Storing diesel fuel on-location has many benefits. Bulk fuel storage tanks are useful for many different industries and applications, including refueling farm equipment and diesel vehicles and powering backup generators during natural disasters. Generator fuel storage tanks are necessary for emergency preparedness. They allow essential services to stay in operation.



Regardless of your storage tank’s usage, regular maintenance is a top priority for both function and safety. It’s important to maintain your fuel tank year-round, so you can rely on high-quality fuel when you need it. Learn all about fuel tank maintenance, including standard guidelines, cleaning and refilling tips.


What Are Fuel Tanks?


Aboveground storage tanks (ASTs) are a popular bulk fuel storage solution. Though they have a few limitations, they tend to be the best option. Some might consider ASTs an eyesore, detracting from a property’s beauty — placing your AST out of the way is a good way to combat this while also promoting safety. Another issue is wear and tear — since they sit aboveground outdoors, ASTs are exposed to all of the elements, including high wind, rainfall, ice, snow, hail, sunlight and extreme temperatures. You can take several measures to increase your AST’s resilience against the elements. They may also be subject to car crashes or vandalism, but proper placement can decrease the likelihood of these concerns.


Despite their potential drawbacks, ASTs have many advantages compared to underground storage tanks. ASTs are easier to maintain and relocate, safer for the environment and are subject to fewer federal regulations. Underground storage tanks have many issues, which ASTs address. For one thing, underground leaks are difficult to detect and expensive to clean. A fuel leak underground is likelier to affect freshwater and become an environmental disaster. In addition, underground tanks are much more challenging to relocate, clean and maintain when needed.



For these reasons, above-ground storage is safer, simpler, less expensive and overall preferable. If your operation or facility needs bulk fuel storage, ASTs are the best option. However, it’s vital to follow all guidelines regarding proper placement, maintenance, cleaning and servicing. Learn more about best practices for fuel ASTs.


Standard Storage Guidelines and Recommendations for Fuel Tanks


Proper storage and maintenance are important for a safe, operational fuel tank. You’ll need to make sure your AST construction, placement and surrounding area meet all federal, state and local regulations. Be sure to follow all specifications and seek any ordinances unique to your area. Familiarize yourself with any relevant laws. Standard AST guidelines require proper initial setup, as well as performing regular maintenance tasks. Here are some recommendations for storing your fuel in an AST.


Choose an Appropriate Storage Tank


Only use designated outdoor storage tanks for outdoor placement. You should never repurpose indoor or underground storage tanks for above-ground use. Only ASTs can withstand outdoor elements — other storage tanks may present safety hazards if installed outdoors. For instance, a black-painted fuel storage unit will not withstand direct sunlight exposure or high temperatures. It will be subject to rapid overheating, which can cause a safety hazard.


Be Mindful When Choosing an AST Location


AST location is critical for safety. Be thoughtful when planning your AST’s placement on your property. Proper placement will limit the likelihood of AST-related fires or pollution events. The tank needs to be accessible yet somewhat isolated. Your AST should sit on a high, well-drained, flat-ground site at least 50 feet away from any buildings, roads, water sources, power lines and property lines. A well-drained site will ensure minimal buildup of rainwater, which can corrode fuel tanks and harbor bacteria. Flat ground is necessary to keep spills or leaks from escaping downhill, where they might reach water sources, storm drains or flammable materials.


Choose a Secure Base Material


It’s important to choose a secure base material for your fuel storage tank. Though a wood base may support a tank for several years, it can rot over time, causing your AST to fall and spill. Choose a strong base material to hold your storage tank — concrete is a recommended option. Use a thick, wide reinforced concrete slab rather than small blocks under each AST leg. Consider the elements your base will need to withstand, including wind, rain, snow, ice and extreme temperatures.



Add a Roof Structure


A roof structure will help minimize rainwater accumulation and condensation. It’ll also help limit ultraviolet radiation exposure by providing some sun protection. Make sure your roof structure allows air ventilation so it will not trap potentially dangerous, explosive vapors.


