Models That Predict In-Stream Pollutant Concentration at Zones
of initial Dilution
In certain cases, the short-term lethal effects of pollutants are of greater inter est than the fully mixed concentration. This is particularly true at localized areas, where transportation surface runoff discharges into the receiving waters, typically termed the zone of initial dilution (ZID). Methods for determining the size of ZID exist at state agencies and are given in several standard texts in hydrology (Dupuis, 2002).