A Beginner’s Guide to Navigating the Complexities of PFAS Sampling
For environmental consultants working in the field of water quality and soil remediation, the emergence of PFAS (per- and polyfluoroalkyl substances) as a significant environmental contaminant has created a unique set of challenges. While the risks posed by PFAS have been known for years, the widespread presence of these “forever chemicals” in the environment has raised new questions around testing, regulation, and remediation. As PFAS sampling becomes increasingly critical in environmental assessments, consultants face a range of difficulties—from technical hurdles to regulatory ambiguities—that complicate their work and decision-making.
Below, we explore some of the historical challenges and ongoing ambiguities in PFAS sampling, and how environmental consultants can navigate this evolving landscape.
1. A New and Uncharted Contaminant
The first challenge is simply the novelty of PFAS as an environmental contaminant. While many chemicals have been studied and regulated over decades, PFAS were initially used in a wide range of industrial and consumer products (such as firefighting foam, nonstick cookware, and water-repellent fabrics) without full awareness of their long-term health and environmental impacts. PFAS are notorious for their persistence in both the environment and the human body, leading them to be dubbed “forever chemicals.”
Because PFAS contamination is relatively new on the regulatory radar, environmental consultants often face challenges in determining the best methods for detecting these chemicals in various matrices, including water, soil, and air. This is complicated by the fact that there are thousands of different PFAS compounds, each with unique chemical properties. Establishing which PFAS compounds need to be tested, and in what concentrations, requires specialized knowledge and protocols that are still evolving.
2. Sampling Techniques and Laboratory Analysis
Once environmental consultants understand the risks associated with PFAS, they must contend with the technical challenge of sampling and analysis. Unlike more commonly tested pollutants, such as lead or mercury, PFAS compounds require specialized sampling methods and equipment to ensure accurate results. For instance, the use of Teflon-coated containers or plastic sampling materials is often prohibited, as they can introduce PFAS contamination into the samples. Even subtle contamination during collection, handling, or transport can skew results, leading to potentially inaccurate conclusions.
Furthermore, laboratory analysis of PFAS is complex and expensive. High-resolution mass spectrometry and liquid chromatography are typically required to detect low concentrations of PFAS in environmental samples. Consultants must choose the correct testing method, as the performance of these analytical techniques can vary depending on the laboratory’s equipment, expertise, and protocols. The need for highly sensitive tests adds time and cost to the process, which can be a concern for clients with limited budgets.
3. Ambiguous Regulatory Landscape
Another major difficulty for environmental consultants is navigating the regulatory landscape around PFAS. While some states have taken aggressive action to limit PFAS levels in drinking water and enforce clean-up requirements, federal regulations have lagged behind. In 2016, the U.S. Environmental Protection Agency (EPA) issued a health advisory recommending that levels of PFAS in drinking water should not exceed 70 parts per trillion (ppt). However, this was a non-enforceable guideline rather than a legally binding limit, leaving significant uncertainty about the thresholds for PFAS contamination that require action.
As of 2024, the EPA has moved forward with stricter regulatory proposals, including the establishment of enforceable limits for PFAS in drinking water and the listing of PFAS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Yet, state-level regulation remains inconsistent, with some states like California, Michigan, and New Jersey setting much lower PFAS limits than the EPA guidelines.
This patchwork of regulatory standards means that environmental consultants must stay abreast of both federal and state-level changes to ensure compliance. Different states may have different requirements for the types of PFAS compounds to be tested, the levels that are considered safe, and the methods to be used. Navigating these regulations requires expertise, vigilance, and a deep understanding of both local and national legal frameworks.
4. Remediation Challenges
Finally, once PFAS contamination has been identified, the challenge shifts to remediation. PFAS are notoriously difficult to remove from water and soil, requiring specialized treatment methods like activated carbon filtration, ion-exchange resins, or high-pressure reverse osmosis. Even these methods are not always fully effective at eliminating PFAS from contaminated sites. This presents a significant challenge for consultants who are tasked with recommending appropriate remediation strategies that meet regulatory standards and minimize long-term environmental damage.
Moreover, many older sites contaminated with PFAS were not subject to the same level of oversight as more recent sites, creating potential gaps in historical knowledge about the extent of contamination. This can make it difficult to estimate remediation costs and timelines accurately, further complicating the consultant’s role in ensuring successful clean-up and ongoing monitoring.
