Backfill material properly compacted (when sand is used a mechanical compation is required). No gaps underside the tanks.
FILL POST-INSTALLATION TEST TABLE (test when tank is backfilled)
Tank ID
Hydrostatic interstitial monitor record level
or interstitial vacuum/ pressure gauge reading
or interstitial vacuum/ pressure test record (initial + final + difference)
with primary containment vacuum/ pressure test record (initial + final + difference)
Observation wells installed in backfill according to design drawings.
Manufacturer's installation checklist (other documents) completed and copy sent to tank manufacturer.