Hillmann Consulting, LLC was initially engaged by a confidential lending client to test two Underground Storage Tanks (UST) for a mortgage application; subsequently a GPR survey, tank exposure and abandonment were added to the scope of work. The work was required to be conducted in a short timeframe in order to make the closing dates.
The initial site visit was to test two known UST, as recommended in a Phase I Site Assessment. While two USTs were reported, and two vent pipes were found, only two fill ports – one direct and one remote – and one manway could be located. The tank test could not proceed without two direct fill ports. In addition, one of the vent pipes that was found was not located near the known UST and it was suspected that a third UST might be on site. The next undertaking was a geophysical survey. During the subsurface survey, it was determined that three tanks were onsite; the two known tanks and one previously unknown tank. The two known tanks were tested and passed the tightness test, and the third tank was exposed and determined to be a 3- to 6-thousand gallon #6 fuel oil tank with product in the tank. This tank extends below the current building and is presumed to have been installed prior to the construction of the building, which was built in the 1940’s. The tank is scheduled to be abandoned in place.
With this very short timeframe, good project management as well as close management of the subs allowed onetime completion of the original scope. The onsite scientist’s attention to detail allowed the previously unaccounted for vent pipe to lead to the discovery of a previously unknown storage tank. This discovery helps minimize future environmental impacts to the site and reduces the financial exposure to the client.