EPA data as of Oct 2026 · page updated 2026-10-30

City of Oakdale

City of Oakdale (EPA ID CA5010014) in Oakdale, CA supplies groundwater (wells) to about 23,235 people: 1 violation since 2016, latest lead result 0 ppb, PFAS not detected.

Service area

EPA service-area boundary (state-supplied or EPA-modeled)
Water utility service area PFOA/PFOS ≥ 4 ppt Lead > 15 ppb 5+ violations Superfund site (active) proposed cleaned up Circles: other water systems flagged nearby; size = people served. Tap any symbol for details.

System facts

People served23,235
Connections8,395
Sourcegroundwater (wells)
WholesalerNo

Health-based violations

Contaminant or ruleHealth-based violations since 2016
Lead and Copper Rule Revisions1

A health-based violation means a contaminant exceeded its legal limit (MCL) or a required treatment technique was not met, as reported by the state to EPA’s SDWIS. All are listed as resolved or archived; the latest began Oct 2024.

Lead

Jan 20230 ppb
Jan 20200 ppb
Jan 20170 ppb
Jan 20140 ppb
Jan 20110 ppb
Jan 20080 ppb
Jan 20070 ppb
Jan 20065 ppb

90th-percentile lead per sampling round (90% of the homes sampled were at or below this level). Black line: EPA’s 15 ppb action level; under the Lead and Copper Rule Improvements the action level becomes 10 ppb from 2027.

PFAS

CompoundHighest resultSamples with detectionEPA limit
PFBSnot detected0 of 14—
PFHxAnot detected0 of 14—
HFPO-DA (GenX)not detected0 of 14—
PFDAnot detected0 of 14—
PFOAnot detected0 of 144 ppt MCL
PFOSnot detected0 of 144 ppt MCL
PFNAnot detected0 of 14—
PFHpAnot detected0 of 14—
PFHxSnot detected0 of 14—
PFPeAnot detected0 of 14—
PFBAnot detected0 of 14—

EPA Fifth Unregulated Contaminant Monitoring Rule (UCMR 5), samples 2023–2025; ppt = parts per trillion (ng/L). The 4.0 ppt maximum contaminant levels for PFOA and PFOS were set by EPA in 2024; water systems have until the end of the decade to comply.

ZIP codes served

ZIP codes whose center lies in this system’s service area or that the state lists for it.

What this is — and isn’t. These are records your water utility and state reported to the EPA, and the EPA’s radon map for your county. They describe the system and the area, not the water from your own tap or the air in your home. For that, read your utility’s annual Consumer Confidence Report and test: lead and radon tests are inexpensive.

Questions

Has City of Oakdale had drinking water violations?

Health-based violations since 2016: Lead and Copper Rule Revisions. All are listed as resolved.

What is the lead level in City of Oakdale water?

The latest 90th-percentile lead result (Jan 2023) was 0 ppb. EPA’s action level is 15 ppb (10 ppb from 2027).

Does City of Oakdale have PFAS in its water?

None of the tested PFAS were found above EPA’s reporting limits in 2023–2025.