7
8
Lay a gravel base (10-20mm pea
gravel) to a height of 200mm.
Ensure the gravel base is level.
Lay a gravel base (10-20mm pea gravel) to
a height of 225mm. Ensure the gravel base
is level.
9
Place the lentils on the gravel base perpendicular to the length of the modules.
The 100mm side of the lentils must lie flat on the gravel base. Ensure that each
lentil is level.
The lentils must be spaced far enough apart that each module is supported at
the locations outlined in the following image:
10
Continue filling the excavation with gravel (10-20mm pea gravel) until the
height of the gravel is level with the top of the lentils. The gravel must be
levelled.
11
A trench, for the rising main, must be dug from the pump chamber/water
treatment plant to the Puraflo modules inlet assembly. We recommend a
300mm wide trench with a 650mm depth. The rising main must be surrounded
by 150mm of gravel all around. The rising main pipe should be 500mm below
ground level to prevent freezing. Backfill the rest of the trench with existing
soil.
12
Using the glue provided, the 32mm PVC outlet pipes must be attached to all
modules before they are placed alongside each other as the pipework that feeds
into the sample chamber(s) will be inaccessible when the modules are in place.
13
Using the lifting ropes, lift the Puraflo modules into position, according to the
layouts in Section 3.3, taking note of the left and right-hand alignments marked
on the modules. Position the modules until they are just touching and they form
a V where they meet at the outlet.
