After determining the regulations related to your particular business and storage procedures, it’s time to choose the containment pads you want to add to your facility. Don’t just settle for pre-made containment pads that come with a high cost and are often less durable than you might assume. They can’t replace large scale custom pads made with geotextile liner. Find out why you should base your SPCC around custom containment pads for your farm, oil refinery, railroad yard, or other high risk environments.
Sized to Your Equipment
The biggest benefit of a custom lined containment area is the exact fit for the needs of your storage tanks and other pieces of equipment. Pre-made containment pads come in a limited number of size options, often requiring you to buy a much larger pad than you actually need to stay over the volume requirements of your storage tanks. Designing a containment area from scratch allows you to minimize wasted material and keep costs low while installing as much safety and spill prevention equipment as possible. It’s easier to meet EPA and state agency requirements when you stick to methods that cost less and adapt to fit your facility’s specific needs.
Durability and Long-Term Use
Pre-made and portable containment pads tend to rely on disposable foam or plastic edges that only handle a few uses before starting to degrade and risk leaks. In contrast, custom-made containment pads built from durable chemical resistant liner material will last through years of daily heavy duty use and may even go decades with only basic maintenance in less demanding uses. While a pre-made pad may work for an emergency or unusual change in procedures, routine daily spill risks are better managed by a more permanent solution.
Shape and Layout Options
As with size, pre-made spill containment pads are also highly limited in their shape and layout options. Basic square and rectangular pads make up the bulk of these ready-to-use devices. If you’re trying to fit containment pads in tight spaces or around unusually shaped containers, custom pads are definitely a better choice. You don’t want to cut or alter the pre-made containment units since they’re made from materials that are hard to seal or weld after these changes.
Fast Wedge Welding Equipment
Installing a custom geotextile liner doesn’t take as long as you might expect thanks to automated fast wedge welding equipment. These devices press a heated wedge down onto the overlapped seams of liner material to seal them tightly together in seconds. The team working on the containment pad can move quickly down the seam to cover dozens of feet per hour without missing any spots or leaving behind weak seals. With multiple installers on the site, even the largest secondary container pad can be constructed and sealed within a few days. If there are any missed areas discovered by vacuum testing, they’re quickly resealed with the same welding equipment.
Vacuum Testing to Verify Seams
Unlike other forms of large-scale containment pad sealing like spray-on coatings and bentonite clay layers, sealed membrane liners are easily tested after installation to verify the pad is properly sealed. This vacuum testing unit can also work for checking a sealed system on a regular basis to verify it’s still working properly and not in need of patching. A large rectangular vacuum frame is placed over a section of the seam and pressurized for 10 seconds. If no air bubbles appear along the seam, it’s properly sealed. As with the efficient welding process, vacuum testing goes surprisingly quickly even for large containment areas.
Picking a Berm Material
If you’re making a large, secondary containment pad from scratch for all the benefits of a custom design, you’ll have to pick a material for the berms. The berms are the raised areas around the edges of the space to trap the proper volume of liquid or other material. You’ll need to determine how the pad will be used and if it’ll be accessible by vehicle or not before choosing a berm.
- Earth, packed into ridges with sloped sides and covered in an impervious material like a chemical-resistant liner.
- Concrete, which is highly durable but expensive to pour and prone to cracking eventually. It also requires a liner or coating if you’re storing highly corrosive chemicals.
- Railroad ties, wrapped in a layer of geomembrane to protect the preserved wood from exposure to the spilled chemicals.
- Foam, the primary option for drive on/off containment pads made with flexible liners. The foam pops back up after the vehicle pulls onto the center of the containment space.
- Corrugated pipe, made from plastic or metal. These installations are usually only temporary and require a layer of liner to create a watertight seal.
Creating Drive On/Off Containment Pads
If you’re trying to build a drive on/off containment pad from scratch, you have three main options for creating a vehicle-proof system. Collapsible dense foam berms are one of the best options, but the foam will eventually wear out and require replacement along the edges. For another option, consider portable ramps that allow a truck to drive up and over the edges of the containment berms. Make sure the ramps are freestanding and support the weight of the vehicle without transferring it onto the containment pad edges. Finally, a drop-down wall is a final option. However, these systems are harder to install on custom containment pads than the options listed above due to the need for a tight seal. When it’s your preferred choice, try a prefabricated metal-framed containment edge gate to ensure your liner seals tightly around all the edges.
Keep pre-made containment pads on hand for small-scale and emergency spills, but plan to make custom pads for more permanent installations. Replacing portable and temporary spill protection on a routine schedule will quickly increase operating costs. Investing in a permanent lined containment pad for each major hazardous storage area will pay off over the years with minimal maintenance and reliable performance.
