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A water well is an excavation or structure created in the ground by digging, driving, boring or drilling to access groundwater in underground aquifers. The well water is drawn by an electric submersible pump, a trash pump, a vertical turbine pump, a hand pump or a mechanical pump (e.g. from a water-pumping windmill). It can also be drawn up using containers, such as buckets that are raised mechanically or by hand. Typically, groundwater is naturally clean and safe for consumption. Because the overlying soil acts as a filter, groundwater is usually free of disease-causing microorganisms. However, contamination may occur following improper installation of well casings or caps, after a break in the casing or as a result of contaminated surface water entering the well. Contamination can also occur if wells are drilled in fractured bedrock without an adequate layer of protective soil and with less than the recommended minimum casing length. Ground water perhaps constitutes the largest source of dug-well water . It is located below the soil surface and largely contained in interstices of bedrocks, sands, gravels, and other interspaces through which precipitation infiltrates and percolates into the underground aquifers due to gravity . According to Oni et al , ground water is the water that has percolated downward from the ground surface through the soil pores and as such, it is not quite susceptible to pollution because most of the pathogenic organisms and many undesirable substances are removed by filtration action of soil particles. However, ground water may become contaminated due to increase in concentration of dissolved minerals like Mg2+, Ca2+, K+, etc . The quest for improved water sanitation, good hygiene and a disease free environment is of paramount importance in maintaining good health. Therefore, an access to safe water, free from contaminants and pathogenic organisms will go a long way to improving the well being of an individual .
In order to prevent illness, wells should be properly maintained and the water regularly tested for the presence of microbial contaminants. Well water should also be tested occasionally for possible inorganic and organic chemical contaminants. Generally, the extent of treatment required for water is determined by the quality of the raw water source .
Proper siting, location, construction and maintenance of wells will help to minimize the likelihood of contamination. Quality of water obtained from a well can be influenced by many local and regional factors. Some of these factors are natural, and others are the result of human activity. Although there are a wide variety of possible factors, some of the more common factors can be evaluated through the following tests:
The drinking qualities of dug well water are largely dependent on the concentration of biological, chemical and physical contaminants as much as environmental and human activities . Chemicals pollute water supply through industrial process and agrochemical applications while physical contaminants result from erosion and disposal of solid wastes .
Ensuring that water quality in aquatic environments remains within natural ranges is essential for maintaining viable, abundant and diverse communities of organisms. People have specific water quality requirements for drinking water, recreation, agriculture and industry, although the specific water quality requirements vary by sector. Degradation of water quality erodes the availability of water for humans and ecosystems, increasing financial costs for human users, and decreasing species diversity and abundance of resident communities. This study is aimed at determining the quality of water obtained from wells within and around a cement factory and how it can be improved upon and made useful for human consumption and use.
The study area, Gboko is located in Benue state, North Central Nigeria. Situated on longitude 9oE and latitude 7.0oN and 7.50oN, Gboko is a densely populated area inhabited dominantly by average-life dwellers. The inhabitants of the villages around the factory are peasant farmers. Heavy Mining activities are carried out around the factory under study. Production dust is also released into the atmosphere alongside the heavy vehicular traffic activities within and around the factory premises.
MATERIALS AND METHODS
Water samples were collected from four wells around the cement factory and labeled A, B, C, D and E. Locations B, C, D and E were sited in settlements around the factory while location A was sited within the factory premises. Care was taken to ensure that no accidental contaminations occurred during sampling and that samples were a representation of the water to be examined. Well water samples were collected in clean plastic containers by drawing water from the located wells using a clean plastic bucket. Some of the sample parameters were immediately analyzed and the remaining samples were stored in a refrigerator for further analysis.
Physical analyses of the samples were carried out by physical observation of the appearance, colour, taste, odour and turbidity. These were determined by the use of sensory evaluation panel as adopted by Edema et al . The samples for chemical analyses were refrigerated and analyzed within 24hours. All plastics and glass wares utilized were prewashed with detergent water solution, rinsed with tap water and soaked for 48 hours in 50% HNO3, then rinsed thoroughly with distilled-deionised water. They were then air dried in a dust free environment.. Chemical analyses were done according to AOAC  and Food and Agricultural Organization FAO .