Make Sure the Storage Area Is Free of Weeds


The area surrounding the AST needs to be clear of any weeds or grasses. Any vegetation around or beneath an AST can present a fire hazard. Vegetation might disguise a leak, their root systems can damage the containment floor, and their moisture can accelerate corrosion. Be sure to keep the area surrounding your AST free from any weeds or plants. It’s also a good idea to place a dumpster within walking distance of the AST to discourage debris accumulation.


Mount Fire Extinguishers in Easy-to-Reach Locations


Overfilled or overheated equipment can cause a fire safety hazard. You should always keep a fire extinguisher near your AST in an easy-to-reach place. Small fires can become widespread disasters within a few moments, so having a fire extinguisher on-hand is a must. It’s important to keep it in working condition should you ever need to use it. Schedule monthly fire extinguisher inspections.


Install Tanks in an East-West Orientation


When you first install your tanks, be sure to place them in an east-west orientation. This will reduce the tank’s exposure to solar radiation. Long-term radiation exposure can cause fuel tank weathering, resulting in a brittle tank. Fuel tank durability is an important element of safety — a brittle tank presents increased safety hazards. Proper maintenance can also reduce weathering effects, as can a roof or covering.


Choose Fire-Guarded or Vaulted Tanks


Fuel storage tanks need fire-guarding or vaulting in case of an emergency. The fire-guard or vault should be strong enough to prevent fuel ignition for at least two hours during a fire unless the flashpoint is higher than 100 degrees Fahrenheit.


Have a Secondary Containment or Double-Walled ASTs


Fuel storage tanks can fail or leak for many reasons. It’s important to have the right preparations in place in case this occurs. You can either invest in a double-walled tank or include a secondary containment area. The secondary containment area must have the capacity to fit the AST’s contents and can be a dike or tub. You might prefer a double-walled tank, as dikes and tubs require managing rainwater.



Add Proper Signage and Warnings


Open flames and smoking near an AST are extremely dangerous. You’ll need to incorporate a sign reading “flammable — keep fire and flame away” with bright red, tall letters, visible from a distance. You should also add several “No smoking” signs. Be sure anyone who may come close to your AST is aware of its flammability and mark your AST with a detailed description of its contents and volume. This is important for refueling purposes. Filling a tank with the wrong fuel can be disastrous.


Maintenance Tips for Fuel Tanks: How Do You Clean a Fuel Tank?


Regular fuel tank maintenance ensures clean, ready-to-use fuel when needed and limits contamination issues. Maintenance is crucial no matter how often you use your fuel, even if your fuel is set aside for emergency use only. Fuel left sitting unused for long periods can cause issues, and you’ll need clean fuel from a reliable tank at a moment’s notice. Maintaining your tank ensures the best fuel quality, and maintaining your fuel ensures tank integrity. Use these tips to limit harmful water vapor and microbial growth buildup in your fuel tank.


Take Steps to Limit Water Buildup


Water buildup is detrimental to your AST, as it can lead to both tank corrosion and fuel contamination — microorganisms like bacteria and fungi require water to survive, and water can cause damaging ice blockages to form. Outdoor storage means exposure to rain and humidity is unavoidable, but you can take steps to address water-related concerns. The following strategies will help limit water buildup and ensure your AST’s integrity. You can minimize water accumulation by:


  • Maintaining tank insulation: Proper insulation helps stabilize temperatures and limit condensation concerns. Rapid temperature swings cause condensation to form. A stable temperature can prevent this issue.
  • Having a roof structure: A roof covering over your AST will limit the rainwater accumulation around the tank and reduce the chance of water entering the tank. As mentioned above, a roof can also help limit damaging ultraviolet light exposure.
  • Recycling fuel through water separators: It’s a good idea to use water separators, recycling the fuel and allowing safe discharge of the water.
  • Removing sludge and water from the tank: As part of regular cleaning, it’s important to remove any built-up sludge or water.
  • Checking the state of the vent and fill cap: A leaking vent or fill cap will allow water into the tank, which will damage the tank and contaminate the fuel. Make sure these parts of your AST are in optimal condition.
  • Scheduling routine tank inspections: It’s always a good idea to have a professional inspect your AST to check for water-related issues. The more often you can schedule inspections, the better, as it’s preferable to catch issues as soon as possible.


