How Leaks Happen
Many storage tanks are a form of metal, which can rust or corrode over time. When corrosion occurs, petroleum products contained in the tanks begin to leak. The same corrosion can happen in the pipes that carry the oil to different locations. Another cause of oil contamination can be accidental overfill of the container. General negligence while removing the product from the tank can also lead to spills.
Ways to Contain Leaks
There are many ways to help detect and contain leaks. These can be double-walled tanks, liners and dikes that sit bellow the tank, and deep vaults that can catch the oil that spills. According to the Environmental Protection Agency (EPA), these secondary containers must be made of an impermeable product that oil cannot seep through, thus protecting the immediate area from contamination. In addition, secondary containment must be able to hold 110 percent of the total amount of the primary containment. These areas must constantly be cleared of water or other debris to ensure there is always enough space to catch the entirely of a primary tank's contents. Once a tank has been out of use for over a year, it should be declared as out of service, and all pieces of the tank system, from the tank itself to the secondary containment, should be removed from the area.
The EPA is federal body that regulates secondary containment, and the document that lays out the regulations, 40 CFR Part 112, also has a list of regulations that detail leak prevention. All tanks must be routinely monitored to ensure no leaks have occurred. These checks can also identify places that may be problem areas on the tank in the future. Though not included in the 40 CFR Part 112, the EPA also recommends that tanks be placed in areas that have corrosion prevention measures, such as elevating the tanks or placing them on continuous concrete slabs. Underground piping systems should also be double-walls, to help prevent leaking once the oil has left the tank.