- BACKGROUND TO THE STUDY
Water is life, but most importantly, clean water is a necessity to human life. It is public knowledge/domain that water is a colourless, tasteless and odourless substance that is essential to all forms of life that we know of. In another language, water is a colourless, transparent liquid compound of hydrogen and oxygen that has no taste or smell (Mather, 1984, Wilson, 1995). It is found in the atmosphere, and above or below the surface of the earth, as liquid, solid and gaseous state. A lot of water occurs in our planet and it exists in many places and forms, mostly in oceans and polar ice caps, but also as clouds, rain water, rivers or fresh water. Water is continuously in a state of flux that is, moving through the cycle of evaporation, precipitation and runoff back to the sea. All known forms of life need water. Human beings consume water which has quality compatible with human body. Water quality is a term used to describe the chemical, physical, and biological characteristics of water (Yuncong and Kati, 2011) that make it useable for certain activities. The chemical, physical, and biological attributes of water affect suitability of water for human use (drinking, irrigation, industry use) and ecosystem health. This natural resource has become scarce and polluted with the ever growing world population. Water pollution occurs when hazardous substances come into contact and either dissolve or physically mix with the water (USEPA, 2014). Change in any one of those processes affects the delicate balance with the other processes and ultimately results in changes to the ecosystem often in a negative direction.
The decline of water quality and the consequent reduction in the availability of clean water has become a global issue of concern as human population grows, industries and agricultural activities expand and climate change threatens to cause major alterations to the hydrological cycle. Water quality issues are complex and diverse and are deserving of urgent global attention and action. This should be so because water is a finite resource that is very essential for human existence, agriculture, industrial, etc. Comprising over 70% of the earth’s surface, water is undoubtedly the most precious natural resource that exists on our planet (David and Brad, 2009). Without any doubt, inadequate quantity and poor quality of water pose potent threats to sustainable development.
In the 1980’s, the United Nations through various agencies aimed to make clean water and sanitation available to everyone by the end of the decade. Although great strides were made, the biggest obstacles to success was the limited financial and technological resources in the developing countries and the rapidly growing population of these countries. Despite attempts to tackle water supply challenges, over 20 million people still die every year from water-borne diseases such as bilhazia, guinea-worm, cholera,and diarhheoa; millions more are affected by the insects that breed in fresh water and cause malaria and riverblindness (Malcolm , David , and Geoff, 2003). As water drains from the land surface, it carries the residues from the land. Surface runoff, especially, under the first flush phenomena, is an important source of non-point source pollution. Runoff from different types of land use may be enriched with different kinds of contaminants. For example, run-off from agricultural lands may be enriched with nutrient and sediments. Likewise, runoff from highly developed urban areas may be enriched with rubber fragments, heavy metals as well as sodium and sulphate. As a result, the quantity of water available for runoff, stream flow as well as the physical, chemical and biological processes in the receiving water bodies can be affected hence its pollution. Although man has recognized the usefulness of water, we disregard it by polluting the surface water like rivers, lakes, oceans, etc and changing the atmospheric chemistry by emission of great amounts of acidifying gases such as sulphuric oxides and carbon monoxide (Terry, 1996).
In Nigeria, the colonial economic development policies and plans contained little or no stringent rules to conserve the natural resources or to limit pollution. Thus the formative years of institutional environment regulation in Nigeria was characterised by the absence of clear scientific criteria and standards on toxic wastes and or pollution levels control in the environment (Joseph, 2004).
Water is both an abundant and scarce resource. Less than one percent of water on earth is available to terrestrial and fresh water ecosystems, including all human usage. Rapid human development, including urban and agricultural activities, demand a large and reliable supply of clean fresh water. Over half of accessible fresh water runoff has already been appropriated for human use, and the issue of water supply will become more urgent in this century due to growing demands from human societies and uncertainties associated with global climate change (Weixing, Joseph and Karen, 2008).
