4 Ways Bidets Are Good for Septic Systems

A bidet next to a septic tank

Today’s article is on bidets and the septic system—whether they’re good for septic systems, their effects, etc.

Most toilet paper nowadays is designed with sewer systems in mind: two-ply, triple-ply, antimicrobial additives, etc. So, a lot of folks want to know if washing with water instead of paper can offer any benefits for a septic system and if the overall effect is a net positive.

In past articles, we’ve looked at plumbing requirements for a bidet, focusing mostly (but not all) on standalone bidets. This article applies equally to all types of bidets including handheld sprayers, electric and non-electric seats, attachments, and toilet-bidet combos.

Are Bidets Good for Septic Tanks

Bidets are good for septic tanks. By replacing toilet paper, they are less prone to clogging toilets. Some models offer more benefits for septic systems than others. Namely, bidets that use less water and those that completely remove the need for toilet paper.

Electric bidets are the best because they contain dryers which eliminate the need for TP completely. Most seats and attachments use smaller (and often aerated) water streams cutting down water usage which is good for septic systems. Handheld sprayers and standalone bidets aren’t as good in this respect.

What we’ll do here is go over the benefits of bidets for septic systems. Keep in mind that the best thing you can do for your septic system, regardless of whether you have a bidet, is to follow guidelines put out by the major health and environmental institutions.

The EPA lays out these guidelines (1):

  • Don’t flush anything but human waste and toilet paper. No kitty litter, baby wipes, etc. They didn’t mention it, but stuff other than TP labeled as “septic safe” should be avoided.
  • Avoid using excess water.
  • Have your tank inspected regularly, about once a year.

Top Benefits of Bidets for Septic Systems

Most Toilet Paper is Bad for Septic Systems

Sometimes problems arise due to folks using the toilet paper incorrectly, more so than a type of TP being bad per se. But a lot of toilet paper on the market these days is less than ideal for septic systems even when used correctly.

In general, toilet paper is supposed to be fine for your septic system. It’s made out of biodegradable material (usually wood pulp and sometimes light cotton) so it’s easier to dissolve compared to other types of paper.

In fact, TP is one of two things deemed safe by the EPA to be flushed down toilets whether a property uses a septic tank or sewer system—the other being human waste (2).

But the safety of toilet paper for septic systems assumes you’re using the right TP and in the right quantities. Rarely are either of these two conditions being met.

While all toilet paper is biodegradable, thicker paper is harder for the anaerobic bacteria in septic tanks to access.

For this reason, most experts recommend avoiding anything but single-ply paper (3). Who does that? Single-ply TP is the kind you encounter in cheap gas stations. Ya know, the restrooms located outside that you have to get a key to access. The kind of paper that rips easily and feels like sandpaper. You get the idea.

Two- and three-ply paper are more comfortable, effective at cleaning, and common on supermarket shelves. While not ideal, two-ply can be okay if made to be septic tank friendly—some TP has spray-on additives that render it more biodegradable.

While some rolls of TP are better for septic systems than others, none are as good as avoiding paper altogether. By cleaning with water, you can save your septic system the hassle of having to deal with more paper than it was designed to process.

Say Goodbye to Clogged Inlet Pipes and Baffles

Let’s face it, most people don’t use the right amount of toilet paper. If you were to read the directions on an average package of rolls, you’d be horrified to see that most will instruct the user to flush after every 2-3 squares or so. Again, who does this?

Excessive TP use is among the main causes of clogged inlet pipes that run from the home to the septic tank. And when the inlet baffle to the tank is clogged, you can expect to find TP about as much as you could expect to find plaque in a blocked artery.

There are other causes of blocked pipes like root growth and damage (i.e., animal and vehicle traffic), but excess TP makes the top of the list.

For those who have to wipe a lot, there are two options: flush multiple times or clog your toilet.  Neither is good for your septic system.

Most experts warn against using excess water, citing it as a major cause of septic tank failure (4). This warning applies mostly to showers and appliances that use dozens of gallons throughout the day.

But in the US, each flush of the toilet uses 1.6 gallons at minimum. Older homes may have toilets that still use 3.5 gallons per flush. Folks with GI problems and/or weak plumbing often have to flush multiple times per bowel movement to flush down all the toilet paper. So the gallons can add up depending on the situation.

Flushing lots of water down the toilet may not cause any problems on its own, but it certainly doesn’t help and will only make existing problems with the septic system worse.  

A well-functioning septic system relies on clean pipes and passageways.  When blocked, the toilet bowl drains very slowly or stops draining altogether. If you know what you’re doing, you can use a snake to unclog the passage, but a lot of people end up having to hire a professional.

If you don’t use much TP, then this benefit may not apply to you. I did have one eco-conscious friend whose claim to fame was that he could get by on only a single square of toilet paper per bowl movement. I find it hard to believe that he could’ve been getting a thorough clean with only one square.

If he did, my hat is off to him. He’s an exception. Most of us aren’t blessed with such pristine bowel functioning and have to wipe several times to get a decent clean. If that’s the case for you, then you may benefit from switching to a bidet.

A Better Wetter Alternative to Wet Wipes

A picture from several years ago (before switching to a bidet) after sustained use of moist wipes eventually led to an eruption of wet wipes in my front yard.

Are Bidets Good for Septic Tanks

A lot of consumers make the switch from TP to wet wipes to get a better clean. I used them myself for a long time and they are effective. While moist wipes are definitely a step in the right direction for personal hygiene, they’re terrible for sewer systems and doubly terrible for septic tanks.

