Changes

* 0.35 for more loamy Blend B (water quality treatment priority)  

* 0.35 for more loamy Blend B (water quality treatment priority)  

|-

|-

| [[choker layer|Choker course]]

| [[choker layer|Choker layer]]

| colspan="2" |100 mm

| colspan="2" |100 mm

| 0.4

| 0.4

|-

|-

| Perforated pipe and surrounding aggregate

| [[Pipes|Perforated pipe]] and surrounding [[Aggregates|aggregate]]

| Is equal to underdrain pipe diameter

| Is equal to underdrain pipe diameter

| Not applicable

| Not applicable