Infiltration Systems Treatment Criteria
Design to exfiltrate the WQv less pretreatment volume
Design storage reservoir to de-water WQv within 48 hours after storm
Assume a porosity value (i.e., volume of voids/total volume) of 0.4 used for stone reservoirs
Downstream detention often needed for Cpv and Qp
Notes:
Infiltration systems should be sized to treatment the water quality volume minus the pretreatment volume. This volume should be infiltrated within 48 hours.