They’re supposed to be more septic-friendly these days but public health authorities still recommend not flushing wipes down the toilet, especially those with septic tanks (5).

Now you could just do what you’re supposed to do and throw them in the trash bin. But again… you guessed it… who does that? Wet wipes usually go straight in the toilet.

Septic systems rely on anaerobic (non-oxygen-breathing) bacteria to process waste. The tanks are both air-tight and kept deep in the ground. They’re kept sealed to keep odors in but also to keep oxygen out for the sake of the bacteria.

Before being returned to nature, the sewage spends around 24 hours in the tank during which the microbes go to work on dissolving human waste, trash (if there’s a garbage disposal), and toilet paper.

Moist wipes pose two challenges for septic tanks:

  • Harsh chemicals. Most wipes are coated and soaked in various chemicals. They’re probably harmless for human skin—preservatives, chemicals for fragrance, etc. But some are antimicrobial which is the last thing you want. Overall, wipes would be a small contributor of antimicrobial chemicals (harsh cleaning chemicals being the main sources) but they definitely don’t help. Note, the effect is likely to be small and may be canceled out if your bidet uses an antimicrobial nozzle or bowl cleansing solution.
  • Synthetic fibers. The “paper” used for moist wipes is prone to clogging the septic system. TP is made out of wood pulp, a biodegradable material. Also, TP is manufactured in away that allows it to easily dissolve in water. To be more septic and sewer-friendly, some manufacturers have taken to using plant-based fibers. But a lot of wipes are still made with synthetic fibers that anaerobic bacteria can’t digest because they lack the needed enzymes.
  • Thicker material. Even when wipes use plant-based fibers that are biodegradable, thick durable paper is difficult for microbes to process regardless of its chemical composition. Wipes have to be tough and if you’ve tried wetting regular toilet paper, you know why. When wet, regular toilet paper comes apart and turns into lint-like remnants. Hence, moist towelettes use durable paper that won’t come apart when wiping. This might be great for users, but it’s bad for plumbing.

So, both the composition and thickness of wipes make them difficult to process. Any paper that’s strong during use will remain strong when traversing the septic system—so much so that it can take up to several decades for wipes to fully degrade.

No More Toilet Drain Cleaners

Using TP inevitably leads to clogging at some point or another and sometimes a plunger just isn’t enough. You have to call in the heavy-duty drain cleaners.

Some companies, like S. C. Johnson & Son that put out Drano, claim that their stuff is septic safe. I’m not sure whether that’s true or not, but most septic system experts recommend not using drain cleaners (6). If you read the above section, then you know why.

The tiny amount of antimicrobial chemicals in wet wipes is nothing compared to the number of harsh chemicals dumped into your septic tank each time you use drain cleaner to deal with a clogged toilet.

What About Water Usage?

As we know by now, excessive water is a major cause of septic system failure. The more incoming water there is to the septic tank, the less time there is for scum and sludge to separate.

Septic tanks need plenty of time to separate the water from sediment and scum–sediment being the solids that sink to the bottom and scum being the substances that float on top.

So, for this reason, I’m sure some are wondering if the extra water used for bidet cleansing could be considered a negative for the septic tank.

To the extent that bidets result in extra water use (they may not), it’s not enough to negatively impact septic system function. Due to new technology like the ability to use aerated water streams, most bidets use very little water overall. Since this leads to less flushing, the user’s water consumption could go down.

To put it in perspective, let’s have a look at the water consumption of most household appliances:

  • Toilets use 1.2-3.5 gallons per flush (GPF). Modern toilets use about 1.2 GPF. Older toilets installed a few decades ago (yet remain) use 3.5 GPF.  
  • Bathroom sinks use between 1-2 gallons per activity. Activities include washing, brushing teeth, and shaving. How much is used depends on the person (water conservation practices, etc.) and faucet technology (e.g., whether there’s an aerator).
  • Bath and showers use 5-30 gal per bath or shower. The amount used depends on the person and bath technology (low-flush showerhead, etc.).
  • Dishwashers use 10-20 gallons per load. How much is used depends on the dishwasher model and chosen settings.
  • Kitchen sinks water use varies a lot but can reach several gallons a day. It’s harder to estimate and depends on whether dishes are washed manually, the use of a garbage disposal (to wash food down the drain), food prep (rinsing produce), hand washing, and kitchen cleaning.
  • Clothes washers can go through 10-50 gallons per day. The amount used depends on the model, water settings, multiple rinse cycles, etc.

Contrast the above numbers with bidet toilet seats and attachments that use a measly 0.3gal per person per day. The average person has three bowel movements per day and the average wash length is a minute. Bidet seats and attachments use about 0.1gal per minute. So, that’s 0.3gal per person which comes to 1.2gal daily for a four-person family.

And those numbers assume that each bowel movement is at home. Since most spend half their waking hours at their job during the week, the amount is probably a lot lower.


So, it makes sense that bidets would be good for a septic system. Until there are studies that look at the incidence of septic failure among bidet users, there’s no way to quantify the effect.

Ultimately, it probably depends on the person. Large households that go through tons of toilet paper would probably see more benefits than a one-person household where the inhabitant uses toilet paper sparingly.

If you don’t go through much toilet paper, rarely clog the toilet, and stay away from moist wipes, then you may not have much to gain by making the switch to a bidet.

Even if the septic tank isn’t affected, bidets offer countless benefits. They provide a superior clean and you’ll save on a lifetime of toilet paper (several thousand dollars). Even the more expensive bidets pay for themselves several times over.

That’s it for now. Thanks for reading.

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