Petroleum Storage Tank
Removal, Assessment, & Cleanup

� 2009 Sensible Solutions Environmental, P.C. All rights reserved.

The fill and vent pipes to a UST, in the center of the photo, were hidden by vegetation, but found by SSE when the home inspector suspected that the home was once heated with fuel oil.

Sensible Solutions' tank and soil inspections are performed only by a NC-licensed geologist, to ensure accurate interpretation of field observations (you get our very best from the very start).

The inspection of a UST begins by measuring the diameter of the tank, through the fill pipe (if present), and the volume of fluids in the tank. A probing rod will then be used to locate the ends of the UST. The diameter and length will provide the exact capacity of the tank.

Once the ends of the UST are located, a hand auger will be advanced through the soil within one foot of each end of the tank. The removed soil will be inspected for stains and odors.

Because a "little bit" of leakage (called de minimis) may be in the original fill soil surrounding the tank, which the

State may not be too concerned about (an experience-based judgment call will be made in the field), the borehole will be advanced 1 to 2 feet into the native soils beneath the bottom of the UST.

Caution: all too frequently, a consultant will show you contaminated soils from near the bottom of the UST, without inspecting the native soils 1 to 2 feet farther down, which may not have been impacted by leakage (possibly a de minimis release). Then, you may be told that 57 tons of soil need to be excavated for disposal. In addition, there is usually no need to send a sample to the lab to determine whether or not the tank and impacted soils need to be removed (when leakage is obvious, the State's cleanup levels have been exceeded).

Experience tells us that if the soils in question have any detectable odor of fuel oil, then the contaminant levels probably exceed the State's Maximum Soil Contaminant Concentrations (MSCCs). There is no need to send a sample to the lab to tell us what we already know (saves you money). If the soil in question has a good, earthy odor, as it should, then the soils are very likely clean, or clean enough. A sample could be collected for lab analysis during the tank inspection, but SSE recommends sampling at the time of tank removal. If the soil in question is questionable, a sample should be submitted for qualitative lab analysis (less than $150 per sample) to determine the next step. Quantitative analysis is generally 5 times more expensive than qualitative. Therefore, SSE attempts to keep the initial sampling to a minimum.

Based on field observations, SSE can usually get an idea of how much soil will have to be excavated in order to get clean closure. SSE will not excavate more than is necessary (averages about 25 tons).

Sensible Solutions charges $75 for most UST and soils inspections (often no charge).
Most inspections can be done within 1 hour of approval.
SSE recommends that the property owner and/or buyer and their agents be present for the inspection.

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