After completing your business in the restroom, you might wonder what exactly happens to that “business” after you flush the toilet. After all, it has to go somewhere, and when refuse doesn’t make it through your home’s plumbing system, significant problems can occur.

Below, we’ll take a closer look at what happens to what you flush and why some items are riskier to place in your toilet than others.

What Happens After You Flush?

After you flush your “business” down the toilet, it travels through the waste pipes in the drain-waste-vent part of your home’s plumbing system. The waste pipes and drain pipes then meet up below your house in one main drain. This main drain takes the wastewater to your septic system (if you have one) or to the municipal sewer line.

From there, your “business” continues its journey through your city’s sewage system until it reaches the local wastewater treatment plant. There, the waste will be processed in a series of stages. First, the waste is allowed to accumulate in a tank, where it will separate into two layers. A solid layer (full of people’s “business”) will form at the bottom. The wastewater at the top is taken away from the sludge at the bottom, and both are processed separately to get rid of pathogens, pollutants, and other harmful contaminants.

After its journey through the treatment plant, some water can be safely returned to local waterways. What’s left from the processed sludge often ends up in landfills, but some of it also gets converted into crop fertilizer and fuel to power waste treatment facilities.

Why You Shouldn’t Use the Toilet as a Trash Can

Now that you know what happens to what you flush, it probably makes a little more sense why we need to be so careful about what goes down our toilets. Experts agree that the only things that should ever be flushed are “number one,” “number two,” and “toilet paper.”

Even items that appear to be similar to toilet paper can cause backups in your home’s plumbing as well as municipal sewers. Paper towels, napkins, facial tissues, feminine hygiene products, and diapers are designed to hold up against a lot of moisture, rather than breaking down into tiny pieces the way toilet paper does. Even so-called “flushable” and “septic-safe” wipes don’t break down as easily in water as toilet paper does. (Watch a real-life example of flushable wipes versus toilet paper in The Fit RV’s video.)

It’s also important to consider how the environment can be affected by what you flush. For example, the dissolved chemicals from flushed household cleaners often pollute local marine systems. Disinfectant wipes can actually kill the good bacteria that wastewater treatment plants need to treat sludge. To help prevent your family from tossing garbage in the toilet, it’s best to keep a trash bin in each of your home’s bathrooms.