What Should Not Go Into the Sanitary Sewers
While sewer backups can occur for a number of reasons, there are many ways a homeowner can reduce their risk. One very important way is to know what is and isn’t acceptable to flush down a toilet or pour down a drain.
Here are some things that definitely should not go into the sewer system. Where text is in blue, click on the text to read more about this item.
Fats, Oils, and Grease – Any and all cooking oils, grease, fats and other similar products should not be poured down the drain! While they may be liquid while being poured, they will very soon cool down and solidify, and this usually happens somewhere within your own plumbing, or your own sewer lateral. While it may seem to make sense that flushing it down with hot water will help, it doesn’t – it might just make it a bit further down the drain before it solidifies and plugs up your own plumbing, or the municipal sewer system.
Pour grease, fat, or lard into a clean juice carton whose top has been cut off. Let the material solidify and then place in your household garbage. Small amounts of cooking or vegetable oils, should be poured into a small plastic screw-top bottle. Seal the lid tightly and place in your garbage.
Feminine Hygiene Products – Feminine hygiene products generally do not breakdown quickly and tend to plug up pipes and cause problems for sewage pumps located within the municipal sewage collection system. Even if the packaging claims they are biodegradable, that doesn’t mean they are suitable for toilet flushing! Disposal should be in the garbage, even if the packaging suggests otherwise.
Paper Products – The only paper product suitable for flushing is toilet paper. Other paper products, like facial tissues, paper towel, newspaper, cardboard, and wipes of any kind are simply not suitable for flushing. When items like these are flushed, they don’t break down quickly, and can cause buildups of material and blockages that may cause a sewage backup. Some paper products belong in your recycling grey box (like newspapers and clean cardboard), while other items belong in the garbage (soiled pizza boxes, parchment paper, and wipes of every kind).
Wipes – There are many different kinds of wipes available today, including baby wipes, feminine hygiene wipes, and antibacterial wipes. Generally, these do not degrade quickly and will cause blockages in the sewer system. Many of them have packaging that claims they are biodegradable, or even flushable, but they are not. (For example, see this CTV news story on wipes.) Wipes are better off in the garbage.
Hair – Large masses of hair from haircuts or cutting a pet’s fur often stay clumped together and do not break apart into loose materials quickly. Large masses of hair are sometimes found in lift station pumps and stuck in sewer mains. Hair should be thrown in the garbage.
Dental Floss – While it might seem insignificant, dental floss in the sewer system creates a risk, mainly at municipal pump stations. It is usually a fairly tough and tear-resistant product that gets caught up in pump impellers. Used dental floss should be disposed of in the garbage.
Diapers – Diapers are large enough that they can’t be flushed. In spite of that, they have been found lodged in sanitary laterals as the cause for a home’s sewage backup. Diapers are not flushable, and need to go in the garbage. This applies to all types of diapers, biodegradable or not. They are simply too big for the sewer.
Food scraps and “garburators” – Food scraps and grinds that make their way into the sanitary sewer put additional stress on the treatment process and also add solids to the sanitary sewage stream that compromise the flow in the sewers.
There is a better place and use for food scraps: your backyard composter.
Pharmaceuticals – Pharmaceuticals are an increasing problem, in that sewage treatment systems are not designed to deal with the myriad of chemicals that are in them. These items can be brought to local pharmacies for disposal. Visit the Ontario Medications Return Program website.
Needles – Some people mistakenly dispose of hypodermic needles into the sewer system. Since all hypodermic needles are classified as biohazard risks, their presence in the wastewater collection system presents special problems and dangers for wastewater collection and for wastewater treatment employees. Never flush needles down the toilet.
All hypodermic needles should be disposed of safely through the drop-off program organized by Health Products Stewardship Association (HPSA). Residents can visit the Association's website to find the nearest pharmacy that will accept pharmaceuticals and sharps for safe disposal. Residents are encouraged to contact their pharmacy before dropping off pharmaceuticals or sharps, as certain handling restrictions may apply (i.e. sharps need to be brought in a specific biohazard container).
Chemicals – The treatment process is designed specifically to treat domestic sewage and human waste. It is not designed to treat the huge variety of chemicals that are present in other day-to-day products.
You should never dispose of the following materials down a drain or your toilet:
Oils, greases, anti-freezes and fuels from cars, lawnmowers, bikes, etc.
Pesticides and herbicides
Paints and paint thinners, solvents, turpentine and nail polish remover
Flammable or corrosive products
All waste chemicals should be treated as Household Hazardous Waste.
Pet Waste - The treatment process is not designed to handle some of the unique pathogens that may accompany pet waste. Pet waste, including kitty litter, should be disposed of in the garbage.