Analyze whether an above-ground or underground storage tank is best. Pictured is an OPW FlexWorks Loop System underground fuel delivery system.

Analyze whether an above-ground or underground storage tank is best. Pictured is an OPW FlexWorks Loop System underground fuel delivery system.

At a Glance

A few factors to consider when constructing a fleet fueling facility are:

  • Choose a location that reduces driving time for most drivers.
  • Know and follow environmental regulatory requirements.
  • Decide between an underground or above-ground tank.
  • Determine which type of fuel to dispense.
  • Calculate the ongoing costs associated with maintaining fuel facility.

Just like any other major capital-­intensive project, constructing a fleet fueling facility requires substantial preparation. At the same time, there are considerations specifically related to this type of project, from selecting the location to addressing environmental considerations, to deciding the type of fuel to dispense. This article, part two of a three-part series of articles about project management, addresses factors fleet managers should consider when planning the construction of a fuel facility.

Choosing Site Location & Size

Like they say in the business world, “It’s all about location, location, location!” When evaluating possible sites for a future fuel station, there are many important factors to consider. Simply choosing the least costly location may not make good business sense in the long term. A well-planned fuel station can not only make good operational sense by reducing the driving time between sites, but also significantly cutting down fuel costs.

Nearly all government fleets include large trucks that get poor fuel mileage. Very large trucks (such as waste haulers, sewer jet trucks, and fire apparatuses) normally obtain less than five miles per gallon of diesel when fully loaded. With diesel prices at around $4 per gallon, fuel station location becomes a critical factor in the planning process. Choose a location that will benefit all user departments and that is adjacent to the most heavily traveled areas.

The size of the property also plays an important role. Does the land area accommodate the size of the planned station? The area should be large enough to place the storage tanks far enough away from the dispenser island so as to avoid blocking or shutting down dispensers during site refueling. The site should allow for easy ingress and egress, especially during heavy (rush hour) traffic conditions. The site should be large enough to allow for future expansion and installation of alternative-­fuel dispensing equipment, such as compressed natural gas (CNG) compressor units and propane tanks.

Remember, fuel stations that are not co-located at other facilities may pose problems with security and unexpectedly increase operational budgets, such as the expense of security guards should vandalism and fuel theft become a problem.

Consider Environmental Regulations

Be aware of regulations that apply to fueling sites. Environmental Protection Agency (EPA) restrictions are normally placed upon locations that are close to rivers, streams, and underground aquifers. Local zoning codes may also place restrictions on site placement.

Additionally, avoid areas that could be inaccessible during severe weather conditions, such as floods and ice storms. Fuel stations that are located in an area where there are steep inclines in the roadway may make the site inaccessible when roads are iced-over. During floods, consider not only access road conditions, but also the probability of flood waters overflowing onto the site and possibly contaminating the fuel in underground storage tanks or damaging pumps and fuel/tank interface systems.


Choosing Storage Tank Size & Type

There are basically two different types of fuel tank installations: Above-ground storage tanks (AST) and underground storage tanks (USTs), with each containing their advantages and disadvantages.

● Above-ground storage tanks are obviously less expensive to install and manage. Generally, because they are above ground, they possess less of a regulatory burden than the USTs. However, large ASTs take up a lot of space and are required to be occasionally re-painted. In some circumstances, local building codes may require a containment wall be built around the tanks in the event of a spill. ASTs are subject to lightning strikes, impacts from flying objects during a severe storm, and vehicular accidents. ASTs also require automatic shutoff devices or overfill alarms or ball float valves. Lastly, ASTs tend to sweat more internally, so tanks need to be cleaned more often.

● Underground storage tanks are more costly to maintain and require a series of yearly tests to ensure compliance with Federal EPA & state guidelines. All new installations of USTs are double-wall tanks with interstitial sensors to detect leaks in the primary holding tank. USTs are also subject to contamination from flooding when the access port in the catch basin fails to seal properly. In areas where the water table is very shallow, UST installations may not be feasible. Active cathode protection systems may also be required to prevent the tank from rusting.

In regards to tank capacity, size does matter! Remember that the amount of fuel inside the tank is not only for day-to-day operations, but also serves as a reserve capacity in the event of a fuel emergency.

Don’t simply configure the tank size to an estimated average of fuel usage over a period of time. Spend the additional money and add additional capacity in case of emergencies. Larger fuel tanks also require less monitoring between refueling, and reduces the price of fuel deliveries. The price you pay per gallon varies depending on the type of fuel load you are ordering. Bulk fuel can be delivered using two different transport methods, tank wagon or full load. Full loads usually consist of deliveries of more than 8,500 gallons and are less expensive because of the cost of fuel versus the transportation costs. The “tank wagon” rate is always more expensive per gallon.

