ABSTRACT
Water
is essential for growing food., for household water uses including drinking,
cooling, sanitation., as a critical input into industry, for tourism and
cultural purposes., and for its role in sustaining the earth’s ecosystem (Mark
et al., 2002). In addition to water value for direct human consumption, it is
integrally linked to the provision and quality of ecosystems service. Domestic
water is used for drinking, cooking, bathing and cleaning, However, access to
safe drinking and sanitation is critical in terms of health especially for children.
For instance, unsafe drinking water contributed to numerous health problems in
developing countries such as the one billion or more incidents of diarrhea that
occur annually (Mark et al., 2002)
In
Nigeria, inadequate supply of pipe borne water is a major concern; hence many
homes have wells as a source of water for household uses. The groundwater of
forty wells in Agbowo community was assessed for Total Aerobic Bacteria Counts
(TABC) and Total Coliform Counts (TCC). The location and distances of wells
from septic tanks were determine using the Global Positioning System (GPS)
device and a tape rule respectively. All the wells sampled had high
TABC(4.76±1.41 log CFU/mL) and TCC (2.29±0.67 log CFU/mL) counts which exceeded
the international standard of 0 per100 mL of potable water. There were no
significant differences in the bacterial counts between covered and uncovered wells
(p > 0.05). The mean distance (8.93±3.61m) of wells from the septic tanks
was below the limit (15.24 m or 50 ft) setby United State Environmental
Protection Agency (USEPA). TABC increased with a decrease in distance between
thewells and septic tanks though not significant (p < 0.05) A very weak
positive correlation (r2=0.021)ensued between thedistance from septic tank and
CC, while a weak negative correlation (r2 = ‒ 0.261) was obtained between the TCC and TABC. This
study accentuates the need to set standards for the siting of wells from septic
tanks while considering allpossible sources of well contamination as well as
treatment of ground water before use.
CHAPTER
ONE:
INTRODUCTION
Background of the Study
Groundwater
from shallow and deep (borehole) wells has become the major source of potable
water in most semi-urban and rural areas of Nigeria. This is especially so
because, aside its assumed low susceptibility to pollution the method is a
readily available and reliable but cheap source of domestic water supply. For
instance, Eduvie (1995) stated that groundwater is usually preferred to surface
water because it is available in most areas, potable without treatment and of
low cost technologies. As a result of the foregoing, governments and
individuals in Nigeria have explored groundwater in forms of shallow and deep
wells for the supply of potable water. The use of the method became more
pronounced especially during the last fifteen years in a way to meet the
Millennium Development Goals (MDGs) of potable water supply target in the [6].
However, there is spatial variation of groundwater quality based on the type of
geological formation in an area, exposure to pollution sources and method of
abstraction amongst other factors [7, 8]. Consequently, there is the need for
the assessment of the quality of groundwater at local scales in the country for
safety purpose. The quality of groundwater is a measure of its wholesomeness.
This means that such water should not contain any physicochemical and microbial
substances in amounts that are harmful when consumed by man. Thus any source of
water for human consumption must conform to the quality control guidelines set
by both international and national agencies such as the World Health
Organization (WHO) and the Nigerian Industrial Standard (NIS), respectively.
This is necessary to avoid the negative health implications of the consumption
of such water [9-11]. Studies have shown that many health challenges such as
mortality, morbidity and poverty are consequences of consumption of water from
unwholesome sources [12-14]. In addition, about 80% of the diseases causing
deaths in developing countries are contracted through the consumption of
polluted water [15]. Naturally, groundwater is usually of high quality, but as
a result of urbanization, indiscriminate siting of septic tanks and pit
latrines, refuse dumps and mining activities, the quality of many ground water
resources has been degraded [16]. For this reason, there is the need to
continuously assess the quality of water from this source, especially in areas
where people depend solely on it.
