water increasing their resistant to such treatment. Over
dosage will also have side effects, for instance excess io-
dine in water causes goitre, while potassium permanga-
nate adds colour to water and stains materials.
Beside chemical elements in water, microbiological
organisms as well as physical characteristics and radio-
logical materials have their effects on health. The micro-
biological quality of water determines and helps in diag-
nosing various forms of diseases that can be linked to
water either for its transmission sustenance or eradication.
Drinking water should not contain pathogenic micro-
organism, and should be free of bacteria that indicate
excremental pollution. Water to be used for washing, ba-
thing and cooking as well must be free of pathogens car-
rying contagious diseases. It is therefore important that
drinking water and house-hold use water samples from
source to storage vessels be tested regularly for possible
indicators of dangerous microbiological organisms. Such
indicators include faecal streptococci, clostridium welchi
and the coliform aerogens group; all these indicators are
excreted in large numbers from warm blooded animals
and their detection in water-denoted faecal pollution.
Some macroscopic biological organism through their life
cycle or activities especially aquatic lives contributes to
health impacts of water on human being. Larvae crusta-
cea and large numbers algae or filamentous growth (i.e.
spirogyra) should not be allowed in house-hold use water.
They affect taste, odour and appearance of water. Good
water for domestic use must be free of disease-carrying
organisms like bacteria-cholera and typhoid, protozoa-
amoebic dysentery, viral infections hepatitis, worms-gui-
nea worn, angus-ring worm of the foot, etc. Moreover,
radiological materials are harmful; therefore their intake
should be kept to a minimum. Radium and Strontium are
particularly harmful when taken internally. Emission of
radioactive materials gets into water unconsciously wher-
ever it is used. In hospitals where it is used for X-Ray
and curing of other ailments the storage vessel even wa-
ter pipes made of metal not to mention plastics pipes can
be penetrated by radioactive materials.
Anchored on various records of water-related health
crises being noted in the Ogbomoso South Local Gov-
ernment (OSLG) Area, this research work focuses on the
investigation of the contamination levels of some se-
lected wells in the area and studying their associated
health implications on human beings. With the present
dearth of information on such occurrences in the study
area, a study of this nature is expected to provide techni-
cal explanations on the causes and implications of these
incidents of water-borne diseases on human health. The
OSLG has an area of 68 km² and with a population of
100,815 people [12]. With increase in agricultural activi-
ties and domestic chores in the area, there is greater need
for the adequate supply of good quality water for the
growing population. As the well water is naturally pro-
vided to every being, and then the environmental and
health implications that were attached to this natural re-
source cannot be over emphasized. This research there-
fore ultimately targets minimizing the deleterious effects
associated with the consumption of contaminated well
2. Methodology
2.1. Structured Questionnaire
Two different sets of questionnaires were prepared ac-
cording to the National Environmental Standard Regula-
tion and Enforcement Agency (NESREA) guidelines
format. The first set sought information which bothered
on water sources, its quality, supply and treatment were
administered in 10 selected major locations in the LGA
which include: Ajegunle, Arinkinkin, Arowomole, Care-
taker, Esanu-Aje, Ita-Olola, Malete, Oke-Alapata, Ora-
Gada and Sunsun. The other set which was administered
in the six (6) randomly select ed Health Institutions in the
LGA viz: Oyo State General Hospital, Alaafia Tayo,
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Oo re-Ofe, Bethel, Favour, and Grace Hospitals have ques-
tions on water borne-diseases and health-related issues.
2.2. The Sampling
Ten (10) wells were randomly selected, one in each ma-
jor locations in the LGA viz: Ajegunle, Arinkinkin,
Arowomole, Caretaker, Esanu-Aje, Ita-Olola, Malete,
Oke-Alapata, Ora-Gada and Sunsun. One (1)-litre plastic
containers were used to collect the water samples from
the well visited. The containers were thoroughly washed
in the laboratory with distilled water and labeled accord-
ingly. At the sampling point, the containers were again
rinsed with the samples to be collected .
2.3. Laboratory Analysis of Samples
The well water samples collected were taken directly to
the laboratory without any preservation for the physical
and chemical analysis. The parameters of interest and
their tests are as follows:
1) Temperature: This was carried out with the aid of
a thermometer in situ while taking the samples.
