Nitrate, Chloride and Calcium Contamination of Hand-dug Well Water from Household Pit-latrine in Asamankese, Eastern Ghana

Abstract

The aim of this study was to assess nitrate, chloride and calcium contamination in hand-dug well water as a result of effluent infiltration from household pit-latrine. The study also compared wet and dry season effluent contamination levels. The results were compared to the natural background levels, Ghana Standard Board (GSB) and World Health Organization (WHO) guideline limits for drinking water. Generally, the result of the study indicated a 100% contamination of water with nitrate (NO3 -), chloride (Cl-) and Calcium (Ca2+) beyond the natural background of 0.23 mg/l, 7.8 mg/l and 12 mg/l respectively for safe drinking water. In addition, 21.7% and 8.3% of the samples analysed for nitrate and chloride respectively, were contaminated at levels that could pose serious health hazards. This could be attributed to the effluent leachate infiltration from the household pit-latrine through the soil into nearby hand-dug well water. Nitrate cannot be retained by soil and is easily washed out of the soil by percolating water. Sodium chloride, a common ingredient in the diet of most Ghanaians, is a strong electrolyte and passes through the digestive system unchanged. Chloride is therefore used as a measure of the extent of sewage discharge into water bodies. Analysis of variance at 95% confidence interval showed that calcium significantly differed in temporal variation (p = 0.00), chloride significantly differed in spatial variation while nitrate was significantly different in both spatial and temporal variations. It is recommended that the West Akim Municipal Assembly and Ghana Health Service should conduct regular inspections and monitor the construction of pit-latrines in the various households. Keywords