Physiochemical And Heavy Metal Assessment Of Water From Boreholes

1.0 INTRODUCTION

1.1 BACKGROUND OF THE STUDY

Water is one of the essential commodities needed by all forms of life in ecosystem. It is themost abundant in the earth crust (about 75%).Despite its relative abundance, good qualitydrinking water is not readily available to man (Onweluzo and Akuagbazie, 2010). Sachetpackaged drinking water is very common in Nigeria. It is often found as a major source  of water at  food canteens and sold by many food vendors in the country (Adiotomre and Agbale,2015). The non- availability of good quality drinking water has resulted in number of health challenges as water is known to be a primary causative agent of many contagious diseases. In developing countries of the world, 80% of all diseases and over 30% of deaths are related to drinking water (Olaoye and Onilude, 2009; Onweluzo and Akuagbazie, 2010). This giveschance to private individuals to invest in the production of packaged drinking water (Dada,2009). Packaged table water can be referred to as ready to drink packed and machine-sealed water. This water is referred to as “purewater” by many of the locals in Nigeria and other African neighbouring countries like Ghana, Niger, Benin, Togo, etc (Adiotomre and Agbale,2015). The main source of packaged table water is water from borehole, springs, taps etc. Sachet water produced in small scale industries is mainly treated by aeration, double or single filtration using porcelain molecular candle filter or membrane filters and in rare instances, disinfection is applied. The level of treatment generally depends on the source of water.

Water is said to be potable when its physical, chemical and microbiological qualities conform to specified standards (Onweluzo, and Akuagbazie, 2010). According to Federal Ministry of Health Statistics, only about 30% of Nigerians have access to potable water while the United Nations estimated that about 1.2 billion people all over the world lack access to potable water (Oyekuetal., 2011; Ajewole, 2015).

However, physicochemical parameters are parameters that ascertain the quality of water. These parameters comprise the physical which can be access physically like colour, odour, taste, turbidity etc. and chemical parameters that can be determine using chemical test, e.g.chloride, alkalinity, free carbon dioxide, calcium, magnesium etc. Some of these parameters can be determine by titrimetric method, while some using highly sensitive equipment like spectrophotometer, atomic absorption spectrometer (AAS) etc.

1.1.1 The Importance of Water Quality Assessment

Water quality assessment process is an evaluation of the physical, chemical and biological nature of a water body in relation to intended uses particularly as it affects human health (Chapman, 1996). The quality of water may be described in terms of concentration and state (dissolved or particulate) of some or all the organic and inorganic materials present in the water, together with certain physical characteristics of water. It is determined by in-situ measurements and by examination of water samples on site or in laboratory. The main elements of water quality monitoring are, therefore, on-site measurement, the collection and analysis of water samples, the study and evaluation of the analytical results, and the reporting of the findings. The results of analyses performed on a single water sample are only valid for the particular location and time at which the sample is taken (Marky and Raman, 2011).

Unsatisfactory water supply and unwholesome sanitation conditions can result in poor human health. This portends the fact that there are very strong relationship between water and health (WHO/UNICEF, 2004). It is a natural resource whose scarcity or poor quality can cause a chain of unpleasant situations for mankind, especially in developing countries like Nigeria where access to improved drinking water is still a serious problem. There are many ways in which poor water quality and sanitary conditions can give rise to poor health (McJunkin, 1982; WHO, 2008). Water-related diseases are responsible for 80% of all illness/deaths in developing countries, killing more than 5 million people every year (UNESCO, 2007). Water borne diseases, as well as water related diseases which include cholera and other diarrheal diseases, as well as other water related parasitic diseases like schistosmiasis, guinea worm and river blindness are very common (WHO, 2006). In developing countries, thousands of children under the age of five die every day due to drinking of contaminated water (WHO, 2006). Thus lack of safe drinking water supply, basic sanitation and hygienic practice are associated with high morbidity and mortality. In fact, one of the goals of the United Nations Millennium Development Goals (MDG) is to reduce persistent poverty and promote sustainable development worldwide especially in developing countries through the improvement of drinking water supply and sanitation. The MDG target for water is to half, by 2015, the proportion of people without sustainable access to safe drinking water and basic sanitation (UNESCO, 2007). The WHO (2008) estimates that if these improvements were to be achieved in Sub-Sahara Africa alone, 434,000 child deaths due to diarrhoea alone would be averted annually.

1.1.2 Groundwater and Pollution

Groundwater exploitation has been with man way back in the ancient times. The civilizations of the ancient time had its success anchored on water supplies from groundwater as well as surface water. It is reported that in 1183 BC, crusade prisoners in Egypt constructed wells from excavated rocks which they called Joseph’s well to ensure the citadels and water supply. The drilling instead of the usual digging of wells began in the 12th century with successful drilling of well at Artois of France in 1226 (Osiakwan, 2002).

In the basement rocks, groundwater occurs in the weathered regolith and the fractured zones which sieves as the aquifer zone and usually occurs at depth ranging from 0m to a maximum of 60m. This underground water is protected from surface contamination by a layer of clay and fine grained sediments. The level of groundwater in the borehole may undergo change due to the recharge and discharge. The rate at which a borehole is recharged may vary due to variation in rainfall events, or as influent flows from nearby streams and rivers. A geological material that stores and transmits groundwater freely is known as an aquifer (Back et al., 1993).

