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4/11/2023 12:00 PM 

Ultra Short Chain PFAS

We are excited to announce Weck Labs' new capability to analyze ultra-short chain PFAS targets in water samples! Using sophisticated LC-MS/MS technology, we can now accurately detect and measure ultra-short chain PFAS, including PFMOAA, PFPrA, TFA, PFMeS, PFEtS, and PFPrS, at low ng/L levels. Ultra-short chain PFAS, characterized by containing three or fewer carbon atoms, are particularly challenging to detect and remove due to their small size and high mobility in the environment. These compounds are industrially relevant and are used in the production of lithium-ion batteries, AFFF, and other fluorine-based compounds. Ultra-short chain PFAS targets also originate from the degradation of other PFAS compounds, such as atmospheric oxidation of volatile fluorinated compounds and certain PFAS destruction technologies. Our innovative method allows us to provide comprehensive analysis of both potable and non-potable water.

EPA Releases Draft Sewage Sludge Risk Assessment for PFOA & PFOS

On January 14, 2025, the U.S. Environmental Protection Agency released the Draft Sewage Sludge Risk Assessment for Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonic Acid (PFOS). The draft risk assessment reflects the agency’s current understanding of the potential risks to human health and the environment posed by the presence of PFOA and PFOS in sewage sludge that is land applied as a soil conditioner, fertilizer surface disposal or incinerated.

Weck provides PFAS testing of soils, biosolids, wastewater and drinking water.

New Maximum Contaminant Levels (MCLs) for Six PFAS

EPA established legally enforceable levels, called Maximum Contaminant Levels (MCLs), for six PFAS in drinking water: PFOA, PFOS, PFHxS, PFNA, and HFPO-DA as contaminants with individual MCLs, and PFAS mixtures containing at least two or more of PFHxS, PFNA, HFPO-DA, and PFBS using a Hazard Index MCL to account for the combined and co-occurring levels of these PFAS in drinking water. EPA also finalized health-based, non-enforceable Maximum Contaminant Level Goals (MCLGs) for these PFAS.

The final rule requires:

Public water systems must monitor these PFAS compounds and must complete initial monitoring (by 2027), followed by ongoing compliance monitoring. Water systems must also provide the public with information on the levels of these PFAS in their drinking water beginning in 2027.

Public water systems have five years (by 2029) to implement solutions that reduce these PFAS if monitoring shows that drinking water levels exceed these MCLs.

Beginning in five years (2029), public water systems that have PFAS in drinking water which violates one or more of these MCLs must take action to reduce levels of these PFAS in their drinking water and must provide notification to the public of the violation.

In California additional requirements apply:

For PFAS with response levels where detected levels of a substance exceed the response level (i.e. PFOA and PFOS), CA requires the public water system shall either (1) take the source out of service immediately; (2) utilize treatment or blending); or (3) provide public notification of the response level exceedance within 30 days of the confirmed detection.

Additionally, the exceedance of the response level must be reported in the annual consumer confidence report.

Note: A response level is established by the California State Water Board’s Division of Drinking Water (DDW) and is an advisory level at which DDW recommends the source be taken out of service. The response level established for any PFAS analyte will be posted on the Division of Drinking Water’s webpage.

Weck Labs' Expertise in PFAS

Weck Labs' expertise in testing for PFAS spans more than 17 years and we provide continuous development to meet new regulatory drivers. Weck Laboratories currently offers several methods for determination of PFAS including EPA methods 537.1, 533, Draft 1633 and methods compliant to the Department of Defense (DoD) QSM 5.4 Tables B-15 and B-24. Weck can currently test for 44 PFAS compounds.

Learn more about Weck Labs PFAS Testing Here

EPA 537.1 and EPA 533 Method Comparison

EPA 533 is a newer method that encompasses more targets than 537.1, with 25 targets for 533 compared to only 18 targets for 537.1. While there is some overlap between the 537.1 and 533 target lists, the 533 targets focus on the shorter-chain PFAS which are more likely to be found in the environment. The extraction technique for 533 relies on anion exchange, which is much more selective for PFAS than the reversed-phase extraction for 537.1, reducing some potential matrix effects in field samples. 537.1 uses conventional internal standard quantitation, but 533 uses isotopic dilution quantitation for the highest possible level of data quality. Isotopic dilution effectively allows the laboratory to perform a matrix spike on every single sample and automatically account for challenging matrices on a per-sample basis. Overall, 533 is a more robust and complete method for PFAS analysis in drinking water than 537.1. The data quality is higher with 533, and it can tolerate a greater variety of matrices. 533 is suitable for various sample types, such as source water, water re-use, and finished drinking water. Both methods require that Field Reagent Blanks (FRBs) be sampled and analyzed if field samples have hits above the MRL. Some regulatory programs may require that all FRBs be analyzed so be sure to verify the requirements and budget for the additional cost. Weck Labs is approved by the US EPA for UCMR 5 for both EPA 533 and 537.1

UCMR 5 Approval Letter

EPA Draft Method 1633 and DoD QSM Compliance Method

In 2021, the U.S. Environmental Protection Agency (EPA), in collaboration with the U.S. Department of Defense (DoD), published Draft EPA 1633 method to test per- and polyfluoroalkyl substances (PFAS) in different environmental matrices. The 3^rd draft version of the method was issued in December of 2022. EPA Draft Method 1633 is an isotope dilution LC-MS/MS method which incorporates testing of up to 40 PFAS compounds. While broadly conforming to the DoD Quality Systems Manual Table B-15 quality standards for PFAS analysis, EPA 1633 standardizes the procedures and extends them to more complex matrices such as wastewater, biosolids, leachate and tissue. QSM v5.3 Table B-15 lists the specific requirements for analyzing PFAS in matrices other than drinking water. QSM v5.4 was published in late 2021, adding Table B-24 to refine Draft Method 1633 for DOD projects in wastewater, surface water, groundwater, soil, biosolids, sediment, landfill leachate, and tissue. Weck Laboratories is accredited by the Departments of Defense and Energy for both QSM 5.4 Table B-15 Compliance method and EPA 1633 (QSM 5.4Table B-24).

DoD ELAP Accreditation

Weck Laboratories will add specific state certifications for EPA 1633 as accreditations become available.

PFAS Target List by Method

News from the US EPA

Proposed National Primary Drinking Water Regulation

In March 2023, EPA took a key step to protect public health by proposing to establish legally enforceable levels for six PFAS known to occur in drinking water, fulfilling a foundational commitment in the Agency’s PFAS Strategic Roadmap. EPA is also proposing health-based, non-enforceable Maximum Contaminant Level Goals (MCLGs) for these six PFAS.

The proposed rule would require public water systems to:

Read more: Per- and Polyfluoroalkyl Substances (PFAS) | US EPA

PFAS in Clean Water Act Permitting

In December 2022, EPA issued a companion memo providing guidance to states on how to use the Clean Water Act's National Pollutant Discharge Elimination System (NPDES) permitting program to reduce harmful PFAS pollution. This memo expands upon an earlier memo issued to EPA Regions in April 2022 and is a critical step in EPA's efforts to restrict PFAS at their source.

US EPA Memo

News from California State Water Board

EPA Method 533 required for drinking water compliance monitoring in California

Under PFAS General Order DW-2022-0001_DDW, effective January 1, 2023, public water systems in California must begin quarterly monitoring of samples for PFAS using EPA Method 533.

Copy of General Order

Current notification levels can be found at: Per- and Polyfluoroalkyl Substances (PFAS) | California State Water Resources Control Board

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