2) pH: Some quantities of the water sample were
poured into the beaker and the electrode of the pH meter
dipped into the sample. The meter was switched on and
allowed to stand for 30 minutes while the pH value was
3) Chloride: The apparatus were the weighing balance,
syringes, plastic vessel, and small plastic containers. The
chloride level in mg/l (ppm) was determined by mercuric
nitrate titration. Two drops of diphenylcarbazone indica-
tor were added and mixed carefully by swirling the ves-
sel in circles. Nitric acid was added drop wise until the
solution turns yellow. The titration syringe’s tip was in-
serted into mercuric (nitrite solution) solution and the
plunger pulled out until the lower edge of the plunger
seal is on the 0 ml mark of the syringe. The titration solu-
tion was slowly added drop wise and swirled until the
colour changed from yellow to violet. The millilitres of
titration solution from the syringe scale was read off and
multiplied by 1000 to obtain mg/l (ppm) chloride.
4) Hardness: The apparatus used were titer syringe
plastic vessel, small transparent plastic container and
buffer solution. The cap from the small plastic syringe
was removed and rinsed with the sample water. The
sample was filled to 0.5 ml mark and the cap replaced.
Five drops of hardness buffer solution were added and
mixed carefully. One drop of calmagite indicator was
then added. Take the titration syringe and push the
plunger completely into the syringe. Tip of the syringe
was inserted into ETDA solution and pulled out until its
lower edge is on the 10 ml mark of the syringe. The
EDTA titration solution is slowly added drop wise and
swung to mix after each drop until the colour changes.
The milliliters of titration solution were read off from the
syringe scale and multiplied by 300 .
5) Alkalinity: Apparatus included transparent plastic
vessel, calibrated syringe, bromophenol blue indicator,
and titrant solution. The cap is removed from the plastic
vessel rinsed with the sample and filled with the sample
to 0.5 ml mark. The cap is replaced. Drops of Bromophe-
nol blue indicator were added and the titration syringe
filled to 10 ml with H13811.0 solution. Titration solution
is added drop wise, mixed after each drop until a colour
change is noted. The milliliters of titration solution used
were read off from the syringe scale and multiplied by
300 to obtain mg/l (ppm ).
6) Conductivity: Digital conductivity meter was used.
The conductivity was determined by dipping the elec-
trode into the water sample directly in a beaker and al-
lowed to stand for 30 minutes before taking the reading.
7) Colour: 10 ml of each sample was measured in the
glass bottle given. Bottle was placed in the colour test
machine. Read direct was pressed on the machine. Col-
our reading was shown on the LCD screen of the ma-
8) Nitrate: A 15 ml of water was prepared into two
glasses each containing 5 ml of water sample. One of the
glasses was placed into left hand opening of the checker
disk. This was noted as the blank. A pocket of reagent
was added to the other sample and properly mixed. The
solution was marked as reacted sample and was placed at
the right hand opening of the checker disk at a distance
of about 30 to 40 cm away, and across a light source to
illuminate the sample to be matched. The disk was ro-
tated while looking at the sample through the colour test
window until the colour is matched. Th e value in the test
window is read as mg/l of nitrate or nitrogen (N-NO3).
9) Turbidity: 10 NTU (Nephelometric Turbidity Units)
with 1 - 10 NTU graduated standard was used. A portion
of water sample was poured into a clear and clean test
tube was shaken thoroughly and later inserted into the
sample chamber of standardized turbid meter (1 - 10
NTU graduated). The value was read off directly from
the scale. This procedure was also repeated for other
10) Iron: Apparatus used were colour comparator
cube and plastic vessels. The cap was removed from the
plastic vessel and rinsed with water sample. It was then
filled to the 10 ml mark. 1 packet of the iron reagent HI
3834-0 was added. The cap was replaced and the solution
mixed until solids dissolved. The cap was removed and
the solution transferred into the colour comparator cube.
The colour that matches the solution in the cube was re-
corded as mg/l (ppm) iron.
11) Magnesium: Demineralizer bottle, plastic vessel,
filter paper disc, funnel, pipette were the apparatus used.
