13 Common Items You Need to Avoid Flushing into Your Septic System

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13 Items You Shouldn’t Flush Into A Septic System

Many of the questions people have around septic systems involve the maintenance requirements of the systems themselves.  One of the main questions people have is around understanding the rules of what exactly can go down the drain or be flushed into your septic system and what can’t. In this article, we will clear this up for you once and for all.

So, what are the items you should avoid flushing into your Septic System? Here is a list of 13 items you should absolutely avoid putting into your septic system:

  1. Antibiotics
  2. Cigarette butts
  3. Feminine hygiene products
  4. Coffee grinds
  5. Grease & Oil
  6. Cat Litter
  7. Chemicals
  8. Floss
  9. Cotton Swabs
  10. Disposable Wipes
  11. Paper Towels and Facial Tissues
  12. Latex Condoms
  13. Water Softener Discharge

Each of these items should be avoided for different reasons. In the rest of this article, we will explain why each of them should not be flushed into your septic system and the harm they could do to your plumbing and system. We will also look at some other common household items that should be flushed or poured into your septic system.

What Harm Can Come From Flushing Certain Items into Your Septic System?

Before we go into each of the items listed above into better detail. I thought it was important to explain why you want to avoid flushing certain items into your septic tank.

The obvious answer is that your septic is a major household system, and keeping it working properly is important to not only the value of your home but potentially the health and wellbeing of your family and neighbors. Read this If you want to learn more about what kind of havoc a failed septic system can play on selling a home.

When it comes to keeping your septic system functioning properly it all comes down to maintaining it properly.  Septic systems that aren’t abused don’t require that much maintenance above period pumping and emptying. Read this if you want to know how you can tell if your septic tank is full and needs to be pumped.  If you are in need of a local septic system professional visit our state directory page.

Essentially when we think of the harm certain items can do to your system the fall into two types of broad issues that they can cause with your septic systems plumbing.

  • Clogging: The first issue has a lot of overlap with more traditional public sewer plumbing and systems.  It has to do with avoiding items that can literally clog or impede the flow of waste from your home into your septic tank or from the septic tank to the septic drainage field. Pipes and plumbing can only work if waste and water can flow through them freely.  If you flush or pour some of the items we mention in this article into your septic system, you risk clogging the system.
  • Bacteria Harm: The second group of items that you want to avoid putting into your septic system should be avoided due to the harm they can potentially play on the bacteria in the system. This is where traditional public sewers and septic systems diverge in terms of similarities.  If you are used to a more traditional public sewer system you probably never thought of maintaining bacteria in the sewer system. I know I never did until I moved into a home with a septic system.

Let’s quickly explain where bacteria comes into play in the septic system, so you can better understand how harming the bacteria in the system by flushing certain items down the drain can be an issue.

Why Should I Care About Harming the Bacteria in My Septic System?

Remember how I said this is where you might have some common questions as compared to a public sewer system, well that’s for good reason. You are not alone.

So let’s give you a real high-level explanation of how septic systems work so you will better understand how harming the bacteria in the system can be a really big problem.

In the simplest sense, a septic system is made up of two major components.

  1. The Septic Tank- This is a tank or holding chamber that receives the household waste and holds it until it is treated and the processed wastewater is released into the second component of the septic system, the drainage field.
  2. The Drainage Field- The drainage field receives the effluent or (wastewater) from the tank.

The key to this whole system is the bacteria in the septic tank that feed on the waste and break it down before it runs into the drainage field. If the bacteria in the septic tank are harmed, they may not be able to keep up or break down the waste in the septic tank before it is pushed into the drainage field. This can cause your septic field to get clogged with solids and eventually fail.

When your drainage field fails it usually requires a full replacement, which can cost 10’s of thousands of dollars. So as you can the only thing standing between your checkbook and paying for the huge cost of replacing or repairing your septic tank are those little bacteria you probably never thought of until now.

So now that you understand the two different ways in which common household items can cause havoc on your septic system, let’s take a closer look at each of the 13 items we talked about never flushing into your septic system above.

Why You Should Avoid Flushing Antibiotics into Your Septic System


This is one that usually catches new septic system owners by surprise.  So when it comes to antibiotics it falls into the category of potentially harming the bacteria in your septic system we talked so much about earlier.

Remember Antibiotics can be excreted in urine, so excessive use of antibiotics can kill the bacteria in your septic tank. This is more of a concern in large quantities, the occasional proper use of antibiotics is unlikely to harm your septic system.

But if your home has a higher use of antibiotics than normal you may want to consider calling a septic professional to inspect your system or perhaps use a product like Rid-X to help maintain the balance of bacteria in your system. You can read more about Rid-X here.

Why You Should Avoid Flushing Cigarette Butts into Your Septic System

ITEM #2: Cigarette Butts 

Cigarette Butts are not biodegradable and should not be flushed into your septic system.  These fall into the category of items that could cause your system to clog. If you are going to smoke dispose of your cigarette butts into the normal trash can and not into your septic system, or you could end up paying thousands of dollars for repairs later on.

The filters from cigarettes can clog your septic pumps and cause additional issues.

Why You Should Avoid Flushing Feminine Hygiene Products into Your Septic System

ITEM #3: Feminine Hygiene Products like Tampons and Pads

This is one of the common culprits for a lot of septic and public plumbing issues.  These products consistently end up in the toilet and are not meant to be disposed of in that manner.

This is why you see signs in women’s bathrooms about not disposing of these items in the toilet. These products can’t be broken down by the bacteria in your septic system.

