Across the country, more homeowners are learning about the dangers of PFAS—also known as “forever chemicals”—and discovering just how common they are in drinking water. These persistent, man-made chemicals don’t break down easily, and their presence in water sources has become a growing health concern. If you’ve recently had your water tested or read a water quality report from your municipality and PFAs were detected, there are solutions to eliminate them from your water.
Two popular water filtration options for addressing PFAS are activated carbon and reverse osmosis. While both types of filtration can remove PFAs from water, they vary significantly in their effectiveness and how they work. In this post, Kel Tren WaterCare will explore the science behind PFAs contamination and break down how these two filtration methods provide solutions.
What Are PFAS and Why Are They So Concerning?
PFAS stands for per- and polyfluoroalkyl substances, a group of synthetic chemicals. They are used in a wide range of consumer and industrial products, from non-stick cookware and water-resistant clothing to firefighting foams and food packaging. Because of their strong carbon-fluorine bonds, PFAS are incredibly durable—resisting heat, water, oil, and degradation.
Unfortunately, their durability also means they persist in water sources and the human body. Research has linked long-term exposure to certain PFAS with serious health effects. These health conditions include hormonal disruption, immune system suppression, low birth weights, and increased risk of certain cancers.
With mounting scientific evidence and testing showing PFAS in thousands of water systems, they have become a top priority.. Even low levels of exposure can accumulate over time, which is why it’s critical to remove PFAS at the point of use. But not all filters are up to the task.
How PFAS Behave in Water
Understanding how PFAS behave in water helps explain why specific treatment methods are necessary. These chemicals exist in small concentrations—typically measured in parts per trillion—but that doesn’t lessen their impact.
Both long-chain and short-chain PFAs are hydrophobic (repelled by water) and lipophobic (repelled by oil). This means that they easily migrate through soil and water since they don’t bond to other particles. That mobility makes traditional water treatment techniques—like sediment filtration or chlorination—completely ineffective at removing them. To eliminate PFAS, you need advanced filtration technologies, like activated carbon and reverse osmosis.
Activated Carbon Filtration
Activated carbon is a porous filtration medium made from materials like coal, wood, or coconut shells. These materials are treated to create a vast network of microscopic pores which increase the surface area of the media, allowing for the removal of a wide range of contaminants—including PFAS.
The process by which activated carbon removes contaminants is called adsorption, not to be confused with absorption. Absorption, the process that many of us are familiar with, is when one material draws another material into itself, like a sponge soaking up water. AD-sorption, on the other hand, is when a liquid, gas, or dissolved solid adheres to the surface of another material. The adsorption that occurs with activated carbon filters is effective at removing organic compounds, chlorine, and VOCs.
Activated carbon is also capable of removing PFAS, but only long-chain PFAS. There is a great deal of science detailing the difference between long-chain and short-chain PFAS and why activated carbon is effective at removing the former, but not the latter. To simplify things, just understand that the shorter structure of short-chain PFAS causes them not to stick to a carbon filter like the long-chain PFAS do.
This does not make activated carbon filtration obsolete. Rather, it should be taken into consideration when determining what filtration system fits your home’s needs. An advanced water test can distinguish between long-chain and short-chain PFAS, providing the necessary information to determine if activated carbon is a good choice for you.
Reverse Osmosis Filtration
Reverse osmosis (RO) works on a different principle altogether. Instead of using media to adsorb contaminants, RO systems force water through a semipermeable membrane that physically blocks particles larger than a water molecule. This includes most PFAS, as well as arsenic, fluoride, nitrates, lead, and other trace contaminants. The key advantage of RO systems is their ability to remove both long-chain and short-chain PFAS with very high efficiency—often greater than 95% depending on membrane quality and system design. Because of this, reverse osmosis is considered one of the most effective technologies for PFAS removal.
