Checklist for Fuel Dispensing Facilities Switching to Ethanol-Blended Gasoline

Verify tank material and dispensing equipment compatibility - Some underground storage tanks, tank liners, and above-ground equipment such as nozzles, hoses and meter seals may not be compatible with ethanol-gasoline blends. If any doubt exists as to the compatibility of the tank(s) and/or dispensing equipment, the manufacturer or equipment supplier should be consulted.

Investigate tank and water problems and correct - Underground storage tanks frequently have small amounts of water at the bottom of the tanks, referred to as “water bottoms”. Ethanol-blended gasoline should not be stored in tanks which contain water. Excessive water levels can cause the ethanol in an ethanol - gasoline blend to “phase separate”, resulting in a layer of water and ethanol on the bottom of the tank. Therefore, it is imperative that water be eliminated from the system.

The tank owner or operator should review the maintenance history of all tanks to be used for storage of ethanol-gasoline blends. Any tank with a history of excessive water problems should be reviewed closely. The source of water entering the tank must be identified and eliminated if the tank is to be converted for use with ethanol-gasoline blends. If historic data are not available, it is recommended that historic data be developed and reviewed prior to conversion.

Also check to see if tanks have excessive tilt. Sticking opposite ends of the tank can usually do this. If one end of the tank is lower, it will result in a higher stick reading than the other end. When one end of the tank is lower, water can collect at the low end and go undetected. In such cases, the low end of the tank should be tested for water prior to the first delivery as well as on an on-going basis.
Note: The dipstick must be kept in a dry place to prevent incorrect readings.

Submersible or Suction Stubs Check - In order to minimize risk of carryover of water or particulates from the bottom of the tank, it is recommended that the submersible or suction stubs be positioned between 15 cm (6”) to 20 cm (8”) off the bottom of each tank. Lower submersibles or suction stubs should be raised.

Check to see that the tanks are clean - Unlike gasoline, ethanol can loosen the heavier gasoline components (sludge) that can accumulate over time in gasoline storage tanks. If left unchecked, these deposits can accumulate in fuel and/or dispenser filters. To ensure fuel quality and avoid engine performance problems associated with clogged fuel filters, storage tanks should be thoroughly cleaned prior to first delivery of ethanol-blended gasoline. Heavily contaminated tanks may have to be cleaned by hand or water washing.

Equip pump or dispenser with 10-micron filter – To ensure fuel quality dispensers should be equipped with a 10-micron filter to catch any loosened deposits that may not have been removed during tank cleaning. Water absorbing filters are not recommended with ethanol blends.

Fill line caps should be checked for proper fit and seal - Any improper fit or seal should be repaired. Manhole covers should be checked for proper water run-off and modified if necessary.

Obtain ethanol compatible water detection paste - Obtain an oxygenated gasoline (e.g., ethanol) compatible water detecting paste prior to receiving the first load of ethanol-gasoline blend and check for water bottoms. If high water bottoms are present, they should be pumped off and disposed of in accordance with federal and provincial laws. Recheck for water bottoms and remove if necessary.

Check to see that the tanks are clean - Unlike gasoline, ethanol can loosen the heavier gasoline components (sludge) that can accumulate over time in gasoline storage tanks. If left unchecked, these deposits can accumulate in fuel and/or dispenser filters. To ensure fuel quality and avoid engine performance problems associated with clogged fuel filters, storage tanks should be thoroughly cleaned prior to first delivery of ethanol-blended gasoline. Heavily contaminated tanks may have to be cleaned by hand or water washing.

The initial load should fill tanks to at least 80 % of capacity - This will allow the solvent effect of the ethanol to loosen any sediment or varnish type deposits from the sides and upper portions of the tank.