Infiltration pond design for highway runoff treatment in semiarid climates

Highway runoff disposal without concern for its specific characteristics may be associated with high material and environmental costs. An understanding of storm water management has enlightened the importance of the impacts that nonpoint pollution may cause to both surface waters and groundwater. Several systems for highway runoff treatment exist, often based on detention and infiltration processes. This paper suggests a method for design and evaluation of the design of infiltration ponds for use in semiarid climates. The design principle is based on capture and infiltration of the most polluted runoff. It takes into account the rainfall and soil hydraulic characteristics for the determination of the design volume. Seasonal variations in rainfall and evaporation were considered. The soil characteristics-hydraulic conductivity, texture, pH, and cation exchange capacity-the volume of runoff which is infiltrated, and the infiltration area are used to calculate the movement of the most mobile heavy metal, Zn, in the soil. The method presented was based and applied to highway runoff but can be used for treatment of stormwater runoff from other sources.