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Updated 2026-10-15
County water report

Orange County Water Quality: 24 Cities Ranked by the Records

Orange County, California: 24 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.

Find my systemOpen on the mapPrivate wells in Orange County
Across the county's systems

Highest result for each contaminant

One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.

Perfluorooctanesulfonic acid (PFOS)Detected in 11 systems of 24 tested4.0 ng/L federal MCL (2024) · US EPAHighest29 ng/L
LithiumDetected in 24 systems10 µg/L EPA health reference level (screening, not a legal limit) · US EPAHighest67.2 µg/L
Perfluorooctanoic acid (PFOA)Detected in 7 systems of 24 tested4.0 ng/L federal MCL (2024) · US EPAHighest10.8 ng/L
Perfluorohexanesulfonic acid (PFHxS)Detected in 12 systems of 24 tested10 ng/L federal MCL (2024) · US EPAHighest10.9 ng/L
Water hardnessDetected in 5 systemsAesthetic, no federal health limit · USGSHighest15.8 gpg
Lead (90th percentile)Detected in 8 systems of 24 tested15 µg/L federal action level · US EPAHighest6 µg/L
Perfluorobutanesulfonic acid (PFBS)Detected in 4 systems of 24 tested2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPAHighest7.6 ng/L
Perfluorohexanoic acid (PFHxA)Detected in 7 systems of 24 tested400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLEHighest12.4 ng/L
3 more contaminants detectedShow
Perfluorobutanoic acid (PFBA)Detected in 8 systems of 24 testedNo federal or state limit; shown for transparencyHighest20.6 ng/L
Perfluoroheptanoic acid (PFHpA)Detected in 1 system of 24 testedNo federal or state limit; shown for transparencyHighest4.8 ng/L
Perfluoropentanoic acid (PFPeA)Detected in 10 systems of 24 testedNo federal or state limit; shown for transparencyHighest17.7 ng/L
21 PFAS tested, none detected in any systemShow

Tested in these 24 systems: CITY OF ANAHEIM, CITY OF BREA, CITY OF BUENA PARK, CITY OF FOUNTAIN VALLEY, CITY OF FULLERTON, CITY OF GARDEN GROVE, CITY OF HUNTINGTON BEACH, CITY OF LA HABRA, CITY OF LA PALMA, CITY OF NEWPORT BEACH, CITY OF ORANGE, CITY OF SANTA ANA, CITY OF SEAL BEACH, CITY OF TUSTIN, CITY OF WESTMINSTER, EL TORO WATER DISTRICT, GOLDEN STATE WC - PLACENTIA/YORBA LINDA, GOLDEN STATE WC - WEST ORANGE COUNTY, IRVINE RANCH WATER DISTRICT, LAGUNA BEACH COUNTY WD, MESA WATER DISTRICT, MOULTON NIGUEL WATER DISTRICT, SANTA MARGARITA WATER DISTRICT-ID9, YORBA LINDA WATER DISTRICT

  • 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
  • 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
  • 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
  • 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
  • 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
  • 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
  • Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
  • N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
  • N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
  • Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
  • Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
  • Perfluoro-3-methoxypropanoic acid (PFMPA)
  • Perfluoro-4-methoxybutanoic acid (PFMBA)
  • Perfluorodecanoic acid (PFDA)
  • Perfluorododecanoic acid (PFDoA)
  • Perfluoroheptanesulfonic acid (PFHpS)
  • Perfluorononanoic acid (PFNA)
  • Perfluoropentanesulfonic acid (PFPeS)
  • Perfluorotetradecanoic acid (PFTA)
  • Perfluorotridecanoic acid (PFTrDA)
  • Perfluoroundecanoic acid (PFUnA)
24 cities

Cities ranked by the records

Showing 6 of 24 cities · scores are system-level, not tap tests

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works.

PFAS in Orange County11 of 24 city reports had a PFAS sample above a 2024 EPA limit
  1. Anaheim29 ng/L
  2. Garden Grove19 ng/L
  3. Orange17 ng/L
  4. Cypress16 ng/L
  5. Santa Ana14.2 ng/L
  6. Fullerton13.3 ng/L
  7. Buena Park6.8 ng/L
  8. Placentia6.5 ng/L
4.0 ng/L federal MCL · PFOS, ng/LPFAS in California
Lead

0of 24 cities above the 15 µg/L action level

Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.

Lead in California
Hard water

5cities report hardness · hardest Garden Grove, 15.8 gpg

5 of 5 are hard on the USGS scale. An aesthetic measure with no federal health limit.

Hard water explained
Who supplies the county

Largest water systems

  1. IrvineIRVINE RANCH WATER DISTRICT · CA3010092
    450,323 served
  2. AnaheimCITY OF ANAHEIM · CA3010001
    350,254 served
  3. Santa AnaCITY OF SANTA ANA · CA3010038
    316,184 served
  4. Huntington BeachCITY OF HUNTINGTON BEACH · CA3010053
    201,000 served
  5. Garden GroveCITY OF GARDEN GROVE · CA3010062
    174,226 served
  6. Laguna NiguelMOULTON NIGUEL WATER DISTRICT · CA3010073
    168,315 served
  7. FullertonCITY OF FULLERTON · CA3010010
    140,054 served
  8. OrangeCITY OF ORANGE · CA3010027
    120,770 served
  9. CypressGOLDEN STATE WC - WEST ORANGE COUNTY · CA3010022
    114,693 served
  10. Costa MesaMESA WATER DISTRICT · CA3010004
    110,000 served
Questions

Frequently asked

How does Orange County tap water compare across cities?

PurityMap ranks 24 cities in Orange County by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Irvine's main water system: IRVINE RANCH WATER DISTRICT · PWSID CA3010092 · Purity Score 100 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many Orange County cities had a PFAS sample above a 2024 EPA limit?

11 of 24 Orange County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Anaheim (PFOS 29 ng/L), Garden Grove (PFOS 19 ng/L), Orange (PFOS 17 ng/L). That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. PFAS were detected at any level in 15.

Is there lead in Orange County tap water?

Utilities report lead as a 90th-percentile result from home taps. 8 of 24 Orange County cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

Have Orange County water systems had drinking-water violations?

1 city in Orange County has a health-based violation in the federal SDWIS record within about the last ten years. Each city report lists the contaminant, year and whether it was resolved.

Does Orange County have hard water?

Hardness is published in utility water-quality reports for 5 Orange County cities on record; the hardest is Garden Grove at 15.8 grains per gallon. Hardness affects scale and appliances; it is not a health finding.

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