PFAS in Summerville water, explained.

PFAS (per- and polyfluoroalkyl substances) are a family of synthetic chemicals used since the 1940s in non-stick coatings, firefighting foams, water-repellent textiles, and industrial manufacturing. They are called "forever chemicals" because they resist breakdown in water, soil, and the human body. EWG testing of Summerville CPW data (PWSID SC1810003, 2014 to 2023) detected five PFAS compounds: PFUnA at 7.1 ppt, PFDoA at 4.5 ppt, HFPO-DA at 8.0 ppt, PFHxA at 2.7 ppt, and PFPeA at 3.3 ppt.

If your home is served by Summerville CPW, Berkeley County Water and Sanitation, or Dorchester County Water Authority, your water is sourced from Lake Moultrie via Santee Cooper, which carries approximately 7 ppt PFAS at the source. Five specific PFAS compounds have been detected in the finished CPW distribution system. The only way to confirm the current level in your kitchen sample is to pull a fresh tap sample; EWG, CCR, and UCMR data describe averages across multi-year monitoring windows.

PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate) are two long-chain PFAS compounds that the EPA 2024 National Primary Drinking Water Regulation set at an individual MCL of 4 parts per trillion each. The five PFAS compounds EWG reports for Summerville CPW do not include PFOA or PFOS specifically in the published detection table; the five detected are PFUnA, PFDoA, HFPO-DA (GenX), PFHxA, and PFPeA. Source water at Lake Moultrie is reported at approximately 7 ppt combined PFAS, which is above the 4 ppt MCL and drives the $96M remediation project.

At the residential scale, reverse osmosis is the most effective treatment and the only one with broad NSF/ANSI 58 certification for PFAS reduction. A point-of-use RO system installs under the kitchen sink and plumbs to a dedicated tap for drinking and cooking. Granular activated carbon (GAC) captures some PFAS but must be replaced on schedule. Standard water softeners do not remove PFAS -- they address hardness only. Boiling does not remove PFAS; it concentrates them.

No, but it is the most reliable residential option. The EPA 2024 technology evaluation lists granular activated carbon (GAC), anion exchange resins (AIX), and reverse osmosis (RO) as the three treatment technologies suitable for PFAS compliance. At the municipal scale, GAC is under evaluation for the $96M Santee Cooper project. At the residential scale, RO certified to NSF/ANSI 58 is the widely-available solution because performance is verifiable through certification and the membrane rejects a broad spectrum of PFAS compounds rather than relying on adsorption capacity.

No. Conventional ion-exchange water softeners swap calcium and magnesium for sodium. They do not remove PFAS. A softener is the right tool for hardness (and Summerville water runs 5.5 to 7.2 grains per gallon, which is moderately hard) but it is the wrong tool for PFAS. PFAS requires reverse osmosis, GAC, or anion exchange specifically.

No. PFAS compounds are thermally stable and do not break down at boiling temperature. Boiling actually concentrates PFAS as water evaporates off as steam. Boiling is the correct response to a microbiological boil-water advisory (like the March 2026 Summerville event); it is not a response to PFAS.

On April 10, 2024 the EPA finalized the PFAS National Primary Drinking Water Regulation (NPDWR). It sets an individual MCL of 4 parts per trillion for PFOA and PFOS, and 10 ppt for PFHxS, PFNA, and HFPO-DA (GenX). It also establishes a Hazard Index for mixtures of those compounds. Original compliance window was 5 years (2029); EPA announced in 2025 that it intends to retain the PFOA/PFOS MCLs but extend the compliance deadline to 2031, and potentially rescind individual MCLs for PFHxS, PFNA, and HFPO-DA. Final rulemaking is pending as of April 2026.

The original EPA 2024 rule set a 2029 compliance deadline. EPA announced in 2025 that it intends to extend the deadline to 2031 for PFOA and PFOS compliance. Summerville CPW is executing its portion of the $96M Santee Cooper regional PFAS remediation project -- $43.5M is CPW's share -- with expected completion between 2029 and 2031 depending on the final federal rulemaking. Until the project comes online, in-home point-of-use reverse osmosis is the interim option CPW itself acknowledges on its public PFAS page.

The $96M figure is the total capital cost of a regional PFAS remediation project led by Santee Cooper Regional Water System, the wholesale supplier that sources Summerville's water from Lake Moultrie. Summerville CPW's share is $43.5M, or approximately 45.3 percent. The project will install new treatment infrastructure -- granular activated carbon (GAC) is the primary candidate technology under evaluation. Rate increases of 12.2 percent effective August 2024 fund CPW's share. Expected completion is 2029 to 2031.

The Puronics Pur-Alkaline 6-stage reverse-osmosis system is the point-of-use RO we install at the kitchen tap. The exact certification scope for the recommended model is provided in writing before install -- verify any listing at info.nsf.org. Puronics whole-home conditioners (Hydronex iGen) are WQA-tested but are NOT currently NSF listed for contaminant reduction as of April 2026 -- the whole-home conditioner addresses hardness and chlorine, not PFAS. For PFAS-specific reduction, the point-of-use RO unit is where the cert-matched conversation belongs.

Bottled water is not a PFAS solution. The FDA does not regulate PFAS in bottled water, and testing by Consumer Reports and others has found PFAS in multiple brands. Bottled water is also more expensive than a home RO system over any multi-year horizon -- a family of four spending $100/month on bottled water spends $12,000 over ten years, which is roughly the installed price of a whole-home system with a certified point-of-use RO combined. A certified RO unit installed once is the more defensible choice both by cost and by performance.

The EPA 2024 rule cites peer-reviewed research associating certain PFAS compounds at elevated exposure with thyroid hormone disruption, elevated cholesterol, liver enzyme changes, reduced vaccine response in children, reduced birth weight, and increased risk of certain cancers including kidney and testicular cancers. This site does not make individual health claims. For health questions about your family's exposure, speak with your doctor. The EPA rule documentation at epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas is the primary reference.