Installation Manual:
AdvanTex
®
AX20-RT Treatment Units
NIM-ATX-AXRT-1
Rev. 1.0, 1/10
© 2010 Orenco Systems
®
Inc.
9
Step 7: Partially Backfill AX20-RT Excavation
Step 7a:
Fill the AX20-RT unit with about 16 in. (410 mm) of
water for internal support. Be sure to fill on both sides of the tank
baffle.
Step 7b:
Backfill around the unit with a 16-in. (410-mm) layer
of backfill material. Native material is acceptable if there are no
large or sharp rocks that may damage the unit walls. If native
material is not usable, backfill with ½-in. aggregate or pea gravel.
Do not backfill with sand. Use a mechanical compactor to thor-
oughly compact the fill, to minimize settlement and provide sup-
port for the walls of the unit.
Step 7c:
After the first layer of backfill is complete, fill the tank
with water to just above the midseam flange on both sides of the
tank baffle and then add another 16-in. layer of backfill. Compact
the backfill so that the backfill level is 2-3 in. (50-75 mm) below
the midseam flange.
Step 8: Test Watertightness of AX20-RT Unit
Step 8a:
After backfilling the AX20-RT excavation to just below
the midseam flange, make sure that the unit is filled with water
to at least 1 in. (25 mm) above the midseam flange on both sides
of the tank baffle.
Step 8b:
Wait at least 15 minutes and then inspect the midseam
of the unit for leaks. There should be no drop in liquid level and
no visible leakage from the seam.
8a
7c
Backfill and compact to 2-3 in. below midseam.
