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City of Atwater water quality report, rewritten

Serves
29,479
Connections
8,502
Water source
Groundwater
Based in
Atwater, CA
County
Merced
Owner
Local government
The ZIP code it serves

95301

PWSID CA2410001 · EPA data

Read this first

  • PFOS (above the health goal) was found in three of 16 samples, highest 45 ppt. Above the 4.0 ppt legal limit in at least one sample. Compliance is judged on a running annual average, not one sample.
  • PFOA (above the health goal) was found in three of 16 samples, highest 33 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 (above the health goal) was found in eight of 16 samples, highest 59 ppt. Above the 10 ppt legal limit in at least one sample. Compliance is judged on a running annual average, not one sample.

No health-based violations on file since 2016.

What handles it

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.

PFAS and lithium: EPA UCMR 5, samples taken from Oct. 31, 2023 to May 7, 2024. Each blue tick on a scale is one sample where it was found.

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.

PFOS (above the health goal)

Comes from the source

45 (above the legal limit in at least one sample)ppt

Highest of 16 samples; found in three

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

What handles it

PFOA (above the health goal)

Comes from the source

33 (above the legal limit in at least one sample)ppt

Highest of 16 samples; found in three

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

What handles it

PFHxS (above the health goal)

Comes from the source

59 (above the legal limit in at least one sample)ppt

Highest of 16 samples; found in eight

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

What handles it

PFBS

Comes from the source

7.8ppt

Highest of 16 samples; found in three

Below EPA’s hazard index benchmark of 2,000 ppt. PFBS has no legal limit or health goal of its own.

What handles it

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
PFPeA27 ppt8 of 16None covers it
PFHxA25 ppt5 of 16None covers it
6:2 FTS13 ppt1 of 16None covers it
PFHpA12 ppt3 of 16NSF/ANSI 53: Total PFAS Reduction
PFBA11 ppt2 of 16None covers it
PFPeS8.2 ppt2 of 16None covers it

Tested and not found

Below EPA’s minimum reporting level in every sample taken from Oct. 31, 2023 to May 7, 2024. Not found means not measured above that level, which is not the same as zero.

All 21 compounds tested and not found
  • 11Cl-PF3OUdS
  • 4:2 FTS
  • 8:2 FTS
  • 9Cl-PF3ONS
  • ADONA
  • HFPO-DA (GenX)
  • Lead
  • Lithium
  • NEtFOSAA
  • NFDHA
  • NMeFOSAA
  • PFDA
  • PFDoA
  • PFEESA
  • PFHpS
  • PFMBA
  • PFMPA
  • PFNA
  • PFTA
  • PFTrDA
  • PFUnA

Violations since 2016

No health-based violations on file with EPA since 2016.

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, PFOA Reduction, Total PFAS Reduction

    Other certifiers’ wording: Perfluorooctane Sulfonate (PFOS); Perfluorooctanoic Acid (PFOA); Perfluorohexane Sulfonic Acid (PFHxS)

    For: PFOS, PFOA, PFHxS

  • NSF/ANSI 58

    Claims: Perfluorooctane Sulfonate (PFOS), Perfluorooctanoic Acid (PFOA)

    For: PFOS, PFOA

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 Atwater’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 Oct. 31, 2023 to May 7, 2024.

Other California utilities

All California utilities

Sources

What to do next

  • Read up on the 3 marked results

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

    Start with PFOS

  • Get the utility’s own report

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

    How to read it

  • 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

  • Compare certified filters

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

    Compare five-year costs