Does Reverse Osmosis Remove PFAS? What Columbus Homeowners Need to Know

PFAS — per- and polyfluoroalkyl substances, commonly called "forever chemicals" — have become one of the most significant drinking water concerns in the United States. They've been detected in water supplies across Ohio, and the EPA set new maximum contaminant levels (MCLs) for several PFAS compounds in 2024.

The good news: reverse osmosis is one of the most effective technologies for removing PFAS from drinking water. Here's what Columbus homeowners need to know.

PFAS are a family of thousands of synthetic chemicals used in manufacturing since the 1940s. They're found in non-stick cookware, water-resistant clothing, food packaging, firefighting foam (AFFF), and hundreds of industrial applications.

The "forever" in "forever chemicals" refers to their persistence — PFAS don't break down in the environment or in the human body. They accumulate over time.

Health concerns associated with PFAS exposure include:

• Increased risk of certain cancers (kidney, testicular)
• Thyroid disease
• Immune system effects
• Developmental issues in children
• Elevated cholesterol

The EPA's 2024 PFAS rule set MCLs of 4 parts per trillion (ppt) for PFOA and PFOS — the two most studied PFAS compounds — and 10 ppt for several others. These are among the strictest drinking water standards ever set.

Ohio has documented PFAS contamination in multiple water systems, particularly near industrial sites, military bases, and areas where AFFF firefighting foam was used. The Ohio EPA has been testing public water systems and publishing results.

Columbus city water (Columbus Division of Water) has tested at levels below the new EPA MCLs, but "below the legal limit" doesn't mean zero. Many health advocates argue the safe level of PFAS exposure is as close to zero as achievable.

Private well owners in Central Ohio — particularly in Delaware, Licking, and Fairfield counties — should test for PFAS, as wells near industrial or agricultural areas can be affected.

Yes — and it's one of the most effective methods available for point-of-use PFAS removal.

RO removal rates for common PFAS:

• PFOA: 94–99% removal
• PFOS: 94–99% removal
• PFAS short-chain compounds: 85–95% removal (slightly lower due to smaller molecular size)

The RO membrane's semi-permeable structure physically blocks PFAS molecules from passing through. The contaminants are concentrated in the reject water and flushed to drain.

Important: The pre-filters in an RO system (sediment and carbon) do not remove PFAS. Only the RO membrane itself provides PFAS removal. This is why a quality RO membrane — not just a carbon filter — is essential.

Activated carbon (GAC) filters: Granular activated carbon can adsorb some PFAS, but removal rates vary significantly by PFAS compound and carbon type. High-quality activated carbon with long contact time can achieve 70–90% removal for some PFAS. Less effective than RO for comprehensive PFAS removal.

Whole-house carbon filters: Can reduce PFAS throughout the home but are less effective than point-of-use RO for drinking water. Useful as a first-stage treatment before RO.

Ion exchange (anion exchange resin): Highly effective for PFAS removal — comparable to RO. Less common in residential applications but used in some municipal treatment systems.

Pitcher filters (Brita, etc.): Standard pitcher filters do NOT remove PFAS. Some newer pitcher filters with activated carbon claim partial PFAS reduction, but they're far less effective than RO.

Step 1: Test your water. If you're on city water, check your annual Consumer Confidence Report (CCR) — Columbus Division of Water publishes PFAS test results. If you're on a well, get a PFAS-specific water test (standard water tests don't include PFAS).

Step 2: Install point-of-use RO for drinking water. Even if your water tests below EPA MCLs, an RO system at your kitchen sink provides an additional layer of protection for the water your family drinks and cooks with.

Step 3: Consider a whole-house carbon filter. For comprehensive PFAS reduction throughout the home (shower water, laundry), a whole-house carbon filter upstream of the RO system provides additional protection.

For drinking water PFAS protection, our alkaline RO system is the most effective point-of-use solution available. It removes 94–99% of PFAS along with lead, nitrates, arsenic, chloramines, and hundreds of other contaminants — while adding back beneficial minerals and producing alkaline water.

For well water homeowners in Delaware, Licking, or Fairfield County, we strongly recommend PFAS testing before purchasing any treatment system — the results will tell you exactly what you're dealing with.

Schedule a free water test → | Learn about our alkaline RO systems →