Backup generators are often idle, which creates the perfect scenario for algae to grow in the diesel fuel tank.

First, mandatory safety vents allow air in and out of the fuel tanks.  Excess air space allows for warm, humid air to enter the tank and condense moisture during the cool evening.  Moisture mixed with diesel is a recipe for contamination.

Moist and dark areas areas are the perfect environment for microorganisms to grow. With backup generators, fuel typically sits undisturbed, which allows organisms to grow.  This scenario often creates particulates, sludge and rust inside your tank.

Contaminated fuel leads to engine filters being clogged, which can cause damage the engine/generator and the generator may not to work when you need it most.

In a normally scheduled generator practice test, fuel is consumed in the testing until the tank level is around 75%, then fuel is ordered.  Since the tank can only be filled to 90-95%, fuel deliveries are usually top-off volumes.  Each one of our service trucks is equipped with an additional 100 gallons of diesel fuel for top-offs.

The most critical factor in whether your fuel starts growing algae and other organisms is fuel quality.

The cleaner your fuel is, and the cleaner your fuel stays, the less likely your fuel develops organisms.

However, there are a number of factors that determine fuel quality…

• Environment — hot summers and direct sunlight make your tanks expand and contract, introducing more condensation
• Amount of fuel in the tank — a half-full tank has more air in it, and leaves more room for condensation to form inside the tank
• Run time — running a generator more frequently disturbs organism growth
• What’s already in the tank — sediment and debris settle and build up over time
• How clean the fuel was when the tank was filled — fuel grade and quality when delivered is vital.

(actual diesel fuel samples from left to right: sludge; high water to fuel ratio; sludge; sludge, rust, particulates; particulates; few visible particulates but enough to clog the smaller fuel injectors on more modern generators; the far right sample has no visible particulates, but a lab report showed it had a severe presence of microorganisms. A visual inspection sometimes isn’t enough.

Unfortunately, even fresh fuel can be contaminated!

Clogged filters and rust on the filler cap are usually the first visible signs that you’ve got these organisms in the tank. But even a quick glance at your fuel can tell you if something’s wrong.

All of these samples (pic above) were taken from the middle of diesel tanks with various states of overgrowth.

If left alone, these organisms will continue to grow and you run the risk that your generator will shut down during an emergency.

Polishing and treating your diesel fuel removes organisms and kills bacteria.

Polishing filters your diesel fuel, removing living organisms and filtering out sludge and sediments that clog your filters, block injectors, and stop your generator from running as intended.  Not only does it maintain your tank and prevent corrosion, but regular fuel polishing also ensures that, in an emergency, your generator will run for more than a few minutes.

Under the right conditions, any fuel tank can develop organisms.  Even a fuel tank that was perfectly clean to begin with.

Regular fuel polishing is key to backup generator performance.

Learn exactly how polishing keeps your fuel and tank clean.

NFPA recommends cleaning your fuel tank at least once per year.

At WPP, diesel fuel polishing service is part of our preventive maintenance program. We strive to maintain and prolong the life of your generator so you have the peace of mind knowing your generator can POWER ON whenever needed.

We start by taking a representative sample of your fuel, from the middle and bottom of the tank. That sample is sent to a lab, we get a full report on what’s going on in your fuel tank, this report is shared with you including recommended action from the results. The report tells us which biocides we should be using, and how much to get you the best results.

Depending on your generator and fuel needs, you might need to clean your fuel more or less often. Critical backup generators, generators in harsh climates, and generators with highly contaminated fuel often require more cleaning to prevent damage and make sure they run properly.

Contaminated Diesel Fuel can Cause Your Generator to Shut Down

Clean fuel offers peace of mind, reduced downtime and prevents costly damage to your generator.

Submit your information below to schedule your free fuel sample. We’ll assess the quality of your fuel, tell you the risks, and get you a plan to keep your fuel clean and generator running.

There’s no obligation and the fuel sample is completely FREE!