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City of GridleyWater quality report

Standards for what was found here

5358
Serves
7,269
Connections
2,282
Water source
Groundwater
Based in
Gridley, CA
County
Butte
Owner
Local government
The ZIP code it serves

95948

PWSID CA0410004 · EPA data

Read this first

  • PFOS was found in two of 10 samples, highest 10.5 ppt. Above the 4.0 ppt legal limit in at least one sample. Compliance is judged on a running annual average, not one sample.
  • PFHxS was found in two of 10 samples, highest 12.8 ppt. Above the 10 ppt legal limit in at least one sample. Compliance is judged on a running annual average, not one sample.

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

What handles it

What was found, stop by stop

  • Below the health goal
  • Above the health goal
  • Above the legal limit
  • No federal data

  1. At the source

    EPA UCMR 5 sampled this utility for 29 PFAS and lithium from June 3, 2024 to Dec. 2, 2024. Each tick under a result’s line is one sample where it was found, dated when you point at it.

    NSF’s PFAS claims are tested to below 20 ppt. EPA’s limit is 4.0 ppt, and EPA says no certification yet shows a filter reaching its levels.

  2. PFOS

    Above the legal limit

    10.5ppt

    Highest of 10 samples; found in two

    Above the 4.0 ppt legal limit in at least one sample. Compliance is judged on a running annual average, not one sample.

    • NSF/ANSI 53 · Look for: PFOS ReductionSame claim, other certifiers’ wording: Total PFAS Reduction; Perfluorooctane Sulfonate (PFOS)

    • NSF/ANSI 58 · Look for: Perfluorooctane Sulfonate (PFOS)

  3. PFHxS

    Above the legal limit

    12.8ppt

    Highest of 10 samples; found in two

    Above the 10 ppt legal limit in at least one sample. Compliance is judged on a running annual average, not one sample.

    • NSF/ANSI 53 · Look for: Total PFAS ReductionSame claim, other certifiers’ wording: Perfluorohexane Sulfonic Acid (PFHxS)

  4. PFNA

    Below the health goal

    9.9ppt

    Highest of 10 samples; found in two

    Detected, below the legal limit and the health goal.

    • NSF/ANSI 53 · Look for: Total PFAS ReductionSame claim, other certifiers’ wording: Perfluorononanoic Acid (PFNA)

  5. Also found, with no federal limit

    EPA measured these PFAS to learn how often they occur. None has a legal limit or a health goal yet.

    CompoundHighest sampleFound inCertification claim
    PFPeA6.5 ppt2 of 10None covers it
    PFHxA5.3 ppt2 of 10None covers it
    PFHpA3.5 ppt2 of 10NSF/ANSI 53: Total PFAS Reduction

  6. In treatment

    No federal results for this stop. Disinfection byproduct, chlorine and fluoride levels are in City of Gridley’s own annual report, which it must send you every year.

  7. In the pipes

    No lead and copper results on file with EPA for this utility.

  8. At your tap

    The last stretch is your own plumbing. A certified lab test is the only way to know what reaches your glass. Lead in your water: what to do

Tested and not found

Below EPA’s minimum reporting level in every sample taken from June 3, 2024 to Dec. 2, 2024. Not found means not measured above that level, which is not the same as zero.

All 25 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
  • PFHpS
  • PFMBA
  • PFMPA
  • PFOA
  • 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—Unaddressed
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 handles it

A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”

  • NSF/ANSI 53

    Claims: PFOS Reduction, Total PFAS Reduction

    For: PFOS, PFHxS

  • NSF/ANSI 58

    Claim: Perfluorooctane Sulfonate (PFOS)

    For: PFOS

At the tap, or for the whole house?

These come with the water itself, so a whole-house system certified for the same claims treats every tap and shower. A filter at the tap treats drinking water for much less. How whole-house systems compare.

Compare five-year costs

Filters with those claims on a certifier’s listing

TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money

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 Gridley’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 June 3, 2024 to Dec. 2, 2024.

Other California utilities

All California utilities

Sources

What to do next

  1. Start with PFOS

    What each marked result does to health, where it comes from, and the certification claim that addresses it.

  2. Read the utility’s own report

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

  3. Test your own tap for lead

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

  4. Compare five-year costs

    What the filters certified for these results cost over five years, cartridges included.