ABSTRACT

Impact of petrole um and seawater contaminated ground surfaces on the quality of rainfall induced runoff was investigated by comparing its quality with quality of rainfall induced runoff from uncontaminated ground surfaces. The petroleum and seawater contaminated runoff and uncontaminated runoff samples were collected from Umm Al-Aish and Raudhatain topographic depressions, respectively, along with collection of rainwater samples during a rainy season of November 2005 to January 2006. A total of nine samples, three of the rainfall, three of runoff from contaminated and three of runoff samples from uncontaminated ground surfaces, were collected. Impact assessment of contaminated ground surfaces on the quality of rainfall induced runoff was based upon comparison of TDS, ions (Ca, Mg, Na, K, SO4, Cl, NO3 and NO2), organics (TOC, COD and TPH) and metals (Cu, Fe, Ni, Pb, Y and Zn) concentrations. Comparison revealed 97.29, 68.16, 97.67 and 67.35% increase in TDS, TOC, COD and TPH, respectively, as compared to runoff from uncontaminated ground surfaces indicating a remarkable negative impact on the quality of runoff. Metals concentrations were detected below detection limits in all the samples. Quality comparison of groundwater samples collected from monitoring wells PI 8 and P1, situated in contaminated and uncontaminated ground surface areas, respectively, revealed percolation of contaminated runoff to fresh groundwater.