Assessment of the Contribution of Road Runoffs to Surface Water Pollution in the New Juaben Municipality, Ghana

Abstract

Road runoffs were sampled from five highways and five urban roads located in the New Juaben Municipality during the late storm events in the month of November 2014 and the early storm events in January 2015. A variety of water quality parameters such as, pH, temperature, turbidity, electrical conductivity (EC), total suspended solids (TSS), total dissolved solids (TDS), aqueous concentrations of Chloride (Cl −), Phosphate (− 3 4 PO), Nitrate (− 3 NO) and Sulphate (− 2 4 SO) ions as well as the total concentrations of some selected heavy metals (Fe, Cu, Zn, Pb, Cd, Ni and Cr) were analysed for both periods. Although the results for the studied parameters, particularly the heavy metals varied for both sampling periods, the general trend indicated an increase in accumulation from November 2014 to January 2015. This was attributed to vehicular deposition as well as other natural and anthropogenic depositions on the road surfaces during the antecedent dry weather period between the two sampling months. The highest increase in pollutant loadings was asso-ciated with the heavy metals and some physico-chemical parameters such as TSS, TDS, EC and tur-bidity. Generally, EC, TDS, TSS and turbidity were above the permissible limits of the Environ-mental Protection Agency (EPA) of Ghana for both sampling periods. However, almost all the mean concentrations of heavy metals recorded for both road runoffs and the control samples were within the permissible limits of the Ghana EPA with some few exceptions.