The introduction of ethanol to gasoline storage tanks brings with it some  significant concerns to the operator. The first and largest concern is water – ethanol and water simply are not compatible. It takes a small amount of water to cause what is known as “phase separation” in a tank. Therefore, it is critical that ethanol-blended gasoline is not exposed to water at any time. That’s why ethanol-oxygenated gasoline is not typically transported in pipelines, which frequently contain water. Instead, the ethanol is generally added to tanker trucks at the terminal, immediately before delivery.

When water does contaminate ethanol-blended gasoline, the water dissolves into the ethanol and disperses throughout the tank. Once it exceeds its maximum tolerance, the alcohol/water mixture will separate from the gasoline. Depending upon the actual conditions, up to 80 percent of the ethanol will separate from the gasoline, forming two separate layers in the tank: Gasoline on top of ethanol-rich water. The gasoline layer, because it has been stripped of most of the ethanol, will be lower in octane and most likely out of specification. The bottom layer, which is a mix of ethanol and water, simply won’t burn.
Debris or particulates, and accumulated sodium salts create similar problems in tanks containing ethanol-blended fuels. For this reason, it is critical that all tanks receiving ethanol fuels should be carefully inspected prior to the first introduction of the fuel to ensure that there is no water, debris or accumulated sodium salts.

More than half of the USTs we inspect prior to the introduction of ethanol-blended fuels require some level of preparation services in order to avoid some or all of the above problems. 

It is a fact that all gasoline tanks contain some level of water. That water must be removed before the introduction of ethanol-blended fuel. Many operators rely upon their Automatic Tank Gauge (ATG) or their dipstick and water-detecting paste to tell them whether they have water, then pump it out until these devices tell them that no water remains. 

This is a mistake. These tools are not sophisticated enough to ensure that there is no water in the tank, the condition necessary before introducing ethanol. In fact, conventional water-finder paste and water detection filters will not detect a phase-separated bottom layer of a tank quickly enough to react to it before problems occur. In our experience, more than half the time, unlevel tanks result in water collecting in an area of the tank that is not detected by the tank gauge or dipstick. There is no way to know that from above ground with a conventional water-detecting device.

Working with major oil companies and regulatory officials throughout the country, Tanknology has developed specific protocols for tank inspection and ethanol preparation services. We have performed these services on thousands of tanks, all across the country. In many cases, we have adapted our protocols to the needs of specific customers and their unique requirements. 

In most cases, we can perform tank inspection and ethanol conversion preparation services in a matter of hours – without taking your site out of operation. 

Because Tanknology is the nation’s largest provider of UST compliance solutions, we have the capacity to react to customer needs in every corner of the country. 

You can rely on Tanknology to ensure that your fuel tanks are in optimum condition for that first delivery of ethanol-blended fuels.