Changes

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

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

*Step 4: Determine maximum permissible ponding depth (''d_p''):

*Step 4: Determine maximum permissible ponding depth (''d_p''):

<math>d_{p}=f'\times19.2</math>

<math>d_{p}=\frac{f'\times48}{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

*19.2 comes from multiplying desired drainage time of 48 hours by void ratio of 0.4. Note that conceptually the drainage of the ponded area is limited by ex-filtration at the base of the practice.}}

*48 is the desired drainage time in hours

*0.4 is the void ratio of [[reservoir gravel|clear stone]] *Note that conceptually the drainage of the ponded area is limited by ex-filtration at the base of the practice.}}

* Step 5: Sum total depth of bioretention, and compare to available space above water table and bedrock. Adjust if necessary.

* Step 5: Sum total depth of bioretention, and compare to available space above water table and bedrock. Adjust if necessary.