The cap was removed and the Demineraliser bottle filled
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with tap water. The cap was replaced and the bottle
shaken for at least 2 minutes to prepare the demineralised
water. One of the large (50 mg/l) plastic vessels was
filled with 25 ml of water sample, up to the mark. Four
(4) drops of Buffer Reagent were added and swirled to
mix. One (1) packet of HI 38079A-0 Oxalate reagent was
added and stirred for 30 seconds by means of the plastic
spoon. This was left for about 5 minutes for the reaction
to complete. A folded filter paper into cone was placed in
the funnel and the funnel placed over the other larger
plastic vessel. The reacted water sample was poured
through the filter paper. Using the 3 ml plastic pipette, 3
ml of the filtered clear water sample was carefully trans-
ferred into the small (20 ml) plastic vessel. The top of the
Demineraliser bottle cap was flipped open. By gently
squeezing the bottle, the demineralised water was added
to the vessel up to the 10 ml mark. Using the 1 mL plas-
tic pipette, 1 mL of Buffer Solution was added and
swirled to mix. One (1) drop of Calmagite indicator was
added and swirled to mix. The syringe’s plunger was
pushed completely into the HI 380798-0 EDTA solution
bottle and pulled out un til th e lower edg e of the seal is o n
the 0.0 ml mark of the syringe. Titration solution was
slowly added drop by drop, swirling after each drop. As
the colour changes from pink to purp le, it was swirled for
15 seconds after each additional drop, until the solution
turns pure blue. The millilitre of titration solution was
read off from the syringe.
Calculation of the mg/l (ppm) of Magnesium in the
sample was as follows: ppm of mg = ml of titrant × 243.
12) Sulfate: Apparatus: plastic vessel, spoon, plastic
pipette, test tube. The plastic v essel was filled with 50 ml
of the sample up to the mark. One (1) packet of HI
38000A-0 Sulfate Reagent was added and swirled gently
to dissolve. Two (2) drops of Complexing Agent was
added and swirled to mix. Two (2) spoons of HI 38000B-
0 reagent were added and swirled gently to mix. This was
left for 5 minutes to allow reaction to occur. The test tube
was kept on a white surface and viewed from the top at
the black spot on the bottom. The plastic pipette was
used to fill the tube with the reacted sample until the
black spot has completely disappeared. The concentra-
tion in mg/l (ppm) of sulfate was read in correspondence
of the level of the liquid in the test tube.
13) Biological Oxygen Demand (BOD): The appara-
tus used include: incubator bottles o f 125, 250 or 300 ml
capacity with ground glass stopped; air-cooled insulator
(this is thermostatically controlled at 20˚C); high quality
distilled or deionized water; phosphate buffer solution;
magnesium sulphate solution; calcium chloride solution;
and iron (III) chloride solution. Preparation of dilution
water was by storing the distilled water in a large incu-
bator bottle whose mouth is plugged with clean cotton
wool as to permit it to be saturated with sufficient Dis-
solved Oxygen. To the distilled water was added 1 ml of
each of the following reagents: phosphate buffer magne-
sium sulphate, calcium chloride and iron (III) chloride
solution. The water sample was pre-heated with 0.5 m
acid or 1 M alkali if necessary to about pH 7 if it contains
chloride compound s, to chlorin ate with ad equate qu antity
of 0.125 M Na2SO3. Several solutions of the prepared
sample were made so as to obtain adequate drop in oxy-
gen content. The following dilutions were found ade-
quate: 1% - 2% for raw wastewater; 2% - 3% for settled
wastewater; 5% - 30% for biological treated wastewater;
3% - 7% for chemically treated wastewater; 35% - 100%
for river water. Suitable amounts of sample were meas-
ured into BOD bo ttles in dup licates by the aid of large tip
volumetric pipette. Bottles were filled to the brim with
dilution water in accordance with the percentage of dilu-
tion required. The stoppers were inserted without leaving
air bubbles. Dilution greater than 1% was made by dilut-
ing the water in a volumetric flask before transferring it,
carefully into BOD for final dilution. Since the sets of
dilutions are made in duplicate, the initial DO was de-
termined on the one set for 5 days in the dark at 20˚C in a
cooled incubator. Thereafter, the DO in the incubated
samples and the blank was determined.
The BOD was then calculated.
14) Coliform Bacteria Determination: Apparatus
used was Petri Dish Incubator. A 50 mg of MacConkey
agar was weighed and 1 litre of deionized water added.
