Comm 10.505 requires all underground storage tanks to have spill containment at fill openings.
If tanks have fills that are located outside, they must be inside a watertight enclosure of non-combustible construction.
The equipment designed and installed for this purpose is commonly referred to as “spill buckets” or “spill containment buckets” illustrated in Chapter 2 – UST System Components.
The spill buckets must be designed to contain spillage at the fill point, and they must have a minimum liquid capacity of 5-gallons. Also, they must be located on top of the tank where connections are made for product transfer piping. Spill containment equipment installed prior to February 1, 2009 is excluded from this requirement.
Spill containment equipment must be equipped with a method to remove product spilled into the containment device (e.g. bucket), or have a push-to-drain mechanism that will direct any product contained in the bucket, back into the tank, or provide a method to pump the contained product out of the spill containment bucket.