Changes

*Begin the drainage time calculation by dividing the area of the practice (''A_p'') by the perimeter (''P'').

*Begin the drainage time calculation by dividing the area of the practice (''A_p'') by the perimeter (''P'').

*To estimate the time (''t'') to fully drain the facility:  

*To estimate the time (''t'') to fully drain the facility:  

:<math>t=\frac{V_{R}A_{p}}{f'P}ln\left [ \frac{\left (d+ \frac{A_{p}}{P} \right )}{\left(\frac{A_{p}}{P}\right)}\right]</math>

:<math>t=\frac{V_{R}A_{p}}{f'P}ln\left [ \frac{\left (d_{T}+ \frac{A_{p}}{P} \right )}{\left(\frac{A_{p}}{P}\right)}\right]</math>

{{Plainlist|1=Where:

{{Plainlist|1=Where:

*''V_R'' is the void ratio of the media,  

*''V_R'' is the void ratio of the media,  

*''f''' is the design infiltration rate (mm/hr),  

*''f''' is the design infiltration rate (mm/hr),  

*''P'' is the perimeter of the practice (m), and

*''P'' is the perimeter of the practice (m), and

*''d'' is the total depth of the practice, including the ponding zone (m).}}

*''d_T'' is the total depth of the practice, including the ponding zone (m).}}

===Groundwater mounding===

===Groundwater mounding===