* Step 1: Based on the median measured infiltration rate of the native soil at the estimated location and bottom elevation of the practice, or estimated from the median grain-size distribution results, decide if an underdrain will be included in the design.<br> | * Step 1: Based on the median measured infiltration rate of the native soil at the estimated location and bottom elevation of the practice, or estimated from the median grain-size distribution results, decide if an underdrain will be included in the design.<br> |