Groundwater, like any other water resource, is not just of public health and economic values (Armon and Kitty, 1994). Water pollution has become a question of considerable public and scientific concern in light of the evidence of their toxicity to human health and biological systems. Heavy metals receive particular concern considering their strong toxicity even at low concentrations (Marcovecchio et al., 2007). Groundwater may contain some impurities or contaminants, which may be above the permissible limit as recommended by WHO even without human activities or disturbances. Natural contaminants can come from many conditions in the water shed or in the ground. This is because water moving through rocks or soil may pick up magnesium, calcium, chlorides, fluorides while some groundwater contain dissolved elements such as arsenic, boron, selenium, lead, cadmium, iron and manganese ( Alloy and Ryres, 2009).

These natural contaminants become a health hazard when they are present in high concentration. Also, groundwater is often polluted by human activities such as the use of fertilizers, animal manure, herbicides, insecticides and pesticides. Other sources of groundwater contamination can originate in the house or other forms such as dormitories, poorly built septic tanks and sewage systems for household wastewater. Leaking or abandoned underground storage tanks and improper disposal or storage waste chemical spills at local industrial sites also contribute to pollution of groundwater. Abandoned wells that have not been plugged or dismantled provide a potential pathway for water to flow directly from the surface into the groundwater. Open wells can become contaminated by the working fluids such as grease and oil from the pump or contaminants from the surface if the well cap is not tightly closed or if the lining is cracked or corroded (USEPA, 2007).

1.2 PROBLEM STATEMENT

Drinking water quality has always been a major issue in many countries, especially in developing countries (Assembly of Life Sciences, 2017). The World Health Organization in its “Guidelines for drinking water quality” publication highlighted at least seventeen different and major genus of bacteria and heavy metals that may be found in borehole water which are capable of seriously affecting human health (WHO, 2016). The proportion of waterborne disease outbreaks associated with borehole water has been increasing over the years (Moe &Rheingans, 2016). To solve this problem, the qualities of borehole water samples need to analysed. This study determines physio-chemical  and heavy metal analysis of borehole table water samples taken from Namoda LGA. Physio- chemical analysis includes analysis of pH, total chlorine, and turbidity and total Iron.

1.3 AIM AND OBJECTIVES

 AIM

The main aim of this study is to investigate the Physico-Chemical Properties and to carry out heavy metal assessmentof five selected boreholes in KauraNamoda Local Government Area Zamfara State. This was achieved through the following objectives.

OBJECTIVES

• To determine the concentration of pH, Chloride, Calcium, TotalHardness, Magnesium, Alkalinity etc. in the three borehole water
• To analyze the physio-chemical status of three different borehole water sold in KauraNamoda Local Government Area Zamfara State
• To ensure that borehole water consumed by the residence of the community is safe.
• To ensure that sachet water companies compliancewith World Health Organization (WHO) and Standard Organization of Nigeria (SON) specificationfor drinking water.

1.4 SCOPE OF THE STUDY

The present study has revealed that some of physico-chemical and heavy metal parameters of the borehole had values beyond the maximum tolerable limits recommended by WHO and SON. Thus, it calls for appropriate intervention, including awareness development work and improving the existing infrastructure in order to minimize the potential health problems of those communities currently realizing of the available water sources.

1.5 SIGNIFICANCE OF THE STUDY

This study is useful in increasing awareness about the importance of maintaining clean borehole water by using easy and effective methods which will reduce the chance of pathogenic microorganism survival and disease transmission for the consumers residing in such environment. This study helps to ensure that the borehole water that reaches the public is safe.

1.6 PURPOSE OF THE STUDY

The purpose of the present study was to ensure quality borehole water consumed by the residence of Kaura Namoda Local Government Area Zamfara State is safe and free of concentration of heavy metals, chloride, chromium, pH, total suspended solid, alkalinity conductivity etc.

1.7 JUSTIFICATION

The major source of drinking water for the inhabitants of KauraNamoda Local Government Area in recent time is the untreated groundwater obtained from boreholes that are drilled across the entire study area mostly by government agencies and individuals. Most of these boreholes are newly constructed and there is no existing information on their water quality. Meanwhile, the area is known for its intensive agricultural activities and most of these boreholes are located within the vicinities of farm lands and therefore could be contaminated. Also, the area is characterized by massive underlying rocks which could contain minerals capable of impacting on the groundwater. It is on this background that the water quality assessment of these boreholes became necessary so as to ascertain their suitability for drinking purposes by comparing with the WHO, NSDW and USEPA standards for drinking water.

1.8 LIMITATION OF THE STUDY

There are more than fiveborehole water within Kaura Namoda Local Government Area, but in this study the analysis is only carried out in five borehole water sold in the Local Government.

1.9 RESEARCH QUESTIONS

At the end of this work, student involved shall be able to give answers to the following questions:

• What are the types of heavy metals identified in borehole water?
• What is water contamination?
• What type of bacteria is commonly found in borehole water?
• What are the heavy metals common in borehole water?