Most RO systems are installed under the kitchen sink, providing purified water for drinking and cooking. Since they process water slowly, they’re not typically used for whole-house applications. However, they’re an excellent final barrier for protecting your health at the point of consumption.
Which One Is Right for You?
Both activated carbon and reverse osmosis are powerful tools for PFAS removal, but they serve slightly different purposes. We have broken down the pros and cons of each system for you:
Activated Carbon:
Pros:
- Excellent choice for whole-house filtration
- Effective against a wide range of pollutants, including long-chain PFAS
- Affordable option for treating large volumes of water
Cons:
- Ineffective at removing short-chain PFAS
- Requires filter replacement
Reverse Osmosis:
Pros:
- Removes both short-chain & long-chain PFAS along with many other pollutants
- Exceptional for point-of-use (single faucet) filtration
Cons:
- Slow water filtration makes it a poor choice for whole-home filtration
- Produces wastewater as a byproduct, making it slightly wasteful
Activated carbon is a great solution for you if you want broad-spectrum filtration at the whole-house level. It’s effective against chlorine, pesticides, VOCs, and long-chain PFAS, and it’s generally more affordable for treating large volumes of water. However, it may struggle with short-chain PFAS and requires regular media replacement to remain effective.
Reverse osmosis, on the other hand, delivers exceptional performance, removing nearly all PFAS. It’s ideal if you are concerned about the cumulative health effects of even trace levels of contamination. The main drawback is that it’s typically limited to a single faucet and can produce some wastewater during operation.
For many clients, the best approach is a combination of both systems: whole-house activated carbon for general water quality and point-of-use RO for drinking and cooking. This layered strategy provides comprehensive protection without sacrificing convenience or performance.
The Importance of Professional Water Testing
Before installing any filtration system, it’s essential to know the specific contaminants present in your water. PFAS are not detectable without laboratory testing, and their concentration levels can vary widely. That’s why Kel Tren WaterCare begins every PFAS consultation with a detailed water analysis.
By utilizing advanced water testing, we can provide you with detailed information about what types of PFAS are present in your water and their concentration. From there, we will work with you to determine what filtration system will not only be the most effective at removing the PFAS in your water but will also be the most cost-effective for your budget.
Long-Term Maintenance and Peace of Mind
When it comes to protecting your household from PFAS, ongoing maintenance is just as important as choosing the right system. Activated carbon filters work by trapping contaminants within their porous structure, but once they reach capacity, they lose effectiveness and can even allow pollutants to pass back into your water. That’s why timely filter replacement is essential to ensure consistent protection.
Reverse osmosis systems operate differently, but they also require regular care. Over time, RO membranes can become clogged with minerals and other impurities, which reduces both water flow and contaminant removal efficiency. These membranes must be cleaned regularly. And when they have worn out, they need to be replaced in order for the system to continue working effectively.
The good news is that with proper upkeep, both activated carbon and reverse osmosis provide reliable, long-term defense against PFAS. Routine maintenance not only safeguards your water quality but also extends the life of your system, making it a smarter investment for your home.
Why Trust Kel Tren WaterCare?
PFAS contamination is a serious concern, but with the right water treatment, it doesn’t have to threaten your family’s health or peace of mind. At Kel Tren WaterCare, we bring decades of hands-on experience in water testing, filtration, and PFAS removal.
Our team has helped countless homeowners and businesses implement customized solutions using science-backed technology that aligns with the latest EPA guidelines, state regulations, and third-party testing standards. When it comes to something as important as your drinking water, expertise and precision matter—and that’s exactly what we deliver.
Unlike one-size-fits-all systems, we provide customized solutions. From advanced activated carbon filters to high-performance reverse osmosis systems, we’ll help you understand your options and choose the best fit for your home, your budget, and your long-term needs.
If you’re worried about PFAS in your water supply, but don’t know whether to choose an activated carbon filtration system or an RO system, contact Kel Tren WaterCare today. We will help you determine the best solution for your home and your needs.
