Design & DIY 6 things that should never go in your septic tank By Allan Britnell Published: July 23, 2021 Updated: March 26, 2024 share Share on Facebook Share on Twitter Share on Pinterest Copy Link Cancel View in Fullscreen 1 2 3 4 5 6 7 Photo by Koldunova Anna/Shutterstock 1. Too much water The main cause of septic failures is too much water. It overflows the tank and forces solids into the septic field where it clogs. Low-flow faucets, toilets, and other fixtures are a great way to reduce this risk. If you do laundry at the cottage, stagger loads over several days. You could also consider installing a no-flush urinal. View in Fullscreen 1 2 3 4 5 6 7 Photo by Coryn/Shutterstock 2. Grease, oil, and kitchen scraps You should minimize the amount of fats and oils that go into any drain system, as these materials will slowly build up and block the pipes. Once in the septic tank, that can bind with other solids making it harder for the bacteria to break things down. Also, don’t use a garburator at the cottage. Your septic system won’t be able to break the material down and you’ll need to have the tank pumped out more frequently. View in Fullscreen 1 2 3 4 5 6 7 Photo by TheRecruit/Shutterstock 3. Harsh chemicals and antibacterial products Limit the use of antibacterial products at the cottage, particularly things such as soap and household cleaners that will get flushed into the septic. Large amounts of these products—or other strong disinfectants such as bleach or toilet bowl cleaners—can actually kill off the essential bacteria in the tank and render your system inoperable. View in Fullscreen 1 2 3 4 5 6 7 Photo by VidEst/Shutterstock 4. Personal hygiene products Anything that isn’t biodegradable should not get flushed down the drain. These things will accumulate in the tank or clog the weeping bed if the get flushed out. This includes feminine hygiene products, condoms, diapers, “disposable” wipes, and other plastics. Also, don’t flush cigarette butts for the same reason. View in Fullscreen 1 2 3 4 5 6 7 Photo by Mironov Vladimir/Shutterstock 5. Meat and roadkill Yep, you read that correctly. In some circles, there’s a rural legend that if you have a seasonal cottage you should drop some raw meat—often in the form of roadkill—to “kickstart” your system for the start of the season. That’s not only not true, but the fur and bones could clog up the system. View in Fullscreen 1 2 3 4 5 6 7 Photo by DedMityay/Shutterstock 6. Medicines Never flush unneeded medications down the drain (at the cottage or at home). Not only do you risk impacting the bacteriological activity in the tank, if they flush all the way through the system, they can end up in the lake where research has shown that some drugs have negative impacts on local wildlife. Most pharmacies will collect and safely dispose of surplus or expired medicine. View in Fullscreen Related galleries 5 CL-approved DIY tricks to simplify life at the cottage Bestselling author Bryn Turnbull’s family cottage used to be covered in frog tchotchkes. Now, it’s a Georgian Bay gem 6 winter maintenance tasks that you never want to ignore 1 2 3 4 5 6 7 6 things that should never go in your septic tank Out of sight, out of mind is a great mindset—in theory, until your septic tank starts acting up. Here are are collection of things that you should definitely not put in your septic system. Related Story Cottage Q&A: Toilet paper and the septic system