Bacteriological Analysis Of Borehole Water

1.0 Introduction

Water is one of the earth’s most precious resources. Although water is essential for human survival, many are denied access to sufficient potable drinking water supply and sufficient water to maintain basic hygiene. Globally, 1.1 billion people rely on unsafe drinking water sources from lakes, rivers and open wells. The majority of these are in Asia (20%) and sub-Saharan Africa (42%). Furthermore, 2.4 billion people lack adequate sanitation worldwide (WHO/UNICEF, 2000).

In developing countries, thousands of children under five years die every day due to drinking contaminated water (WHO, 2004). Thus lack of safe drinking water supply, basic sanitation and hygienic practices is associated with high morbidity and mortality from excreta related diseases.

Water-borne pathogens infect around 250 million people each year resulting in 10 to 20 million deaths world-wide. An estimated 80% of all illness in developing countries is related to water and sanitation and 15% of all child deaths under the age of five years in developing countries result from diarrhoeal diseases (WHO, 2004; Thompson and Khan, 2003).

The lack of safe drinking water and adequate sanitation measures could also lead to a number of diseases such as dysentery, salmonellosis, shigellosis and typhoid, and every year millions of lives are claimed in developing countries.

The evaluation of potable water supplies for coliform bacteria is important in determining the sanitary quality of drinking water. High levels of coliform counts indicate a contaminated source, inadequate treatment or post-treatment deficiencies (Mathew et al., 1984). Many developing countries suffer from either chronic shortages of freshwater or the readily accessible water resources are heavily polluted (Lehloesa and Muyima, 2000).

Microbiological health risks remain associated with many aspects of water use, including drinking water in developing countries (Craun, 1986), irrigation reuse of treated wastewater and recreational water contact (Grabow, 1991). It has been reported that drinking water supplies have a long history of association with a wide spectrum of microbial infections (Grabow, 2000).

The primary goal of water quality management from a health perspective is to ensure that consumers are not exposed to doses of pathogens that are likely to cause diseases. Protection of water sources and treatment of water supplies have greatly reduced the incidence of these diseases in developed countries (Craun, 1986; Grabow, 2000).

In Nigeria urban water supply coverage is only 70% of the total water requirements in the urban areas of Nigeria. Out of the 70% only 40% can boost of regular water supply.
(CWSD, 1999).

One of the goals of the United Nations Millennium Development Goals (MDG’s) is to reduce persistent poverty and promote sustainable development worldwide especially in developing countries. Improvement of drinking water supply and sanitation is a core element of poverty reduction. The MDG target for water is to halve by 2015 the proportion of people without sustainable access to safe drinking water and basic sanitation. The WHO (2004) estimates that if these improvements were to be made in sub-Saharan Africa alone, 434,000 child deaths due to diarrhoea would be averted annually.

This MDG target will at least reduce the above numbers of people without potable water and adequate sanitation. The provision of portable water supply especially in developing countries may not be sufficient because of (a) high population growth, (b) conflict and political instability, and (c) low priority given to water and sanitation programmes.

Boreholes are low-cost technology option for domestic water supply in developing countries and are generally considered as ‘safe sources’ of drinking water. When properly constructed and maintained, they provide consistent supplies of safe and wholesome water with low microbial load and little need for treatment of the water before drinking.

Water exists in several forms in the environment including sea water, sea-ice, fresh water, and water vapour as clouds and mist. As water moves through the environment it picks up gases and elements, flows to the sea and through ground in an endless process known as the hydrologic cycle.

The hydrological cycle ensures that water available on the earth passes through a cycle of evaporation, condensation and ultimately back to water in what seem endless and renewable. Groundwater occurs as part of the hydrologic cycle, which is the movement of water between the earth and the atmosphere through evaporation, condensation, transpiration and precipitation. The underground area where groundwater exists is referred to as an aquifer.

Groundwater comes from three major aquifer zones (underground rock or sediment that is permeable and can conduct water) generally situated from 300 to 1,500 feet below land surface. This drinking-water supply (groundwater) is protected from surface contamination by a layer of clay and fine-grained sediments. The level of ground water in the borehole may undergo changes due to the recharge and discharge rate. The rate at which a borehole is recharged may vary due to responses to withdrawal from wells through pumping, as leakage to vertically adjacent aquifers, as natural flow from an aquifer into streams and springs and also through evapouration from the shallow water tables.

1.1 Problem statement

In an effort to provide safe drinking water to the rural and urban dwellers, the government of Nigeria in conjunction with development partners, Non Governmental organization (NGO’s), Community Based Organisation (CBO’s) and some individuals have exploited the groundwater reserves since ground water is believed to be cleaner and therefore do not need further chemical treatment before consumption.

Several practices such as fertilizer application, agrochemicals, abandoned or inactive mine site, septic tanks, landfill etc, if not managed effectively could result in the contamination of groundwater.

Microbiological health risks remain associated with many aspects of water use. Some microorganisms are native or adapted to saturated sediments and rock, and are present in significant numbers in most water supply aquifers and even deep geological formations (NGWA, 1986). Biofilm formation sometimes encourages the growth of bacteria in wells and ground water. The quality of water in boreholes is also affected by the presence of heavy metals such as, Pb, Mn, CD Cu, Fe, Zn, K, Ni and Na.

Meteorological events and pollution are a few of the external factors, which affect physicochemical parameters such as temperature, pH, and turbidity of the water. They have a major influence on biochemical reactions that occur within the water. Sudden changes in these parameters may be indicative of changing conditions in the water. Internal factors on the other hand include events which occur between and within bacterial and plankton populations in the water body (Nishiguch, 2000).

The United Nations Organisation (UNO) designated 1981-1990 as the International Drinking Water Supply and Sanitation Decade with the aim of providing safe drinking water and adequate sanitation for all. Close to 11,500 boreholes have been drilled nationwide and about 60,000 hand dug wells have been constructed. This represents a total average increase from 14% in 1984 to about 52% in 1990 of the rural population (WRI, 1992).

The Ungwan Rimi can boost of a number of such boreholes which has been in use for several years. Most of the wells since being constructed have scarcely been maintained, rehabilitated or any major assessment carried out on the quality of water being pumped from it. This study was to determine the quality of water from these boreholes, as to ascertain it safety for consumption in relation to standards set by the World Health Organisation (WHO) for drinking water.

1.3 Justification

The issue of accessibility to clean water is of global magnitude. The global environmental outlook report indicates that about 30% of the world’s population lack access to safe drinking water. The consumption of water worldwide increases yearly whiles most of the world’s water resources continue to dwindle due to improper environmental management practices (UNEP, 2000). Globally, more than twenty five thousand people die daily as a result of water related diseases. (WHO, 2002) Nigeria has its fair share of problems from the water sector. To achieve the Millennium Development Goals (MDG) targets, for the period 2004 – 2015, data collected by Community Water and Sanitation Agency (CWSA) and Nigeria Water Company Limited (GWCL) in 1998, as part of their strategic investment plans estimate that, every year an average of 596,000 people need to gain access to an improved water supply.

1.2 Objectives

The objective of this research is to determine the quality of water from the boreholes in the Ungwan Rimi of Kaduna state.

The specific objectives were to;

Determine the levels of these parameters in the borehole water: temperature, pH, Conductivity, total dissolved solids (TDS), colour, turbidity, PO4 ˉ, SO4 ˉ, CLˉ, NO2ˉ Zn, Cd, Pb, Mn and Cu.

Determine the effect of seasonal variation on the parameters.

Access the level of Faecal and total coliform in samples.

Compare the level of the parameters to WHO standards.