Here’s Why Septic Tanks Can’t Handle Plastic and What You Can Do About It.

Septic Tank Sorrows

If you own a septic system, you already know the drill: every few years someone comes to pump it and charges you an arm and a leg. Maybe you clean the prefilter yourself and maybe you’ve even had to deal with the dreaded backup smell when things aren’t working right. It sucks. Septic tanks are designed to let solids settle to the bottom, liquids flow out and keep the whole system running smoothly. But there’s one thing your tank was never built to handle... microplastics. These are tiny plastic fragments less than 5 millimeters long, often smaller than the width of a human hair, and invisible to the naked eye. Because they’re so small, they clump at the bottom of the tank and eventually end up in the rest of your system. Here’s why that’s a problem.

The Science Behind It

Peer reviewed research shows that septic tanks are full of microplastics, especially in the sludge that settles at the bottom. Septic tank sediment samples contained far more plastic particles than the scum layer on top, sometimes reaching thousands of pieces in just a single gram of sludge. These particles can be fibers from synthetic clothing such as polyester or nylon but also films and fragments from other common plastics. This microplastic filled sludge becomes a pathway for plastics to move out into the drain field as the septic tank process continues, where they can seep into soil and groundwater.

Abundance (mean + SD) of microplastic particles in septic tank samples analyzed with laser direct infrared spectroscopy (Liu et al. 2022). https://doi.org/10.1016/j.watres.2022.119293

How This Affects You

When microplastics clog up your drain field, the problems do not stay hidden underground. Wastewater can start backing up through your plumbing system and overflowing from toilets, tubs, and sinks. Outside, you might notice soggy spots in your yard or strong sewage odors where the water is surfacing, attracting pests and exposing your family to untreated sewage.

The bigger danger comes when untreated wastewater leaks into the environment. Sewage carries bacteria, viruses, and other contaminants that can make people sick if it reaches wells, lakes, or streams.

If your home relies on well water, the stakes are even higher. A failing septic system can leak not only bacteria and harmful nutrients but also the microplastics themselves into the groundwater that feeds your well. Unlike municipal water systems, which have some level of treatment before the water reaches your tap, private wells draw water straight from the surrounding soil and aquifers. That means anything seeping out of your septic drain field can end up directly in your family’s drinking supply. Once microplastics and contaminants are in the groundwater, they are nearly impossible to remove without expensive treatment systems. For homeowners, this makes reducing the amount of microplastics entering your septic system one of the most effective ways to protect the safety and quality of your well water.

And then there’s the cost. Once soil pores are clogged with sludge and microplastics, a simple pumping will not fix the problem. At that point you may need to replace your drain field or invest in an advanced pre-treatment system. Both options can run tens of thousands of dollars and tear up your landscaping. As septic experts like to say, an ounce of prevention is worth a pound of cure, and that could not be truer when it comes to microplastics.

How to Prevent This Problem

When Sean, one of CLEANR’s employees, first installed his washing machine wastewater filter, his goal was just to stop microplastics from leaving his laundry and polluting the environment. But the next time he went to clean his septic prefilter, he noticed something unexpected. The mesh that normally clogged up every six months was almost clear. Sean now believes he will only need to clean it once a year, saving him both time and up to one hundred dollars per service visit.

Washing machines release up to 1.5 million microfibers in their wastewater every load, and without a filter those fibers flow straight into your septic system. CLEANR’s washing machine filter captures more than 90 percent of these microplastics right at the source, keeping them out of your tank, your drain field, and your yard. It is an easy change that makes a big impact, protecting both your home and your wallet.

Learn more

About CLEANR

CLEANR builds best-in-class microplastic filters for washing machines that effortlessly remove the largest source of microplastics into the environment. Its technology, VORTX, represents a breakthrough in filtration, with a patented design that is inspired by nature and proven to outperform conventional filtration technologies by over 300%. The company is building a platform filter technology that enables product manufacturers and business customers to materially reduce their microplastic emissions from impacted in-bound and out-bound fluid streams, including residential and commercial washing machine wastewater, in-home water systems, wastewater treatment, textile manufacturing effluents, industrial wastewater, and other sources. www.cleanr.life

Sources:

Liu, N., Cheng, S., Wang, X., Li, Z., Zheng, L., Lyu, Y., Ao, X., & Wu, H. (2022). Characterization of microplastics in the septic tank via laser direct infrared spectroscopy. Water Research, 226, 119293. https://doi.org/10.1016/j.watres.2022.119293
Schultz, L. (2024, March 25). Emerging contaminants and your onsite wastewater treatment system. WaterOperator.org Blog. https://wateroperator.org/blog/Tag/septic-systems#:~:text=Another
Lindbo, D., Godfrey, J., & Rashash, D. (2024). Why do septic systems fail? SoilFacts. NC State Extension. https://content.ces.ncsu.edu/why-do-septic-systems-fail
De Falco, F., Di Pace, E., Cocca, M., & Avella, M. (2019). The contribution of washing processes of synthetic clothes to microplastic pollution. Scientific Reports, 9, 6633. https://doi.org/10.1038/s41598-019-43023-x