Drinking water quality · 2023

· Verified

· PWSID CA1010021

What's in Mendota, City of — Mendota, Ca, CA tap water

F
Water quality score
30/ 100Poor

4 contaminants in Mendota, City of — Mendota, Ca, CA's water sat at or above a federal limit, led by Benzene at 26.0x the limit.

  • !4 contaminants at or above a federal limit — worst is Benzene at 26.0x
  • !1 contaminant within 20% of a limit
  • !15 of 27 core regulated contaminants reported — 12 never appear in this report
  • No open federal violations
+How this score is calculated

Every system starts at 100. Points come off for measured levels, for the federal violation record, and for how much of the core regulated set the utility actually reported. All three inputs are the utility's own published numbers and EPA's own records.

  • 60  contaminants at or above a federal limit
  • 4  contaminants within 20% of a limit
  • 0  open health-based violations
  • 0  open monitoring / reporting violations
  • 0  health-based violations resolved in the last 5 years
  • 6  core regulated contaminants never reported (15/27)

A 90–100 · B 80–89 · C 70–79 · D 60–69 · F below 60. A system reporting under a third of the core set is capped at C however clean its numbers look — a short report is not a clean bill of health.

Full grading methodology, constant for constant →

What to worry about

  • Benzene26.0× the federal limit
    82–130 ug/L · limit 5 ug/L
  • TTHM1.0× the federal limit
    28–82 ug/L · limit 80 ug/L

    Long-term exposure above the federal limit is linked to liver, kidney, and central-nervous-system effects and increased cancer risk.

    Higher than 95% of CA systems that report it · higher than 95% of U.S. systems

  • Selenium1.0× the federal limit
    5–50 ug/L · limit 50 ug/L

    Essential in tiny amounts, but long-term exposure above the federal limit can cause hair and fingernail loss and circulatory problems.

    Higher than 95% of CA systems that report it · higher than 95% of U.S. systems

  • Simazine1.0× the federal limit
    0.004–4 ug/L · limit 4 ug/L
  • PFOS83% of the federal limit
    3.3 ng/L · limit 4 ng/L

    Linked to cancer, thyroid disease, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.

    Higher than 40% of CA systems that report it · higher than 50% of U.S. systems

+38 contaminants were measured and came in below the limitShow all
ContaminantMeasured
PFOA3.15 ng/L
Arsenic0–6.7 ug/L
Chlorine Total0.06–2.46 mg/L
Perfluorohexanesulfonic acid5.8 ng/L
Alachlor1 ug/L
Hexafluoropropylene oxide dimer acid0–5 ng/L
Gross Alpha0–6.07 pCi/L
Atrazine0.5–1 ug/L
Perfluorononanoic acid2.5 ng/L
HAA54.8–14 ug/L
Combined Radium0–1.1 pCi/L
Fluoride0.4–0.64 mg/L
Calcium70–100 mg/L
Chromium, Hexavalent0.05–1 ug/L
CopperNot detected mg/L
LeadNot detected ug/L
Potassium2.2 mg/L
Escherichia coli (E. coli)0
Total Coliform0
11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)0–5 ng/L
4,8-Dioxa-3H-perfluorononanoic acid (ADONA)0–3 ng/L
9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS)2.15 ng/L
Nonafluoro-3,6-dioxaheptanoic acid0–20 ng/L
Perfluoro-3-methoxypropanoic acid (PFMPA)2 ng/L
Perfluoro-4-methoxybutanoic acid (PFMBA)2.2 ng/L
Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA)2.3 ng/L
Perfluorobutanesulfonic acid3.4499999999999997 ng/L
Perfluorodecanoic acid (PFDA)0–3 ng/L
Perfluorododecanoic acid (PFDoA)0–3 ng/L
Perfluoroheptanesulfonic acid (PFHpS)2.1 ng/L
Perfluoroheptanoic acid2.65 ng/L
Perfluorohexanoic acid2.9 ng/L
Perfluoropentanesulfonic acid (PFPeS)2.5500000000000003 ng/L
Perfluoropentanoic acid3.5 ng/L
Perfluoroundecanoic acid (PFUnA)2.15 ng/L
PFBA0–5 ng/L
Bicarbonate20–1000 mg/L
Turbidity1–5 ug/L

What this report doesn't tell you

12 of the 27 contaminants a community water system normally reports do not appear anywhere in Mendota, City of — Mendota, Ca, CA's data. Absent is not the same as absent-from-the-water — it means nobody published a number.

Nitrate / nitriteDisinfectant residualBariumAntimonyCadmiumMercuryThalliumBerylliumCyanideUraniumTetrachloroethylene (PCE)Trichloroethylene (TCE)
Browse the mapFull source report ↗
+Full detail: PFAS testing, water source, historical monitoring, and the federal violation record

Compliance history

Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.

  • Maximum contaminant level exceededHealth-based
    3 violations on record · most recent Sep 2013
    resolved
  • Monitoring
    1 violation on record
    resolved

Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗

Source: Mendota, City of — Mendota, Ca, CA's 2023 Consumer Confidence Report — the annual drinking-water report every U.S. utility is required to publish. The numbers on this page are the utility's own. A water-quality report covers an entire service area, not a single address.
The grade at the top of this page is computed, not editorial. See exactly how we grade water systems — every deduction, every ceiling, every threshold.

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