Assessment of Groundwater Quality From Boreholes and Hand-dug Wells Around Obajana Cement Factory and Its Environs in Lokoja, Kogi State, Nigeria
CHAPTER ONE
Aim of Study
The assessment of groundwater in Obajana and its environs will be done to verify if there are adverse effects on the groundwater around the area as a result of the activities.
Objectives
The above aim will be achieved through the following objectives:
- Determination of heavy metals (Fe, Zn, Cu, Pb, and Mn) concentrations in thegroundwater from hand-dug wells and
- Determination of physicochemical properties of groundwater such as (electrical conductivity, alkalinity, turbidity, pH, phosphate, sulphate, colour, dissolved oxygen, hardness, nitrate, temperature, biological oxygen demand and chemical oxygen demand);
- Statistically correlating the data in the water samples; and comparing pollution level in the groundwater with that of WHO standards for water quality.
Chapter Two
Literature Review
Water
Water is a liquid at ambient conditions, but it often co-exists on earth with its solid state being ice, and gaseous state being water vapor or steam (Ameyibor and Wiredu, 1991). Human bodies are approximately 60% water, blood is at least 50% water and the human brain made of 77% water (Stanistski et al., 2000).
Cement
The production of cement is increasing by about 3% annually (McCaffrey, 2002 and contribution of Portland cement production worldwide to the greenhouse gas emission is estimated to be about 7% of the total greenhouse gas emissions to the earth’s atmosphere (Malhotra, 2002). Calcinations process of cement is heat dependent and contributes to rising global temperature (Metz et al, 2005). The production of one tonne of cement liberates about one tonne of CO2 to the atmosphere, as a result of de-carbonation of limestone in the kiln during manufacturing of cement and the combustion of fossil fuels (Roy, 1999). The catastrophic effects of global warming are self evident in melting of the polar ice, flooding, drought and changing flora and fauna of natural habitat for both plants and animals. In slightly over a century, both marine air temperatures and sea surface air temperatures have increased between 0.4°C and 0.8°C (Sheppard and Soochow, 2007). Cement is also among the most energy-intensive construction materials, after aluminium and steel (Mehta and Burrows, 2001), thermal consumption of the order of 3.3tonne of clinker produced. Electrical energy consumption is about 90-120 kwh/tonne of cement (Giddings et al, 2013; EC, 2001). Materials are rarely found in the size range required. It is often necessary either to decrease or increase the particle size (Morrel, 2006). When, for example, the starting material is too coarse, and possibly in the form of large rocks, and the final product needs to be a fine powder, the particle size will have to be progressively reduced in stages (Pasikatan et al, 2001). The most appropriate type of machine at each stage of the process depends, not only on the size of the feed and of the product, but also on such properties as compressive strength, brittleness and stickiness (Jankovic and Mehta, 2010; Kano et al, 2000).
Sources of Water
Water can be grouped into surface water comprising of oceans, rivers, lakes, reservoirs, lagoons, streams and many others, Ground water which is considered mostly as more pure than the surface water and lastly the rain water which falls as a result of condensation and precipitation of the clouds (Stanistski et al., 2000). Surface water frequently contains substances that must be removed before it can be used as drinking watern while groundwater is pumped from wells and boreholes that have been drilled from aquifers at subsurface and is usually free from harmful contaminants.
Wells
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A Well is an excavation or a structure created in the ground by digging, driving, boring or drilling to access groundwater in aquifers (Roger,1982).The well water may be drawn by an electric submersible 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 (Obiri – Danso et al., 2009).Wells can vary greatly in depth, water volume and water quality. Well water typically contains more minerals in solution than surface water and may require treatment to soften the water. There are basically three types of wells. They include hand-dug wells, driven wells and drilled wells. Hand-dug wells are constructed by hacking at the ground with pick and shovel to dig until the water table is reached. If the ground is soft and the water table is shallow, then water can be obtained from the dug wells. The well is lined with stones, brick, tile, or other material to prevent collapse, and is either covered with a cap of wood, stone, metal or concrete (Roger, 1982). In Nigeria, many of the wells we find in our homes are excavated until reaching the water table and are described as shallow (Obiri – Danso et al., 2009) . The depth of the wells depends on how far the water table could be reached. Driven wells are built by driving a small-diameter pipe into soft earth, such as sand or gravel (Roger, 1982). A screen is usually attached to the bottom of the pipe to filter out sand and other particles. They can only tap shallow water, and because the source of the water is so close to the surface, contamination from surface pollutants can occur. Drilled wells require a fairly complicated and expensive drill rig. They use rotary drill bits that chew away at the rock, percussion bits that smash the rock. Drilled wells can be drilled more than 30.48meters. Often a pump is placed at the bottom to push water up to the surface (Roger, 1982).
Chapter Three
Methodology
Study Area
The cement factory which was founded in 1992, is located on latitude 7°55’0″ N and longitude 6°26’0″E has a community located next to the site of the cement plant and truck park and three communities surrounding the place. The original inhabitants of obajana are oworos, who claim to originate from the yoruba land. Occupations of the people include cattle rearing, rain-fed farming, hunting and petty trading. The agricultural system in the study area can be categorized into an intensive smallholder rain-fed agriculture. Since the only source of water – the Onyi River – dries up during the dry season, there is generally no irrigation farming being practiced in the area. As there is no recognized health institution in Obajana and environs, there are no detailed records on mortality and morbidity. However, records of clinical diagnosis for the oworo people at the general hospital in lokoja shows that majority (80%) of the ailments affecting the people are communicable diseases. Amongst the communicable diseases, malaria was the most prevalent followed by gastroenteritis as the study area is devoid of portable water, thus the high rate of gastroenteritis. The inhabitants in the area and surroundings source their water from hand-dug wells, very few boreholes and the semi-perennial Onyi River system. Obajana lies within the sub-humid tropical zone, and has a mean annual rainfall that range from 1100 to 1320mm. It experiences two main alternating seasons: dry and wet seasons. Rainfall lasts from April/May to September/October, characterized by moisture laden southwesterly winds blowing from the atlantic ocean, while the dry season lasts between November/March with predominantly northeast trade winds (EIA 2004).
