Top 4 Causes of Fuel Contamination—and How to Prevent Them

Fuel contamination doesn’t just happen overnight—it builds up silently, threatening your entire backup power system. Knowing the causes of contamination is the first step toward protecting your tanks, engines, and compliance record.

1. Water Intrusion

Water enters tanks through condensation, damaged seals, or poor delivery practices. It encourages microbial growth, corrodes metal, and destabilizes fuel.

Prevention Tip: Install water-absorbing filters, check seals regularly, and perform periodic water removal during inspections.

2. Microbial Growth (Diesel Bugs)

Bacteria, fungi, and mold thrive in the interface between water and diesel fuel, forming sludge and acids that damage tanks and engines.

Prevention Tip: Regularly polish fuel, maintain biocide treatments, and test fuel samples to catch issues early.

3. Oxidation Over Time

When fuel sits too long, it reacts with oxygen, breaking down into acids and gums that clog filters and injectors.

Prevention Tip: Rotate stock if possible, and test fuel every 3–6 months. If fuel is old, consider polishing or replacement.

4. Dirty or Rusty Tanks

Tanks with internal rust, scale, or previous contamination can quickly compromise fresh fuel.

Prevention Tip: Schedule tank cleanings annually or after long periods of inactivity. Restoration services can extend the tank’s life.

Prevention is Protection

Whether you're managing a hospital, municipality, or mission-critical facility, routine fuel system maintenance is the smartest investment you can make.