What Not to Flush: A Septic-Safe Guide
Trevor Hemond
One of the best ways to protect your septic system is to be careful about what goes down your drains — especially the toilet. Even things labeled “flushable” can cause serious problems in a septic system.
Here’s a simple guide to what should never be flushed and why it matters.
Stick to the basics
Your toilet should really only handle three things:
- Human waste
- Toilet paper
- Water
That’s it. Anything else — even if it seems small or harmless — can cause clogs, throw off the bacteria balance in your tank, or damage your drainfield over time.
Common things people flush (but shouldn’t)
Here are some of the most common household items that don’t belong in your septic system:
- Wipes (even “flushable” ones)
- Paper towels and napkins
- Feminine hygiene products
- Diapers and baby wipes
- Dental floss
- Cotton balls and swabs
- Hair
- Tissues (they don’t break down like TP)
These items don’t break down easily and can quickly cause blockages or build up in your tank.
Harsh chemicals and cleaning products
Avoid flushing or pouring strong chemicals like:
- Bleach
- Drain cleaners
- Paints or solvents
- Pesticides or oils
These can kill the good bacteria in your septic tank — the stuff that helps break down waste. Without that bacteria, solids build up faster and the whole system struggles to function.
Grease and food waste
Even though it might seem like no big deal, avoid putting these down your kitchen sink or garbage disposal:
- Cooking grease or oil
- Coffee grounds
- Eggshells
- Bones
- Starchy leftovers (like rice or pasta)
Grease can harden and block pipes, while food scraps add extra solids to your system that it’s not designed to handle.
Better safe than sorry
When in doubt, throw it out. A good rule of thumb: if it didn’t come from your body or it’s not toilet paper, it probably doesn’t belong in the toilet.
Bottom line
What you flush affects the health of your septic system. Being mindful about what goes down the drain can help you avoid clogs, backups, and costly repairs. A little caution now can save you a lot of trouble later.