EPA Online Tools for Site Assessment Calculation
Notice
The old seepage velocity and travel time calculator determined the advective travel time. This calculation accounted for transport due to advection and sorption only. Because of widespread biodegradation of petroleum hydrocarbons and dispersion in aquifers, the advective travel time can come long after the first arrival time of a contaminant at a receptor. To avoid this situation the onedimensional transport calculators have been revised to calculate the first arrival times.
Try instead:
Continue below for the seepage velocity calculation.