This was allowed to so ak for 10 mins, swirled to mix and
sterilized by autoclaving at 121˚C for 15 mins. The mix-
ture was cooled to 47˚C and poured into petri dish. A dry
surface was ensured before inoculation by partial expo-
sure at 37˚C. A 0.5 ml portion of the sample was taken
and poured into the petri dish, the prepared MacConkey
agar solution was added and the dish covered. This was
placed in the incubator for 24 hrs at 30˚C. This was later
removed and placed on the colony counter for determina-
tion of the number of coliform bacteria formed.
3. Results and Discussion
3.1. Questionnaires
1) Water supply: The questionnaires revealed that the
major source of water supply in the area is from well
which is most available throughout. Figure 1 illustrates
the water supply pattern in the study area. It was also
found out that the mode of collection of water from the
source is majorly by head porterage with few uses of ve-
hicle due to the distance of water source. Furthermore the
respondent also testifies that water is always stored in-
side the tank for later use and that they do not pay for the
water since the wells are many and most of them are pri-
vately owned.
It is clearly shown from Figure 1 that even though th e
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area; effects of water-borne diseases and the availability
of stagnant water in the surrounding. The numbers 1 to
10 in horizontal axes of the graphs in Figures 2 to 9
represents the 10 selected locations in this order; Aje-
gunle, Arinkinkin, Arowomole, Caretaker, Esanu-Aje,
Ita-Olola, Malete, Oke-Alapata, Ora-Gada and Sunsun.
It could be observed from Figure 2 that more residents
use their water directly without subjecting it to treat-
ments as common in most rural areas of developing
countries. Forty (40) is the maximum percentage of those
treating their water before usage. This may be responsi-
ble for the high incidents of water-related diseases noted
in the area.
Figure 1. Water supply patter n in the study area.
Figure 3 shows that most residents believed have hu-
man or animal wastes dominating the contamination of
their water sources and this was closely followed by mu-
nicipal wastes which perhaps generate leachate contami-
nants. Since the level of industrial activities in the area is
very low, it could account for the view that there is low
industrial contamination .
majority of the respondents depend on both well and tap
water, well water remains the source of water with high-
est sole patronage.
2) Water quality: The survey revealed that most resi-
dents used water directly from the source without much
treatment except a few who boil theirs. It was also found
that refuse dumps are located on some uncompleted
buildings within the range of 100 m or more to a few of
the water sources. The respondents confirmed that there
is likelihood of the contamination of their water by
leachates emanating from these waste dumps. Again,
according to the respondents there is no certification of
good water quality by any authority. The respondents
allude the ailments and water borne diseases which had
affected the area in the past to this uncertified water
The results of responses on method of water treatment
revealed that simple boilin g was adopted by about 60% -
70% of those treating their water before consumption in
most locations. Residents of Esanu-Aje and Caretaker
however adopt chemical treatment method of adding
aluminium sulphate (alum) more than others using same
treatment method. Treatments by UV light, Ozonation,
Poly-electrolytes are not common in the area.
As revealed in Figure 5, majority do not subject their
water to any quality control or certification befo re its use.
Physical screening is being used in only 5 locations whe-
reas nearly 50% of the respondents assumed that their
pipe-borne/tap water is already treated by the govern-
ment. It is only in Ajegunle area that few residents claim
to subject their water to lab oratory analysis, probably due
Figures 2 to 9 illustrate patterns of other components
of the questionnaire like the water use prior to or after
treatments; types of contaminants; method of water
treatment; water quality control; occurrence of wa-
ter-borne diseases; proximity of refuse dump to the water
source; incidences of water-borne disease outbreak in the
Figure 2. Water use prior to or after treatments.
Figure 3. Types of Contaminants.
Figure 4. Method of water treatment.
Figure 5. Water quality control.
to their proximity to th e waterworks.
All locations except one had the refuse dumps farther
than 100 m from the water source. Equal numbers of
residents have their dumps both far away from and near
the water source in Malete area.
From the result of the questionnaire survey presented
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in Figure 7 indicates that residents in all the areas had at
one time or the other experienced water-borne diseases.
Those yet to experience it are however on the higher fig-
ures, especially at Sunsun and Ajegunle areas. Even
though this had not been a regular occurrence according
to the respondents, yet at different times residents have
fallen victims of the health challenges caused by con-
taminated water. This is in agreement with an earlier re-
search finding that contaminated water accounts for most
of the diseases in the tropics [13]. As a rider to these in-
cidences, Figure 8 displays the respondents’ awareness
levels of the effects. Except at Ajegunle and Arinkinkin
where equal numbers of residents were both affected and
otherwise, in the rest locations more respondents had
been affected by the water-related diseases in the previ-
ous times.