They can accumulate in your septic system or in public sewer systems and cause failure over time.  Do NOT flush Tampons and/or pads down your septic system. This goes for the applicators as well. While they are made out of cardboard and say biodegradable, they aren’t going to be processed by the bacteria in your septic tank and can cause major issues as well.

Usually the homeowners of the septic system are good about this one once they understand they shouldn’t put femine hygiene products down the toilet and into your septic system, but if you have family and friends visiting that are new to septic systems you want to make sure they understand the Do’s and Don’t of what can go down the drain.

Why You Should Avoid Pouring Coffee Grinds into Your Septic System

ITEM #4: Coffee Grinds

Coffee grinds are another common household item that can cause your septic system plumbing a world of hurt. Coffee Grinds are again not biodegradable and can build up and clog or hurt your system over time.

Make sure you are cleaning coffee filters in the garbage and have a drain cover in your sink to help catch and small particles before they can go into down your drain and clog your pipes.

Why You Should Avoid Pouring Grease & Oil into Your Septic System

ITEM #5: Grease & Oil

Never pour grease or access cooking oil down your septic system plumbing.  Once the grease and oil cool it will harden and clog your pipes.  This goes for public sewer pipes as well.

Why You Should Avoid Flushing Kitty Litter into Your Septic System

ITEM #6: Cat Litter 

This one should be obvious but a lot of people or kids might have their litter boxes in the bathroom, and sometimes the temptation is to put some of that cat litter into the toilet, especially for kids who might want to rush their chores to get back to the fun stuff.

Cat litter is made to clump and harden when it gets wet. This can cause havoc on your plumbing, both septic systems, and public sewer.  Avoid Kitty Litter down your toilets and drains at all costs.

Why You Should Avoid Flushing Harsh Chemicals into Your Septic System

ITEM #7: Chemicals 

You don’t want to pour chemicals into your septic system or any sewer system as the chemicals could endanger the water supply. Some of these common chemical culprits include paints, thinners, oils, varnishes, pesticides, used motor oil.

These should never be poured down the drain.

Harsh household cleaners should be used in moderation. Read this if you want to learn more about using Bleach in your Septic System.

Why You Should Avoid Flushing Dental Floss into Your Septic System

ITEM #8: Dental Floss

This was probably another not so obvious one for most of you. Dental floss is so small most people don’t think of it as causing any harm to your plumbing or septic system. But the fact is it isn’t biodegradable and can cause a lot of the same septic system clogging issues we mentioned before with time and build up. So dispose of your dental floss in the garbage, not down your toilet.

Why You Should Avoid Flushing Cotton Swabs into Your Septic System

ITEM #9: Cotton Swabs

Cotton Swabs have been known to clog a drain or two. They are not biodegradable, but usually, they are flushed in trivial amounts so an immediate clog may not happen. BUT if your septic system uses a septic pump or grinder pump or sewage ejector pump, this material can clog the pump impeller and cause expensive pump damage or motor burnout.

Why You Should Avoid Flushing Disposable Wipes into Your Septic System

ITEM #10: Disposable Wipes 

This is another widely known culprit. But usually, these don’t break down and can cause major clogging issues in your septic system. So while the temptation might be there to treat and dispose of these the same way as toilet paper, you should not flush disposable wipes into your septic system.

Why You Should Avoid Flushing Paper Towels or Facial Tissues into Your Septic System

ITEM #11: Paper Towels and Facial Tissues

Another member of the paper family of products that often end up in toilets across the country. But these should not be disposed up down your toilet. These items may seem benign but the truth is they don’t break down as easy as toilet paper and should be avoided when it comes to disposing of them in your septic system.

Why You Should Avoid Flushing Latex Condoms into Your Septic System

ITEM #12: Latex Condoms 

Condoms won’t usually clog a pipe like some other debris, because they are of modest size and are quite flexible, but condoms are typically not biodegradable. So we listed condoms or other latex products such as latex gloves above as “never flush”.

A condom in the septic tank will probably join other debris in the tank’s floating scum layer, and will be removed at the next tank pump-out. Of course, if the septic tank outlet tee or septic tank baffles are missing, the condom will join other floating debris on its way out to clog the drainfield, so ask your septic pumper to check the condition of the septic tank baffles when the septic tank is next pumped.

BUT if your system uses a septic pump or grinder pump or sewage ejector pump, this material can clog the pump impeller and cause expensive pump damage or motor burnout.

Why You Should Avoid Water Softener Discharge into Your Septic System

ITEM #13: Water Softener Regeneration Cycle Discharge

This is one that many people don’t usually think about, after all, they usually think of water softener as a good thing since they are helping them treat some of the hard water their home might have.

But if a water softener isn’t working properly or stuck in a regeneration cycle. The water discharge is likely to contain high levels of salts and possibly also other minerals that can significantly harm the drain field or soakaway bed of a septic system by killing off soil bacteria and by forming a salt-crust in the absorption trench.

High volumes of wastewater from frequent regen cycles or worse from a water softener that is not working properly, perhaps stuck in “regen” mode, can also flood a drain field and destroy it.

The conclusion of our What to Avoid Flushing into Your Septic System Article

In the end, the only thing that should really go down your drains or toilets is waste, water, and toilet paper.  Anything else you put into your septic system could have a detrimental effect on the health of either the bacteria that are critical to keeping the septic system functioning properly or one of its components.

The best thing you can do to protect your home investment is to maintain the critical systems in your home. Your septic system is no exception to this rule.


If you need to get your septic system serviced find a local professional in our state by state directory. Simply click your state below.