03.04 What are the site considerations for aboveground tanks?

General Location:
The primary site consideration for aboveground tanks is finding a place to put them. Fire and building codes specify required tank separation distances from buildings and property lines. These codes are often based on NFPA 30 and 30A Fire Codes Flammable and Combustible Liquids Code.

Aesthetic / Architectural and Security
Other important site considerations are Aesthetic / Architectural and Security. Aesthetic concerns are often addressed by installing architectural walls around the tank area sometimes in conjunction with landscaping. Security may be inherent if the entire property is protected by fencing and security personnel / security systems, but typically the tank area itself is also secured by lockable doors or fencing.

Access to Tank Area:
Consideration should also be given to access to the site for fire fighting personnel, and for tank re-filling. If truck access adjacent to the tanks is not practical, then fill piping may be installed from the tanks to a remote fill station.

Drainage from Tank and Tank Loading Area:
An important consideration for aboveground tanks is where rainwater or spilled fuel will flow. This is especially important for the fill area where a fuel delivery truck will park and operate. A fuel spill or rainwater with trace amounts of spilled fuel will flow toward the site drainage features. Typically there should be separation of stormwater inlets from tank and tank loading areas, so that if there is a small spill during transfer, that it can be stopped and cleaned prior to flowing into the storm drain. This issue can be addressed in detailed fill procedures, and precautions such as curbing or temporary inlet covers.

Canopies for Tank Areas
Large outside tank areas are typically constructed with concrete containment dikes or curbing. Even with double wall tanks, there may be tank connections, equipment, or piping that may leak – and there is the potential for tank overfills. Rainwater or snow accumulation in these diked and curbed areas can be a maintenance issue. The tank areas may be covered with a roof or canopy to alleviate this problem. The canopies are typically open on the sides so that they are not classified as buildings, however there will be some building code requirements for the canopy structures that needs to be considered.

Pipe Routing to Building
Tanks will be separated from buildings and will require consideration of pipe routing from the tank area to the building. Pipe supports will be required for fuel piping and sometimes for electrical conduit as well. Portions of he pipe routing may be underground requiring the transition detailing for aboveground to underground piping. Piping installed in concrete trenches is sometimes used instead of underground piping, however water intrusion into these trenches can be problematic.