As
population grows and urbanization increases, more water is required and greater
demand is made on ground and surface water. The rate of urbanization in Nigeria
is alarming and the major cities areas are growing at rates between 10-15% per
annum (Yusuf, 2007) and thus, human activities including soil fertility
remediation, indiscriminate refuse and waste disposal, and the use of septic
tanks, soak-away pits and pit latrines are on the increase. Groundwater
pollution has been attributed to the process of industrialization and
urbanization that has progressively developed over time without any regard for
environmental consequences (Longe and Balogun, 2010) which eventually results
in the deterioration of physical, chemical and biological properties of water
(Isikwe et al., 2011).
In
Nigeria, there is the challenge of lack of supply of pipe borne water hence
many homes have wells sited around the house at a distance from the septic
tank. 52% of Nigerians do not have access to improved drinking water supply
(Orebiyi et al., 2010). For most communities the most secure source of safe
drinking water is pipeborne water from municipal water treatment plants. Often,
most of water treatment facilities do not deliver or fail to meet the water
requirements of the served community; due to corruption, lack of maintenance or
increased population. The scarcity of piped water has made communities to find alternative
sources of water: ground water sources being a ready source. Wells are a common
ground water source readily explored to meet community water requirement or
make up the short fall (Adekunle, 2008). This is the situation in many parts of
Nigeria and several other African countries (Adelekan, 2010). These wells serve
as major source of water for household uses (drinking, cooking, washing etc.).
Commonest cause of pollution is attributed to close proximity of septic tanks
to wells, unhygienic usage of the wells e.g. some wells have no cover/lids;
they are dirty and unkempt thus, making the water unfit for use, resulting into
water borne diseases. Groundwater pollution may also be caused by the disposal
of solid or liquid wastes in pits, abandoned boreholes or even stream channels
and landfills (Onunkwo and Uzoije, 2011). Safe drinking water remains
inaccessible for about 1.1 billion people in the world (Mintz et al., 2001).
Those most susceptible to water borne illnesses are children, the elderly, pregnant
women and immunocompromised individuals, making water-borne illnesses one of
the five leading causes of death among children under age five (Gerba et al.,
1996). In 1997, the World Health Organization (W.H.O.) reported that 40% of
deaths in developing nations occur due to infections from water related
diseases and an estimated 500 million cases of diarrhea, occurs every year in
children below 5 years in parts of Asia, Africa and Latin America (Adejuwon and
Mbuk, 2011).
Ibadan
suffers serious water supply problems; cases of dry taps are common in
virtually every part of the city. Sights of children/women searching for water
are common experience (Ifabiyi, 2008). Potable water is one that does not
contain chemical substances or microorganisms in amount that can cause hazards
to health (Alonge, 2005). Water must be substantially free of dissolved salts,
plant, animal waste and bacterial contamination to be suitable for human
consumption. Poorly designed septic tanks and inadequately maintained septic systems
have contaminated ground water with nitrates, bacteria and toxic cleaning
agents. This can serve as a vehicle for spreading illnesses caused by such
microorganisms as; Vibrio cholera, Yersinia enterocolitica, Escherichia coli,
Cryptosporidium spp. and vector borne diseases such as guinea worm,
schistosomiasis, lymphatic filariosis, onchocerciasis, parasitic and viral
infections (Swerdlow et al., 1992; Mackenzie et al., 1995). Feacal (Simango et
al., 1992; Obi et al., 2002; Fenwick, 2006) and chemical (from industries and
farms) contamination, combined with the failure to adequately treat water, have
been incriminated in many water borne epidemics (CDC, 1993; Bridgman et al.,
1995). The risk of contaminated water for people was manifested in Lake Erie, Ohio,
USA in 2004 when 1450 people became ill because of a pathogen in the well water
(Fong et al., 2007). Microbial feacal contamination indicators are Echerichia
coli, Clostridia spp., Streptococci (Binnie et al., 2002; Simpson et al., 2002;
Scott et al., 2002) and other bacteria that could be of human or non-human
origin. Escherichia coli, particularly those possessing virulence markers as;
haemolysin, verocytotoxin and belonging to the enteropathogenic serotypes have
been responsible for gastroenteritis in humans (Griffin and Tauxe, 1991; Bell
et al., 1994; NRC, 1998). Hence, the need to ensure the supply of potable water
is a priority to prevention of water borne illnesses.
