“It is typically recommended that all tanks be removed from the ground when taking a tank out of service. When a tank is removed and a site assessment soil sampling is performed by a qualified individual, a professional determination can be put forward as to the integrity of the tank. Some people refer to the determination as a Tank CERTIFICATION.
There is no standard certification that is mandated by the EPA or the NJDEP for residential heating oil tanks and given by an independent company. What a property owner can receive is a professional determination from the company performing the tank removal activities describing what transpired during the tank removal. This determination can and should contain a statement regarding the visual integrity of the tank and if the tank did or did not leak. The site assessment to evaluate whether contamination is present in the excavation can be carried out in a variety of ways while the tank is being removed and can consist of the following:
•Evidence of contamination can be determined from product odors, product stained soils, and/or visual evidence of free product.
•Inspection of the Underground Storage Tank, (UST), for evidence of corrosion or perforations once the tank is removed from the ground.
•Obtaining soil samples from along the bottom invert of the tank excavation. This is the most accurate.”
According to currenenvironmental.com