Changes

*Step 2: Select an underdrain pipe diameter (typically 100 - 200 mm), assign this as an 'embedding' depth.   

*Step 2: Select an underdrain pipe diameter (typically 100 - 200 mm), assign this as an 'embedding' depth.   

*Step 3: Calculate the maximum possible storage reservoir depth beneath the pipe (''d_s''):

*Step 3: Calculate the maximum possible storage reservoir depth beneath the pipe (''d_s''):

<math>d_{s}=f'\times38.4</math>

<math>d_{s}=\frac{f'\times 96}{0.4}</math>

{{Plainlist|1=Where:

{{Plainlist|1=Where:

*''f''' = Design infiltration rate in mm/hr, and

*''f''' = Design infiltration rate in mm/hr, and

*38.4 comes from multiplying desired drainage time of 96 hours by void ratio of 0.4}}

*96 is the desired drainage time in hours

*0.4 is the void ratio of [[reservoir gravel|clear stone]]}}

===Additional step for system without underdrain===

===Additional step for system without underdrain===