Every day, sites and facilities across the globe either knowingly or negligently operate in unsafe manners. Chemicals are stored incorrectly, spill response plans are non-existent, and little or nothing is in place to protect nearby waterways, should an incident occur.
Not all businesses are required to develop formal emergency plans—like a Spill Prevention, Control, and Countermeasure (SPCC) plan, as prescribed by the Environmental Protection Agency (EPA) here in the United States. Every site and facility where there is a risk of either chemical or oil spillage, however, should have a plan in place. That plan should also be updated at least every three to five years or when a major change takes place at the facility.
The first step in ensuring the safety of everyone and everything in and around a site or facility where liquids are stored is to ensure best practices are being followed. For example, containment equipment or devices should be in place to prevent spills after leaks, cracks, or fissures occur to the original container. Below are some common spill containment best practices many facilities successfully use today.
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).
So, when is 10% ever greater than 100%? It’s actually quite common. For example: if you have eleven 15-gallon drums (165 gallons), 10% of that total volume is 16.5 gallons, whereas 100% of the largest container is just 15 gallons.
Spill Decks & Pallets
One common type of secondary containment is the spill pallet or its lower-profile cousin, the spill deck. Spill pallets are pallets with sump capacity—usually, the capacity required by law or a bit more—either built into the deck itself or via some kind of auto-expanding bladder system. Spill pallet and spill deck sizes vary but are usually designed to hold between one and four 30-55-gallon drums or one or more IBC tanks. Some models can also be securely connected together with bulkhead fittings to create even more sump capacity.
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 pallets are similar but are designed specifically to withstand chlorinated solvents. And 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.
If you’re storing chemicals outside, hardtop spill pallets are the best option. The bottom of a hardtop spill pallet is the same as any other but the drums or IBC tanks inside are encased in polyethylene walls. To access the drums or tanks, hardtop spill pallets usually have roll-top doors on the front (or front and back), and swing-out doors on the bottom half. Ramps are often attached to make loading and unloading drums and tanks onto the pallet easier.
As mentioned, both multi-gallon drums and IBC tanks are candidates for spill pallet storage solutions. The only real difference between the solutions for each is that most IBC spill pallets position the tank higher, so the IBC can be accessed easier since liquids are dispensed at the bottom of an IBC versus the top of a typical 16-, 30- or 55-gallon drum.
Spill Containment Berms
When protecting against the possibilities of larger spills—those from larger containers, vessels, or vehicles—containment berms are the ideal solution. Containment berms are often placed under tanker trucks, railroad tanker cars, wellheads, and larger quantities of drums and IBCs.
Most containment berms are made from a strong, yet flexible PVC or copolymer fabric. Some berms have foam walls wrapped in the same material around their outer perimeters, allowing them to be driven over and then returning to their original state, similar to how memory foam in a pillow or mattress works. Alternatively, there are berms that remain flat until a spill occurs, at which point a foam ring around the top perimeter of the berm rises with the level of the spilled liquid.
Lastly, a hard-walled, high-capacity spill containment bund wall system is ideal for multi-vehicle containment areas, like those found in oilfields. These modular containment berms can be quickly set up and reconfigured as containment needs change, and are ideal when a taller wall or larger containment capacity is necessary.
Special Purpose Secondary Containment
Fuel Tank Spill Containment
While spill pallets and spill containment berms can theoretically be used to capture spills from containers other than what they were designed for, they’re not always the best solution. For example, horizontal fuel tanks with capacities of 250- to 1000-gallons or more would require a fairly large footprint to capture spills from these types of containers. For this, there are large containment sumps available that the tank itself simply sits in.
Spill Containment for Shelving Systems
One common place where spill containment is often ignored is the shelf. In warehouses where liquids and chemicals are stored on rack shelving units, spills or slower drips often pool under the shelves themselves creating slip or more serious hazards. To capture these liquids, low-profile spill containment trays can be placed under the shelves. Typically made from chemical-resistant polyethylene, spill trays are also available as modular kits to allow for custom sizing and containment capacities.
Line & Hose Connection Drip Containment
To capture smaller drips and leaks at the line and hose connections, smaller pipe trays can be placed directly underneath the connection, which is usually cradled by the tray, thereby also providing support to keep the connection off of the ground.
There are also wrap-around sumps (so-to-speak) whereby the hoses connect through a bulkhead fitting in the back of the unit and any leaks or drips are captured by the small sump (usually around three to five gallons).
Utility Trays for Everything Else
When storing or mixing chemicals, paints, or other liquids, there’s always a spill risk. To prevent this, it’s always best to store or mix over something that can capture any drips, leaks, or spills. Chemical-resistant polyethylene utility trays are a good solution.
Available in many sizes, utility trays can be used for long-term storage of smaller liquids on shelves, pallets or floors, or used as temporary containment solutions for leaky machine parts or equipment. Something as simple as filling a small gas can be done over some kind of spill containment device, such as a utility tray.