PFAS in Drinking Water: The 2024 Federal Rule and What It Means for San Fernando Valley Taps

What changed when PFAS went from a health advisory to an MCL?

From 2016 to 2024, the federal PFAS standard was a lifetime health advisory set at 70 parts per trillion for the combined concentration of PFOA and PFOS. Health advisories are guidance values, not enforceable limits. Utilities were not required to test specifically for PFAS compliance, notify customers when detections exceeded the advisory level, or treat their water to meet it. The advisory was a number in a federal guidance document, not a legal obligation.

The April 2024 rule changed that category. A Maximum Contaminant Level is an enforceable standard under the Safe Drinking Water Act. Water utilities that detect PFOA or PFOS above 4 ppt must notify customers, report to state regulators, and implement treatment or source changes to come into compliance. Utilities have until April 2029 to comply, which gives large systems time to engineer treatment solutions, but the monitoring and reporting obligations begin earlier. The limit also dropped substantially: from 70 ppt (combined, in the advisory) to 4 ppt each (individual, in the MCL).

How does California compare to the new federal standard?

California was ahead of the federal rule. In July 2020, the California State Water Resources Control Board finalized MCLs of 10 ppt for PFOA and 10 ppt for PFOS under the California Safe Drinking Water Act (SWRCB PFAS page). At the time, the federal government had only a non-enforceable health advisory. California utilities, including LADWP and LVMWD, have been operating under the 10 ppt state MCLs since then.

The EPA's 2024 federal standard of 4 ppt is stricter than California's 10 ppt standard. Under the Safe Drinking Water Act, utilities must comply with whichever limit is lower: the state MCL or the federal MCL. The operative standard for California utilities is now the federal 4 ppt limit. Utilities that were meeting the 10 ppt California MCL are not automatically in compliance with the 4 ppt federal rule if their PFAS detections fall between those two thresholds.

Which SFV water utilities does this affect?

The two utilities that serve most of the San Fernando Valley service area covered by Noohi Construction are LADWP and Las Virgenes Municipal Water District. LADWP serves the majority of SFV cities, including Woodland Hills, Canoga Park, Northridge, Reseda, Tarzana, Encino, West Hills, Winnetka, and Chatsworth. LVMWD serves Calabasas, Agoura Hills, and most of Westlake Village.

Both utilities publish annual Consumer Confidence Reports that disclose contaminant detections including PFAS. LADWP's CCR is available at ladwp.com/water-quality and LVMWD's at lvmwd.com/water-quality. These are the primary documents for understanding current PFAS detection levels in the distributed water supply. Our earlier article on SFV water quality and source blending covers how to read a CCR in detail.

What home treatment removes PFAS?

Two treatment technologies have documented effectiveness against PFOA and PFOS at the point of use: reverse osmosis and certified activated carbon filters.

Reverse osmosis systems certified under NSF/ANSI 58 with specific PFAS reduction claims have been tested to reduce PFOA and PFOS concentrations by more than 90 percent. The certification is contaminant-specific: an NSF/ANSI 58 certification for TDS reduction does not imply PFAS reduction. Look for the system's contaminant reduction certificate, which lists which compounds the specific model was tested to reduce. Noohi installs reverse osmosis systems throughout the SFV; the kitchen-tap RO configuration is the most common point-of-use solution for drinking and cooking water.

Pitcher-style and faucet-mount carbon filters certified under NSF P473 have also been tested for PFOA and PFOS reduction. Effectiveness varies by model and flow rate; check the specific product's NSF P473 certification rather than the manufacturer's general claims. Whole-home granular activated carbon systems have variable PFAS removal performance and are generally not certified to the same standard as point-of-use RO. For households primarily concerned about drinking and cooking water, a certified point-of-use RO system provides the most consistent and independently verified PFAS reduction.

Should SFV homeowners get their tap water tested for PFAS?

In-home water consultations test for hardness, TDS, pH, and chloramine or chlorine residual. PFAS testing requires a laboratory analysis using EPA Method 533 or Method 537.1, neither of which is a field test. If PFAS exposure is a specific concern, the right resource is a state-certified laboratory. California maintains a searchable list of certified labs at waterboards.ca.gov/drinking_water/certlic/labs/. A lab test for a standard PFAS panel (PFOA, PFOS, and the other six regulated compounds) typically runs $150 to $400 depending on the lab and the panel selected (verify current pricing with each lab; we do not publish prices that change).

For the distribution-system picture, the CCR is free and updated annually. For the point-of-use picture at a specific address, especially one with older plumbing or a private well in the footprint of Calabasas or Agoura Hills, a certified lab analysis is the direct answer. A free in-home consultation covers the standard tap parameters and can help determine whether a lab PFAS test and a point-of-use treatment system make sense for a specific home.

Sources used in this article: EPA PFAS National Primary Drinking Water Regulation (April 2024); California SWRCB PFAS MCLs; EPA UCMR5 (Fifth Unregulated Contaminant Monitoring Rule); EPA Safe Drinking Water Act; NSF International: Certified Water Filters; LADWP Consumer Confidence Reports; Las Virgenes MWD Consumer Confidence Reports.