Which of the following are types of fuel contamination?

• A. Water
• B. Solids
• C. Microbial Growth
• D. All of the above

Answer: (D)

Fuel contamination can take several forms: water, solids, and microbial growth. Water in fuel can be free water that settles at the bottom of tanks or dissolved water that rides with the fuel; it can cause corrosion, fuel-system damage, and even support microbial growth. Solids come from rust, dirt, debris, or corrosion products that can enter the fuel during storage or handling; these particulates can clog filters, wear pumps, and disrupt combustion. Microbial growth occurs when water is present and microbes feed on hydrocarbons, forming slimes and biofilms that foul filters and degrade fuel quality. Because each of these represents a distinct way fuel can become contaminated, all of the listed types are considered fuel contaminants.