Washington State Heating Oil Tank PLIA

By June 6, 2023 No Comments

McAlister GeoScience is ready to provide heating oil tank decommissioning services for your property as a certified service provider with the State of Washington Pollution Liability Insurance Agency (PLIA).  There are several reasons why you would want to decommission your underground storage tank. If you are converting to electric or natural gas, or installing a new above ground storage tank for your home heating needs, your best option would be to decommission your underground heating oil tank. Having your oil tank properly decommissioned, and the soil tested and remediated if necessary, will eliminate any potential problems you may encounter and can satisfy the insurance, mortgage companies, and due diligence by future buyers.

Generally speaking, there are two ways to decommission an underground storage tank, by removing it from the property or abandoning it in place.  Removal of the tank is always preferred and recommended by us here at McAlister GeoScience and all of the governing and oversight agencies involved.  Abandoning the tank in-place really is only a viable option when removing the tank could potentially undermine or otherwise compromise the foundation of the structure.  The process of abandoning a tank in-place includes pumping the tank free of any residual product, triple rinsing, and filling of the tank in place with either a polyurethane foam, concrete slurry, or sand.  Once filled, the tank is sealed with the ventilation and fill pipe cut below ground surface and capped with concrete mortar.  The photographs shown here are from the removal of an underground storage tank at an airport fueling location, but we used it here for demonstration purposes due to the much larger size of the tank and associated excavation.

The removal process begins with permit approval from your local jurisdiction.  A utility locate service is used to identify any and all connections to and from your tank.  The tank is then exposed, cut and cleaned down to the raw steel before it is removed from the ground.  Soil samples are collected from the excavation and submitted for laboratory analysis.  The ideal sampling program would include two samples at the base of the excavation and one sidewall sample from each of the walls of the excavation – north, south, east, and west.  Without collecting samples at the base of the excvation, it is nearly impossible to prove to the State of Washington Department of Ecology the tank has not leaked into the subsurface.  Once the tank has been removed and sampling is completed, the excavation is back filled to grade and the property is restored as close to its original appearance as possible.

Once properly decommissioned, McAlister GeoScience provides copies of all certification and documentation required by your local governing agencies.  As a certified provided with PLIA, McAlister GeoScience can help you work within their system to access the insurance funds  available if your heating oil tank has leaked.  These funds come from a surcharge paid on every gallon of heating oil purchased over the years and are intended to cover the costs of investigation, cleanup, and sometimes even part of your HVAC system upgrade.  Contact us for a free and no-obligation consultation today!

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