Yolo County Water Quality: 3 Cities Ranked by the Records

Name: Yolo County Water Quality Data (2026)
Creator: PurityMap
License: https://creativecommons.org/licenses/by/4.0/

Yolo County, California: 3 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.

Find my system Open on the map Private wells in Yolo 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 2 systems of 3 tested10 µg/L EPA health reference level (screening, not a legal limit) · US EPAHighest46.1 µg/L

CITY OF WOODLAND46.1 µg/LSample date: 2024-04-11 to 2025-03-10
CITY OF DAVIS37.3 µg/LSample date: 2024-02-14 to 2024-11-07
CITY OF WEST SACRAMENTONot detected · below 9.0 µg/L lab reporting limitSample date: 2024-05-16 to 2025-07-02

30 substances tested, none detected in any systemShow

Tested in these 3 systems: CITY OF DAVIS, CITY OF WEST SACRAMENTO, CITY OF WOODLAND

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)
Lead (90th percentile)
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)
Perfluorobutanesulfonic acid (PFBS)
Perfluorobutanoic acid (PFBA)
Perfluorodecanoic acid (PFDA)
Perfluorododecanoic acid (PFDoA)
Perfluoroheptanesulfonic acid (PFHpS)
Perfluoroheptanoic acid (PFHpA)
Perfluorohexanesulfonic acid (PFHxS)
Perfluorohexanoic acid (PFHxA)
Perfluorononanoic acid (PFNA)
Perfluorooctanesulfonic acid (PFOS)
Perfluorooctanoic acid (PFOA)
Perfluoropentanesulfonic acid (PFPeS)
Perfluoropentanoic acid (PFPeA)
Perfluorotetradecanoic acid (PFTA)
Perfluorotridecanoic acid (PFTrDA)
Perfluoroundecanoic acid (PFUnA)

3 cities

Cities ranked by the records

1
DavisCITY OF DAVIS
No PFAS detected
Open city report →
2
WoodlandCITY OF WOODLAND
No PFAS detected
Open city report →
3
West SacramentoCITY OF WEST SACRAMENTO
No PFAS detected
Open city report →

Showing 3 of 3 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 Yolo CountyPFAS detected in 0 of 3 cities; none had a sample above a 2024 EPA limit

4.0 ng/L federal MCL · PFOS, ng/LPFAS in California

Lead

0of 3 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

DavisCITY OF DAVIS · CA5710001
67,826 served
WoodlandCITY OF WOODLAND · CA5710006
61,462 served
West SacramentoCITY OF WEST SACRAMENTO · CA5710003
55,991 served

Questions

Frequently asked

How does Yolo County tap water compare across cities?

PurityMap ranks 3 cities in Yolo 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 Davis's main water system: CITY OF DAVIS · PWSID CA5710001 · 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 Yolo County cities had a PFAS sample above a 2024 EPA limit?

None of the 3 Yolo County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing. PFAS were detected below the limit in 0.

Is there lead in Yolo County tap water?

Utilities report lead as a 90th-percentile result from home taps. 0 of 3 Yolo 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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