J.L. Nieber, A.J. Erickson, P.T. Weiss, J.S. Gulliver, R.M. Hozalski
Capacity testing (level 2) can be applied to infiltration basins to measure saturated hydraulic conductivities at various locations within the practice and estimate an overall average saturated hydraulic conductivity of the basin. Currently, however, it is not feasible to use capacity testing to assess infiltration trenches or permeable pavements.
Infiltration basins
Testing the infiltration capacity of infiltration basins involves a series of hydraulic conductivity point measurements. To obtain an estimate for the infiltration capacity of the entire basin, it is necessary to make numerous measurements. Even in infiltration basins with engineered soil, hydraulic conductivity often has a large variability. There are many techniques available for measuring the infiltration capacity (Dane and G.C. Topp, eds, 2002), as described in Water Budget Measurement.
Infiltration trenches
Infiltration trenches are generally filled with coarse gravel or even crushed rock. Therefore, it is not appropriate to use infiltrometers or permeameters for infiltration trenches. Synthetic runoff testing should be used to evaluate the infiltration rate of infiltration trenches.
Permeable pavements
It is not currently feasible to use soil infiltration measurement devices for permeable pavements because of the structure of the pavement material. Synthetic runoff testing should be used to evaluate the infiltration rate of permeable pavements.
Continue to Synthetic Runoff Testing.