Statistical analysis of shallow well characteristics as indicators of water quality in parts of Ibadan City, Nigeria Olusegun Oguntoke, Oluseye A. Komolafe and Harold J. Annegarn ABSTRACT The inability of private well-owners to conduct well-water tests is a major obstacle to addressing contamination of water for human consumption in Ibadan city. Shallow well characteristics and their water quality were assessed with the aim of identifying observable characteristics that serve as markers of well water status. Field observation and interviews were employed to assess the features of 100 shallow wells. In addition, physicochemical and bacteriological parameters of water samples from selected wells were analysed. Out of 100 wells, the aggregate score of 60% ranged from high to medium risk. The mean concentrations of manganese, iron, total dissolved solids, pH and bacterial population were outside the WHO permissible limit in more than 50% of the sampled wells. Wells with poor locational characteristics had high turbidity and bacterial population (P < 0.05). A regression model showed that improved structural and maintenance scores of wells will reduce bacterial load in the well water; hence their scores can indicate water quality status. Olusegun Oguntoke (corresponding author) Harold J. Annegarn Geography, Environmental Management and Energy Studies, University of Johannesburg, PO Box 524, Kingsway Campus, Auckland Park, University of Johannesburg, Johannesburg, Gauteng 2006, South Africa E-mail: oguntokeo@gmail.com; oluseguno@uj.ac.za Oluseye A. Komolafe Department of Environmental Management and Toxicology, University of Agriculture PMB 2240 Abeokuta, Nigeria Key words | associative analysis, hygiene, markers, underground water, water quality INTRODUCTION A global overview of population access to improved water supply showed that many sub-Saharan African countries lagged behind other countries of the world. According to a WHO/UNICEF report (), almost all countries that had less than 50% coverage of improved water access in 2010 were found in this region of Africa. For instance, while the access in Nigeria was put at 58%, the figures for Ethiopia, Mozambique, Niger, Mauritania, Chad and Angola were much lower. The prevailing poor sanitation level and the gradual decline of government expenditure on public ser- vices in Nigeria due to budget constraints are partly responsible for the low population access to potable water supply (Areola & Akintola ; Ince et al. ). Groundwater is exploited by human populations as an alternative source of water supply for domestic use in Nigeria, due to inadequate water supply from public water sources (Ifabiyi ). Although shallow wells are widely owned by households in urban Nigeria because of the simple technology and low cost involved, water from many of them contained contaminants (Sangodoyin ; Rim-Rukeh et al. ; Orebiyi et al. ). Common con- taminants included the content of septic tanks, leachates from dumpsites, open drains, agricultural wastes and run- off from storms. This situation is further complicated as many well owners are oblivious of the quality status of water from their wells. Water from these wells is hardly tested, even though well owners have a responsibility to maintain their wells. Hence, an average of 6 to 20 persons per well are exposed to risks of using contaminated water for domestic purposes (Orebiyi et al. ). Consumption of contaminated water by human commu- nities in developing countries is responsible for the prevalence of gastrointestinal diseases such as diarrhoea, cholera, typhoid, dysentery and viral hepatitis (Dhawan & Desai ; Payment & Hunter ). Out of 1.8 million cases of mortality attributed to diarrhoea diseases globally in 2004, more than 80% were children from developing countries (WHO ). About 90% of these diarrhoeal dis- eases were attributed to unsafe water supply, inadequate sanitation and poor personal hygiene. According to 602 © IWA Publishing 2013 Journal of Water, Sanitation and Hygiene for Development | 03.4 | 2013 doi: 10.2166/washdev.2013.066 Downloaded from https://iwaponline.com/washdev/article-pdf/3/4/602/384750/602.pdf by guest