Ethanol Blend Retail Guidance Document

A Southgate station's customer put premium gasoline in her vehicle. Two hours later the car wouldn't start. The mechanic found the gasoline in the vehicle tank contained 72% water. If this much water was present when the fuel was purchased how could the car have even left the station's driveway? The Motor Fuel Quality inspector verified that the problem originated at the station with incorrect handling and storage of an ethanol blended fuel.

Ethanol blends require a water free environment. Before converting to ethanol blends stations must first prepare their storage tanks and dispensers to ensure that they are compatible with ethanol blends and are tight against water entry. The system must always be maintained free of water. This is extremely important since ethanol will bond with the water and pull it up into the fuel. Once there it can remain in this cloudy state until the temperature of the fuel cools or the water and ethanol saturation becomes so heavy that it drops away from the lighter gasoline hydrocarbons. The water or water and ethanol mixture settles to the bottom of the container leaving the lighter gasoline on top. This is known as phase separation.

The Department of Agriculture & Rural Development receives many complaints from consumers who have purchased gasoline contaminated with water. Stations who are unfamiliar with the proper steps to take to ensure customer satisfaction with an ethanol blended fuel should contact their fuel supplier for guidance before receiving ethanol products. 

The Department of Agriculture & Rural Development recommends that stations selling ethanol blends take steps to guard against phase separation. As a minimum the station should:

  • Use an ethanol specific water detection paste and dip stick to check the storage tanks daily for water. (An electronic system can be utilized provided it is verified accurate on a monthly basis with a manual check using water detection paste.)
  • Remove any standing water, sediment, or sludge from the storage tank bottom and maintain it in a water free condition.
  • Repair or replace any missing, damaged or loose storage tank caps or cap gaskets.
  • Repair or replace any missing, damaged or unseated vapor recovery caps.
  • Repair or replace any missing, damaged or loose adaptor pipes on the tank fill site. 
  • Remove standing water from the storage tank fill area (hand dip or pump it out -don't flush it into the tank).
  • Remove standing water from sump pump areas.
  • Use a 10 micron pump filter (preferably one designed to stop product flow in the presence of water.)
  • Visually examine the product if a consumer complaint is received, and after heavy precipitation or melting snow to ensure the product is not cloudy or containing visible water, sediment or some other contaminate.
  • State law requires that you STOP SALE anytime the water level in a storage tank exceeds 2 inches or the product is observed to contain water, sediment or is cloudy or contaminated in any manner.

Your diligence in maintaining a water free environment for your ethanol blends will ensure your product and your customers never experience "cloudy" or contaminated gasoline.

The Motor Fuels Quality Act, P.A. 44 of 1984, as amended, can be referenced on the Internet at http://www.legislature.mi.gov. If you have questions or concerns regarding Michigan's Motor Fuels Quality program please contact the department at 517 655-8202 or visit the licensing and certification section of our website at http://michigan.gov/mda

Revised:  5/1/2007