Changes

===For partial infiltration design, to calculate the depth of the storage reservoir needed below the invert of the underdrain pipe===

===For partial infiltration design, to calculate the depth of the storage reservoir needed below the invert of the underdrain pipe===

For designs that include an underdrain, the depth of the storage reservoir below the invert of the underdrain pipe (''d<sub>r'') can be calculated as follows:  

For designs that include an underdrain, the depth of the storage reservoir below the invert of the underdrain pipe (''d<sub>r'') can be calculated as follows:<br>

<math>d_{r}=\frac{f'\times t}{n}</math>

<math>d_{r}=\frac{f'\times t}{n}</math>

{{Plainlist|1=Where:

{{Plainlist|1=Where: