ABSTRACT

The study investigated the sanitary assessment and physiochemical characteristics of hand-dug wells in Ado-Ekiti, Ekiti State, Nigeria with a view to support the operation and maintenance of hand-dug wells by providing clear guidance for remedial action to protect and improve water supply in the study area. The town was zoned into ten areas and 50 wells were randomly selected for sanitary risk assessment using the sanitary inspection forms and ten water samples were collected from the zones and tested for microbial and physiochemical parameters. The microbial parameters tested for were: total coliform count, faecal streptococci and E. coli, while the physiochemical parameters were: colour, turbidity, pH, temperature, sulphate (SO/-), nitrate (NO3-), iron (Fe+\ fluoride (F-), chloride (Cl"), sodium 2 (Na+), calcium (Ca+ ), potassium (K+), magnesium (Mg+2),manganese (Mn+\ total dissolved solids, conductivity, alkalinity and hardness. The wells were found to be at various levels of risk: about 52% were moderately at risk, 22% were at high risk while about 4% were at very high risk of contamination. A II the samples from the private hand-dug wel Is tested positive to total coliform count, E. coli were present in 90% of the water samples while 70% tested positive to faecal streptococci. The physiochemical parameters of the well waters were compared with the guidelines set by the World Health Organization (WHO) and the Nigerian Standards for Drinking Water Quality (NSDWQ), and calcium, iron, pH, alkalinity and manganese were found not to be in conformity with permissible limits.