Fuel Contamination

free water in offf road diesel

Fuels are quite different from those a decade ago. There are numerous problems associated with the quality of fuel. Diesel and gasoline are not problems in and of themselves. However, a combination of factors have contributed to a whole host of serious and potentially dangerous concerns. Between 2004 and 2006, the EPA mandated the reduction of sulfur in fuel and the addition of biofuels (ethanol and biodiesel). These along with the removal of lead produced more than a few unintended consequences. Many in the petroleum industry are trying to determine the proper response to these unforeseen problems.

Before 2004 it was not uncommon for fuel to have a 5 or 6 year shelf-life. According to the most recent research, fuel begins deteriorating before it ever reaches the end user. In fact, if water is present, it can degrade by as much as 95% within 30 days of refining.

Current fuel studies show that the fuel coming out of terminals have minimal biocide, leaving them vulnerable to microbial contamination. Additionally, if fuel is exposed to other contaminants it will exacerbate an already serious problem. Water exposure, cross-contamination and the addition of biofuel contribute to the problem.

Water contamination can happen at any time during the transportation and storage of fuel. During barging and shipping, water exposure is a constant problem. Even when pumped off, some amount of water remains in the fuel. Transport truck delivery also provides a potential for water to enter the fuel. Driver error or incompetency can lead to water entering the fuel. It is not uncommon for drivers to leave tanker access ports open, allowing water and contaminants to enter the fuel. Another common mistake made by drivers occurs when dropping fuel. Standing water often enters the fuel tank when the driver makes the delivery. Many of the most egregious errors take place during seasonal weather events.

Once delivered, water intrusion can occur both naturally and systemically. Naturally, water enters fuel through the process of condensation. Temperature differences or variances change the humidity levels in the fuel system producing condensation. Over time, condensation will settle and become measureable. However, while it is suspended in the fuel it is virtually undetectable. Systemically, water can enter into the fuel through leaks and weaknesses within the fuel system itself. Often leaks are small and water creeps in virtually undetected until the damage is done.

When water enters conventional fuel, it settles, generally dropping out of the fuel at a rate of one foot of fuel per hour. That means a tank with 10 feet of fuel will require 10 hours for the water to settle. Unfortunately, most fuels contain a bio-mix of either ethanol or biodiesel. Both are considerably more water soluble than conventional fuel and contain more suspended water in the fuel.

Ethanol is hydrophilic – it loves water. In ethanol enriched gasoline up to .5% water can be suspended in the fuel before the water begins to drop out. This process is called phase separation. When the water drops it takes with it the ethanol. The ethanol and water mixture is the perfect breeding ground for microbes, the most common of which is “acetobacter.” This bacteria is associated with the creation of acetic acid. When ethanol and water bond chemically, they create a perfect environment for the acetobacter to reproduce at an alarming rate.

Regulations allow up to 5% biodiesel to be mixed with conventional diesel without any labeling or notification. As with ethanol, biodiesel is very soluble. According to the EPA in its most recent study, “Diesel blended with biodiesel can hold in solution more water than diesel without a biodiesel component. This means more water is likely arriving in USTs entrained in fuel today since biodiesel is more common in diesel than prior to 2007.”

Both ethanol and biodiesel are microbial food sources. Most of the microbes affecting fuel require a water interface to multiply. The combination of a readily available food source and interface make today’s fuels difficult to maintain. Microbial growth has become common and the corrosion problems associated with them are very serious.

Additionally, most carriers practice switch loading – transporting gasoline and diesel in the same trailer or truck compartment – contributing to the problem through cross-contamination. The EPA discovered 90% of diesel tanks tested contained ethanol contamination suggesting that cross-contamination is the norm. Recent research confirms that the ethanol contamination in diesel is likely the main cause of corrosion in fuel systems and engines. Research asserts, fuel system corrosion was not a major problem until ethanol was in common use. Ethanol cross-contamination in diesel and the serious corrosion in fuel systems lends to this assertion.

All of this adds up to the need for a fuel quality management program. If you own a fuel system, fuel management is a reality.

Killer Contamination


Imagine having almost ten gallons of contaminants in your fuel tank like the picture shown above.  The site owner had been replacing filters more frequently and noticed higher than usual maintenance costs on his fuel equipment. Imagine the surprise at what was found in the bottom of the tank.

Sample your fuel to determine visual clarity.  If the fuel looks bad something must be done.  In the case of the contaminated fuel, the fuel sampled had become contaminated over a short period of time. Microbes were eating the fuel and leaving behind an acidic byproduct in the tank.   The contaminants removed from the tank were part of a larger problem.  The acids found in the bottom and mid-tank samples, a by-product of the microbial infection, were eating away at the fuel system components.

