Is that "bund" or "bung?"
Please describe what you are talking about
(is it the circular metal "stopper" that screws into the side of a drum?)
I'm pretty sure there are standards.
I am trying (badly)to describe the external concrete wall that should wrap around overground tanks in order to prevent an environmental hazard should a spill/leakage occur.
look for storage tanks, the documents cost about US$50) but here are our simplified standards:
All secondary containment systems shall be:
impervious to the tank contents for at least 72 hours (nonporous)
compatible with the tank contents
resistant to normal environmental conditions (heat, cold, hail, ultraviolet (UV) radiation, etc.)
of sufficient strength and durability to resist tearing, cracking, crumbling, eroding, collapsing, etc. for the operational lifetime of the tank
easily maintainable
of sufficient size to contain 110% of the volume of the tank (tank contents plus fire-fighting or rain water)
of sufficient size to contain all critical piping, fittings, and valves (those items which contain product during pumping activities such as tank filling or withdrawal, or connections/components which could drain the tank if they failed )
The following permanent or temporary containment systems are allowed, unless otherwise noted:
steel catchment basins or spill skids
masonry or concrete berms
earthen berms, only when used in conjunction with an appropriate liner or coating
'visqueen' or other non-reinforced plastic sheeting with a thickness of 40 mils (0.75mm) or less is not appropriate
secondary containment tanks (i.e. double-walled tanks or concrete encased tanks). These tanks (including associated piping and pumps) are exempt from items 2 (f) and 2 (g) above.
All secondary containment areas or systems shall be maintained free of accumulations of water, leaves, weeds, flammable materials, tanks or drums, or anything else that may interfere with the containment purpose or visual detection of leaks or spills.
