Heavy Metal Pollution Levels of Hand-dug Wells in Close Proximity to Septic Tanks

Abstract

The aim of this study is to evaluate the levels of selected heavy metal contamination in well water located in close proximity to septic tanks in the South gate area of the Federal University of Technology, Akure (FUTA). Water samples were collected from five (5) randomly selected hand-dug wells in the study area within 50ft (15.4m) distance to septic tanks. The physical attributes of the wells revealed that the wells were well constructed and all the wells sampled were lined with precast concrete pipe (PCP) rings with covers. Five heavy metals namely Cadmium (Cd), Chromium (Cr), Iron (Fe), Manganese (Mn) and Zinc (Zn) were analyzed in the laboratory using Atomic Absorption Spectroscopy. Cd, Cr and Mn were present in high concentration in some of the water samples evaluated exceeding the WHO permissible limit. However, Fe and Zn contents of the water fell within WHO standard for potable water. Secondary water treatment is recommended before human consumption.