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San Jose Water water quality report, rewritten

Serves
1 million
Connections
237,130
Water source
Surface water
Based in
San Jose, CA
County
Santa Clara
Owner
Private
The 30 ZIP codes it serves

95008, 95014, 95030, 95032, 95033, 95050, 95070, 95110, 95111, 95112, 95113, 95116, 95117, 95118, 95120, 95121, 95122, 95123, 95124, 95125, 95126, 95127, 95128, 95129, 95130, 95131, 95132, 95133, 95136, 95148

PWSID CA43100112026 edition · EPA data

Read this first

  • PFOS (above the health goal) was found in two of 37 samples, highest 6.2 ppt. Above the 4.0 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

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.

PFOS (above the health goal)

Comes from the source

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

Highest of 37 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.

What handles it

  • NSF/ANSI 53Look for: PFOS ReductionSame claim, other certifiers’ wording: Total PFAS Reduction; Perfluorooctane Sulfonate (PFOS)
  • NSF/ANSI 58Look for: Perfluorooctane Sulfonate (PFOS)

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.

EPA UCMR 5, samples taken from April 19, 2023 to Aug. 16, 2023. Each blue tick is one sample where it was found.

Lithium

Comes from the source

10ppb

Highest of 41 samples; found in five

Below EPA’s health reference level of 10 ppb. Lithium has no legal limit or health goal of its own.

What handles it

No certification claim covers this compound yet.

EPA UCMR 5, samples taken from Feb. 15, 2023 to Aug. 22, 2023. Each blue tick is one sample where it was found.

PFHxS

Comes from the source

5.5ppt

Highest of 36 samples; found in 12

Detected, below the legal limit and the health goal.

What handles it

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

NSF’s PFAS claims are tested to below 20 ppt. EPA’s limit is 10 ppt, and EPA says no certification yet shows a filter reaching its levels.

EPA UCMR 5, samples taken from Feb. 16, 2023 to Aug. 23, 2023. Each blue tick is one sample where it was found.

Tested and not found

Below EPA’s minimum reporting level in every sample taken from Feb. 15, 2023 to Feb. 11, 2025. Not found means not measured above that level, which is not the same as zero.

All 28 compounds tested and not found
  • 11Cl-PF3OUdS
  • 4:2 FTS
  • 6:2 FTS
  • 8:2 FTS
  • 9Cl-PF3ONS
  • ADONA
  • HFPO-DA (GenX)
  • Lead
  • NEtFOSAA
  • NFDHA
  • NMeFOSAA
  • PFBA
  • PFBS
  • PFDA
  • PFDoA
  • PFEESA
  • PFHpA
  • PFHpS
  • PFHxA
  • PFMBA
  • PFMPA
  • PFNA
  • PFOA
  • PFPeA
  • PFPeS
  • PFTA
  • PFTrDA
  • PFUnA

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Surface Water Treatment RuleRequired treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR)June 1, 2023 to June 30, 2023—Resolved
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.”

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 San Jose Water’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. 15, 2023 to Feb. 11, 2025.

What to do next

  1. Read up on PFOS

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

    About PFOS

  2. Get the utility’s own report

    San Jose Water 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. Compare certified filters

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

    Compare five-year costs

Other California utilities

All California utilities

Sources