Whichever size you choose, remember that the fuel distributor can only fill the tank to 90 percent of its rated capacity. The last 10 percent of a tank’s capacity allows for fuel expansion. Specify the tank size in such a manner as to allow time for the fuel distributor to refill the tank (before you run out of fuel), while still retaining enough capacity for the delivery of a full load.

Lastly, determine what type of fuel you will offer at the site (E-85, gasoline, diesel, CNG) and plan the space requirements accordingly (See sidebars “Alternative Fuels: Constructing a CNG Fueling Station” on page 31 and “Alternative Fuels: Constructing an Ethanol Fueling Station.")

Specifying Dispenser and Fuel Island Requirements

How many hoses are required for each product line? Limiting the hose availability to one for each product dispensed will dramatically slow down the fueling process and cause long waiting periods during peak refueling hours.

Does the fleet require a multi-lane/­island station? If so, consider the spacing intervals between the islands that will allow for the simultaneous fueling of two large vehicles on the inside lanes. The fuel dispenser island should be designed to allow trucks with a large turning radius to easily navigate around the island. Space the dispensers far enough apart to allow for the refueling of large trucks on the same side of the fuel island.

Also, determine the appropriate size of the fuel kiosk. The kiosk should be large enough to accommodate the electrical panels, fuel pedestal, and automatic tank gauge (ATG) systems. Outfit the island canopy with state-of-the-art LED lighting to avoid frequent maintenance trips to change out the light bulbs.


Fuel Site Automation

Along with the fuel management interface, the ATG system is a critical element in any future fuel station. ATG systems are designed to test the fuel storage tanks for leaks, determine levels of fuel and water contamination, and report the delivery of fuel.  

When configuring an ATG system, ensure it contains the ability to perform continuous statistical leak detection (CSLD). CSLD allows for the ATG system to test the tanks for leaks between the times that the fuel dispensers are in use. In some cases, CSLD is an option on the ATG system. Without the CSLD option installed, the fleet manager would be forced to shut down fueling operations while the ATG is in leak detection mode. Any refueling or fuel delivery activity during the testing cycle will cause the ATG to fail the leak detection test without CSLD installed. Also, some manufacturers have tank size limitations on certain models of their ATG systems, so plan accordingly.

Additionally, determine the availability of internet, phone, or LAN service to remotely connect to the ATG and fuel systems interface. Wireless communications options are available on most ATG and fuel management systems, should there be no availability of hard-wire connections. Make sure the area selected is not in a wireless dead-zone if wireless access is necessary.

Not Just a One-Time Investment

In addition to the expense of building a new facility, ongoing costs need to be factored into the yearly budget:

● Yearly tank registration fees.
● ATG and fuel system upgrade and maintenance.
● Tank cleaning and upkeep.
● Fuel island and dispenser maintenance.
● Annual tank and line testing.
● Stage II vapor recovery tests (if required).
● Utilities (dispenser and fuel island electrical requirements).
● Staffing (security and station attendants).
● Anti-microbial fuel additives (especially if using biodiesel).
● Periodic servicing and capital replacement of CNG compressors and         storage tanks.

Additional Items to Consider When Designing a New Fuel Station

Other points to consider include:

● Is an on-site emergency generator needed in case the commercial power is lost?
● Fencing and security cameras.
● Automatic gate openers with coded access (to allow for accessibility
during the non-work hours, weekends, and holidays).

Is a New Site Necessary?

After considering all these factors, determine if another site is even necessary. Another option is to enter into a contract with a fuel card provider to obtain fuel services from local retail stores. However, remember that in an emergency, or an extended fuel supply disruption, retail fuel stores may not reserve fuel specifically for your organization.  Civil unrest may also ensue, thereby making access to those sites even more difficult, if not impossible.


Alternative Fuels: Constructing a CNG Station

There are three different types of CNG stations that can be constructed:

  1. Time Fill – Used to refuel light-duty cars and trucks over an extended period of time (normally 8 hours). Vehicles are normally connected in series with a central low-volume compressor.
  2. Cascade Fast Fill – Used to refuel light-duty cars and trucks at a fast rate, with some ability (depending on capacity) to handle a certain amount of heavy-duty vehicles. Cascade systems contain several storage tanks connected together that provide high-pressure gas with a limited volume between compressor refill cycles.
  3. Buffered Fast Fill – Used to refuel large, heavy-duty vehicles. These systems usually have a large buffered capacity to handle large volumes of CNG. They have a very large compressor (sometimes running two in tandem) that provides sustained high pressure gas while the compressors are running.

Sizing the CNG fuel station is the most critical aspect in the design specifications. Improperly sized compressors and storage tanks will result in significant delays in fueling the fleet during peak refueling hours, and even shut down refueling operations while the compressor refills the storage tanks. Calculate the required station load (storage capacity) by determining the average amount of fuel flow during peak hours. Apply a conversion factor of 125cfm (cubic feet per minute) to 1 gallon of gasoline for dual fuel and converted vehicles. For example, a converted pickup truck that previously took 20 gallons of gasoline would require 2,500cfm of CNG, calculated using the conversion ratio.

