Underground Storage Tanks Program
Assessing Underground Storage Tanks for Earthquake Damage
Guidance for Tank Owners, Operators, and Service Providers
Following an earthquake it is important to examine all underground
storage tank (UST) systems for damage. A damaged or improperly
operating UST system can pose a significant risk to human health,
safety and the environment. While it is important to assess all UST
systems for damage, older systems with single wall piping and
fiberglass tanks may be particularly susceptible to damage from an
earthquake. The Washington Department of Ecology has recently
published a list of recommended actions for underground storage tank
owners and operators to detect earthquake damage. Below is the list
of steps you should take to assess UST systems for damage in the
event of an earthquake.
- Walk around the site and look for obvious signs that a tank
system is compromised. If you smell gasoline you should immediately
close the site, block it off to traffic and turn off the electricity
to the system. Tank owners should not try to locate the leak.
Instead they should contact the local fire department or their
- If you have an automatic tank gauge or alarm system (Veeder
Root, Ronan, Ustman or a similar system) check to see if any of the
system components are in an alarm mode. Perform an alarm check to
confirm that the alarms are working and run an inventory check to
determine if there are any unusual results. If you find that any of
these situations exist, do not operate the system. Call your service
provider for a more thorough examination and any repairs.
- If you don't find obvious signs of compromise, examine all tank
system access points.
- Spill bucket covers should be removed and the spill
buckets examined for distortion to determine if the seal between
the bucket and the drop tube, or the bucket and the surrounding
pavement has been affected. If you find distortion or product in
the spill buckets, do not operate the system. Contact your
service provider for a more thorough examination and to repair
- Manway covers should be examined for distortion of
the ring. If you can, remove the cover to examine the rubber
seal between the ring and the cover for any damage.
- Look in the sump, if it contains product or there
is a strong smell of product, immediately discontinue use of the
system, turn off the electricity and notify the fire department.
If you have a steel manhole cover and ring, do not replace the
cover as this may create sparks. Block off the area, and notify
your service provider as above. Do not try and pump the product
out of the sump.
- Remove the covers on your dispensers. Look for any
indication of product under the pumps or in the sumps. If you
find free product, see leaking seals or find an unusual smell,
do not use the system. Turn off the electricity and immediately
notify the fire department and your service provider. Do not
allow access to the pump island by persons or vehicles.
- If you have completed all of the above and do not find any signs
of leaks or broken equipment, attempt to operate each of your
dispensers in turn. If the dispensers do not operate, or operate
slowly or erratically, call your service provider to check the
system. (Failure of the dispensers to operate can indicate a leak in
the piping. Continuing to operate them can cause harm to your
- If you have performed all of the above checks and are confident
that your system is functional, we recommend that you have tightness
tests performed on your lines and tanks as soon as possible after an
earthquake. This is especially important if you have an older
system, or if you are using single wall piping or fiberglass tanks.
If you have questions or need assistance call the UST HELPLINE at
1-800-742-7878, toll-free in Oregon, or call your DEQ regional
office. We recommend that you have an emergency plan for
earthquakes, floods and other natural disasters. In the event of an
emergency call your local fire department and the Oregon Emergency
Response System at 1-800-452-0311 (in Oregon).