Most respondents at Arinkinkin, Malete and Ajegunle
areas claimed to notice stagnant waters in their sur
Figure 6. Proximity of refuse dump to the water source.
Figure 7. Incidences of water-borne disease outbreak in the area.
Figure 8. Effects of water-borne diseases.
Copyright © 2013 SciRes. JWARP
roundings (Figure 9). This could be spring boards for
mosquitoes and other vectors capable of affecting human
health negatively. In six (6) other locations surveyed,
equal numbers of respondents have and do not have
stagnant waters within their neighbourhoo ds.
3.2. Results of the Laboratory Analysis on Water
Samples from Selected Wells
The results of the Laboratory analysis conducted on se-
lected wells in Ogbomoso South Local Government were
presented in Tables 1 and 2. The graphical representa-
tions are in Figures 10 to 12. These were compared with
the guidelines on drinking water by National Primary
Drinking Water Regulations (NPDWRs, US), World
Health Organization (WHO) and National Agency for
Food and Drug Administration and Control (NAFDAC)
on Ta b le 3 . The basis of comparison is to determine its
potability of the water for intended use.
1) Appearance—All the ten samples gotten from the
study area were observed to be clear.
2) Colour—Sample taken from Ajegunle and Esanu-
Aje area were observed to have the colour value of 40
TCU and 70 TCU respectively, where other area has no
observable colour. With reference to Figure 10, the
standard was represented by a straight line graphs i.e. 15
TCU according to the specification given by National
Primary Drinking Water Regulations, U.S (NPDW Rs). It
is clearly shown that the sample taken from Ajegun le an d
Figure 9. Availability of stagnant water in the surrounding.
Figure 10. Physical parameters and locations.
Copyright © 2013 SciRes. JWARP
Figure 11. The distribution of chemical parameters in the studied wells.
Figure 12. Graph of the Coliform levels in the study area.
Esanu-Aje areas have colour values above the standard
as it is shown in Figure 10. Meanwhile other locations
(i.e. Arinkinkin, Arowomole, Caretaker, Ita-olola, Male-
te, Oke Alapata, Oora-Gada and Sunsun) have zero col-
our value as clearly shown on the graph in the same Fig-
3) Odour—No odour was noticed from the entire
sample before and after the collection. Thus they have
unobjectionable odour which meet the standard of both
WHO and NAFDAC as case may be.
4) Turbidity—There was no wide variation in the
measured value of the turbidity obtained, as the value
ranges from 0.00 NTU - 13.25 NTU. It is clearly shown
from the analysis that sample taken from Esanu-Aje area
of Ogbomoso south Local Government is highly turbid.
This value is above the recommended limit by WHO,
NAFDAC and NPDWRs which is 5 NTU, while the
sample from Sunsun is the least turbid. Ajegunle and
Esanu-Aje areas have turbidity value above the standard,
as indicated in Table 4. Sample taken from Aje g unl e area
has 7.50 NTU while Sample from Esanu-Aje has 13.25
NTU, while other locations fell below the WHO, NAF-
DAC and NPDWRs standard. By way of comparing tur-
bidity with the colour it is observed that Location with
high turbidity value has the highest colour value and
5) Temperature—Temperature is usually attrib uted to
weather condition, season, and time of days. The samples
Copyright © 2013 SciRes. JWARP
Table 1. Results of laboratory tests for the sample s.
