diesel fuel contamination: causes and prevention

How To Tell If Diesel Is Contaminated

The easiest way to tell if your diesel is contaminated is to examine its colour and consistency. Look at the diesel through clear glass and see if there are dark patches or suspended particles. Clean, undyed diesel fuel should be amber-green. It will darken if it is contaminated or degraded. Look for other signs, such as residue on the diesel tank wall.
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Another way to tell if your diesel is contaminated is to look out for problems in the performance of your vehicle or equipment. The symptoms you see will depend on the type of contaminant and the amount of contamination, but some common issues include:

• Excessive smoke, usually blue or black, coming out of the exhaust pipe during operation
  

• Reduced engine power and torque, including trouble achieving peak performance
  

• The engine doesn't start at all
  

• Rough idle
  

• Sluggish throttle response
  

• Rough shifts in automatic transmission systems
  

• Chugging or hesitation when you accelerate
  

• Poor fuel economy
  

• A strong rotten egg or stale beer odour in the cabin of the vehicle
  

These symptoms may appear abruptly, gradually, or intermittently. If you encounter any of these problems and you recently filled your tank with diesel fuel, take your vehicle to a mechanic immediately. Contamination is only one of many possible explanations, so your mechanic should determine the cause of the problem before attempting any repairs.

How To Correctly Store And Dispense Diesel

Diesel fuel can last for more than a year when stored in good conditions. As a rule, you should always store your diesel fuel in cool conditions of around 21 degrees Celsius and treat it with biocides and stabilisers.
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Other measures that can extend the shelf life of your fuel are:

• Store diesel fuel in containers specifically designed for fuel storage. Any container you use should have a special rubber seal on the lid to prevent air from entering, as well as a pressure relief valve. If these features are not present, there is a high likelihood that your diesel fuel will become contaminated with moisture or other pollutants over time.
  

• Keep diesel tanks upright, full, and with their caps secure. Never store diesel fuel in an open container or where it can be exposed to the elements.
  

• Make sure the diesel tank is clean and dry before filling. Remove any objects such as leaves or grit that may have fallen into the tank. Close the cap tightly to prevent moisture from entering the tank.
  

• Keep diesel fuel tanks away from heat sources such as radiators, furnaces, or stoves. Extreme temperatures also can cause problems with diesel fuel quality, so don't store your diesel tank in direct sunlight or in a place where it will freeze. The best location is inside a building where temperatures are more constant and moisture levels are lower.
  

• Make sure to use diesel fuel within its storage life. If you have stored diesel for two years or more, make provisions to replace it with fresh fuel.
  

• Consider investing in underground storage. Installing underground storage tanks will be costlier than setting up above-ground tanks. However, underground tanks are less susceptible to fire and explosion risks and general damage. Underground tanks also keep diesel fuel cooler and are less likely to be contaminated by water and oxidation. If you are using above-ground storage tanks, consider a canopy or other enclosure to reduce exposure to the sun and water sources.
  

• Empty and clean storage tanks at least every 10 years. Thorough mechanical cleaning eliminates biofilm and other contaminants and helps extend the useful life of your fuel and storage tanks.