|5:1 to 15:1||Underdrain recommended <br> if < 15 mm/hr||1 to 3||5 to 10||0.5 to 6||No (infiltrating); Yes (non-infiltrating)||4m (3m if impermeable liner<br>is used) Building foundation,<br> Underground utilities,<br> Drinking Water Wellhead Protection Areas||No (infiltrating); Yes (non-infiltrating)||2 Yr (infiltrating); None (non-infiltrating) | |5:1 to 15:1||Underdrain recommended <br> if < 15 mm/hr||1 to 3||5 to 10||0.5 to 6||No (infiltrating); Yes (non-infiltrating)||4m (3m if impermeable liner<br>is used) Building foundation,<br> Underground utilities,<br> Drinking Water Wellhead Protection Areas||No (infiltrating); Yes (non-infiltrating)||2 Yr (infiltrating); None (non-infiltrating) |