Underground fuel tanks are ideal for businesses that have limited space for fuel storage facilities.
In addition to being practical, the underground installation of the fuel tanks provides a convenient and space-saving way of storing large amounts of fuel. Underground tanks are commonly used by fuel suppliers, trucking fleets and industrial businesses that need to store large amounts of petrol as these tanks can hold up to 200,000 litres of fuel.
However, underground fuel tanks also come with certain risks that need to be managed to prevent soil contamination. Rust and corrosion are common problems that can result in leakage of the contents, which may also go unnoticed for some time. Leakage from underground fuel tanks, even in small amounts can cause extensive contamination and damage to the soil and ground water with the clean-up involving heavy expenses.
Proper environmental management and maintenance practices can help reduce the risks of rust, corrosion and leakage in industrial fuel tanks.
Follow mandatory standards
Underground fuel tanks must be installed strictly in compliance with the guidelines stated in the Australian Standards AS 1940-1993: Storage and Handling of Flammable and Combustible Liquids. The Australian Institute of Petroleum has also released a code of practice as stated in CP4-2002: Design, Installation and Operation of Underground Petroleum Storage Systems.
Comply with the basic installation principles
Underground tanks must be installed only after due assessment of soil type and ground water level of the area. Underground fuel tanks should not be installed in clayey soils as clay has components that accelerate corrosion. The tank must also be installed in an inert material such as sand to protect it against corrosion.
Additionally, it is important to avoid areas with a high ground water level. Underground fuel tanks should also not be installed within the water table or the saturated areas of soil.
Select a double wall tank
Double wall fuel tanks are recommended for underground installation for more protection against rust, corrosion and leakage. A double wall underground fuel tank is made of a steel primary inner tank enclosed within a fibreglass reinforced plastic outer tank, minimising external and internal corrosion. The double walls also provide protection against leakage.
Regularly monitor the tanks
Regular monitoring of the tanks to detect leaks is essential so that any leakage or breach can be investigated and addressed immediately. Leak monitoring methods include stock inventory monitoring, automated tank gauging or ATG systems and interstitial monitoring. Interstitial monitoring, wherein sensors are installed between the two double walls is the most advanced of all methods and is highly recommended.
Underground fuel tanks not in use for a period of six months must be properly decommissioned following mandatory standards and code of practice to prevent health risks and potential contamination of soil or ground water.
DTE Group specialises in the supply of storage tanks and fluid handling equipment.