Assessment Of The Contribution Of Road Runoffs To Surface Water Pollution In The New Juaben Municipality

ABSTRACT The focus of this research was based upon the contribution of road runoffs to environmental pollution in the New Juaben Municipality. Road runoffs were sampled from five highways and five urban roads during the late storm events in the month of November 2014 and early storm events in January 2015. The choice of these months was to determine the influence of the dry period on the pollutant loads in the road runoffs due to the antecedent dry weather condition. Control samples were also collected for both sampling periods. A variety of water quality parameters such as, pH, temperature, turbidity, electrical conductivity, total suspended solids (TSS), total dissolved solids (TDS), aqueous concentrations of Chloride (Cl − ), Phosphate (PO4 3− ), Nitrate (NO3 − ) and Sulphate (SO4 2− ) as well as the total concentrations of some selected heavy metals (Fe, Cu, Zn, Pb, Cd, Ni and Cr) were analysed for both periods. There was a substantial increase in the concentrations and loads of all the studied parameters in both runoffs and control samples collected in January 2015 with the exception of pH which recorded lower values for the samples collected in January 2015. Although the studied parameters varied for both sampling periods, the general trend indicated an increase in accumulation from November 2014 to January 2015 which is attributed to vehicular and automobile 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 associated with the heavy metals and some physicochemical parameters such as TSS, TDS, EC and Turbidity. Generally, EC, TDS, TSS and turbidity were above the permissible limits of the Ghana EPA for both sampling periods. xiv However, almost all the mean concentrations of heavy metals recorded for all the sampling sites were within the permissible limits of the Ghana EPA with some few exceptions.