Self-Contained Above Ground Storage Tanks: Questions Every Buyer Should Ask
If you’re shopping for an above ground storage tank, you’ve probably come across terms like secondary containment, double wall tanks, self-contained tanks, dike tanks, and overfill protection. It can feel like you’re learning a whole new language.
The good news is that it doesn’t have to be complicated.
Not every tank with secondary containment works the same way. Some designs require more maintenance than others. Some help reduce the chance of costly spills. Others simply meet the minimum requirements. Understanding the differences before you buy can save time, money, and headaches for years to come.
At Clark Welding Tanks, we designed our Cleanworld Self-Contained Tank to give customers another option for above ground liquid storage. Instead of using an open containment area around the tank, the Cleanworld design uses a fully enclosed, integrated secondary containment system that helps keep out rainwater, debris, and pests while still allowing proper atmospheric and emergency venting.
Below are some of the most common questions we hear from customers comparing self-contained tanks with other UL 142 above ground storage tank options.
What Is a Self-Contained Above Ground Storage Tank?
A Cleanworld Self-Contained Tank is a UL 142 above ground storage tank with a fully enclosed, integrated secondary containment system built into the tank package.
The inner tank stores your product while the outer containment provides 110 percent secondary containment. Because the containment area is fully enclosed, rainwater, leaves, trash, and pests stay out of the containment area, helping reduce the maintenance that often comes with open containment systems.
Unlike many traditional containment designs, the Cleanworld secondary containment system is sealed and vented. This allows the containment area to breathe properly for atmospheric pressure changes and emergency venting while helping keep unwanted water and debris out.
How Is a Cleanworld Self-Contained Tank Different From a Double Wall Tank?
Many people assume every tank with secondary containment works the same way. That’s one of the biggest misconceptions we hear.
A traditional double wall tank uses a metal-on-metal tight-wrap design. While it provides secondary containment, it handles overfills differently than a Cleanworld Self-Contained Tank.
Our patent-pending design includes an integrated overfill diverter. If a tank overfills, the diverter directs the product into the enclosed secondary containment area where you can recover it instead of allowing it to spread across the ground.
Overfills happen more often than people realize. Most overfill prevention valves only slow down the fuel delivery truck’s pump. The driver still has to recognize the change and stop pumping. If the driver gets distracted or continues pumping, product can discharge through the tank vents. That can contaminate the stored product, create an environmental cleanup issue, and cost valuable time and money.
The Cleanworld Self-Contained Tank adds another layer of protection by giving overfilled product a controlled place to go.
Are Self-Contained Tanks Only Used for Fuel?
No.
These tanks can store a wide variety of liquids depending on your application. Common products include:
- Diesel fuel
- Gasoline
- Kerosene
- Motor oils
- Hydraulic oils
- Antifreeze
- Other compatible industrial liquids
Depending on the product being stored, we can fabricate these tanks from mild carbon steel or stainless steel.
One of the first questions we ask is, “What product are you storing?” That answer helps determine the right tank configuration, fittings, coatings, and accessories for your project.
Why Do So Many Buyers Choose a Self-Contained Tank?
For many customers, the biggest concern isn’t storing the product. It’s preventing spills and reducing maintenance.
A Cleanworld Self-Contained Tank helps address both.
The integrated overfill diverter directs overfilled product into the enclosed secondary containment area where you can recover it. That can help reduce cleanup costs, protect the environment, and save valuable product that might otherwise be lost.
Just as important, the enclosed containment helps eliminate many of the maintenance problems that come with open containment systems.
Why Not Just Build a Concrete Dike or Open Containment Around the Tank?
Concrete containment and open dike systems have their place and may be the right choice for some projects. However, they also come with trade-offs.
Open containment areas collect rainwater. They also collect leaves, trash, dirt, and other debris. Standing water can attract mosquitoes and create additional maintenance. Someone has to inspect it, clean it, and keep it in good condition.
Concrete containment structures also become a permanent part of the property. They often require additional site preparation, longer construction schedules, and coordination between multiple contractors. If your operation moves or your needs change years later, the concrete structure usually stays where it was built.
A Cleanworld Self-Contained Tank arrives as one complete package. Because it’s built on heavy-duty skids, you can often relocate it if your operation moves or your site changes in the future.
We’ll cover steel containment systems and concrete containment in greater detail in a future article.
Are Self-Contained Tanks Easier to Install?
In many cases, yes.
Cleanworld Self-Contained Tanks are built on heavy-duty 8-inch beam skids with 4-inch crossmembers.
The installation process is similar to setting a traditional above ground storage tank, but the tank and containment arrive together as one complete unit.
Instead of unloading a separate containment system, positioning it, and then setting the tank inside it, your crew unloads and places one complete assembly.
That can reduce installation time and simplify the project.
Another advantage is familiarity. The same accessories used on many traditional UL 142 above ground storage tank installations also work with a Cleanworld Self-Contained Tank. Pumps, meters, cabinets, hose reels, ladders, platforms, and many other accessories install much like they would on a conventional tank.
How Do You Monitor the Secondary Containment?
