1) Measure and excavate hole for proper sizing and to be sure the
hole follows the curvature of the tank. The bottom of the hole must
be level and undisturbed. If rock or potentially sharp objects are
present at the bottom of the hold, provide a 6 to 8 inch base of
pea gravel. Never place tank directly on sharp objects or rocks.
However, if there is a good, level, undisturbed base, this may not
be necessary.
2) Place tank into hole using lifting lugs at each end of tank,
or manually set the tank by hand. It is not necessary or recommended
to use manhole opening or inlet and outlet piping to lift tank into
place. Level tank with carpenter or laser level.
3) The maximum factory recommende burial depth for septic tanks
is 24" from tank top to surface grade. Pump tanks are recommended
to be installed at similar depths but may be buried at a depth not
to exceed 48 inches.
4) Begin backfilling columns with either pea gravel or sand if
present. Excavated aggregates may be used so long as the material
is loose and can avoid the common voids associated with heavy clay
materials. If water is present directly beneath tank bottom, place
bucket gently on top of the tank while filling tank with water to
offset hydrostatic pressures. If high water may be a continual threat
it is then recommended that pea gravel or sand is used in backfilling
columns. Re-level tank if necessary.
5) Begin backfilling around the tank; continue to compact aggregate
around tank to eliminate voids within the backfilling material.
Filling the takn with water during this process is not required
as long as water is not present beneath the tank, and extremely
heavy clays are not being used as backfill material.
6) Once the tank has been completely backfilled, it is suggested
to fill tank with water, if high water tables or heavy soil conditions
exist. This process is beneficial in allowing the product and soils
to begin settling into place. It is also advantageous for those
unexpected rainfalls that may hit prior to tank settling.
7) The act of filling the tank with water in good site conditions
to eliminate deformation of the tank is not necessary.
8) Pump tank installation should follow similar procedures, however,
it is acknowledged by the manufacturer that the tank will not remain
at full capacity for extended periods of time as long as the appropriate
procedures listed above for high water tables and poor soil conditions
were instituted, the appropriate minimum liquid depth should range
between 6 to 18 inches.
