Tackling PFAS with Innovation: Orange County Water District’s Approach

glass of water

| By Craig Butt & Prem Parmar

For the past 90 years, the Orange County Water District (OCWD) has provided a safe and reliable local groundwater supply to Southern California. As regulations and requirements for water quality have changed dramatically since 1933, OCWD has continuously adopted new methods and technologies to manage both water supply and water quality in its local groundwater basin. Besides testing for harmful bacteria and heavy metals like lead and copper, OCWD also tests for chemical residues of common pharmaceuticals and personal care products (PPCPs), as well as petrochemicals, pesticides and other contaminants.

Over the last decade, OCWD has expanded its testing for per- and polyfluoroalkyl substances (PFAS). Found in everything from dental floss and food wrappers to firefighting foams and fabrics, PFAS are frequently called ‘forever chemicals’ due to their environmental persistence. Scientists have identified thousands of PFAS chemicals so far, although only a small set of this family of chemicals are currently under regulatory guidelines for water treatment facilities.

On March 16, 2023, the U.S. Environmental Protection Agency (EPA) released the proposed National Primary Drinking Water Regulation (NPDWR) for six PFAS, which puts limits on the concentration of these compounds that can be found in drinking water. EPA anticipates finalizing the regulation by the end of 2023. To keep up with these requirements, OCWD and other water utilities around the United States will see further increase in testing demands to ensure compliance.

Adopting New Methods for PFAS Detection

Mass spectrometry (MS) continues to be the mainstay of PFAS analysis for drinking water. MS measures the mass-to-charge ratio of ions by separating ions and displaying the results as spectra. MS can be very sensitive by itself, but when combined with liquid chromatography (LC), which separates the chemicals in a sample, LC-MS quantifies molecules with exceptional sensitivity.

OCWD’s workflow with SCIEX LC-MS products can measure PFAS in drinking water samples down to the parts per trillion level. This is a vanishingly small amount of PFAS. As the Massachusetts Water Works Association pointed out on X, a part per trillion is a drop of water in 20 Olympic-sized swimming pools — or $1.20 of all U.S. currency currently in circulation.

OCWD acquired its first LC-MS instrument back in 2006 to begin analyzing PPCPs in support of their world-renowned Groundwater Replenishment System (GWRS) for indirect potable reuse. Testing expanded to PFAS analyses during the federally mandated Unregulated Contaminant Monitoring Rule 3 (UCMR3) from 2013-2015, and has been relied on ever since. OCWD continues to perform all of its LC-MS analysis in-house and has seen both time and cost advantages, while also retaining control of data quality — all of which helps OCWD confidently work with its retail agency partners to provide the 2.5 million local residents with safe drinking water.

Sending a sample out to an external lab can potentially create a several-week lag before results are returned. By performing in-house analyses, OCWD can provide turnaround times within 24 to 48 hours as needed. Each day waiting on results can cost utilities money — making it important to produce data as quickly as possible.

Technology continues to grow our understanding of emerging contaminants. While PFAS have been around for many years, new analytical testing methods have increased our understanding of its biological impact and how to keep our populations safe with awareness and testing. Addressing PFAS in the environment will require much effort, and continued regular testing of the environment around us will help support effective management of these forever chemicals.

Craig Butt is a senior staff scientist for food/environmental and global technical marketing at SCIEX, focusing on developing PFAS analysis methods in environmental matrices.

Prem Parmar is the laboratory director for OCWD’s Philip L. Anthony Water Quality Laboratory. He is responsible for managing the lab’s personnel and operations, strategic and advanced planning activities and compliance with federal and state lab requirements.

Leave a Reply

Your email address will not be published. Required fields are marked *