Nigeria is the most populous country in Africa. With a population of over 170 million, the country is endowed with generous resources of water bodies. The span of water bodies within the country is estimated at 900 km2 (Ekiye, Ebiara and Luo, 2010). These bodies of water provide resources for fishery, transportation, irrigation, recreation and domestic uses. Different regulations put in place to protect the aquatic environment in Nigeria have not been effective in controlling the indiscriminate dumping of wastes and effluents into open water bodies. These wastes and effluents range from chlorides, phosphates, oil and grease, nitrates, heavy metals from municipal and industrial sources. The heavy metals present in most Nigerian rivers and found in concentrations well above acceptable and permissible levels are lead, copper, zinc, nickel, chromium, cadmium and iron (Olayinka and Alo, 2004, Esoka and Umaru, 2006, Eniola, Chukwu and Olaide, 2010).
Degradation of water quality is most severe in the four states that contain 80 percent of the nations industries namely Lagos, Rivers, Kaduna and Kano States (Ekiye, Ebiara and Luo 2010). This poses a threat to health and economic development in Nigeria (Ajibade, 2004, Olayinka and Alo, 2004, Adekunle, Adetunji, Gbadebo and Banjoko (2007), Anyakoha and Uyimadu, 2008, Adewolu, Akintola, Jimoh, 2007, Mustapha, 2008, Owodehinde, Whenu and Fakoya, 2009). Maintaining and constant monitoring of the quality of water has become a major concern to all hence the need for present research.
- STATEMENT OF THE RESEARCH PROBLEM
Demand for good water quality for use is on the increase. For land based forms of life, however, about 97% of water is not available for consumption because of its salinity (David, 2002). Even the 3% that is fresh water often is not readily available for human use as much of it is either locked in glacialice or is stored underground. It is also important to point out that water as a geographical entity is not distributed uniformly over the surface of the earth, yet pollutants are being discharged into surface water bodies that run through urban areas thereby leading to the deterioration of its quality.
As a result of rapid population growth and increase in standard of living/industrial activities, every corner of the globe is however making increasing demands upon water resource in its surrounding thereby altering its quality. In Nigeria, urban population growth and industrial demands on water have been on the increase, and water quality has experienced remarkable changes. Rapid population growth, industrialization and urban development with their attendant environmental problems have continued in Kaduna state and have created stress on water quality of Kaduna River.
A healthy environment is one in which the water quality supports and protects health. Ensuring adequate protection of surface water of Kaduna River will necessitate continuous monitoring of the water quality as population grows and industrialization increases. Poor water quality usually becomes a major constraint on development if not adequately considered within a given development programme. This is because water resource conditions are complementary to many other development inputs. But domestic use, agricultural production, industrial activities and other factors can alter the chemical, biological and physical characteristics of water in ways that can threaten ecosystem integrity and human health. The major sources of water quality problems are from human settlements, industrial and agricultural activities which are the predominant land use zones in Kaduna metropolis. Negative factors/problems related to these activities include unhygienic disposal and inadequate treatment of human and livestock wastes, high cost/deficient management and treatment of industrial residues, inappropriate agricultural practices and unsafe solid waste discharge. For example, reports show over 80% of sewage in developing countries is discharged untreated directly into water bodies, (UN water, 2011). Industries are responsible for dumping an estimated 300-400 million tonnes of heavy metals, solvents, toxic sludge and other wastes into water each year (UN Water, 2011).
Nitrate from agriculture is the most common chemical contaminant in the world’s surface water. In addition, a growing number of new contaminants are being detected in the world’s waterways. These include contaminants that contain endocrine-disrupting compounds such as pharmaceutical products, steroids and hormones, industrial additives and agents as well as gasoline additives (UN water, 2011). These contaminants present a new challenge to water quality management as data on their ecotoxicology and associated risks are lacking. In addition, their synergistic interactions with existing contaminants and pollutants may result in complex concoctions that are difficult to treat and whose impacts are as yet unclear.
