Per- and polyfluoroalkyl substances (PFAS) are a large family of synthetic chemicals used since the 1940s in countless industrial and consumer products. This group of compounds is often called “forever chemicals” because the strong carbon-fluorine bond in their structure makes them highly resistant to degradation. Because of this persistence, PFAS have been widely detected in water sources across the country, and well water can be significantly contaminated. While public water systems are subject to federal regulation and mandated testing, private wells are not. The responsibility for testing, confirming contamination, and implementing a solution rests entirely with the homeowner.
How PFAS Enters Groundwater Systems
PFAS compounds are highly mobile and easily dissolve in water, allowing them to travel through soil and rock layers to reach underground aquifers. One major source is industrial discharge from facilities that manufacture the chemicals or use them in processes like metal plating and textile production. Improper disposal practices or accidental releases at these sites allow the substances to seep directly into the ground.
Another significant source is the use of Aqueous Film-Forming Foam (AFFF) for extinguishing fuel fires, particularly at military bases and civilian airports. When this foam was used in training exercises, the high concentrations of PFAS chemicals were discharged directly onto the ground, creating persistent plumes of contamination that migrate far from the original source. Landfills and wastewater treatment plants also contribute, as conventional treatment processes do not remove PFAS.
The chemicals simply pass through most wastewater plants and are discharged into surface water, or they concentrate in sewage sludge, known as biosolids. When PFAS-laden biosolids are applied to agricultural land as fertilizer, the chemicals can leach into the soil and move downward to contaminate groundwater. The U.S. Environmental Protection Agency (EPA) has established Maximum Contaminant Levels (MCLs) for six PFAS in public water systems under the Safe Drinking Water Act. However, these federal regulations do not apply to private well water.
Factors Determining Well Contamination Risk
The risk of your private well being contaminated is dependent on its geographic location relative to known or potential sources of PFAS. Wells located within one to two miles of airports, military installations, industrial parks, or large waste disposal sites are considered to be at a higher risk. The local board of health or state environmental agencies may have information about historical or confirmed contamination sources in your area.
Environmental factors influence how quickly and how far PFAS travel. Highly permeable soil, such as sand or gravel, allows contaminants to move more easily into the groundwater supply than dense clay soil. Wells drawing water from shallow aquifers are generally more susceptible to contamination than deeper wells because they are closer to surface sources of pollution.
Older wells, constructed before modern sealing standards, are more vulnerable to surface contamination than newer, properly cased wells. The presence of high organic carbon content in the soil can reduce the mobility of certain PFAS compounds by binding them to the organic material. Assessing these local factors is a practical first step for any well owner considering a testing regimen.
Practical Steps for Well Water Testing
Testing your well water for PFAS is the only reliable way to confirm contamination levels, and this process requires specialized scientific analysis. The first step is to locate a state or EPA-certified environmental testing laboratory that specializes in trace organic compounds. These labs use validated EPA methods, such as Method 533 or 537, which are designed to detect PFAS down to the parts per trillion (ppt) levels.
Once you select a lab, they will provide a specialized testing kit with sample bottles and detailed collection instructions. Following these instructions precisely is necessary, as PFAS are present in many common household materials and can cause cross-contamination. This usually involves using disposable nitrile gloves, avoiding contact with the inside of the bottle caps, and collecting the water sample directly from the well or an untreated tap after flushing the line for several minutes.
The cost for a comprehensive PFAS test typically ranges from $340 to $600, depending on the lab and the number of compounds analyzed. Results are returned within two to four weeks and report the concentration of each detected PFAS compound in nanograms per liter (ng/L), which is equivalent to parts per trillion. Interpretation involves comparing results against the EPA’s enforceable MCLs for public water systems or against your state’s specific health advisory levels, which may be stricter. If the levels exceed these guidelines, switch immediately to an alternative water source for drinking and cooking and move toward installing a certified treatment system.
Home Filtration and Remediation Technologies
Once PFAS contamination is confirmed, treatment systems can effectively reduce the level of these chemicals in your water. The most widely used and cost-effective method is Granular Activated Carbon (GAC) filtration. GAC works through a process called adsorption, where PFAS molecules stick to the highly porous surface of the carbon medium as water passes through the filter.
GAC systems can be installed as a Point-of-Entry (POE) system to treat all water entering the home, or as a Point-of-Use (POU) system on a single tap, like the kitchen sink. The effectiveness of a GAC filter depends on the type of PFAS present and the required maintenance, as the carbon must be replaced regularly before saturation occurs. For maximum removal efficiency, Reverse Osmosis (RO) systems are highly effective, achieving up to 99% reduction of PFAS.
RO systems force water through a semi-permeable membrane that blocks the contaminants and are installed as POU units at a single faucet due to their slower flow rate and water waste. When selecting any filtration system, look for third-party certification marks, specifically NSF/ANSI Standard 53 or 58, which verify the system’s ability to reduce PFAS to safe levels. Regular maintenance and filter replacement according to the manufacturer’s schedule are necessary to ensure the system continues to protect your water quality.