Protecting Your Groundwater Through Farmstead
Assessment:
Assessing Your Petroleum Product Storage Practices
AE-1078, July 1998
John Nowatzki, Water Quality Associate
Bruce Seelig, Water Quality Specialist
Thomas Scherer, Agricultural Engineer
Fuel storage tanks are commonly found on
farmsteads throughout North Dakota. Many people, however, don't
realize that these tanks are a potential source of groundwater
contamination. A fuel storage tank leaking at a rate of one drop
per second can lose almost 250 gallons of fuel in one year and
could contaminate over a billion gallons of water or 375 water
towers containing 500,000 gallons of water each.
This circular contains a brief discussion of each question on
the Farmstead Assessment checklist, and a section discussing what
you can do and who to call if you answer "Yes" to any
of the questions.
1. Do you have an underground fuel storage tank?
Underground fuel storage tanks have a life expectancy of
15 to 20 years. The potential for leaks increases with tank
age. Special management practices for underground tanks are
described in Section 5 of the publication.
2. Do you have a fuel storage tank less than 20 feet from
your well?
The most important consideration of your liquid petroleum
storage tank location is how close it is to your drinking
water well. Currently, there are no requirements in North
Dakota regarding minimum distances between a well and fuel
storage tanks. In Minnesota, for example, state regulations
require that a new water well be at least 20 feet from any
existing fuel storage tanks. Putting distance between your
well and your fuel storage tanks helps protect your water
supply from both leaks and spills.
Fuel storage tanks, whether they are aboveground or
underground, should be located down-slope from your well.
Your fuel storage tanks also should be located away from
areas of heavy traffic that could damage underground tanks.
3. Do you have a fuel storage tank, of any type, more than 15
years old or a bare steel fuel storage tank more than 3 years
old?
As fuel storage tanks age, the chance of leaks developing
increases. Underground storage tanks have a life expectancy
of 15 to 25 years. Fuel storage tanks are made out of a
variety of materials, the most common of which is uncoated
steel. Uncoated steel tanks offer no protection against
corrosion. Highly corrosive conditions such as saline, wet,
or acid soils can significantly increase the rate of
corrosion of underground metal tanks and piping.
4. Have you failed to inventory your fuel use or check your
fuel storage tanks for leaks?
Regularly monitoring your fuel use and comparing it to the
measured amount of fuel in the tank can discover leakage.
This is one of the easiest ways to prevent groundwater
contamination. Monitoring your fuel use does not require a
big expenditure of time or money and can help you detect a
leaking fuel storage tank before significant losses of fuel
occur.
An easy way to monitor your fuel use is to have a stick on
which you determine the level of fuel in your storage tank.
You need to check the level of fuel in the tank before you
withdraw fuel, to make sure the level in the storage tank has
not changed since your last use. If the level changes between
withdrawals, then your tank may be leaking.
5. Is protection against leaking or spills from your fuel
storage tanks lacking, i.e., no catch basin or concrete catch
pad and containment?
A concrete or other non-permeable containment area that
will hold the contents of your fuel storage tanks is cheap
insurance compared to cleaning up a fuel leak. For new
underground tanks, a high liquid level protection device can
be installed. This allows for careful monitoring of fuel
levels. For existing underground tanks, regular monitoring as
mentioned above is your only option for groundwater
protection.
Underground tanks:
All underground storage tanks should be coated to prevent
corrosion. There are basically three different types of
protective measures that can be taken:
- Using a fiberglass tank instead of a uncoated steel
tank. However, fiberglass tanks may not be suited for
alcohol-blended fuels.
- Coating a steel tank with a layer of non-corrodible
material, such as fiberglass-reinforced plastic.
- "Cathodic protection." A common type of
cathodic protection uses sacrificial anodes attached
to the underground tank. Sacrificial anodes are
pieces of metal more electrically active than the
bare steel tank. Because the anodes are more active,
they are attacked and corroded instead of the metal
in the tank. Therefore, the storage tank is protected
from corrosion until the attached "anode"
is depleted.