It was estimated that the contaminated fuel had cost the owner more than 35% higher maintenance costs on his fuel system. It likely cost him customers as well. Do you know what is in your tank? Dixon Pumps sells fuel samplers and equipment to clean your tank and fuel. Call us and we will help you find the answer.

Bad Fuel = Corrosion

corrosion on parts

One of the constants in the petroleum equipment industry is corrosion. THe problem continues to cost the industry billions of dollars each year. When I talk with tank owners, they think that corrosion is a result of moisture.  Although that is a contributing factor, the real culprit is microbial contamination.

All fuel has some level of contamination.  If left uncheck and unmanaged, the fuel will continue to degrade at an alarming rate.  Microbial influenced corrosion or MIC results in damage of varying degrees.  As microbes reproduce in the fuel, their waste by-products continue to disperse throughout the fuel system.  The waste is likely acidic.  Acidic sludge and slime will accumulate at the bottom of the tank.  This acidic layer, its dispersants and off-gassing vapor cause damage.

Fact – acid on metal equals corrosion.  Over time, if left unattended, the microbial growth within the fuel system will result in accelerated corrosion.  The corrosion will be evident inside the tank and outside the tank on the fuel system components.  STP components in the sumps, tank risers and dispenser parts are all affected.  Eventually a catastrophic event could occur resulting in a release of fuel into the ground.  At the very least, higher maintenance costs to equipment will result both for the fuel system owner and the equipment the fuel is being pumped into.

What can be done?  First, take regular bottom samples. Be proactive rather than reactive.  This will save you both time and potential liability. Start managing your fuel and saving money.

Water, Water, Water

water in sump2

If fuel contains water, then finding out where the contamination is entering the system is a priority. A thorough fuel system assessment is essential. Two of the most important aspects of fuel quality management is keeping water out of the system and reducing any noticeable corrosion.

An assessment will identify obvious areas where water might be entering the system. If water is entering the system and a leak is undetermined by a visual assessment, then a line and tank test should be completed. Continued investigation is necessary until the leak(s) are found.

If water enters tank instantly or quickly, then fuel might become emulsified from top to bottom. If water enters more slowly then it may settle to the bottom and not emulsify the fuel or become heavily entrained. To find out, a fuel sampler can be used to pull samples at different levels. This can help narrow down your search for a leak.

If you do not own a fuel sampling device, call Dixon Pumps today or go on our online store. We include instructions on how to use it. Don’t let water cost you money. Buy a sampler today.

Contamination Warnings

There are numerous risks associated with contaminated fuel. The liabilities and financial risks are high if ignored. How do I know I have a problem? The warning signs and problems are complex. Fuel system history is very important because it reveals the breadth of the issues. While the following list is not exhaustive, it is a good starting point. The problems are warning signs that likely indicate a more sinister issue lurking in your tank.

  • Premature filter changes
  • Corroded or clogged filters
  • Dispenser slow flow
  • Premature hanging hardware failures
  • STP Failures
  • Visual evidence of corrosion in the sumpscorrosion on monitor riser area Alabama
  • Shear valve failure
  • Meter failure – clogged and corroded
  • Proportional valve failure
  • Leak detector failure
  • Probe failure
  • Constant water issues in the tank
  • Line and tank leaks
  • Dispenser overruns

These are a few of the problems caused by contamination in a fuel system. Engines also exhibit warning signs caused by contaminated fuel. Below is a list of common engine problems associated with contaminated fuel:

  • Engines not starting, rough starts or stalling
  • Clogged engine filters
  • Reduced engine power
  • Poor fuel economy
  • Premature injector failureinjector damage
  • Discolored fuel (dark, cloudy, emulsified)
  • Excessive exhaust emissions
  • Increased injector and pump repairs
  • Premature cylinder wear
  • Repeated fuel delivery system failures or repairs

Ultimately, all of the associated warning signs and risks add up to higher maintenance costs. The risks are very real. There are four risks to consider when dealing with fuel quality.

  1. Operational Risk – not managing fuel quality carries the risk of operational downtime and losses. When the power goes off due to bad fuel, the most obvious risk is operational.
  2. Reputational Risk – sustained power loss can become a reputational problem with any organization and the individuals responsible for maintaining power. If fuel quality is not at the forefront of your maintenance program then the loss of reputation is likely.
  3. Health and Safety Risk – no doubt that the loss of power poses a health and safety risk to those affected. This is especially true in the emergency management and healthcare sectors.
  4. Value Risk – there is a financial risk when fuel quality is ignored. The ideal management program reduces financial risk! Do not wait until it is too late. Call Dixon Pumps and ask us how we can help.