All containers for bacteriological analysis in addition to previous treatment, were sterilized in an autoclave at 121oC for 15minutes. Microbiological analyses were carried out using the multiple tube technique as described by Uzuegbu and Eke .
All chemical and microbiological analyses were done in triplicates.
RESULTS AND DISCUSSION
Table 1: Physical Parameters of Well Water around a Cement Factory.
NTU-Nephelometric Turbidity Units.
Ts - Taste Od - Odour, nCr - Not Clear
Table 2: Bacteriological Analysis of Well Water around a Cement Factory.
Coliform Count (CFU)
E. Coli (CFU)
Table 3: Chemical Parameters of Well Water around a Cement Factory.
Hardness as CaCO3 (mg/L)
Calcium (Ca2+) (mg/L)
Magnesium (Mg2+) (mg/L)
Chloride (Cl-) (mg/L)
Sulphate (SO42-) (mg/L)
Nitrate (NO3-) (mg/L)
Results are represented as mean Â±standard deviation
Turbidity refers to water clarity. The greater the amount of suspended solids in the water, the murkier it appears, and the higher the measured turbidity. Higher turbidity levels are often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria and dissolved chemicals. . Water samples of A, B, C, D and E were 103, 2, 15, 46 and 1NTU respectively. This shows that only Wells B and E fall within the WHO standard.
The temperatures of the sample collected from the four wells A, B, C, D and E were found to be 23.2oC, 21.9oC, 22.6oC, 22.5oC and 21.7oC respectively. This falls well within the WHO standard of between 20 - 32oC.
In water, a small number of water (H2O) molecules dissociate and form hydrogen (H+) and hydroxyl (OH-) ions. If the relative proportion of the hydrogen ions is greater than the hydroxyl ions, then the water is defined as being acidic. If the hydroxyl ions dominate, then the water is defined as being alkaline . The hydrogen ions entering a drainage basin in rainwater are neutralized by carbonate and silicate minerals as water percolates through soils. This neutralization capacity in soils determines whether or not acid precipitation will cause water quality impacts in receiving water bodies. The ability of rocks and soils in any given drainage basin to buffer the acidity of rainwater is related to the residence time of water in the soil as well as the levels of calcium carbonate, bicarbonate, and silicate minerals . Samples A, B, C, D and E had values as 7.1, 7.8, 7.3, 7.4 and 7.1 respectively. Even though these fall within WHO range of 6.5-8.5, it indicates some level of alkalinity.
Hardness as CaCO3.
Natural sources of hardness principally are limestone, which are dissolved by percolating rainwater made acidic by dissolved carbon dioxide . Industrial sources include discharges from operating and abandoned mines. When hardness exceeds 18 mg/l, it generally causes problems, and a water softener should be considered. Water softened to zero hardness is corrosive. It is therefore desirable to blend a proportion of non-softened water with extremely soft water . When water containing bicarbonate or "temporary" hardness is heated, carbon dioxide is driven off, converting the bicarbonate into carbonates which precipitate to form the hard scale found in cooking utensils, pipes, hot water tanks, and boilers. This scale reduces the capacity of pipes to carry water and does not transmit heat well . The average hardness of the samples were 160.33mg/L, 100.33mg/L, 80.33mg/L, and 120.33mg/L respectively for Well A, B, C, D and E respectively. This indicates that sample A is hard, B, C and E are moderately hard while D is soft. Even though these fall within the WHO requirement of 100-250mg/L, A has much taste and would require much soap to form lather during washing, likewise B, C and E. The water samples of well D would require little soap to form lather and hence is good for washing and drinking. Also household equipment, such as aluminium pots, will be protected from scaling .
Nitrate and Nitrite occur naturally as ions as parts of Nitrogen Cycle. Concentrations of nitrate and nitrite can also be high in water as a result of contamination from agricultural run-off (fertilizers), run off from refuse dumps, and contamination of water with human and animal wastes. The main risk from nitrate and nitrites is methemoglobinemia or 'blue-baby' syndrome, to which babies under 0.5-1 year are more prone . Nitrate in drinking water has also been linked to human health problems such as stomach cancer and negative reproductive outcomes . High nitrate concentrations have also been linked to lower productivity in livestock . The mean Nitrate values are 38.03mg/L, 45.97mg/L, 38.03mg/L, 46.53mg/L and 24.7mg/L for Wells A, B, C, D and E respectively. Water samples from Wells B and D are high and close to the maximum contaminant level (MCL) of (50mg/L as NO3-) as recommended by the World Health Organization (WHO).