Sampling Sites
The town was categorized into three suburbs based on the main road network in the town, Obajana community, Oyoo community, and Iwaa/amogbe respectively. Hand-dug wells that were open for communal use were considered in this study. 12 wells,8 boreholes were selected from Obajana community, and 6 wells,4 boreholes from the each of the suburbs for sampling, which gave a total of forty sample sites as listed in Tables 3.1 – 3.5 with tables showing the sampling sites / location, designated codes groundwater type and coordinates for sampling sites. Figures 3.1 – 3.4 shows pictures of hand-dug wells and boreholes from some of the sites, while Figure 3.5 shows map of Lokoja indicating Obajana and surrounding communities and Figure 3.6 shows map of Obajana and environs with the location of the cement factory.
Chapter Four
Results
Physicochemical Parameters
The results of the physicochemical parameters analysed for the hand-dug wells and boreholes water samples from Obajana are presented in Tables 4.1 – 4.4, each table shows the comparison for the mean concentration of the physicochemical parameters to that of the WHO standard for drinking water. Table 4.5 shows the correlation matrix of physicochemical parameters.
Chapter Five
Discussion
The results obtained for various analyses carried out on the physicochemical properties of the groundwater samples and their comparison with the World Health Organization (WHO) standards specified for drinking water as shown in Tables 4.1, 4.2, 4.3 and 4.4. The Tables, shows the mean values of the parameters determined in this research along with the recommended standards.
pH and Temperature
The pH ranged from 5.53 to 7.89 pH units. With the exception of Obajana 1, 2, 3 from site 1, Obajana 5,6 from site 2, Oyoo 4,and 5 from site 4, all other samples fell within the WHO range for portable water. This pH result shows that the well waters of the exceptional areas is slightly acidic. pH values lower than 6.5 are considered too acidic for human consumption and can cause health problems such as acidosis which could have adverse effects on the digestive and lymphatic systems of human (Nkansah et al, 2010). Water temperature recorded during the sampling period for the various sites did not differ significantly. Temperature ranged from 26 to 33ºC .With the exception of Obajana 2 in site 1, Obajana 5 in site 2, Iwaa 1 and 10 in site 3, Oyoo1 and 9 in site 4 This may be due to sampling season as pollution of ground water might have occurred.
Chapter Six
Summary, Conclusions and Recommendations
Summary
The groundwater (hand dug wells, boreholes) in Obajana and its environs of Kogi state were collected and analysed for various physicochemical parameters and some metal ions like lead, copper, iron, manganese and zinc.
Independent sample t-test of wells and boreholes close to the cement factory was carried out and it showed that 5 variables(turbidity, nitrate, lead, iron and zinc) significantly differ with its confident level being less than 0.05, manganese however do not differ in these sites, same independent sample t-test was carried out on sites far away from the cement factory and it showed that turbidity, lead, zinc, manganese and iron are statistically significantly different with its confidence level being less than 0.05, only nitrate do not differ between the two sites.
Further comparison (independent sample t-test) was done between the sites far away from the cement factory and sites close to the cement factory and it showed that Turbidity, Nitrate, Iron, and manganese do not differ significantly as confident level showed greater than 0.05, lead and zinc differ significantly in this comparison.
Conclusions
The results of the above work showed that most of the physicochemical parameters e.g. total alkalinity, total hardness, turbidity, dissolved oxygen, biological oxygen demand, electrical conductivity, sulphate, phosphate, copper, and iron were respectively within the acceptable limits of WHO’s recommended. However pH, lead, nitrate, manganese, zinc, were mostly found to exceed the maximum permissible limit as recommended by WHO at some study sites, further analysis showed that there is an equal amount of manganese in the four sites. Iwaa showed the highest case of heavy metals compared to the remaining sites .
Dissolution of rock minerals with the ground water is a possible reason for pollution. All the above results confirmed the high pollution of the ground water sources and hence, they are not suitable for consumption without any prior treatment.
Recommendations
Continuous water quality monitoring in the study area should be frequently carried out.
It is advised that underground waters from Obajana and its environs, should not be used as drinking water without prior
c. In addition to metal studies, frequent research on lead, zinc, manganese which are water contaminants of concern must be evaluated in the wells and boreholes. Heavy metals slowly accumulate in the kidney, liver, pancreas, bones, CNS where they degrade health without being noticed or diagnosed. Chelation is a primary method (by the use of a chelating agent which has the ability to hold the metal ion while being discharged by the liver or kidney into urine or feaces) used to remove heavy metals and can be done locally with the use of intravenous chelators or supplements. Many of the amino acids (which is known as the building block of life and healing) found in the protein of meat are good chelators. Red meat ,fish ,fowl and seafood are food that should be encouraged in this area as they provide natural chelators of toxic heavy metals (Kent, 2013).
A number of filtering devices which include carbon, ion exchange resins, activated alumina are also effective in the reduction of lead (EPA, 2013). Reverse-Osmosis can be carried out by government agencies as remedial measures. The overall implication of this observation calls for an urgent water resources management strategy (including treatment of the water) in the area in order to circumvent the fast deteriorating water resources quality, which may pose associated health risk and environmental hazards
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