Underground Tanks
NORA suggests dealers consider using
licensed and certified contractors
for the closure of underground tanks.
NORA recommends the guidelines
of NFPA 30 be followed whenever an
underground storage tank is being
abandoned or removed.
The NFPA 30 Annex suggests:
“Closure of underground tanks
either in place or by removal requires
owners and operators to measure
for the presence of a release where
contamination is most likely."
Underground Tanks
Abandonment Procedure
• Remove liquid and all residual material
from the tank and connecting lines
• Dispose of waste products in accordance
with all local, state and federal regulations
• Disconnect and remove all connecting
lines
• Empty the tank of all residual material
• Purge and inert the tank
• Test the tank atmosphere
• Remove fill pipe and vent pipe
• Cut holes in the tank as necessary
• Fill the tank to capacity with solid inert
material such as clean sand, concrete
slurry or other approved material. All
voids in the tank must be filled
• Completely backfill the area to grade
42 National Oilheat Research Alliance
NORA cautions that closure of fuel
storage tanks requires preparation
of a safe workplace and requires
adherence to OSHA safe work
practices, including proper confined
space entry and the use of individuals
certified as competent persons in
excavation as applicable.
For abandonment of an in-ground tank
NORA recommends an environmentally safe
and solid inert media be placed inside the
tank. Use media that will not contribute to
the deterioration of the tank, will not shrink
over time, and will not emit any hazardous
substances during or after abandonment.
It is important to understand that it
is very difficult to assess the site for
evidence of a release when in-ground
tanks are abandoned in place.
In areas where it has been approved, the
abandonment of tanks using a non-shrinking
foam that can be installed through the fill pipe
offers several advantages:
• The damage to the customers’ property
is minimized
• The chance of leaving voids or partially
filling a tank is minimized
• The chance of ground settlement is
minimized
• If the tank has to be removed later, it’s
easier than removing tank filled with sand
or slurry
For further information regarding tank abandonment see:
NFPA 30 - nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/
detail?code=30
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