Quality and Safety Assessment of Borehole Water around Simpson Transfer Loading Station in Lagos, Southwest Nigeria

Abstract

The Simpson Transfer Loading Station in Lagos, Nigeria was established to treat and compact waste, thus reducing waste volume before being conveyed  to permanent dumpsites and ultimately saving costs. This study was conducted to determine the effects of the facility’s operations on nearby borehole  water. Physicochemical parameters; total dissolved solids (TDS), pH, alkalinity, acidity, color, hardness, calcium, magnesium, chloride, sulphate, nitrate,  phosphate, and electrical conductivity were analyzed using standard methods. Heavy metals; lead, arsenic, copper, cadmium, and chromium were  analyzed. The sampled water was assayed for the presence of bacteria, coliforms, and fungi. Possible health risks that might be associated with the  ingestion of heavy metals that might be present in the water were also investigated. The results of the physicochemical analysis revealed that TDS,  hardness, calcium, chloride, sulphate, nitrate, phosphate, and electrical conductivity exceeded the limits recommended by the World Health Organization.  All of the heavy metals analyzed exceeded their tolerable levels. The microbiological examination revealed non-permissible bacteria  counts, but coliform and fungi were undetected. The health risk assessment showed that average daily ingestion of the heavy metal was normal, but  daily dermal exposure to Pb exceeded the allowable limits. Moreover, the hazard quotient and carcinogenic risk of all the heavy metals exceeded the  permissible limits. Except bacteria, all the parameters were higher in the wet season than in the dry season. From these results, it can be inferred that the water is not suitable for  consumption. Environmental safety needs to be adhered to by the management of the facility