Parameters Ajegunle Arinkinkin ArowomoleCaretakerIta-OlolaMaleteOke-Alapata Oora-Gada Esanu-Aje Sunsun
Chloride (mg/l) 300 150 200 200 210 320 400 250 380 200
Hardness (mg/l) 90 156 165 90 60 90 120 75 108 90
Iron (mg/l) 0 0 0 0 0 0 150 0 0 0
Colour (TCU) 40 0 0 0 0 0 0 0 70 0
Turbidity (NTU) 7.50 0.28 1.03 0.66 0. 27 0.60 1.97 3.10 13.25 0. 00
pH 7.24 5.99 6.40 6.33 5.99 7.26 8.12 7.99 8.21 7.46
Nitrate (mg/l) 46.07 45.19 46.07 69.5526.5432.16123.59 62.46 127.58 89.93
Conductivity(mg/l) 198 320 333 341 318 605 625 205 663 585
Total dissolve solid
(mg/l) 99 160 166.5 170.5159 302.5312.5 102.5 331.5 292.5
Alkalinity (mg/l) 186 75 135 120 75 270 150 165 147 240
Sulfate (mg/l) below 20 20 below 20 below 2021 60 80 below 20 60 65
Magnesium (mg/l) 41.31 29.16 48.6 48.5 19.4448.6 46.17 48.6 36.45 46.17
Temperature (˚C) 30 30 29.4 30.3 30.1 30.6 30.8 30.3 30.6 30.2
Dissolve Oxygen
(mg/l) 4.3 3.0 4.5 5.0 3.2 3.91 5.09 4.02 3.50 3.71
BOD 5(mg/l) 4.19 4.28 4.31 4.27 4. 09 4.21 4.19 4.27 4.09 4.18
Coliform/ml 200 100 200 800 700 100 200 100 900 300
Appearance cloudy clear clear clear clear clear clear clear cloudy clear
Odour Unobjectionable
from the study area have a maximum temperature of
6) pH—The pH of well water, the samples varied from
slightly acidic to slightly alkaline with the pH range of
6.0 to 8.21. The pH was found highest in Esanu-Aje
(8.21) and Oke-Alapata (8.12) and Lowest in Arinkinkin
(6.0), Ita-Olola (6.0) and Caretaker (6.33). Generally, the
water is found to be slightly acidic in most area and alka-
line in some parts as no health implications were attached .
From Table 3 the pH values fell within the maximum
acceptable concentration.
7) Tota l dissolved solids—The total d issolved solid in
these areas vary over a range of 99 - 332 mg/l. The high-
est value occurs at Esanu-Aje (332 mg/l), Oke-Alapata
(313 mg/l) and Malete (303 mg/l) and lowest occur at
Ajegunle (99 mg/l), the Total Dissolved Solids of all the
samples are within the maximum accepted concentration
when compared with the standard given by the W.H.O as
indicated in Tabl e 3. Any slight increase above the stan-
dard given by the W.H.O is an indication that some indi-
vidual living in the area is prompt to gastro intestinal irri-
tation. The conductivity from Esanu-Aje is also very high
(663 mg/l) and very low at Ajegunle (198 mg/l).
8) Total Alkalinity—varies from a minimum of 75
mg/l at Arinkinkin and Ita-Olola which could be as a
result of contamination by carbonate salt. From Figure
11 it is clearly shown that Arinkinkin and Ita-Olola have
the values that fell within the standard while others have
the value above the standard given by NAFDAC.
9) Chloride—The chloride content of the well in the
study area fells within the range of 150 - 400 mg/l which
indicates that some areas exceed the WHO (1993) rec-
ommended limits (250 mg/l). The highest value o ccurs at
Oke-Alapata (400 mg/l) and lowest value occurs at
Arinkinkin (150 mg/l) as indicated in Table 1, this could
be as a result of laundry activities taking place near the
area. Excess of the chlorine in water sample results in
cancer diseases.
10) Nitrate—The value of the nitrate content ranges
from 26.54 - 127.58 mg/l. The highest value occurs at
Esanu-Aje (127.58 mg/l) and the lowest value occurs at
Ita-Olola (26.54 mg/l) as clearly shown in Figure 11.
When compared with the standard, this range exceeds the
maximum acceptable concentration given by W.H.O, this
is an indication that the samples contain nitrate in excess
which can cause shortness of breath and blue-baby syn-
drome in infants below the age of six months who drink
water containing nitrate in excess.
Copyright © 2013 SciRes. JWARP
Copyright © 2013 SciRes. JWARP
Table 3. World health organization (WHO), national agency for food and drugs administration control (nafdac) and npdwrs
standards for drinking water.
