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Updated 2026-10-15
County water report

San Bernardino County Water Quality: 24 Cities Ranked by the Records

San Bernardino 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 San Bernardino 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.

Perfluorooctanoic acid (PFOA)Detected in 11 systems of 24 tested4.0 ng/L federal MCL (2024) · US EPAHighest30 ng/L
LithiumDetected in 10 systems of 24 tested10 µg/L EPA health reference level (screening, not a legal limit) · US EPAHighest56.2 µg/L
Perfluorooctanesulfonic acid (PFOS)Detected in 10 systems of 24 tested4.0 ng/L federal MCL (2024) · US EPAHighest19 ng/L
Perfluorohexanesulfonic acid (PFHxS)Detected in 14 systems of 24 tested10 ng/L federal MCL (2024) · US EPAHighest36 ng/L
Water hardnessDetected in 5 systemsAesthetic, no federal health limit · USGSHighest14.2 gpg
Perfluorononanoic acid (PFNA)Detected in 1 system of 24 tested10 ng/L federal MCL (2024) · US EPAHighest4.6 ng/L
Lead (90th percentile)Detected in 8 systems of 24 tested15 µg/L federal action level · US EPAHighest2.9 µg/L
Perfluorobutanesulfonic acid (PFBS)Detected in 8 systems of 24 tested2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPAHighest13 ng/L
7 more contaminants detectedShow
Perfluorohexanoic acid (PFHxA)Detected in 14 systems of 24 tested400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLEHighest17 ng/L
1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)Detected in 1 system of 24 testedNo federal or state limit; shown for transparencyHighest50.3 ng/L
Perfluorobutanoic acid (PFBA)Detected in 4 systems of 24 testedNo federal or state limit; shown for transparencyHighest11 ng/L
Perfluorodecanoic acid (PFDA)Detected in 1 system of 24 testedNo federal or state limit; shown for transparencyHighest3.9 ng/L
Perfluoroheptanoic acid (PFHpA)Detected in 6 systems of 24 testedNo federal or state limit; shown for transparencyHighest8.2 ng/L
Perfluoropentanesulfonic acid (PFPeS)Detected in 2 systems of 24 testedNo federal or state limit; shown for transparencyHighest7.4 ng/L
Perfluoropentanoic acid (PFPeA)Detected in 14 systems of 24 testedNo federal or state limit; shown for transparencyHighest18 ng/L
17 PFAS tested, none detected in any systemShow

Tested in these 24 systems: ADELANTO, CITY OF, BIG BEAR CITY CSD, CHINO HILLS, CITY OF, CHINO, CITY OF, COLTON, CITY OF, CUCAMONGA VALLEY WATER DISTRICT, EAST VALLEY WATER DISTRICT, GOLDEN STATE WATER CO - BARSTOW, HESPERIA WD, HI DESERT WD, LAKE ARROWHEAD CSD, LIBERTY UTILITIES (AV RANCHOS) CORP., LOMA LINDA, CITY OF, MONTE VISTA WD, MUSCOY MWC NO. 1, ONTARIO MUNICIPAL UTILITIES COMPANY, REDLANDS CITY MUD-WATER DIV, RIALTO, CITY OF, RIVERSIDE HIGHLAND WATER COMPANY, SAN BERNARDINO CITY, SAN GABRIEL VALLEY WC - FONTANA, UPLAND, CITY OF, VICTORVILLE WATER DISTRICT, YUCAIPA VALLEY 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)
  • 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)
  • Perfluorododecanoic acid (PFDoA)
  • Perfluoroheptanesulfonic acid (PFHpS)
  • 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 San Bernardino County13 of 24 city reports had a PFAS sample above a 2024 EPA limit
  1. Grand Terrace19 ng/L
  2. Colton18 ng/L
  3. Highland12 ng/L
  4. Hesperia11.1 ng/L
  5. Big Bear City9.9 ng/L
  6. Lake Arrowhead7.2 ng/L
  7. Redlands5.8 ng/L
  8. Montclair5.6 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 San Bernardino, 14.2 gpg

4 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. FontanaSAN GABRIEL VALLEY WC - FONTANA · CA3610041
    228,270 served
  2. San BernardinoSAN BERNARDINO CITY · CA3610039
    214,665 served
  3. Rancho CucamongaCUCAMONGA VALLEY WATER DISTRICT · CA3610018
    213,375 served
  4. OntarioONTARIO MUNICIPAL UTILITIES COMPANY · CA3610034
    185,010 served
  5. VictorvilleVICTORVILLE WATER DISTRICT · CA3610052
    140,721 served
  6. HighlandEAST VALLEY WATER DISTRICT · CA3610064
    108,600 served
  7. HesperiaHESPERIA WD · CA3610024
    101,836 served
  8. ChinoCHINO, CITY OF · CA3610012
    90,187 served
  9. UplandUPLAND, CITY OF · CA3610050
    78,376 served
  10. RedlandsREDLANDS CITY MUD-WATER DIV · CA3610037
    78,025 served
Questions

Frequently asked

How does San Bernardino County tap water compare across cities?

PurityMap ranks 24 cities in San Bernardino 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 Fontana's main water system: SAN GABRIEL VALLEY WC - FONTANA · PWSID CA3610041 · 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 San Bernardino County cities had a PFAS sample above a 2024 EPA limit?

13 of 24 San Bernardino County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Ontario (PFOA 30 ng/L), Grand Terrace (PFOS 19 ng/L), Colton (PFOS 18 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 16.

Is there lead in San Bernardino County tap water?

Utilities report lead as a 90th-percentile result from home taps. 8 of 24 San Bernardino 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 San Bernardino County water systems had drinking-water violations?

1 city in San Bernardino 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 San Bernardino County have hard water?

Hardness is published in utility water-quality reports for 5 San Bernardino County cities on record; the hardest is San Bernardino at 14.2 grains per gallon. Hardness affects scale and appliances; it is not a health finding.

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