250 mg/l for chloride is the level above which the taste of the water may become objectionable to the consumer. The salty taste might not be apparent even up to higher level of chloride as high as 1000mg/l . In addition to the adverse taste effects, high chloride concentration levels in the water contribute to the deterioration of domestic plumbing, water heaters, and municipal waterworks equipment . High chloride concentrations in the water may also be associated with the presence of sodium in drinking water. Elevated concentration levels of sodium may have an adverse health effect on normal, healthy persons. Chlorides with sodium cations have a detectable salty taste, but if combined with the cation calcium or manganese, . Increased level of chlorides in water increase its corrosivity and hence an increase in the levels of metal in the water. WHO  does not provide a health based guideline figure for chloride, but notes that there may be a detectable taste above 250 mg/l . The Chloride concentrations of samples in A, B, C, D and E are 21.80mg/L, 23.56mg/L, 37.64mg/L, 33.64mg/L and 67.81mg/L respectively. These all fall within the WHO recommendation of 250mg/L.
High concentrations of sulfate in drinking waters have three effects: (i) water containing appreciable amounts of sulfate (SO42-) tends to form hard scales in boilers and heat exchangers; (ii) sulfates cause taste effects; and (iii) sulfates can cause laxative effects with excessive intake . Not many of the residents have experienced frequent diarrhea. This may be because, the laxative effect of sulfates is usually noted in transient users of a water supply because people who are accustomed to high sulfate levels in drinking water have no adverse response . Diarrhea can be induced at sulfate levels greater than 500 mg/l but typically near 750 mg/l . The concentrations of 48.0mg/L, 43.0mg/L, 13.0mg/L, 13.0mg/L and 21.33mg/L for A, B, C, D and E respectively show that the sulphate levels of all the Wells fall within the WHO recommendation.
Drinking water is tested for the presence of two groups of bacteria, total coliform bacteria and E.Coli bacteria. Results show the number of bacteria of each group in 100 ml of water sample.Â Total coliform bacteria are always present in animal wastes and sewage but are also found in soil and vegetation.Â E.Coli bacteria are only found in intestinal contents of warm-blooded animals.Â E.Coli bacteria tend to die more rapidly outside the body; consequently their presence in water indicates relatively recent contamination.Â The presence of total coliform and the absence of E.Coli bacteria may indicate a surface water contamination or a more remote sewage contamination. The results of the analyses showed that D and E have higher contaminations of 151 Coliform bacteria counts;18 E. Coli bacteria counts and 127 coliform bacteria;9 E. Coli bacteria counts respectively while A, B, and C have 40 Coliform;19E.Coli, 52Coliform;10E.Coli, and 35Coliform;5E.Coli CFU respectively. The prevalence of coliform indicates that the contamination of the well waters is due mostly to soil and vegetation than human waste. This water is not fit for drinking.
The result shows that the Sulphate (SO42-) levels, Nitrate (NO3-), Chlorides, pH and Temperature of all the samples fall within the WHO recommended levels while all the wells examined had odour, taste, high turbidity except two (above WHO recommendation). Hardness as CaCO3 exceeded the WHO recommendation of 250mg/L. The microbiological analyses of the well water did not meet the WHO recommendations. The wells are not good for drinking but can be used for washing even though much soap will be required to form lather.
Alternative sources of drinking water should be made available to the people living in the industrial area so as to enhance good health.
Consistent analyses should be carried out on the water and environment to safeguard the health of the people.
Frequent health awareness Programmes should be carried out in order to educate the people living in these areas on basic hygiene and general steps to enhancing good health.
Air pollution control measures should be taken to enhance a pollution free environment.
The excessive release of Carbon II oxide (CO) and Carbon IV oxide (CO2) should be stopped to avoid greenhouse effect and subsequent health hazards accompanying it.
Good mining practices should be insisted upon so as to safeguard the environment and ecosystem.
Corporate Organizations' responsibility to host Communities should be insisted upon by the Government in order to safeguard the health and improve the welfare of such communities.