Microbes are living cells found in water and water vapor. They feed off hydrocarbons in the fuel. Microbial contamination occurs when water enters fuel. One of the natural ways water enters fuel is through the process of condensation. What we can conclude from this is, “water is always present.” It is impossible to keep water out of a fuel system. So our goal is to reduce its volume, reduce its long term damage, and educate our customers. Total eradication of the microbes will never happen because water is always present giving rise to new colonies of bugs.
One way to kill the infestation is to introduce biocides to the fuel. This is actually done to all refined fuels; however, studies show that by the time refined fuel makes it to the end user, the life of the biocide is spent. The low sulfur, likely cross-contaminated product is delivered to a tank that contains some level of water. The water may or may not be detectable so it may not be on anyone’s radar. No one is looking for it until it becomes an obvious and often costly problem.
While biocides are used to kill microbes in all refined fuels, studies have shown that much of their effectiveness is gone by the time the fuel makes it to the end user. In coastal regions like Florida another variable adds to the problem of microbial growth. Today there is less available terminal storage than at any point in the last twenty years. Additionally, demand is up so the higher through-put in the terminal system does not allow for adequate settling of fuel being shipped throughout the state. Remember, all fuel contains suspended water. The water is carried along the transportation system to its final destination and bingo – a microbial breeding ground. Biodegradation begins almost immediate in many cases. Tank owners are not likely aware of the potential problems and the costly maintenance issues they face as a result.
Microbial Influenced Contamination (MIC) results in damage of varying degrees. There is no way to escape it. As the microbes grow and reproduce, waste by-products continue to disperse throughout the fuel system. The waste is most often acetic acid which can be identified by its vinegar like odor. Sludge and slime accompanies the acidic waste to create a biological layer at the bottom of the tank and any low lying areas in the fuel system itself.
The acidic layer, its dispersants, and off-gassing vapor are what damage the fuel system. Over time a catastrophic event such as a serious tank or line failure, could happen resulting in a release of fuel into the ground. At the very least, the consequences include compounded maintenance costs to the fuel system and to end user’s equipment.