Maine DEP Monthly Environmental Column Focused On 'Fueling Your Summer Safely'

June 20, 2011

Samantha DePoy-Warren, Maine DEP Spokesperson/Director of Education & Outreach

A note about In Our Backyard: In Our Backyard is a monthly, staff-written informational column developed by the Maine Department of Environmental Protection and available to the press and the public. E-mail your environmental questions to or send them to In Our Backyard, Maine DEP, 17 State House Station, Augusta, ME 04333.

Fueling your summer safely By David McCaskill, Maine Department of Environmental Protection

One look at the rising mercury reminds us that summer is nearly here and that means it is time to till the garden, mow the lawn and cool off when the chores are done with a boat ride round the lake. And fueling many of these staple to-do’s of summer is gasoline.

Although seemingly indispensable in our modern lifestyle, gasoline is one of the most dangerous chemicals with which we routinely come in contact because all of the compounds it contains are toxic. It is extremely flammable and noxious and - when spilled on the ground - can be highly harmful to the environment and to the water we drink to beat the summer heat.

Recently there has been much concern about engine performance and storage issues with gasoline containing ethanol or E10. Because of ethanol’s affinity for water, improperly stored E10 gasoline can undergo something called “phase separation.” Phase separation occurs when the ethanol in the gasoline absorbs excess water until it actually separates from the gasoline. The gasoline then floats on top of this water/ethanol combination that sits in the bottom of the tank. Because most small engines receive their fuel from the bottom of the tank, the engine will not work. Ethanol is also a powerful solvent that will clean out the gunk and “build up” in fuel tanks and engines, resulting in clogged fuel filters and carburetors.

So how do you prevent these issues from occurring? Properly storing gasoline, in approved containers away from your living area, is one way to make sure that groundwater contamination and fire from gasoline spills don’t endanger us and our families. The flammability of gasoline is also important to keep in mind. Starting a brush fire with gasoline is begging for trouble - the initial flash from burning gasoline catches many people off guard and can cause major burns when the gasoline vapors in the air also catch fire.

Only buying what we need for each job ensures we’re not stuck with "old" gas at the end of the season. If you store gasoline for more than 30 days, add a stabilizer (available at most hardware and small engine repair shops) approved for use with ethanol. Keep the container or tank 95 percent full to allow for thermal expansion of the fuel and limit the air space, which reduces condensation and therefore water build up. If you do find yourself with old gummy or phase separated gasoline, you should consider it a hazardous waste. The only safe way to dispose of it is to take it in on your local hazardous waste drop-off day or an approved hazardous waste disposal site (call your town office for the one nearest you).

Where gasoline is concerned, less is best, storing only what fuel we need and preventing spillage. It’s best that we limit our exposure to gasoline, no matter how useful, because it is, and always will be, a hazardous material. For more information on the safe use and storage of household gasoline, check out

And most importantly, if you leak or spill gasoline or any other fuel or hazardous waste as you fill up your tiller, lawnmower or boat, or if you witness a spill or think there is a threat of one, please report it immediately to the Maine DEP at 1-800-482-0777. The sooner we know about it, the sooner we can determine the risk and prevent any threats to the environment and human health.

This column was submitted by David McCaskill, a Senior Environmental Engineer with the Maine Department of Environmental Protection's Bureau of Remediation and Waste Management.