Practice Problems: Sizing Residential Subsurface Seepage Systems 1
Sizing of subsurface seepage systems is done by applying the soil loading rate to the average daily flow, or the number of bedrooms for residential settings.
The soil loading rate can be calculated by using either a percolation (perc) test or a soil evaluation. The procedure for conducting percolation tests is found in section 905, Appendix A, Illustration G of the administrative code.
Information on using soil evaluations and loading rates is found in Section 905, Appendix A, Illustration M
Information on calculations for gravel trenches is found in Appendix A, Illustration H, Exhibit A. Exhibit B is used for gravelless pipe.
Residential Practice problems.
A perc test average is 240 minutes. The residential 4 bedroom house is being built.