Distribution of hydrocarbon concentrations from urban runoff.

Hydrocarbon runoff data from Madrid have been analysed in order to determine the effect of time, area characteristics and water flow on the runoff concentration frequency distribution. In this study, aliphatic and aromatic hydrocarbon concentrations obtained from runoff sampling from different areas of Madrid at different times of the year were used. The cumulative frequency distributions of a number of the hydrocarbons are characterized as modal lognormal distributions. The close correlation found between aliphatic and aromatic hydrocarbon concentrations can be expressed by a regression line.