Volumetric leak detection in large underground storage tanks

The US Environmental Protection Agency (EPA) regulation for underground storage tanks (USTs), published in the Federal Register (40 CFR Parts 280 and 281) on September 23, 1988, specifies the technical standards and a variety of release detection options for minimizing the environmental impact of tank leakage. With several exceptions, the shop-assembled tanks covered by the regulation range in size from small (a few hundred gallons in capacity) to very large, with no clearly defined upper limit. Many large-volume storage facilities have tanks that are nominally 190,000 L (50,000 gal) in capacity. Unfortunately, there is not enough information to help owners and operators of large tanks select a testing system that will be in compliance with the regulations. Furthermore, it is not known whether volumetric tests can achieve the same level of performance in large tanks as they do in smaller ones. To expand the understanding of large underground storage tank behavior as it impacts the performance of volumetric leak detection testing, an experimental program was devised and conducted on actual tanks at Griffiss Air Force Base, Utica, New York