Field inspectors in nine states have reported many rapidly-corroding underground storage tank components. This prompted the National Institute of Standards and Technology (NIST) to conduct a laboratory study to pinpoint why and how this corrosion takes place. Their study results were released and is being published Corrosion Science.
The incidents reported by field inspectors involved gasoline-ethanol blends and the presence of Acetobacter aceti, a bacteria which converts ethanol to acetic acid (found in vinegar). The vapors of this acid can eat through a millimeter of steel alloy in a year.
The NIST finding has meant that they’ve changed their recommended component change intervals for underground gasoline storage tanks. These smaller intervals will mean many fuel sellers will have to replace submersible pump casings and similar steel-based components more often, usually at a cost of $1,000 to $2,500 each. The underground tanks themselves, if of older, steel construction, may also require replacement as would other metal parts such as pipes and more.
An earlier NIST study had also found ethanol to be a big part in premature pipe cracking.
I assumed all the stuff in contact with the product would be non-metallic. I was in this industry for years and metal in contact with anything that is not compatible is just bad economics. I am surprised there are any metal tanks left. Those were the first components to change. I don’t really care what blend the government mandates as long as every car o the road was designed specifically for that blend.
Pumps and their housings are usually metal or at least partially so. I’ve often wondered myself why those aren’t made of high-grade plastics or fiber.
What should the tanks be made out of John?