Due to poor institutional funding by Nigeria government, studies on the levels of polynuclear aromatic hydrocarbons (PAHs) and other organic contaminants in the country are very scanty. Most studies on organic compounds date back to the 1970s and 1980s when there were some equipment and little funding to conduct research (Taiwo, Olujimi, Bamgbose, and Arowolo, 2012). Poor funding had resulted in poor human resources base coupled with lack of instrumentation to monitor the level and distribution of these organic pollutants in the environment.
Many water quality variables are subject to large fluctuations in space and time. Understanding these fluctuations in the physical environment and determining whether such changes are natural or a result of anthropogenic influence can be a difficult problem. Although an assessment of water quality is a cumulative evaluation of overall system conditions, it is difficult to measure all the physical, chemical, and biological properties of a water body. Instead, a few variables that provide general indications of environmental conditions are selected (Robertson and David, 1993).
Water quality is to an extent an index of water pollution, the indices presently used in Nigeria are inadequate to indicate the damage that is done by heavy metals, metalloids, organic and inorganic compounds and blue green algae. Water pollution has continued to generate unpleasant implications for health and economic development in Nigeria and developing World in general, the consequences of which include 4.6 million deaths from diarrheoa and a sizeable number of casualties from ascariasis (Esrey, Potash, Roberts and Shiff, 1991). The pollution of natural and artificial waters by waste matters resulting from human activities constitutes one of the most important, difficult and complex problems confronting public health authorities in Nigeria. Water quality of rivers is generally linked to the land use in the catchment. Land use can affect the quality and quantity of runoff during and after rainfall (Richards and Host 1994).
Kaduna metropolis is drained by Kaduna River. Rapid urban industrialization, socio-economic development, population growth and increase in industrial activities in Kaduna metropolis appear to cause both water pollution and water resources depletion of Kaduna River. The river cuts across the city, dividing it into northern and southern halves. The southern part of the city is widely known as the industrial belt of the city. It accomondates three industrial layouts namely Kakuri, Makera and Kudenda. The northern part of the city consists of commercial centres, high and low income residential houses, millitary barracks and educational institutions. This river also serves as the main source of water for Kaduna metropolis, and its industries and irrigation agriculture that take place within and near the channel of the river. It is also used for drinking, bathing, swimming and fishing by the rural population living down stream of the river. Therefore, considering the roles that rivers and streams play in water supply to the inhabitants of their immediate environments and the increasing human activities around them, the neeed for constant monitoring and assessment of the quality of such water bodies becomes highly imperative. Also reversing the damage done to any water resource is usually complicated and expensive, minimizing further harm to river water quality as a result of land use activities has become most imperative. River water quality study offers a measure of hope for identifying, planning and management of our water resources. Consequently, a study of the spatial variations that exists in the pollution level of Kaduna River in relation to land use activities of the metropolis and the extent of economic and industrial activities along the Kaduna River and how they contribute to the pollution of the river forms the problem of this research. An earlier study on Kaduna River water quality was that carried out by Beecroft, Yammama, and Koii (1987). Emphasis on their work was directed on flow and loading in the drains and on the cyclic variations in the discharges of most significant of the Kaduna River. The authors studied the general pattern of behavior of flow and water quality in the drains. Mahre, Akan, Moses and Ogugbuaja (2007) studied the pollution indicators in Kaduna River. Water and Sediment samples from the River were collected and analyzed for pH, temperature, total dissolved solid, phosphate, nitrate, sulphate and the organic pollution indicators. From the results, the concentration of heavy metals in water and sediment samples, BOD and COD were found to be above the recommended permissible limits set by Federal Environmental Protection Agency (FEPA) Nigeria, World Health Organization (WHO)/European Union (EU).
