A common question here at UltraTech is which spill containment solution is best for 55-gallon drums—spill decks or spill pallets. Each product has its pros and cons, which we’ll discuss in detail below, but the quick answer is that spill decks are easier to access and manage because of their lower profile, while spill pallets offer more sump capacity without any additional accessories.
Design & Functionality
Spill decks have a much lower profile than spill pallets. Many spill pallets today are around 12-14″ tall for four-drum models, and up to 17″ tall for two-drum pallets. This is because spill pallets are designed to contain larger spills in their integrated sump without any additional accessories. A spill pallet’s sump should hold enough liquid to comply with federal secondary spill containment regulations here in the U.S. but understand that some spill pallet manufactures tend to exaggerate true sump capacity specifications.
The additional height of the spill pallet isn’t really an issue if the drums are stored on the pallet for long periods of time. When frequent access or moving of the drums is necessary, however, spill pallets could be considered less functional than spill decks. As an example, spill decks with a standard 55-gallon drum and funnel on top are still easily accessible, whereas the much taller spill pallet places the top of the drum at around 52″. For comparison, the typical kitchen counter is around 36″. Securing a drum funnel on top of that drum adds an additional 11-12″. As you can probably surmise, pouring liquids—especially hazardous liquids—into a 55-gallon drum that is 53″ high up can be quite dangerous.
By contrast, standard spill decks are about 6″ tall but will need to be linked together to comply with most secondary spill containment regulations. Spill decks are linked together using a bulkhead fitting, which allows spilled liquids to flow from one deck to another. A “t-strip” is installed between the connected pallets to keep liquids from spilling in between them. Linking spill decks together obviously increases the footprint of the solution by 100% per spill deck (a tad more given the gap between each linked spill deck)—something that just isn’t feasible for many applications.
Another option to make individual spill decks compliant with secondary spill containment regulations is to install a hidden containment bladder that automatically unfurls to capture large spills or drum leaks that the sump can’t capture on its own. This bladder system greatly reduces the spill deck’s footprint because additional decks or the larger spill pallet solution isn’t required for regulatory compliance. It is important to note, however, that the bladder itself requires room to unfurl in the event of a spill. Technically, this makes for a larger required footprint overall but installing the bladder system so that it unfurls into unused space—which could require significant planning in and of itself —can help solve this issue.
One big advantage of the spill pallet is that most have integrated forklift pockets, which makes moving them around the site much easier. Pallet jacks can also be used. To make moving 55-gallon drums on and off of both spill decks and spill pallets, some manufacturers offer loading ramps that connect to the units. These ramps are usually designed to be slip-free and wide enough to be used with a standard drum dolly.
There are several variations of spill pallets and spill decks and they’re usually made from polyethylene, making them compatible with a wide range of chemicals. Fluorinated polyethylene spill decks and pallets are similar but are designed specifically to withstand chlorinated solvents. Steel spill pallets are best for flammable liquids since polyethylene will melt under extreme heat.
There are also flexible spill pallets, which are made with a strong PVC fabric but function the same way as their hard-walled equivalents. These are more economical spill pallets and are typically used as a temporary drum or tank storage solution.
Indoor vs. Outdoor Use
Most polyethylene spill decks and pallets are designed to be weather- and UV-resistant for a good number of years. An open spill deck or spill pallet will collect rainwater and debris in its sump. That’s no good. The ideal solution for an outdoor application is a covered or “hard top” spill pallet. These hard top spill pallets are specially designed to contain spills from 55-gallon drums outdoors while keeping the sump free of rainwater and debris thanks to their polyethylene covers—hence the term “hard top.” The covers on the hard top spill pallets are typically roll-top or hinged. Swinging doors on the front of the hard top spill pallets allow for easy loading and unloading of drums.
Galvanized steel spill pallets can also be used for both indoor or outdoor 55-gallon drum storage and spill containment. These heavy-duty spill pallets are ideal for flammable liquids storage, even though the Occupational Safety and Health Association (OSHA) provides no specific direction regarding the safe storage of flammable liquids in plastic containers. Again, we do know that polyethylene will melt in a fire.
When it comes to meeting EPA Container Storage Regulation 40 CFR 264.175 and Spill Prevention, Control and Countermeasures Rule 40 CFR 12, both spill decks and spill pallets will cover you assuming proper configuration and use. As mentioned above, without add-on accessories, spill pallets will have more sump capacity in a smaller footprint because they’re significantly taller than standard spill decks.
In the U.S., all secondary containment systems must have sufficient capacity to contain at least 10% of the total volume of the primary containers or 100% of the volume of the largest container, whichever is greater. This is a federal law but individual states and municipalities may have even stricter regulations (although they cannot be less stringent than the federal law).
While confusing to some, the simple math is that if you have two 55-gallon drums full of liquid (110 gallons), your secondary containment system must hold at least 55-gallons, given that 10% (11 gallons) is much less than 100% of the largest container (55-gallons).
In the event of a spill, the sumps of both spill decks and spill pallets will need to be drained. Some say that the ability to install a sump drain onto most spill pallets makes cleanup after a spill easier. Others argue the drain itself could cause leaks if not sealed properly. The sidewalls of most spill decks are usually too low for drain plugs to be installed.
The sumps of both spill decks and spill pallets can be emptied using a sump or bladder pump, available from most spill pallet manufacturers. For spill decks with bladder systems, the bladders can be emptied using the same type of pump. It is important to note that the bladders of a spill deck system cannot be reused once deployed with liquid and will need to be replaced.