Water Quality Evaluation of Leachate Produced from Pavement Specimens under Controlled Laboratory Conditions

ABSTRACT An experimental apparatus and procedures were used to evaluate the organic and inorganic quality of leachate produced from ten different asphalt and concrete pavement specimens under controlled laboratory conditions. Triplicates of both fresh and aged specimens were tested at three controlled laboratory temperatures of 4, 20, and 45 °C. Leachate samples were taken at various times during each experiment for eight hours to examine the metal pollutants concentration variability. Results showed that, in general, the leachate concentrations for most water quality parameters were below or near the method detection limit. However, dissolved chromium and vanadium concentrations were consistently detected from concrete specimens, particularly during the first three hours of the experiment and gradually reduced to below the reporting limit at the conclusion of the experiments. From this study we can conclude that the concentration of chemical constituents solely generated from pavement surfacing materials is negligible and the pollutants in roadway runoff is mostly related to other road use and land use sources.