5. Essential Equipment for PFAS Sampling and Monitoring
PFAS sampling presents unique technical challenges that require the use of specialized environmental monitoring equipment to ensure accurate results and prevent contamination during the sampling process. The equipment used varies depending on the specific medium being tested (e.g., groundwater, surface water, soil, air) and the site conditions. Here are some of the key tools commonly used by environmental consultants when collecting samples for PFAS analysis:
Water level meters are essential for determining the depth of groundwater wells and monitoring fluctuations in groundwater levels over time. When sampling for PFAS in groundwater, it’s important to accurately measure the water table to ensure that the correct sample depth is selected. For example, consultants may need to sample from specific aquifers or monitor how PFAS is distributed in different strata of groundwater. Digital water level meters offer high precision and are capable of detecting small variations in water level, which is crucial for understanding PFAS migration.
Bladder pumps are frequently used for groundwater sampling, particularly in wells where contamination may be spread across different depths. These pumps are designed to extract groundwater without causing turbidity or introducing contaminants, which is crucial when collecting samples for PFAS analysis. Bladder pumps use an compressible bladder that is compressed with pressurized air to displace water, drawing a clean sample from the groundwater. This method helps minimize the risk of cross-contamination and ensures the samples are representative of the targeted groundwater zone.
Unlike traditional bailers or submersible pumps, bladder pumps have the advantage of maintaining a low risk of disturbing the aquifer, which is particularly important when sampling for low-concentration contaminants like PFAS. Proper purging of the well (removal of stagnant water before sampling) is also essential to ensure accurate results.
Water quality meters are used to measure a variety of parameters such as pH, conductivity, turbidity, dissolved oxygen, and temperature, all of which can provide important insights into the conditions of the sampling site and help evaluate the potential for PFAS presence. For example, pH and conductivity measurements can help identify specific groundwater characteristics, which can influence the solubility and transport of PFAS compounds.
Additionally, these meters are valuable for ensuring that the samples are taken under ideal conditions, such as when the water is free of significant turbidity (which could interfere with PFAS detection). Many modern water quality meters are portable and capable of providing real-time data, making them useful for field-based assessments where immediate feedback is needed.
In some PFAS sampling situations, peristaltic pumps are used to collect samples from surface water or groundwater. These pumps move water through flexible tubing using rollers that squeeze the tubing, creating suction. They are particularly effective in situations where the flow rate needs to be controlled, such as when collecting multiple samples at different depths or ensuring a steady flow of water from a specific zone in a well. Peristaltic pumps are easy to use, low maintenance, and can be used to collect samples without introducing contaminants to the water being tested, however they are limited to wells which have a depth-to-water of less than 28 feet.
Because PFAS are so persistent and resistant to degradation, preventing contamination during the sampling process is crucial. Special disposable sampling equipment is often used to avoid introducing trace amounts of PFAS into the samples. This includes using PFAS-free materials for bottles, tubing, and gloves. Glass and polypropylene containers that are certified to be PFAS-free are preferred to ensure that no PFAS are leached into the samples during collection or transport.
In addition, consultants often use dedicated sampling kits that are pre-cleaned and sealed in PFAS-free conditions, reducing the chance of cross-contamination. At the site, consultants will also use single-use sample collection tools to avoid contamination from previously collected samples or from other site locations.
6. The Challenge
PFAS sampling presents a complex and evolving challenge for environmental consultants. While the science of PFAS contamination and remediation is still developing, consultants are at the forefront of assessing environmental risks and guiding clients through the intricacies of detection, regulation, and remediation. As new standards emerge, methods become more refined, and technologies evolve, consultants will need to adapt to stay ahead of the curve.
In the meantime, collaboration with scientists, regulators, and industry stakeholders will be critical in ensuring that PFAS sampling is done effectively and responsibly. Through education, innovation, and a commitment to transparency, environmental consultants can help mitigate the long-term impacts of PFAS contamination on both the environment and public health.
For those in the industry, the future of PFAS testing will undoubtedly require flexibility, precision, and an understanding of both the technical and regulatory complexities surrounding this persistent class of chemicals.