Parameters Maximum Accepted
Concentration (W.H.O) Maximum Allowable
Concentration (NAFDAC) Maximum Contaminant
Level (NPDWRs, US)
Colour 2TCU - 15 Colour Unit
pH range 7.0 - 8.5 6.5 - 8.5 6.5 - 8.5
Turbidity unit 5NTU 5NTU 5NTU
Odour Unobjectionable Unobjectionable Unobjectionable
Total Alkalinity 100 mg/l 100 mg/l 100 mg/l
Total Hardness 100 mg/l 100 mg/l -
Iron (Fe) 100 mg/l 100 mg/l 100 mg/l
Sulfate 250 mg/l 250 mg/l 250 mg/l
Nitrate 3.0 mg/l - -
Chloride 250 mg/l 250 mg/l 250 mg/l
Conductivity - - -
Total Dissolved 1000 mg/l - -
Solid Magnesium 200 mg/l 200 mg/l Not Exceeding 250 mg/l
Coliform - - -
Dissolved Oxygen - - -
BOD - - -
Source: NAFDAC (2001), Consumer Safety B ulleting.
11) Sulfate—The sulfate content of the well in the
study area ranges from below 20 - 80 ppm. The sample
taken from Oke-Alapata has the highest sulfate content
as 80 ppm while Ajegunle, Arinkinkin, Arowomole and
Oora-Gada have the lowest sulfate content and this is
indicated by graph in Figure 11. When compared with
the standard the range falls within the maximum accept-
able concentration. Potential health effects from the in-
jection of water with excess su lfate content are; gastroin-
testinal irritation (loose stools, diarrhoea, etc) especially
in infants or individuals not acclimated to high level.
12) Iron—The iron value ranges fro m 0.00 - 150 mg/l.
There is no Iron detection in Ajegunle, Arinkinkin,
Arowomole, Caretaker, Esanu-Aje, Ita-Olola, Oora-Gada,
Oke-Alapata, and Sunsun except sample taken from
Malete area that was polluted with Fe. The value of the
Iron in Malete exceeds WHO recommended value (100
mg/l) as shown clearly in Ta ble 1 and Figure 11. Possi-
ble Implications of presence of Iron are the staining of
laundry, plumbing, appliances which will impact con-
taminants into the water.
13) B.O.D—According to drinking water standards as
given by W.H.O, NAFDAC and NPDWRs, Biochemical
Oxygen Demand (BOD) and E. coli should be com-
pletely absent in a sample of water in order to be safe for
drinking and other intended use. From the bacteriological
tests carried out, shows that samples collected from the
wells have bacterial contaminants and BOD was detected.
This is as a result of faecal contamination which results
in the following health implications; Urinary tract infec-
tions, bacteraemia, meningitis, diarrhoea, (one of the main
causes of morbidity and mortality among children’s),
acute renal failure and haemolytic anaemia.
14) Bacteriological parameters—It was observed
that some of the sampled wells are without lids and are
susceptible to faecal contamination, especially those lo-
cated within 20 m radius to dumpsites. The results of
microbial tests conducted on these samples are as pre-
sented in Table 4 and Figure 12.
3.3. Health Related Issues on Water in the Study
Area Based on the Questionnaire Survey
For the survey, Alaafia Tayo, Oore-Ofe, Bethel, Favour,
Grace, Oyo State Hospital management board, maternity
and Ireti-Ayo Hospitals were selected at random in the
study area. The survey conducted on the hospitals and the
health workers revealed that overall average number of
patients often reported daily is 164. The diseases or ail-
ment often reported are cholera, Typhoid Fever, Diar-
rhoea, Dysentery, Blue baby syndrome, Malaria, schis-
Copyright © 2013 SciRes. JWARP
Table 4. Results of the DO, BOD and the coliforms.
Locations Dissolved Oxygen mg/l BOD mg/l Coliform/ litre
Ajegunle 4.3 4.19 200
Arinkinkin 3 4.28 100
Arowomole 4.5 4.31 200
Caretaker 5 4.27 800
Esanu-Aje 3.5 4.09 900
Ita-Olola 3.2 4.09 700
Malete 3.91 4.21 100
Oke-Alapata 5.09 4.19 200
Oora-Gada 4.02 4.27 100
Sunsun 3.71 4.18 300
tosomia, cancer, carcinogenic diseases. The respondent
revealed that the major causes of the aforementioned
diseases are; contaminated water, mosquito bites, tsetse
flies and poor envir onmenta l managem e n t .
As shown in Table 5, the respondents revealed that
water can cause diseases and that water associated dis-
eases are common in the study area. Figures 13 to 15
indicate the results of the responses of the Health Offi-
cers on the water-related sicknesses .
