Dear Dot: How Do I Dispose of Cooking Oils?



Dear Dot, 

I recently read an article about “fatbergs” in our sewers and I’m afraid I might have been part of the problem. I’m wondering what is the best way to dispose of cooking oil?

—Concerned Cook, Bainbridge Island, Washington

Dear Concerned Cook,

The bacon grease jar is a mainstay in my kitchen. I’ve long been a faithful adherent to the practice of collecting oil for fear of blockages in our own plumbing, though I don’t seem to be as concerned about blockages in my arteries. But imagine the shock I felt when I heard that this greasy waste can grow into something nightmarish when it reaches the sewer systems (or our septic systems!). Even the name makes me shiver — fatberg. Eek.  

For those who are not yet privy to the horrors of the fatberg, picture a sewer-dwelling iceberg made of oil and grease, globbed together with other items that shouldn’t have been flushed down the toilet. And they are huge! Some stretch beyond 800 feet. Fatbergs can obstruct the sewer system and cost cities millions of dollars to remove. While we sleep soundly above, these bergy behemoths have been wreaking havoc on sewers around the world.

In the interest of supersizing my jar-sized contribution to battling these bergs, I sought out Captain FOG (the acronym stands for fats, oils and grease), to guide us through the p’s and q’s of oil disposal. His real name is Barry Orr, Sewer Outreach and Control Inspector for the City of London, Ontario. He earned this nickname when he started the city’s enforcement program and even starred as Captain FOG in an educational comic called “The Adventures of Fatberg.” 

“I'd say environmentally, you should be concerned, and financially, you should be concerned,” Captain FOG tells me. The major problem with fatbergs blocking the sewer main is that the water does not stop flowing. Instead, it picks up grease and other nasties. This contaminated water could flood someone’s basement or overflow into creeks and rivers, eventually reaching the ocean. When sewage reaches these bodies of water, it can harm aquatic life and contaminate our drinking water. 

This can be collectively expensive, as cities throw millions of taxpayer dollars down the drain to remove fatbergs. And, if your neighbor’s basement floods, it is not just their insurance rates, but yours, that can go up. 

“See how we're all connected?” Captain FOG asked me. Basement floods! Bad drinking water! Higher insurance rates! The apparently benign act of pouring oil down the sink has more far-reaching consequences than I had thought. 

But Captain FOG came to the rescue with simple actions we can take to shrink potential bergs. First off, see if your city has any handy programs to make use of leftover oil/grease/fats. London, Ontario, for example, instituted the Your Turn Cup program. The city provides residents with biodegradable cups to pour cooled fat, oil, and grease into and that can be easily stored in the freezer until it is full. Note that aside from cooking oil, you should also avoid dumping butter, salad dressing, gravy, and sauces down the drain — these can go in the cups as well. Residents can then toss the cups in their garbage or — far better! — drop the cups off at the City of London EnviroDepot where the oil will be recycled into biofuel. Captain FOG’s motto? “Why treat it as waste when I can treat it as a resource?”

Some municipalities may not offer special cups but still have biofuel facilities that accept your cooking oil. Bainbridge Island, for example, has a number of free drop-off recycling stations for cooking oil. In this case, collect oil in your own biodegradable containers (an old coffee cup might suffice). Strain it to remove food particles first, and store containers in the freezer until they are ready to be brought to the recycling center. Check with your local facility for their guidelines. RecyclerFinder can help you locate a facility near you. 

Some green bin programs accept oil and will process it in an anaerobic digester. 

If your city or town isn’t tackling fatbergs and other greasy menaces, you can throw oil in the trash. It’s not ideal, but it’s also not the worst option. “The bottom line is, don't ever put it down your drain,” Captain FOG says. Again, collect oil in a biodegradable container and store it in your freezer until it fills up. Then, toss it in the trash. If you’re looking at minimal oil residue on pans and dishes, wipe it with a paper towel and throw that in the trash too.

But a warning: Do not pour your oil in your backyard compost — it will attract pests. 

So now we know how to tame the fatberg. But wait, oil isn’t the only villain, according to Captain FOG. Wet wipes and other items flushed down the toilet are inciting these blockages too. Many wet wipe brands advertise the product as flushable, but they don’t decompose quickly enough in the sewers to prevent them from, uhh, agglomerating to form these pesky obstructions. While these are the biggest offenders, sewer workers find other items such as feminine products, paper towels, used condoms, dental floss, and even tiny toothbrushes in fatbergs.

The solution to this, according to Captain FOG, is to throw away these items instead of flushing them. “Your toilet really was only designed for human waste and toilet paper,” he says. He also suggests that there should not only be legislation that clarifies what is not flushable, but that we find alternatives that are flushable. 

Captain FOG is the superhero we need to rescue us from a greasy future. 

Gratefully grease-free,


Got a question for Dot? Let her know here:

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