EPA Issues Guidelines to Prevent Diesel Tank Corrosion

Like a hidden health condition lurking beneath apparent wellness, corrosion in diesel storage tanks often develops unseen until significant damage occurs. A startling EPA study reveals that while 75% of tanks show no visible surface corrosion, over 80% exhibit moderate to severe internal degradation. These findings underscore the urgent need for proactive corrosion prevention measures in fuel storage systems.

Whether constructed from fiberglass or steel, regular visual inspections serve as essential maintenance—equivalent to routine health checkups that can detect problems before they escalate.

• Monitor unusual deposits: Sludge or particulate accumulation resembling coffee grounds or black sand often indicates steel corrosion or microbial activity. Red/orange particles may signal active rust from tank walls, while slimy residues suggest microbial biofilm.
• Track filter clogging frequency: Accelerated filter blockage, especially when accompanied by these deposits, serves as an early warning of internal degradation.

• Recognize early indicators: Initial corrosion often manifests as subtle pitting near water accumulation zones, surface discoloration, "sandpaper" textures, or tiny coating blisters—long before visible rust appears.
• Focus on critical areas: Prioritize examining welds, seams, drop tubes, manways, and any moisture/sludge accumulation points where corrosion initiates beneath microbial layers.

• Conduct monthly filter checks as standard practice
• Increase to weekly inspections during high-humidity seasons or when microbial activity is suspected
• Perform immediate examinations following system pressure drops, slow fueling, or alarm triggers

The EPA emphasizes that neglecting water removal from underground storage tanks (USTs)—particularly in infrequently used systems like emergency fuel reserves—creates preventable corrosion risks.

Long-term water accumulation in unchecked tanks creates significant safety hazards and expensive repair scenarios, with dormant systems being particularly vulnerable.

• Supplement electronic water monitors with trained personnel inspections and water-finding paste tests
• Establish fixed monthly inspection cycles coinciding with filter checks
• Maintain detailed records of all findings and corrective actions

EPA research confirms that tanks with high particulate loads—especially iron oxide, biomass fragments, and corrosion byproducts—demonstrate severe internal degradation. Pre-storage filtration removes the raw materials driving these destructive processes.

• Filter incoming fuel to eliminate water droplets, transport tank rust, and distribution system contaminants
• Select high-efficiency filters designed for simultaneous particulate and water removal
• Implement consistent fuel quality monitoring even with robust filtration systems

When corrosion is suspected or detected, tank owners should promptly consult UST service specialists for comprehensive evaluations. The EPA emphasizes that most operators lack the technical resources to properly assess or repair corrosion damage internally.

The agency particularly stresses immediate attention to corrosion-compromised leak detection equipment, given the potential for environmentally catastrophic fuel releases if degraded components fail.

The EPA's final recommendation addresses direct chemical intervention through two complementary treatments:

• Essential for both eliminating existing microbial colonies and preventing future microbiologically influenced corrosion (MIC)
• Select products based on kill duration (optimal 4-week effectiveness), fuel/water phase integrity, and pH resistance

• "Filming amines" create protective surface layers at minute concentrations (1:10,000 to 1:20,000 ratios)
• High-performance inhibitors additionally function as sludge/biomass dispersants, gradually cleaning tank systems

Effective chemical treatment requires proper application methods—either direct injection or additive distribution during fuel recirculation—and may benefit from professional service partnerships offering comprehensive fuel maintenance programs.