This might be more appropriate as a community wiki...

We have a septic system and I'm extremely paranoid about what can (and cannot) be put down our sink drains. I know the general answer is "nothing but water" but I'm particularly curious about:

  • Toothpaste
  • Hand soap (not labeled as anti-bacterial)
  • Rinsing paint brushes
  • Facial hair from shaving
  • Left over coffee

How careful should I be?


  • 1
    While there are some universal things, others might be prohibited by local laws. – ChrisF Oct 20 '10 at 8:06
  • @ChrisF Interesting! I didn't know that some areas had local laws concerning this. – Mike B Oct 20 '10 at 15:41
  • What about laundry drains? I've heard that lint in the exhaust water of a washing machine can gum up septic systems rapidly. Most people don't filter it out at the drain, apparently. – Jacob Sep 8 '15 at 1:04

Tooth paste and soap (even a little anti-bacterial) are certainly fine. Basically, you just don't want to put any harsh chemicals in there that will kill the bacteria eating away at the waste.

I would avoid food and thicker items as they will not break down. I try not to allow hair, coffee grounds as they might not break down. I would definitely avoid paint.

Also avoid paper products that wont break down. Feminine products can cause havoc. Almost all toilet paper is septic safe these days, but read the packaging to be sure.

If you just bough a new house, or built one, I would recommend you have someone come out and pump the basin sooner that later. That way you know for sure that the tank is clean and in good working order and you can have a fresh start. I have heard way to many horror stories for new builds where the contractors used the tanks as a trash can and that later caused problems. Then remember to have the system flushed out every 3-5 years based on usage and local laws.

  • Thanks -- we had a new system installed so we know that it's in good conditions. I just want to keep it that way. =) – Mike B Oct 20 '10 at 15:36
  • I rinsed off some paint brushes yesterday (oops) -- at most maybe a 1/6 cup of paint (mostly deluted with water). Do I need to do anything to correct that? Riddix? Yeast? – Mike B Oct 20 '10 at 15:51
  • probably fine with that little especially since it was diluted with water. latex based i assume? not oil based? – mohlsen Oct 20 '10 at 19:53
  • Admittedly, I don't know. It was Behr premium interior paint and primer combo. – Mike B Oct 21 '10 at 7:34

If you have a garbage disposal, don't use it. Just throw the food away. Keep extra solids to a minimum.

  • 3
    Garbage disposals are fine as long as you dont use them for full out trash like many people do. No egg shells, banana peels, potato skins, celery stalks, etc. I have seen so many people pushing this crap down the disposal, it causes havoc on non-septic systems let alone septic ones. just use it for the little bits of stuff that fall of the plates and typically sits in the sink until you rinse it out. – mohlsen Oct 21 '10 at 11:35

All the things you asked about are fine avoid pouring harsh chemicals down the sink in large amounts. I have never seen a laundry clog a septic system up and we have been installing and pumping systems for 20 years and I mean never. ou do however want to avoid the garbage disposable it is one of the worst thing you can do to a sytsem. Think of it this way your body when food enters it breaks it down and suck all the valuable stuff out of the food to feed you body. It is then disposed of after it has been thoroughly broken down in your body. When you put food down the drain or garbage disposable the septic system has to break it down from start to finish.This make bacteria much more active and propagate to levels not needed they also produce waste in the form of nitrogen that's the balk scum in the clarifying area of an aerobic septic system. So more food more Bactria. From years of experience I will say this a family who uses the garbage disposable lets say just two people this just happened, and I've seen it over and over who used the disposal daily will need a aerobic system pumped every 2 years as opposed to 7-8 years for a family who doesn't use a disposal.

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