Changes

{{Plainlist|1=Where:

{{Plainlist|1=Where:

*''f''' = Design infiltration rate (mm/h), and

*''f''' = Design infiltration rate (mm/h), and

*48 = Maximum permissible drainage time for ponded water (h)}}<br>

*48 = Maximum permissible drainage time for ponded water (h)}}

Note that in designs without underdrains, conceptually the drainage of ponded water is limited by infiltration through the base of the practice.<br>

Note that in designs without underdrains, conceptually the drainage of ponded water is limited by infiltration through the base of the practice.<br>

For practices with underdrains see recommended maximum surface ponding depth for each filter media blend in the table above.<br>

For practices with underdrains see recommended maximum surface ponding depth for each filter media blend in the table above.<br>