City Council Agenda
Memo to: Manteca City Council
From: George Montross, Director of Utilities
Date: November 17, 2026
Subject: PFAS Chemical Detections at City Wells
title
Approve a resolution acknowledging that the Manteca City Council was notified by staff that various Per- and Polyfluoroalkyl Substances, chemicals commonly used in a wide range of industrial processes, were detected in raw groundwater from several City Wells at levels exceeding the State Water Board’s Division of Drinking Water (DDW) Notification Level and authorize staff to forward the resolution to the DDW.
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Background:
On April 10, 2024, the United States Environmental Protection Agency announced the final National Primary Drinking Water Regulations for several Per- and Polyfluoroalkyl Substances (PFAS) chemicals, see table below. As part of the regulation, all public water systems were required to conduct initial monitoring for these PFAS chemicals. The City of Manteca completed the initial monitoring and several groundwater wells had PFAS chemical detections. These detections were reported to City Council on October 21, 2025. The City continues to monitor our groundwater wells for these PFAS chemicals and during 2026 we had Perflouorooctanoic Acid (PFOA) and Perfluorohexane Aulfonic Acid (PFHxS) detections, requiring new notifications.
Additionally, on October 29, 2025, the State of California updated their Notification Level (NL) and Response Levels (RL). Several PFAS chemical NL and RL concentrations were lowered and one chemical was added to the list, see table below:
Chemical Name
Abbreviation
Notification Level (NL)
Response Level (RL)
What Changed?
Perflouorooctanoic Acid
PFOA
4.0 ppt
10 ppt
Lowered NL from 5.1 ppt
Perfluorooctane Sulfonic Acid
PFOS
4.0 ppt
40 ppt
Lowered NL from 6.5 ppt
Perfluorobutane Sulfonic Acid
PFBS
500 ppt
5,000 ppt
No Change
Perfluorohexane Aulfonic Acid
PFHxS
3.0 ppt
10 ppt
Lowered RL from 20 ppt
Perflu...
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