1) Turbidity: is a measure of the degree to which the
water loses its transparency due to the presence of sus-
pended particulates. It is clearly shown from the results
of analysis that sample taken from Esanu-Aje area is
highly turbid and the water in the area is said to lose its
2) Chlorine: This causes environmental harm at low
levels. Chlorine is especially harmful to organisms living
in water and in soil. Results obtain from the analysis re-
vealed that excessive chloride contents was noticed in
Ajegunle, Arowomole, Caretaker, Esanu-Aje, Ita-Olola,
Figure 13. Average number of patient reported by the hospitals in the study area.
Figure 14. Possibility of water causing diseases.
Copyright © 2013 SciRes. JWARP
Figure 15. Occurrence of water-related diseases in Ogbomoso.
Table 5. Questionnaire results of health related issues on water in the study area.
Location Can water cause diseases Average numbers of patient reported dailyIs water associated diseases common in ogbomoso
Yes No Yes No
Ajegunle 10 0 20 7 3
Arinkinkin 10 0 30 9 1
Arowomole 10 0 16 10 0
Caretaker 10 0 10 8 2
Esanu-Aje 10 0 15 9 1
Ita-Olola 10 0 10 7 3
Malete 10 0 8 9 1
Oke-Alapata 10 0 30 6 4
Oora-Gada 10 0 15 5 5
Sunsun 10 0 20 6 4
Malete, Oke Alapata, Oora-Gada and Sunsun while chlo-
ride content observed at Arinkinkin fells within the stan-
dard given by WH O.
3) Iron: From the results of the analysis, there is no
iron detection in Ajegunle, Arowomole, Arinkinkin,
Caretaker, Esanu-Aje, Ita-Olola, Malete, Oke Alapata,
Oora-Gada and Sunsun except sample taken from Malete
area that was contaminated by iron.
4) Nitrate: The results showed that the sample ob-
tained from Esanu-Aje area has high nitrate contents
which exceed the standard given by WHO, NAFDAC
and NPDWRs. The uptake of these high concentrations
of nitrogen can cause problems in the thyroid gland and
it can lead to shortages of vitamin A. In the stomachs and
intestines of animals nitrates can convert into nitrosa-
mines, a dangerously carcinogenic kind of substance.
Humans have radically changed natural supplies of ni-
trates and nitrites. The main cause of the addition of ni-
trates and nitrites is the extensive use of fertilizers.
Combustion processes can also enhance the nitrate and
nitrite supplies, due to the emission of the nitrogen ox-
ides that can be converted to nitrate and nitrites in the
Copyright © 2013 SciRes. JWARP
5) Microbiological parameters: The pattern of the
coliform levels in the samples is as presented in Figure
12. The measurement was exaggerated as coliform count
per litre. The presence of coliform bacteria could be ac-
counted for as a result of faecal contamination of the
wells which are not covered. Again a few of the wells
were carelessly located downstreams of the septic tanks
in residential building s within a radius of 5 to 10 m. This
gives rise to situations whereby traces of coliform were
found in the samples thereby posing great health risks to
the residents.
4. Conclusions
The study reveals that one of the main sources of water
supply to the residents of the study area is wells which
fall into two categories namely shallow and deep well.
The water supply in the study area is not fully sup portive
to health as some measured parameters have values ex-
ceeding those of the standards. The reason for this could
be the fetching method through the use of ropes and
buckets that exposes the wells to invisible contaminants
and pollutants. Also the irregularity in the treatments of
the wells is a major threat to the water quality. Water-
related diseases like amoebic dysentery, typhoid fever,
cholera etc. are therefore often reported at the surveyed
To abate the problems it is recommended that water
for drinking should be subjected to treatment processes
like coagulation and filtration to control excess turbidity
and total solids, asid e boiling. Also, lime softening is also
recommended for locations where samples indicate ex-
cessive hardness in comparison with the standards. For
areas with microbial contaminants, each household should
endeavour to disinfect their wells least once in a month.
Also, personal hygiene within each household must be
improved and always emphasized. There is need for con-
stant surveillance by public health officials to enforce
water quality control measures and ensure that water
delivered to consumers is at all times safe and potable.
The personnel at the waterworks also need to optimize
the available resources in terms of funds and equipment.
Each component of water supply system from source
through treatment process storage and distribution must
be ascertained functioning well time to time without any
risks or failure.
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