Obviously, fleets with a lot of heavy vehicles (garbage trucks and buses) will require that you significantly increase the compressor and buffered storage tank specifications. If you have a diverse fleet of vehicles (light and heavy duty) you may be required to install two different CNG systems to accommodate the differences in maximum allowable fueling pressures and nozzle sizes.

Lastly, keep in mind that CNG storage tanks do expire. The useful life is determined by the manufacturer, but generally the tanks are rated for approximately 20 years. Failure to replace the tanks at the appropriate intervals will shift the blame of any accidents onto the owner of the tanks. If purchasing used storage tanks, pay close attention to the manufacturer’s expiration criteria.

Alternative Fuels: Constructing an Ethanol Fuel Station

A warning when constructing an ethanol fuel station: beware of water contamination.

While we all seek to lessen our dependency on foreign oil, use of ethanol-based alternative fuel (E-10 and E-85) comes with some precautions. Probably the most important precaution is defined as phase separation.

Unlike other fuels, ethanol is a hydrophilic compound that is highly susceptible to water. When water comes into contact with ethanol (at any mixture ratio), it is absorbed by the ethanol and continues that process until it reaches the saturation point, at which time separation occurs. During the phase separation process, the ethanol and water separate, with the water taking some of the octane rating with it. Initially, (with low levels of water contamination) phase separation will have a nominal effect on the quality of the fuel. However, as phase-separated water continues to increase, so will its effects on the fuel’s combustibility. Without a proper tank cleaning, the fuel will eventually become unusable.

With that said, never construct an E-85 ethanol station in areas that supply fuel to water craft or marine vessels. Because the fuel is susceptible to water or water vapor, do not dispense ethanol (even mixture of E-10) in boats or other marine motors. If constructing an ethanol station, keep in mind that some ATG equipment is not capable of detecting phase-separated water from ethanol. If you suspect water contamination in the ethanol supply, probe the tank using a water-finding paste that is specifically designed for use with ethanol.

Phase Separation: An At-Home Experiment

If you want to see how fast phase separation occurs, perform this small experiment. Take a clear plastic water bottle (the kind you buy in a convenience/grocery store) and leave approximately ½ inch of water in the bottle. Mark the water level on the bottle with a permanent marker. Top off the bottle with E-10 or E-85 and shake vigorously for about five seconds. Place the bottle on a level surface and monitor the water level. In a matter of seconds you should increase your water level nearly two-fold. This is phase separation. The process will occur each and every time you add fresh fuel to the now contaminated water, even if separation had previously occurred.


Tips from Fuel Management Professionals

Five fuel management professionals weight in on fuel facility construction:

  1. Plan for communications ahead of time so there’s a way to transfer data from the fuel island. This can be through conduit, a Category 5 cable, a wireless option, or even a phone line to be used for credit or fuel cards or a fuel management system. Make sure there is an adequate amount of electrical supply at the fuel island in case additional units or components are needed for future growth.
    Russ Whelan, regional sales manager, FuelMaste
  2. Consider the impact that future technologies may have on a new fuel facility. Since many advancements in fleet technology require wireless communication, more fleets are utilizing wireless technology for data communications. Having the vision to design a fuel facility for technology integration can mitigate future costs while supporting a fleet’s technology growth path.
    — Mike Wade, director of marketing, EJ Ward
  3. Consider hiring a professional to properly lay out the configuration of a fuel island.  Sometimes, fuel islands are set up with two dual hose dispensers allowing for four vehicles to fuel simultaneously; however, due to the small size of the fuel island, only two vehicles fit at the island at once. Professionals will also help plan for the future by running extra conduits while the ground is open, avoiding costly expenses down the road as fleet needs change or expand.
    — Joseph Basile, VP, Fueling Technologies, AssetWorks
  4. When choosing dispensers, keep in mind the types of vehicles that will be fueling there. Smaller vehicles will require less flow than larger vehicles that may need a 40-50 gallon-per-minute dispenser. Large vehicles with multiple tanks may need multiple dispensers; in this case, both a master and satellite dispenser may be needed.
    — Kevin DeVinney, director, Dispensers & Fleet Systems, Gasboy
  5. A tank gauge combined with a fuel control system can be used to reconcile data to avoid manual reconciliation. The tank gauge tells how much fuel is in the tank, while the fuel system tells how much is dispensed and to whom. Using these two systems together can facilitate the discovery of theft, negligence, or tank leakage.
    — Jason Kaple, director of marketing and business development, OPW

Helpful Links

Listed are some useful links to use when planning the construction of a fuel station:


About the Author

Steve Riley is automotive director for the City of Coral Gables, Fla.