EVALUATION OF GROUNDWATER QUALITY ASSESSMENT AND MODELING

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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Item Type: Project Material  |  Attribute: 43 pages  |  Chapters: 1-5
Format: MS Word  |  Price: N3,000  |  Delivery: Within 30Mins.
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