Environmental hazards of throwing leftovers down the drain

Ecological Damage Environmental Hazards Environtmental Issue

Raise your hand if you’ve never poured leftovers down the drain?

Unfortunately we’re all guilty of this, whether it happened because we were in a rush, whether it happened for a matter of convenience, or whether it happened because we didn’t think any harm would come from it, we’ve all done it at least once.

Sadly though, this should never happen, because, whether you have a garbage disposal or not, there is real harm in washing away certain substances. You may be focused solely on your sink and think that your brand new drains will be able to keep up with the leftovers you are washing away (FYI they won’t), but in truth, you need to start looking at the bigger picture. Research in fact informs us that this form of dumping is doing a whole lot of damage to the world’s natural environment, particularly to oceans, rivers and lakes. 


There is no ‘away’

Raising awareness about what can be poured down the sink and what can’t, is critical not only to prevent sewer blockages, but also to prevent environmental damage to waterways. Of course good wastewater habits are important all year round, but they’re especially necessary during the holiday season, when most people enjoy more elaborate home cooked meals, and the amount of washing up could make us lazier when clearing up dishes. 

Here are a few items you should never pour down the sink, no matter how lazy you might be feeling:

  • Cooking oil.

    Oils, which include salad dressings as well as mayonnaise, are a major contributor to clogs as they mix very easily with other debris creating drain blockages. Oil can be drained and stored for re-use or, after its cooled, it can be wiped away with kitchen roll and disposed of in the bin. The best alternative though is to pour it in a container, wait until it’s full, and then take it to a local waste center that accepts grease.

  • Motor oil.
    Protect waterways by always keeping oil, transmission fluids and all other chemicals (including anti-freeze) far away from pipes.

  • Household cleaning solutions, Solvents and Paint.
    The content of these solutions are all toxic for the water’s ecosystems and it’s important that they are dispose of correctly to avoid the environment from becoming contaminated. Switch to natural alternatives, and dispose of any harmful substances you may still have laying around, by contacting your local hazardous waste facilities.

  • Grease and Fat.
    According to the U.S. Environmental Protection Agency, almost half of all sewer blockages in the U.S. are caused by grease. This happens because when grease is washed away it’s usually in a liquid state, but shortly after being dumped it solidifies acting as a binder and clogging your pipes with every little thing that’s not water. Grease includes cooked/melted fat from meat, poultry, sausage, bacon, skin and gravy, as well as dairy products such as butter (vegan nut butter is no exception), margarine, cheese, yogurt and ice-cream.
    Grease also includes milk, which in this scenario is considered a highly polluting substance due to its high oxygen demand. Pouring milk down the drain poses a danger to ecosystems as bacteria that feed off the discarded milk use up the oxygen, leaving fish and other small organisms with less, ultimately suffocating them.
    Just like oil, the best way to dispose of grease is to let it cool down before placing it into a jar and taking it to a local waste center. Of course if you find yourself with expired milk on your hands, you could use it as a substitute for butter, yogurt or sour cream, or, by creating a ratio of half milk half water, you could also use it to water your plants! See those plants grow with a healthy dose of calcium in their diet!

  • Coffee grounds and Egg Shells.
    Did you know that most plumbers say that coffee grounds are one of the most likely sources of a clog in your kitchen pipes? These two substances can easily be kept away from your pipes by repurposing them in your compost.

  • Flour, Pasta and Rice.
    These three also apparently harmless substances continue to swell up once they’ve been poured down pipes, also causing problems to your drains. To avoid having to deal with a lot of leftover food (especially during the holidays), try serving smaller portions, and if you still end up with leftovers, be careful to scrape every last meal residue off the plate before placing it in the sink.

  • Produce stickers.
    Generally made of plastic, the tiny sticker that are commonly found on fruit and vegetable packs will not only initially stick to the sides of the drains creating blocks, but could also eventually find a way of entering waterways where they won’t dissolve, and could be mistaken for food by wildlife or marine life.

  • Medication.
    Pills are designed for humans, meaning that their contents can pose a great threat to aquatic life when they make their way into oceans, rivers or lakes. The best way to dispose of unused or expired medicines is to drop them off at your local pharmacy.


As far as toilets go, the rules are pretty simple: don’t flush anything besides toilet paper and human waste. This includes condoms, sanitary towels, paper towels, and wet wipes. 
Some of these items contain harmful content of human fluids, others could be mistaken for food by aquatic life, and others have the tendency to expand or absorb moisture and will eventually clog drainage pipes.

Also, please do not be fooled by ‘Flushable kitty litter’, even though the name suggests there is no harm in flushing it down the toilet, it has been known to actually create huge problems for septic systems. But perhaps, most importantly, even if you find it to be truly flushable, cat litter can pick up bacteria from your cat’s feces which is resistant to the chemicals typically used to treat water. This means that when what’s left of the litter makes it’s way into the water supply, those parasites can become a threat to many animals. Give your vet a call and find out whether there are suitable disposal units in your area for safely disposing of pet waste.

Your sink goes a long way!

In conclusion, just remember that your drain is not a garbage bin, and that whatever you wash down your sink, or flush down your toilet, may eventually end up in the ocean, where it could cause immense damage to entire ecosystems.


How many of these No-No’s were you aware, or were you guilty of? Please help us spread the word!

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