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Updated 2026-10-15
County water report

Solano County Water Quality: 7 Cities Ranked by the Records

Solano County, California: 7 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 Solano 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.

LithiumDetected in 3 systems of 7 tested10 µg/L EPA health reference level (screening, not a legal limit) · US EPAHighest45 µg/L
Perfluorooctanesulfonic acid (PFOS)Detected in 1 system of 7 tested4.0 ng/L federal MCL (2024) · US EPAHighest10 ng/L
  • CITY OF VACAVILLE10 ng/LSample date: 2023-11-15 to 2025-09-11
  • CITY OF BENICIANot detected · below 4.0 ng/L lab reporting limitSample date: 2025-01-07 to 2025-10-07
  • CITY OF DIXONNot detected · below 4.0 ng/L lab reporting limitSample date: 2023-04-03 to 2025-05-14
  • CITY OF FAIRFIELDNot detected · below 4.0 ng/L lab reporting limitSample date: 2024-01-23 to 2024-10-01
  • CITY OF RIO VISTANot detected · below 4.0 ng/L lab reporting limitSample date: 2024-01-09 to 2024-07-09
  • CITY OF VALLEJONot detected · below 4.0 ng/L lab reporting limitSample date: 2024-02-05 to 2024-12-16
  • SUISUN-SOLANO WATER AUTHORITYNot detected · below 4.0 ng/L lab reporting limitSample date: 2024-01-25 to 2024-10-08
Perfluorooctanoic acid (PFOA)Detected in 1 system of 7 tested4.0 ng/L federal MCL (2024) · US EPAHighest5.1 ng/L
  • CITY OF VACAVILLE5.1 ng/LSample date: 2023-11-15 to 2025-09-11
  • CITY OF BENICIANot detected · below 4.0 ng/L lab reporting limitSample date: 2025-01-07 to 2025-10-07
  • CITY OF DIXONNot detected · below 4.0 ng/L lab reporting limitSample date: 2023-04-03 to 2025-05-14
  • CITY OF FAIRFIELDNot detected · below 4.0 ng/L lab reporting limitSample date: 2024-01-23 to 2024-10-01
  • CITY OF RIO VISTANot detected · below 4.0 ng/L lab reporting limitSample date: 2024-01-09 to 2024-07-09
  • CITY OF VALLEJONot detected · below 4.0 ng/L lab reporting limitSample date: 2024-02-05 to 2024-12-16
  • SUISUN-SOLANO WATER AUTHORITYNot detected · below 4.0 ng/L lab reporting limitSample date: 2024-01-25 to 2024-10-08
Perfluorohexanesulfonic acid (PFHxS)Detected in 1 system of 7 tested10 ng/L federal MCL (2024) · US EPAHighest9.2 ng/L
  • CITY OF VACAVILLE9.2 ng/LSample date: 2023-11-15 to 2025-09-11
  • CITY OF BENICIANot detected · below 3.0 ng/L lab reporting limitSample date: 2025-01-07 to 2025-10-07
  • CITY OF DIXONNot detected · below 3.0 ng/L lab reporting limitSample date: 2023-04-03 to 2025-05-14
  • CITY OF FAIRFIELDNot detected · below 3.0 ng/L lab reporting limitSample date: 2024-01-23 to 2024-10-01
  • CITY OF RIO VISTANot detected · below 3.0 ng/L lab reporting limitSample date: 2024-01-09 to 2024-07-09
  • CITY OF VALLEJONot detected · below 3.0 ng/L lab reporting limitSample date: 2024-02-05 to 2024-12-16
  • SUISUN-SOLANO WATER AUTHORITYNot detected · below 3.0 ng/L lab reporting limitSample date: 2024-01-25 to 2024-10-08
Lead (90th percentile)Detected in 1 system of 7 tested15 µg/L federal action level · US EPAHighest2.3 µg/L
Perfluorobutanesulfonic acid (PFBS)Detected in 2 systems of 7 tested2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPAHighest3.7 ng/L
  • CITY OF VACAVILLE3.7 ng/LSample date: 2023-11-15 to 2025-09-11
  • CITY OF BENICIA3.3 ng/LSample date: 2025-01-07 to 2025-10-07
  • CITY OF DIXONNot detected · below 3.0 ng/L lab reporting limitSample date: 2023-04-03 to 2025-05-14
  • CITY OF FAIRFIELDNot detected · below 3.0 ng/L lab reporting limitSample date: 2024-01-23 to 2024-10-01
  • CITY OF RIO VISTANot detected · below 3.0 ng/L lab reporting limitSample date: 2024-01-09 to 2024-07-09
  • CITY OF VALLEJONot detected · below 3.0 ng/L lab reporting limitSample date: 2024-02-05 to 2024-12-16
  • SUISUN-SOLANO WATER AUTHORITYNot detected · below 3.0 ng/L lab reporting limitSample date: 2024-01-25 to 2024-10-08
Perfluorohexanoic acid (PFHxA)Detected in 1 system of 7 tested400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLEHighest3.4 ng/L
  • CITY OF BENICIA3.4 ng/LSample date: 2025-01-07 to 2025-10-07
  • CITY OF DIXONNot detected · below 3.0 ng/L lab reporting limitSample date: 2023-04-03 to 2025-05-14
  • CITY OF FAIRFIELDNot detected · below 3.0 ng/L lab reporting limitSample date: 2024-01-23 to 2024-10-01
  • CITY OF RIO VISTANot detected · below 3.0 ng/L lab reporting limitSample date: 2024-01-09 to 2024-07-09
  • CITY OF VACAVILLENot detected · below 3.0 ng/L lab reporting limitSample date: 2023-11-15 to 2025-09-11
  • CITY OF VALLEJONot detected · below 3.0 ng/L lab reporting limitSample date: 2024-02-05 to 2024-12-16
  • SUISUN-SOLANO WATER AUTHORITYNot detected · below 3.0 ng/L lab reporting limitSample date: 2024-01-25 to 2024-10-08
Perfluorobutanoic acid (PFBA)Detected in 1 system of 7 testedNo federal or state limit; shown for transparencyHighest6.3 ng/L
  • CITY OF BENICIA6.3 ng/LSample date: 2025-01-07 to 2025-10-07
  • CITY OF DIXONNot detected · below 5.0 ng/L lab reporting limitSample date: 2023-04-03 to 2025-05-14
  • CITY OF FAIRFIELDNot detected · below 5.0 ng/L lab reporting limitSample date: 2024-01-23 to 2024-10-01
  • CITY OF RIO VISTANot detected · below 5.0 ng/L lab reporting limitSample date: 2024-01-09 to 2024-07-09
  • CITY OF VACAVILLENot detected · below 5.0 ng/L lab reporting limitSample date: 2023-11-15 to 2025-09-11
  • CITY OF VALLEJONot detected · below 5.0 ng/L lab reporting limitSample date: 2024-02-05 to 2024-12-16
  • SUISUN-SOLANO WATER AUTHORITYNot detected · below 5.0 ng/L lab reporting limitSample date: 2024-01-25 to 2024-10-08
23 PFAS tested, none detected in any systemShow

