UNDERGROUND STORAGE TANK CORRECTIVE ACTION TECHNOLOGIES

Abstract

ABSTRACT Of the estimated 1.4 million underground petroleum and chemical storage tanks in the United States, between 100,000 and 400,000 may leak. The average cleanup cost is estimated by industry sources at $70,000, but corrective action may cost more than $1 million if water supplies are affected. Leaks can occur for several reasons, the most common of which is corrosion of the tank or associated piping systems. To detect leaks, a tank monitoring program can use any of four methods: (1) volumetric (quantitative) leak testing; (2) qualitative leak testing; (3) inventory controls; and (4) environmental effects monitoring, in which wells outside the tank are tested. Response to an underground storage tank leak takes two forms: the initial response to control immediate impacts, and permanent corrective measures. To be effective, the initial response technologies should be in place within hours of the discovered release. Such action usually consists of removing any remaining product in the tank and minimizing immediate risk to public health and the environment. Permanent corrective action focuses on site characterization and assessment to determine the need for further action, on calculation of transport rates, on assessment of the hazard to the environment and public, and on collection of data for selecting and designing further corrective actions.