Humidity and ethanol vapor can cause corrosion in the sumps of underground storage tanks containing ethanol-blended fuels at an alarming rate. Ethanol vapors are very hydroscopic, and combined with moisture, form dilute ethanol that condenses on surfaces inside the sump. Bacteria feed on the dilute ethanol within the sump and create acetic acid. Acetic acid causes an aggressive environment within the sump, causing severe corrosion that eats through traditional coatings and attacks the critical pumps and sensors. The process of the formation of dilute ethanol and its conversion into acetic acid will continue as long as there are ethanol vapors and humidity present within the sump.

Product Information

Zerust Sump Saver is a liquid inhibitor with a proprietary blend of Soluble Corrosion Inhibitors (SCIs) and Vapor Corrosion Inhibitors (VCIs). The product has been designed to address ethanol induced corrosion in Underground Storage Tank (UST) sumps.

It is a colorless liquid with a faint ammonia smell which is sprayed over all the parts inside the sump. It does not attack paints or plastic and is safe for multimetal use. The liquid may evaporate leaving behind a white powder residue. In this case the residue contains the active inhibitor ingredients and will continue to work until it has been consumed.

Sump Saver is not only safe to use on copper and copper alloys, but actively protects these parts from corrosion. Zerust Sump Saver can be ordered as a standalone product or as part of a starter kit.


Increase the life of sump assemblies of piping sump equipment of underground storage tanks.
Reduce maintenance related down time.



Zerust provides a starter kit for quick deployment and evaluation of the Sump Saver solution.

The kit comes with the following:

  • 1x Hand operated sprayer for Spray-G1x
  • 1x Hand operated sprayer for Sump Saver
  • 1x 32oz bottle of Spray-G; enough for 3-4 sumps
  • 6x 16oz bottles of the Sump Saver; enough for 1 sump for 6 months

Once a sump has been inspected and cleaned, the kit allows gas station owners and/or maintenance crews to apply the solution and evaluate the efficacy over a 6 month period. The kit comes with detailed handling, application and disposal instructions and can be used even by untrained personnel.

The Sump Saver™ liquid acts by:
1. Neutralizing acidic species upon contact
2. Filling the sump space with Vapor Corrosion Inhibitors (VCIs) that neutralize contaminants in the hard to get areas that the liquids may not have covered.
Sump Saver is gradually consumed by the ongoing production of acidic species within the sump and is replenished with the monthly reapplication.

NOTE: In cases where the levels of vapor release within the sump are so great and the production of acetic acid is so prolific that corrosion attacks are successful despite the deployment of the Sump Saver solution, Zerust recommends that the components be checked and fixed or replaced if necessary to minimize the leaks that could cause such severe corrosion.