PFAS Regulations, Monitoring, and Testing

PFAS Testing Regulations: What’s Changed

All Sweetwater Authority drinking water currently meets state and federal safety standards.

The State of California has updated its PFAS testing and reporting requirements, as scientific understanding of these compounds continue to evolve. The State has expanded the list of PFAS compounds it monitors and, in some cases, lowered the thresholds that trigger notification or further evaluation.

Key updates include:

  • More PFAS compounds monitored: The State now tracks five PFAS compounds, adding PFBS to the list
  • Earlier notification: For most PFAS compounds, public water agencies must notify regulators at lower concentrations than before, increasing transparency and early awareness
  • Earlier response for some compounds: The State lowered response levels for PFHxS and PFHxA, meaning action may be considered sooner if these compounds are detected
  • No change for others: Response levels for PFOA, PFOS and PFBS remain the same

These updates reflect a more cautious, health- protective approach by the State and do not necessarily indicate an increased health risk. This information was presented to the Sweetwater Authority Board on Nov. 12, 2025, and Sweetwater Authority continues to monitor PFAS closely and comply with all state and federal drinking water regulations.

PFAS
New NL (ng/l)
New RL (ng/l)
Previous NL (ng/l)
Previous RL (ng/l)
Perfluorooctanoic acid (PFOA)
4.0
10*
5.1
10

Perfluorooctanesulfonic acid (PFOS)

4.0
40*
6.5
40

Perfluorohexanesulfonic acid (PFHxS)

3.0
10
3
20

Perfluorohexanoic acid (PFHxA)
1,000
10,000
None
None

Perfluorobutanesulfonic acid (PFBS)

500*
5,000*
500
5,000*


PFAS Snapshot: Testing Results through January 2026

Sweetwater Authority continues to closely monitor PFAS in its water system in compliance with California regulations and reporting requirements. The most recent testing was completed by the Authority in January 2026. These testing results were presented at the Jan. 27 Community Advisory Work Group and are included on pages 12-16.

Notification Levels and What They Mean

Currently, three PFAS compounds are above California’s Notification Levels: PFOA, PFHxS and PFOS. Exceeding a Notification Level does not mean the water is unsafe. It simply triggers transparency requirements, so governing bodies and the public are informed.

Sweetwater completed all required notifications:

  • PFOA and PFHxS: December 2024
  • PFOS: December 2025

Response Levels and Ongoing Monitoring

Two compounds, PFOA and PFHxS, are being closely monitored because their levels are near the State’s Response Level of 10 ppt. Based on the most recent testing:

  • PFOA: approximately 8.4 ppt
  • PFHxS: approximately 8.6 ppt

Because both remain below the Response Level threshold, no regulatory action is required at this time.

Proactive System Management

Encouragingly, PFAS concentrations are trending downward. Operational adjustments — including water transfers from Loveland Reservoir and strategic blending — have helped reduce concentrations across the system.

Rather than waiting to respond only if thresholds are exceeded, Sweetwater Authority actively manages its water system using trend data and ongoing testing to maintain stability, protect public health, and ensure continued regulatory compliance.