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City of Oakdale water quality report, rewritten

Serves
23,235
Connections
8,335
Water source
Groundwater
Based in
Oakdale, CA
County
Stanislaus
Owner
Local government
The ZIP code it serves

95361

PWSID CA50100142026 edition · EPA data

Read this first

Nothing in the federal data for this utility is above a health goal. That covers PFAS, lithium, lead and copper; it does not cover everything, so read what this report cannot tell you below.

1 health-based violation since 2016. Details are below.

What was found

Highlighted: above the health goal, or EPA’s health benchmark where there is no goal. Circled: above the legal limit in at least one sample, or the action level. Every scale puts that line at its middle.

None of the contaminants in the federal data below were found at or above EPA’s reporting levels.

Tested and not found

Below EPA’s minimum reporting level in every sample taken from Feb. 24, 2025 to Aug. 20, 2025. Not found means not measured above that level, which is not the same as zero.

All 31 compounds tested and not found
  • 11Cl-PF3OUdS
  • 4:2 FTS
  • 6:2 FTS
  • 8:2 FTS
  • 9Cl-PF3ONS
  • ADONA
  • HFPO-DA (GenX)
  • Lead
  • Lithium
  • NEtFOSAA
  • NFDHA
  • NMeFOSAA
  • PFBA
  • PFBS
  • PFDA
  • PFDoA
  • PFEESA
  • PFHpA
  • PFHpS
  • PFHxA
  • PFHxS
  • PFMBA
  • PFMPA
  • PFNA
  • PFOA
  • PFOS
  • PFPeA
  • PFPeS
  • PFTA
  • PFTrDA
  • PFUnA

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Lead and Copper Rule RevisionsThe required inventory of lead service lines was not completed or submitted on time.EPA: LSL InventoryOct. 17, 2024—Addressed
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 1 monitoring or reporting violation not shown.

What this report cannot tell you

  • Levels of everything else. Federal bulk data carries results for PFAS, lithium, lead and copper, and violations for the rest. Nitrate, arsenic, disinfection byproducts and other levels are in City of Oakdale’s own annual report, which it must send you every year.
  • Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.
  • Anything after the latest data. SDWIS data is from 2026 Q2; UCMR 5 samples are from Feb. 24, 2025 to Aug. 20, 2025.

What to do next

  1. Nothing here is above a health goal

    In the federal data for this utility. That data does not cover everything, which is why the next step matters.

    Every contaminant TapBuff tracks

  2. Get the utility’s own report

    City of Oakdale must send you a water quality report every year. It lists nitrate, arsenic and byproduct levels this page cannot.

    How to read it

  3. Test your own tap for lead

    Your service line, solder and fixtures decide the lead at your faucet, not the utility’s average.

    Lead in your water: what to do

  4. Decide if you want a filter at all

    A filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.

    NSF/ANSI standards, decoded

Other California utilities

All California utilities

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