Changes

*Step 2: Select an underdrain pipe diameter (typically 100 - 200 mm), assign this as an 'embedding' depth. *Note that this component does not apply if a downstream riser is being used to control an extended saturation zone.   

*Step 2: Select an underdrain pipe diameter (typically 100 - 200 mm), assign this as an 'embedding' depth. *Note that this component does not apply if a downstream riser is being used to control an extended saturation zone.   

*Step 3: Calculate the maximum permissible water storage depth beneath the pipe (''d_{s, max}'', mm):

*Step 3: Calculate the maximum permissible water storage depth beneath the pipe (''d_{s, max}'', mm):

<math>d_{s, max}=f'\times t divide n</math>

<math>d_{s, max}=f'\times t times 1/n</math>

{{Plainlist|1=Where:

{{Plainlist|1=Where:

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

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

*''t'' = [[Drainage time]] (hrs). Check local regulations for drainage time requirements.}}

*''t'' = [[Drainage time]] (hrs). Check local regulations for drainage time requirements; and

*''n'' = [[Porosity]] of the reservoir aggregate}}

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

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