The United States. has approximately 8.5 million regulated and non-regulated aboveground storage tanks (ASTs) and underground storage tanks (USTs) for hazardous materials (HAZMAT). While these tanks represent a large investment and good maintenance practices would be in the best interest of the owners, Federal and State environmental regulators are concerned with the environmental impact of spills from leaking tanks. The U.S. Environmental Protection Agency set a December 1998 deadline for UST owners to comply with requirements for corrosion control on all tanks, as well as overfill and spill protection. In case of non-compliance, tank owners face considerable costs related to clean up and penalties. The total annual direct cost of corrosion for HAZMAT storage is $7.0 billion, divided between $4.5 billion for ASTs and $2.5 billion for USTs.
The total cost of corrosion for storage tanks is $7.0 billion per year (ASTs and USTs). The cost of corrosion for all ASTs was estimated at $4.5 billion per year. A vast majority of the ASTs are externally painted, which is a major cost factor for the total cost of corrosion. In addition, approximately one-third of ASTs have cathodic protection (CP) on the tank bottom, while approximately one-tenth of ASTs have internal linings. These last two corrosion protection methods are applied to ensure the long-term structural integrity of the ASTs.