Effects of emissions from Kaduna Refining and Petrochemical Company (KRPC) on Soil fertility in Rido area of Kaduna metropolis, Nigeria was carried by Vivan, Yakubu, Michael, Ya’u, Ishaya and Shehu (2014). Soil samples collected were taken to the laboratory for analysis and emphasis placed on those soil properties directly affecting soil fertility status which are: water holding capacity, soil acidity, macro nutrients (Nitrogen, Phosphorus and Potassium), micro nutrients (Calcium, Magnesium and Sulphur). Results from the laboratory analysis on those properties affecting soil fertility were compared with National standard (maximum permissible limits) on those properties and discovered soil contaminations with liquid gaseous and solid waste disposal from the refinery. They noted that environmental pollution in the form ofemissions and effluent discharge in these areas poses serious threat to the ecosystem particularly soil, often with undesirable effects.
However, there are limited studies on impact of land use on water quality in the Kaduna River. The present study looks at the various land use zones along the stretch of the river within the Metropolis to verify the quality of the river water within each of the land use zones. This was not captured by the work of Beecroft et al (1987) and there is need for information of this type in situation where people rely more on water from Kaduna River. This is an important contribution as a strategy for managing the health and economic activities of the people using the water of the river. For this purpose, the effects of Kaduna metropolitan land use on Kaduna River water quality has been chosen. This study is intended to come up with significant and important findings which will contribute to solving of Kaduna River water quality problems related to human activities of the metropolis and significantly further the frontiers of knowledge in this area of study.
- AIM AND OBJECTIVES OF THE STUDY
The aim of this study is to determine the effects of Kaduna metropolitan land use on Kaduna River water quality in Kaduna State, Nigeria.
To achieve our stated aim, the following objectives are put forward; to:
- identify the sources of pollution in Kaduna River.
- assess the quality level of Kaduna River in the metropolis in relation to land use zones.
- determine the spatial and seasonal variation of water quality in Kaduna River within the Kaduna metropolis.
- assess the level of awareness of residents of the metropolis on the effects of their activities on the quality of the Kaduna River.
- examine the uses and consequences of pollution of Kaduna River on human health.
- make policy recomendations for improving the quality of Kaduna River.
1.4 NULL HYPOTHESES
The following hypotheses are put forward:
- The physico-chemical properties of Kaduna River is not significantly related to discharges from industries and human activities along its channel.
- There is no statistically significant variation in the seasonal quality of Kaduna River within the Metropolis
- There is no statistically significant difference in the spatial quality of Kaduna River within the Metropolis.
- There is no statistically significant relationship between the health of the residents and the use of Kaduna River water quality.
- THE STUDY AREA
Kaduna metropolis occupies a total area of 260 km2 and is located at latitudes 10˚ 38ʹ 31ʺN and 10˚ 24ʹ 86ʺN and longitudes 7˚ 29ʹ 08ʺ E and 7˚ 23ʹ 56ʺ E. It is located in the central area of what used to be called the Northern Region of Nigeria (Jehu, 2002).
The British colonial officials led by Lord Frederick Lugard selected Kaduna as the regional headquarters of Northern Nigeria in 1912. Kaduna State derived its name from a Hausa plural word “Kadduna” meaning crocodiles (Ajibade and Okwori, 2009). This name was given to the town because of the presence of crocodiles in the river in the past that now divides the town into two, also called Kaduna River. During the colonial era, Kaduna grew both as a garrison town and an administrative centre. With the creation of states by the Federal Government in 1967, Kaduna ceased to be the capital of Northern Nigeria. It became the capital of Kaduna State and has emerged as a strategic centre for industries, defence, commerce and educational institutions.
Kaduna today ranks second only to Kano in Northern Nigeria in terms of population, industrial and commercial activities. As at 1991, Kaduna metropolis had a population of 337,639. At a growth rate of 3.5% per annum, it was expected to have a population of 600,000 or more by the year 2000 (Kaduna State Population Commision, 1993). As at 2006, Kaduna state had a population of 6,113,503. Kaduna metropolis comprising of Kadua South and Kaduna North had a total population of 767,306 (Federal Republic of Nigeria). Figure 1. shows the map of Kaduna State. Figure 2 shows the map of the study area.