Tested in these 7 systems: CITY OF BENICIA, CITY OF DIXON, CITY OF FAIRFIELD, CITY OF RIO VISTA, CITY OF VACAVILLE, CITY OF VALLEJO, SUISUN-SOLANO WATER AUTHORITY

  • 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)
  • Perfluoroheptanoic acid (PFHpA)
  • Perfluorononanoic acid (PFNA)
  • Perfluoropentanesulfonic acid (PFPeS)
  • Perfluoropentanoic acid (PFPeA)
  • Perfluorotetradecanoic acid (PFTA)
  • Perfluorotridecanoic acid (PFTrDA)
  • Perfluoroundecanoic acid (PFUnA)
7 cities

Cities ranked by the records

Showing 6 of 7 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 Solano County1 of 7 city reports had a PFAS sample above a 2024 EPA limit
  1. Vacaville10 ng/L
4.0 ng/L federal MCL · PFOS, ng/LPFAS in California
Lead

0of 7 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
Who supplies the county

Largest water systems

  1. VallejoCITY OF VALLEJO · CA4810007
    121,420 served
  2. FairfieldCITY OF FAIRFIELD · CA4810003
    120,720 served
  3. VacavilleCITY OF VACAVILLE · CA4810008
    99,650 served
  4. Suisun CitySUISUN-SOLANO WATER AUTHORITY · CA4810005
    29,105 served
  5. BeniciaCITY OF BENICIA · CA4810001
    27,131 served
  6. DixonCITY OF DIXON · CA4810009
    12,540 served
  7. Rio VistaCITY OF RIO VISTA · CA4810004
    11,206 served
Questions

Frequently asked

How does Solano County tap water compare across cities?

PurityMap ranks 7 cities in Solano 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 Vallejo's main water system: CITY OF VALLEJO · PWSID CA4810007 · 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 Solano County cities had a PFAS sample above a 2024 EPA limit?

1 of 7 Solano County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Vacaville (PFOS 10 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 2.

Is there lead in Solano County tap water?

Utilities report lead as a 90th-percentile result from home taps. 1 of 7 Solano 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.

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