Comparative assessment of the potable quality of water from industrial, urban and rural parts of Lagos, Nigeria

Abstract

The physicochemical properties metal concentration of drinking water from different sources in Lagos area of Nigeria were determined with a view of comparing the effects of industrialisation, population density and
urbanisation on the water quality from Lagos metropolis (Lagos Centre) and Ikorodu area (a relatively less industrialized and urbanized town of Lagos State) as a case study. The different sources of drinking water
considered were wells, boreholes, surface water and pipe borne water. The results revealed the water to be generally acidic (pH less than 7 ranging from 6.29 to 6.90) with mean values of 6.62 ± 0.31 and 6.49 ± 0.18 for Lagos Centre and Ikorodu area respectively, with significant difference in the pH of the well, tap, and borehole waters. In the urban Lagos Centre, well water had the highest DO, BOD, and acidity; the borehole water had the highest EC and TDS; while the pipe borne water had the least EC and TH. Similar result was reported for the ural Ikorodu area. The 495 and 399 μS/cm mean conductivity values for the well water from Lagos Centre and Ikorodu area respectively were significantly higher than that of the borehole, surface, and pipe borne water for both area. The physicochemical properties such as total solids (TS), total suspended solids (TSS), dissolved oxygen (DO) and alkalinity were generally significantly higher than the WHO, EU & NIS standard limits, with the values for Lagos Centre significantly higher than that of Ikorodu area. The Pb, Ni, Mg, and Fe concentrations exceeded the permissible limits set by WHO, EU and NIS for all the samples, with the Lagos Centre having the highest values. However, Cu, Zn, Na, Cr, and Ca concentrations were within the  permissible limits with the Lagos Centre samples having the highest values. Cd was not detected in any of the samples. This research has revealed the adverse effect of industrialisation, high population density, rapid urbanisation, etc., on the potable water sources in Lagos State of Nigeria, which could result in serious health hazards but with more pronounced negative implications on the Lagos Centre.

Keywords: Borehole Water, Pipe Borne Water, Surface Water, Effluent, Leachate.