Underground storage tank installations allow for more storage capacity of Diesel Emission Fluid (DEF) than most other storage solutions. Tanks are often made to customer specifications, but usually hold between 6,000 to 12,000 gallons, and are normally made of fiberglass, stainless steel, or carbon steel with a liner.
The most significant advantage of underground DEF tanks is the lower running costs compared to above ground tanks. Many bulk storage containers require special equipment and maintenance costs to maintain the appropriate DEF storage temperature of 14°F (-10°C) to 86°F (30°C), but underground storage tanks do not. However, the start-up costs for an underground storage tank are high, including the site excavation, and transportation and anchoring the tank. In some U.S. states, such as California and Texas, there are also fees for owning an underground tank.
The U.S. Environmental Protection Agency (EPA) undertook an Underground Storage Tank Program in the 1980s to ensure that the risks of spillages, usually from petroleum, were minimized. Now underground storage for petroleum and other fuel and fuel additives are widely available.
