Secondary containment is one of those requirements that is either obviously mandatory or vaguely advisable depending on what you are storing, and the vague cases are where people skip it and regret it.
The rule
The working standard is capacity for 110% of the largest single container in the containment area. For a 275-gallon tote that means a bund holding at least 303 gallons; for a 330 it is 363.
Where multiple containers share one bund, it is 110% of the largest — not the sum — on the reasoning that they are unlikely to all fail at once. Some jurisdictions and some insurers require more. Check yours rather than assuming.
When it is genuinely required
- Regulated hazardous materials, in most storage configurations.
- Anywhere the yard or floor drains to a storm sewer — in that situation a spill is a discharge to surface water, and the enforcement position is unforgiving.
- Near any watercourse, drain or soakaway.
- Wherever your insurer or your customer's audit says so, which is increasingly often regardless of the regulatory position.
The purpose-made option
A polyethylene bund pallet sized for one IBC runs $350–$700 new. They are excellent: moulded in one piece, chemically resistant, with a removable grate and a drain plug. If you are storing regulated product, buy one — this is not the place to improvise.
The improvised option that actually works
For static, non-regulated storage — site water, rainwater, wash-down chemistry, waste consolidation — a cut-down IBC makes a genuinely good containment tray, and we build them.
Cut a 275 horizontally at about a third height and you get a tray roughly 48 × 40 × 15 inches: about 310 gallons to the brim, which clears the 110% requirement for a full 275 above it. Cap the cut edges, keep the cage as the structure, and it will outlive the container standing in it.
Where the improvised version is the wrong answer
Regulated hazardous materials, anything with a fire-code dimension, and anywhere an inspector will want to see a rated product with documentation. A cut tote has no certification and no test data, and no amount of it being obviously adequate substitutes for that. Use it for water and general site chemistry; buy the rated product for anything regulated.
Three things people get wrong
<strong>Rainwater.</strong> An outdoor bund fills with rain and its available capacity quietly drops to nothing. Either cover it or check and empty it, and remember that whatever you pump out may itself be contaminated.
<strong>The drain plug.</strong> Bunds with a drain plug get left open because it is convenient. A bund with an open drain is a tray, not containment.
<strong>Material compatibility.</strong> A polyethylene bund under a container of something that attacks polyethylene is decorative. Check the bund against the product, not just the container.
The cheap version of the whole argument
Containment costs a few hundred dollars once. A spill costs a cleanup, a report, an insurance claim and — if it reaches a storm drain in New York — an enforcement action. We fit containment on things we are not required to, purely because the asymmetry is so lopsided.
Priya Raghunathan is the compliance & documentation at IBC Tote Recycling NY in Astoria, Queens. We publish the figures we work from — if you think one of them is wrong, tell us.