The
increasing dependence on ground water as a source of potable water has spurred
efforts to protect the quality of this limited resource. It has been estimated
that the total volume of waste disposed off via septic tanks is approximately
800 million gallon per year, virtually all of which is disposed in the
subsurface (USEPA, 1977). This makes septic tanks the leading contributor to
the total volume of waste discharged directly to ground water. Assessment of
water is therefore very crucial to safeguard public health and the environment
(Lin et al., 2010). Climatic conditions, land use patterns, vegetative cover,
topography, soil and geologic characteristics, well condition, location of
potential pollution sources, and agricultural management practices can affect
the transport and contamination of groundwater by bacteria (Bourne, 2001).
STATEMENT OF THE
PROBLEM
Various
factors affect the microbiological quality of groundwater. In areas where the
depth to bedrock is shallow, there is little interaction with the soil and,
therefore, contaminants are not effectively removed (Conboy and Goss, 2000). It
is noteworthy that Individual houses in Agbowo, Ibadan, are closely parked
together in an in orderly fashion with high number of inhabitants. Refuse
dumps, pit latrines and open sewers are common. Environmental sanitation is
almost nil. All these suggest possible chances of pollutants and contaminants
entering these wells. Improving the quality of groundwater resources offers an
important economic opportunity for the gradual improvement of the quality of
life (Valenzuela et al., 2009). Therefore, evaluation of the microbial quality
of water is an important weapon to the achievement of potable water for daily
consumption.
RESEARCH OBJECTIVE
Research
objectives are statements that the research project will attempt to achieve.
They provide the guidelines for establishing research agenda of activities
necessary to implement the research process (Hair et al, 2006; 663).
The
main objective of this study is to assess the bacteriological quality of ground
water at the Agbowo community via the use of microbial counts (Total aerobic
plate and Total coliform) to determine the microbial quality of the ground
water and the relationship between the distances of the wells to septic tanks.specifically
the objective of the study is:
1. To
determine the differences in the bacterial counts between covered and
uncovered wells
2. To
determine if the mean distance of wells
from the septic tanks was below the limit set by United State Environmental
Protection Agency (USEPA).
RESEARCH QUESTIONS
Research
Question is the question which the researcher set out to answer. It is
essentially a hypothesis asked in the form of a question (Kerlinger 2006). For
this study the following research questions are raised:
1. What
are the differences in the bacterial counts between covered and uncoveredwells?
2. Isdistance
of wells from the septic tanks was below the limit setby United State Environmental
Protection Agency (USEPA)?
Research Hypotheses
Research
hypothesis is a formal statement that presents the expected relationship between
an independent and dependent variable (Creswell 2006).
1. Ho:
there are nosignificant differences in the bacterial counts between covered and
uncovered wells?
2. Ho: The distance of wells from the septic tanks
is not below the limit setby United State Environmental Protection Agency
(USEPA)?
Significance of the
Study
This study on
completion would provide a ready guide to policy makers on environmental
harzard and it would contribute to the existing literature body.
Scope/ Limitation of
the Study
Samples were
collected from the Agbowo community in the Ibadan North Local Government Area
of Oyo state, Nigeria. Agbowo which is located on
latitude 7°26’ 39’’ N and longitude 3° 54’ 57’’ E is one of the largest
communities in Ibadan North. Ibadan north has a population of 306,795, (NBS,
2006) making it densely populated and having the highest residents in the
state. The community is largely occupied by students and staff of the
University of Ibadan and The Polytechnic Ibadan as well as other local occupants.================================================================
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