Every Cleanworld Self-Contained Tank includes a standard monitoring and inspection opening in the secondary containment.
This is an important feature because it gives you several ways to monitor the containment area.
You can:
- Perform a manual visual inspection.
- Install a leak indicator gauge.
- Install a leak alarm.
- Monitor the containment as part of your regular inspection program.
This monitoring opening comes standard on every Cleanworld Self-Contained Tank. It isn’t an optional accessory.
What Sizes Are Available?
Clark Welding Tanks builds Cleanworld Self-Contained Tanks in capacities from 185 gallons to 20,000 gallons.
Before recommending a size, we like to learn more about your operation.
Some of the questions we ask include:
- What product are you storing?
- How many gallons do you need?
- Will you use the tank for storage, dispensing, or both?
- What equipment will you fuel?
- Where will you install the tank?
- Does your local fire marshal, inspector, or permitting authority have specific requirements?
- Does your project include engineer specifications that call out a particular tank design?
The answers help us recommend a tank that fits your operation today and continues to serve you well for years to come.
Can a Cleanworld Self-Contained Tank Be Customized?
Absolutely.
If you can add it to a traditional above ground storage tank, chances are we can add it to a Cleanworld Self-Contained Tank.
Common options include:
- Pumps
- Meters
- Hose reels
- Cabinets
- Ladders
- Stairs
- Platforms
- Weather protection
- Security features
- Custom paint colors
- Flanged or threaded openings
- Monitoring equipment
- Atmospheric vents
- Emergency vents
You can also install an overfill prevention valve in the fill opening just like you would on many traditional tanks.
The Cleanworld Self-Contained Tank doesn’t replace good spill prevention practices. Instead, it adds another layer of protection if an overfill occurs.
Does a Self-Contained Tank Replace an Overfill Prevention Valve?
No.
We still recommend using the proper overfill prevention equipment for your application.
Many overfill prevention devices work by slowing the fuel delivery truck’s pump as the tank approaches capacity. That gives the driver a warning that it’s time to stop pumping.
Like any safety device, it still depends on someone responding to that warning.
The Cleanworld integrated overfill diverter adds another level of protection by directing overfilled product into the enclosed secondary containment area where you can recover it.
When Would a Different Tank Be a Better Choice?
Every project is different.
We believe the Cleanworld Self-Contained Tank is one of the best options available in the UL 142 product line for customers who want enclosed secondary containment and easier maintenance.
There are situations where another tank may make more sense.
For example, if your project requires a vertical tank because of limited space, another design may be a better fit. Building this style of enclosed containment on a vertical tank is much more difficult.
If your engineer, insurance carrier, or local code requires a UL 2085 Fireguard® tank, then that’s the tank you should use. You can learn more in our Fireguard® tank buyer’s guide.
Some customers also choose an STI Flameshield® tank for projects where that design best fits their requirements. We explain those applications in our Flameshield® tank buyer’s guide.
Our goal isn’t to sell the same tank to everyone. Our goal is to help you choose the right tank for your job.
What Is the Biggest Mistake Buyers Make?
The biggest mistake is buying a tank before understanding what they actually need.
Some buyers rely on myths. Others assume every tank with secondary containment works the same way.
Some believe the most expensive tank must be the best choice. Others focus only on buying the lowest-priced tank they can find.
The best tank isn’t always the most expensive or the least expensive.
It’s the one that meets your project requirements, satisfies local permitting requirements, works well for your operation, and saves you time and money over the life of the tank.
Doing a little research before you buy can prevent expensive surprises after installation.
Why Choose Clark Welding Tanks?
At Clark Welding Tanks, we believe buying an above ground storage tank shouldn’t be confusing.
Every project is different, and every customer has different requirements. That’s why we spend time asking questions before recommending a tank. We want to understand your application, your site, your local requirements, and how you’ll use the tank long after it’s installed.
Whether you’re storing fuel for a fleet, supplying equipment on a construction site, fueling farm equipment, supporting an emergency generator, or storing industrial liquids, our goal is the same. We want to help you choose the right tank for the job.
Our product line includes standard UL 142 above ground storage tank models, Cleanworld Self-Contained Tanks, STI Flameshield® tank systems, and UL 2085 Fireguard® tank models for applications that require protected tank construction.
We believe good customer service starts with listening. Sometimes a Cleanworld Self-Contained Tank is the best choice. Sometimes another design is a better fit. Either way, we’ll explain your options and help you make an informed decision.
Still Have Questions?
Before ordering an above ground storage tank, ask yourself these questions:
- What product am I storing?
- How many gallons do I need?
- Will I store product, dispense it, or both?
- What equipment or vehicles will I fuel?
- Where will I install the tank?
- Does my local fire marshal, inspector, or permitting authority have specific requirements?
- Does my project include engineer specifications that call out a particular tank design?
Answering these questions before you buy can save time, reduce unexpected costs, and help you choose a tank that serves your operation for years to come.
If you’re comparing above ground storage tanks or want to learn more about the Cleanworld Self-Contained Tank, Contact Clark Welding Tanks. We’ll help you find the right solution for your application.