Fuel contamination of gas, diesel, ethanol or biodiesel is no laughing matter when it reaches the consumer.
Recall back in August of 2012, the giant recall of contaminated gas in Indiana and the northern midwest.
It's not certain how much the recall ended up costing BP, the manufacturer of the gasoline, but it caused a lot of drivers some expensive repair bills ($1300 or more per case), all because the gasoline was contaminated with some sludgy compounds that shouldn't have been there.
Recall another recent blog post we did where diesel storage tanks were tested and found to be contaminated with ethanol that was contributing to tank corrosion. This is a leftover symptom from the fuel distribution system having to handle both ethanol and diesel fuel. So fuel contamination affects both consumers and business or mass fuel users, and can end up costing both parties. Fuel that is properly stored and moved through a clean distribution system shouldn't cause anyone problems with respect to contamination products. It is only when something in the system moves away from best practices that these problems arise. Beyond making sure gasoline and ethanol don't mix with diesel, best practices would normally include housekeeping to take away accumulated water, making sure tank integrity was sound (to prevent water from getting in), and treating stored fuel with antioxidants and metal deactivators to keep reaction precursors in the fuel from interacting and breaking the fuel down.