Aboveground tanks:
All aboveground tanks should be made of high quality
steel. Above-ground tanks must be approved and built to the
specifications and tolerances developed by the Underwriters
Laboratories, Inc. Tanks that are used and designed for
underground storage should NEVER be used above-ground.
Underground storage tanks used for aboveground storage can
easily fail, because the structural support provided by the
soil does not exist aboveground.
Tanks no longer in use:
Tanks that are to be out of service for extended periods
of time should be removed if feasible. This is also a good
way to determine if a tank has been leaking.
The tank should be emptied before removal. Dig a hole
large enough to allow you to easily lift the tank out of the
ground.
After removal, check the hole and the tank for any signs
of leakage. Make sure vapor and sludge are removed from the
tank before it is cut or transported to a scrap dealer.
Owners and operators should always notify the State
Department of Health and Consolidated Laboratories - Division
of Waste Management and local fire officials before removing
an underground storage tank.
Leaks and Spills
All leaks and spills should be dealt with immediately. For
help, call the North Dakota State Department of Health, Division
of Waste Management, at (701) 328-5166.
If you have questions concerning underground storage tank
rules, call the North Dakota State Department of Health, Division
of Waste Management, at (701) 328-5166. Aboveground fuel storage
tank regulations and standards are mandated through the North
Dakota Office of the Fire Marshal, at (701) 328-5390.
Underground storage tank regulations in North Dakota do not
apply to farm or residential tanks of 1,100 gallons or less
capacity that are used for storing motor fuel for noncommercial
uses. However, this does not release individuals from the legal
accountability for environmental damage that may result from
leaking storage tanks. All clean-up costs for leaking tanks are
still the responsibility of the owner. It is in the best interest
of every storage tank owner to follow good management practices.
Any underground storage tank greater than 1,100 gallons
capacity (commercial or noncommercial use) must be registered
with the North Dakota State Insurance Department - Petroleum Tank
Release Compensation Fund.
Any aboveground storage tank used for noncommercial purposes
may also be registered (regardless of size). This registration is
not mandatory. However, registration qualifies the owner for
financial assistance if a leak causes environmental damage. For
further details regarding tank eligibility and procedures,
contact the North Dakota State Insurance Department at (701)
328-4903.
Assessing Petroleum Product Storage Practices
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If you
answered
"Yes" to the
following What you Other
questions should do Who to call references
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Question 1. Consider removing North Dakota North Dakota
your underground Department of Health. Underground
fuel storage (701) 328-5166. Storage Tank
facility. Carefully Rules. North
monitor fuel levels Dakota Department
in the tank. of Health.
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Question 2. Consider moving your North Dakota North Dakota
fuel storage Department of Health. Underground
facility. Carefully (701) 328-5166. Storage Tank
monitor fuel levels Rules. North
in the tank. Dakota Department
of Health.
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Question 3. Find out how old the EPA (Region 8 Denver) Musts for USTs:
tank is and what Regional office about A Summary of the
material it is made U.S. EPA rules. New Regulations
from. Monitor fuel (303) 293-1514. for Underground
levels to detect Storage Tank
leakage. Systems. U.S. EPA.
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Question 4. Start monitoring North Dakota State Handling and
fuel usewith a stick. Insurance Department, Underground Storage
Division of Tank of Fuels. WQ01,
Release Fund about Michigan State
Reimbursement, University,
liability and Extension Service.
insurance for cleanup (Available
costs. through NDSU
Extension Ag &
Biosystems
Engineering
Office, Fargo).
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Question 5. Construct a catch Local county Underground Fuel
basin for aboveground Extension office for Storage Tanks:
tanks and monitor plans of a catch Tips For Farmers
underground tanks basin or pad. and Homeowners.
for leakage. WQ37, Michigan
Extension Service.
(Available through
NDSU Extension
Ag & Biosystems
Engineering
Office, Fargo).
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AE-1078, July 1998
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