Evaluation of Water Quality in Shallow Wells at Mokowe Village in Lamu County

Abstract

Inadequate supply of fresh piped water at Mokowe Village in Lamu County has forced the residents to depend on alternative water sources such as shallow wells for their daily needs such as shallow wells. However, most of the wells are located near residential houses less than 30 m from the pit latrines. This closeness contaminates the aquifer that supplies water to the wells. Gastrointestinal infections are among the challenges experienced in Mokowe Village. This study investigated the quality of water in shallow wells at different times of the day. The objective of the study was to evaluate the physicochemical parameters and microbial contamination of water from two main shallow wells, namely Salim Hassan and Baoni, with respect to their distance from the pit latrines. Water samples from Himwa tap was collected as a control. Total coliforms and Escherichia coli (E.coli) were analyzed by the most probable number (MPN) method. Physicochemical parameters analyzed were fluorides, nitrates, iron, sodium, potassium, pH, total dissolved solids (TDS), chloride, magnesium, calcium and total hardness, These were determined using DR 6000 Spectrophotometer, flame photometer, pH meter gravimetric analysis and wet methods (titration) respectively. Odour and taste were determined using organoleptic methods while colour was analyzed using a colour comparator. Total coliforms and Escherichia coli levels in the two wells were very high in the rainy season compared to dry season while Himwa tap water had no E.coli. However, total coliforms counts in Himwa tap water was beyond the permissible levels given by National Environment Management Authority (NEMA). Chloride, nitrate, sodium, potassium and calcium were beyond the allowable Maximum Contamination Level (MCL) provided by NEMA. Levels of pH for all the water samples were within the NEMA standards. The results indicate that water from the two main shallow wells were highly contaminated hence prompt chlorination and water quality monitoring should be undertaken. It was recommended that the public health office should ensure compliance on distance from the buildings when a new well is being constructed.