Aboveground Storage Tanks
The regulations for Indiana’s aboveground storage tank (AST) systems—which consist of a tank or combination of tanks, the piping, and additional equipment connected to it—are summarized below.
Registration and Secondary Containment Requirements
Owners of AST systems that hold a volume greater than 660 gallons and have at least 10 percent of their outer surface above ground are required to register them with IDEM and provide secondary containment. Certain ASTs are exempt based on contents, capacity, and proximity to a wellhead protection area. The rule [PDF] and 327 Indiana Administrative Code 2-10 [PDF] describe the exemptions and secondary containment requirements. To register an AST, use State Form 55906 - Reporting of Aboveground Storage Tanks (available on the IDEM Forms page). IDEM’s Office of Water Quality provides further details about these requirements.
The Office of Indiana State Chemist regulates ASTs that store fertilizers, herbicides, and pesticides in excess of 2,500 undivided gallons or 7,500 gallons total. Those ASTs must meet the requirements in 327 IAC 2-10 for storage containers, secondary containment, certification, use, and storage facility location registration.
Aboveground storage tanks at industrial facilities are often exposed to storm water. The runoff at these locations can discharge industrial pollutants into nearby storm sewer systems and waterbodies . Therefore, certain sites are required to get a storm water permit.
Petroleum products have the potential to release vapors into the air. If a site stores large quantities of them in ASTs, it will likely need an air permit.
Tanks used to treat or store hazardous waste are regulated regarding design, installation, inspections, testing, spill response, and closure. Tanks that store hazardous waste for more than 90 days or are not at the location of the hazardous waste generator must have a Resource Conservation and Recovery Act (RCRA) permit and secondary containment.
The Indiana Department of Homeland Security requires businesses to submit a report if they store more than 10,000 pounds of a hazardous substance (or smaller quantities of extremely hazardous substances) on site at any time. It also has a plan review process for tanks that store flammable and combustible materials, as regulated by the Indiana State Fire Marshal. AST owners should contact their local fire department for any additional requirements.
Spill Prevention and Reporting
The U.S. Environmental Protection Agency requires spill prevention planning and secondary containment for ASTs at non-transportation facilities that store 1,320 or more gallons of oil and/or oil products. Containers that are less than 55 gallons in size do not need to be included in calculating storage capacity.
AST owners or operators are required to contact IDEM to report any suspected or confirmed release or spill within 24 hours of discovery.
Closing an AST
With the exception of tanks permitted under RCRA Subtitle C, AST owners do not need to notify IDEM or the Indiana State Fire Marshal that they are closing an AST, but they must follow the 2008 Indiana Fire Code, Section 3404.2.14.