Contaminant buildup and distribution on urban impervious surfaces at parking lots

This paper presents the results of experimental investigations on contaminant buildup, distribution and dynamics on asphalt surfaces of parking lot in Belgrade, Serbia. The investigated pollutants were solids, nutrients, oils and grease, chlorides, sulphates and heavy metals. Contaminant buildup was found to be highly influenced by traffic intensity and local climate conditions. The highest surface loads were found for solids, chemical oxygen demand, iron and zinc. Pearson's correlation revealed a strong correlation between total suspended solids, heavy metals and phosphorus, but settleable solids, oils and grease, total nitrogen, biochemical oxygen demand and chlorides are weakly correlated to other contaminants. Bonding of contaminants to the solid phase of the urban runoff was examined and results show that much higher concentrations were associated with finer fractions. The parking lot contaminant spatial distribution results for the examined sites were largely scattered and did not follow any particular pattern.