Schedule Regular Cleaning


Regular cleaning is vital for any AST — it ensures desirable fuel performance, minimizes safety hazards and lengthens the lifespan of your fuel storage unit. A lack of cleaning can compromise your fuel. When used, compromised fuel might damage an engine or generator. In addition, sludge and residue buildup increases the risks of fires or explosions.


Cleaning involves removing sludge buildup. Tanks have to be drained of all fuel, moisture and other liquids, scrubbed with industrial cleaners, rinsed thoroughly and dried. As you might guess, this can be a time-consuming and strenuous task, so you may want to take advantage of a professional service.



Treat for Bacteria


Treating your fuel tank for bacteria is an essential maintenance task. Microbial growth can cause several issues, including tank corrosion, clogged filters and reduced fuel performance. Keeping the tank water-free is an important step in restricting microbial growth, but other steps may also be necessary. You may need to use diesel fuel biocides or other additives to address infestations and prevent future growth. A professional cleaning service will treat any bacteria buildup with appropriate biocides.


In addition to fuel biocides, other fuel additives offer many benefits. They increase fuel efficiency, help disperse water and stabilize the fuel. Proper use of additives allows longer-term fuel storage, which is ideal if you use your AST to store fuel for a backup generator. Consider using fuel additives to improve fuel performance and reduce potential downtime.


Keeping Your Fuel Tank Full


Keeping a fuel tank full has many benefits, regardless of the fuel tank’s application or usage. Retaining a fuel level of at least 80% can reduce the probability of several issues. It’s a good idea to pre-schedule routine fuel deliveries from a professional service — that way, you can continue daily operations with peace of mind. Here are a few reasons you should keep your fuel tank full.


  • Prevents condensation: Condensation forms in a fuel tank’s empty spaces. Condensation increases the risk of contamination and corrosion. If the condensation freezes, it can create icy blockages, which may affect the fuel’s performance. Keeping the fuel tank full eliminates the empty space in which condensation might form. It’s an effective way to limit this issue.
  • Prevents fuel pump failure: If a tank’s fuel level gets too low, fuel pumps might pull in air, generating heat. This heat can wear down the fuel pump or cause it to fail. If this happens, you might not have a working fuel pump when you need it, causing unintended downtime. Repairing a fuel pump can be expensive and time-consuming. To avoid a situation like this, keep your fuel tank full enough that your pumps will never pull air.
  • Prevents dirt and rust blockages: Regular cleaning is one way to prevent dirt and rust buildup. Keeping your tank full is also an important measure against dirt and rust damage. Empty space in a fuel tank can allow sediment to collect, which may block the fuel filter. This would also cause unexpected downtime and necessitate expensive repairs.


Contact Foster Fuels Mission Critical


ASTs provide necessary and convenient fuel storage solutions for a wide range of industries and applications. Whether you use your AST’s fuel often or only during emergencies, proper fuel and fuel tank maintenance are necessary. They ensure clean, usable fuel and working equipment whenever needed, preventing unexpected downtime and costly repairs. Preventing downtime is especially important in emergency situations when immediate repairs are not always an option.


At Foster Fuels Mission Critical, we’re a full-service fuel company. We offer routine fuel delivery, fuel tank maintenance, safety training, 24-hour emergency fueling and many other services. We’re fuel experts, ready to help you store clean, optimal fuel for any application. If you have any questions about maintaining, cleaning or refilling your AST, contact Foster Fuels Mission Critical Today.