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Cal/Am Water Company - San MarinoWater quality report

Serves
47,995
Connections
14,544
Water source
Surface water bought from another system
Based in
Rosemead, CA
County
Los Angeles
Owner
Private
The 7 ZIP codes it serves

91107, 91108, 91731, 91770, 91776, 91780, 91803

PWSID CA1910139 · EPA data

Read this first

  • Lithium was found in four of 16 samples, highest 91.9 ppb. Above EPA’s health reference level of 10 ppb, a screening level rather than an enforceable limit.

No health-based violations on file since 2016. EPA lists 1 monitoring or reporting violation, which are paperwork and testing lapses rather than water quality findings.

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 May 16, 2023 to Jan. 29, 2025. Each tick under a result’s line is one sample where it was found, dated when you point at it.

  2. Lithium

    Above EPA’s health benchmark

    91.9ppb

    Highest of 16 samples; found in four

    Above EPA’s health reference level of 10 ppb, a screening level rather than an enforceable limit.

    What handles it: No certification claim covers this compound yet.

  3. 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
    PFBA5.3 ppt1 of 16None covers it

  4. In treatment

    No federal results for this stop. Disinfection byproduct, chlorine and fluoride levels are in Cal/Am Water Company - San Marino’s own annual report, which it must send you every year.

  5. In the pipes

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

  6. 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 May 16, 2023 to Jan. 29, 2025. Not found means not measured above that level, which is not the same as zero.

All 29 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
  • PFBS
  • PFDA
  • PFDoA
  • PFEESA
  • PFHpA
  • PFHpS
  • PFHxA
  • PFHxS
  • PFMBA
  • PFMPA
  • PFNA
  • PFOA
  • PFOS
  • PFPeA
  • PFPeS
  • PFTA
  • PFTrDA
  • PFUnA

Violations since 2016

No health-based violations on file with EPA since 2016. There is 1 monitoring or reporting violation: a sample missed, late or not reported.

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 Cal/Am Water Company - San Marino’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 May 16, 2023 to Jan. 29, 2025.

Other California utilities

All California utilities

Sources

What to do next

  1. About Lithium

    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

    Cal/Am Water Company - San Marino 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. NSF/ANSI standards, decoded

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