How do I safely dispose of watered-down gasoline?

My gas can, which was sitting outside, turned out to have a defective cap, and now I have several gallons of unusable gasoline. What’s the easiest & safest way to dispose of it?


Check with your city or county for where you can dispose of hazardous waste. In my area, it’s the county that handles it - batteries, paint, refrigerant, gas, oil, even old computer parts.

They have weird hours and are only open a few months of the year, but that’s really our only option.

Well there’s always a drain.

Gasoline and water don’t reasdily mix. They separate VERY quickly, with the gas being on top. If you have a clear glass container and some sihphoning equipment, you should be able to remove the gasoline pretty easily.

I would also check with the Fire Department. That is who we take our hazardous household products to here.

That’s illegal in most areas.

A couple legal ideas:

Filter the gas through felt - the gas will go through, but the water will not pass through the felt.

Gas in an open-top container such as a bucket - freeze it. The water will freeze and can be removed in one lump.

A local auto dismantler may accept it - they already have to drain the fluids out of scrapped cars.

A chamois cloth will filter out water too.

I’ll be giving the felt a try as it’s lot’s cheaper than getting a chamois.

Eh, (getting caught is) not very probable.

This is good advice. Just pour it into a clear glass container and let it separate, pour the gas off the top and put it in the lawn mower or another container. If you are careful you might only end up with water contaminated with a cup of gas or even just a few drops.

That water can be put on a few weeds. Or if you live in an urban area where that isn’t a good idea, take it to wherever you take used motor oil for recycling.

But getting smote by Mother Earth is.

I might be wrong but I thought at one time I heard that gas line antifreeze, will get rid of the water or mix with it and allow you to burn it.

[Moderator Note]

It’s still not at all helpful to propose illegal methods in response to a GQ question. Let’s try to be more responsible when answering questions in this forum

General Questions Moderator

Try STA-BIL, sort of like dry gas.

You can put it in a metal bucket, and light it. The gasoline will burn off, leaving the water intact!

S^G [/d&r]

Seconded - this is easy to do and works well. Much better to use the gas than to discard it.

In my area, the town dump has a tank for used motor oil, and they’re open on Saturdays year round. That’s where I’d take it.

Unfortunately, it’s several gallons, and the largest glass container I have is probably about 1/2 gallon. While I would prefer to use it than to discard it, I really don’t want to have to handle it like this (which would require two gas cans, the siphon and the glass jar). Probably easiest to dispose of it in my town’s hazardous waste program.

Unless you live below the Antarctic Circle, that would be a very dangerous thing to do. Gasoline fumes will concentrate inside a freezer, and it is not inconceivable that the motor, fan or other ignition source could cause an explosion and fire.

Our recycling center took away the oil collection container, because people put water and gas in the oil container. Don’t put water or gas in the oil collection container.

Also, when you take the can out of the freezer it will be cold. Water will condense in the gas. You are right about the ignition potential. Laboratories use special freezers that are specifically designed for flammable materials.