Drinking water quality · 2026

· Verified

What's in City of Fairfield, CA tap water

78 contaminants were measured in the City of Fairfield, CA water system's 2026 annual report. Each is shown below against its federal limit 4 sit at or above that limit.

Reporting year
2026
Contaminants measured
78
Over federal limit
4
Approaching the limit
0
Worst contaminant
Color
18.4× the limit
Service area
CA
state-level CCR
Source
Utility CCR

Where your water comes from · EPA SDWIS

City of Fairfield, CA's drinking water comes from surface water, drawn from 3 sources.

Source

3surface water
  • NBR WTP - NORTH BAY AQUEDUCT - RAW
  • NBR WTP - PUTAH SOUTH CANAL - RAW
  • WATERMAN WTP - PUTAH SOUTH CANAL - RAW

Treatment

2treatment plants
  • NORTH BAY REGIONAL WTP - TREATED
  • WATERMAN WTP-FINISHED WATER

Distribution

0storage units

Historical readings · EPA Six-Year Review (2012–2019)

2 contaminants historically over EPA limits in City of Fairfield, CA

About this data

Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.

ContaminantWorst detectionEPA limitYears (2012–2019)
CHROMIUM
worst: 2013
0.152 mg/L
1.5×
15.2× the national p90
0.1 mg/L
'13'16'18'19
GROSS BETA
worst: 2017
4.1 mrem/yr
1.0×
4 mrem/yr
'17
TTHM
worst: 2019
0.077 mg/L
96%
0.08 mg/L
'12'13'14'15'16'17'18'19
ARSENIC
worst: 2016
0.00468 mg/L
within
below national p90
0.01 mg/L
'12'13'14'15'16'18'19
CADMIUM
worst: 2019
0.0023 mg/L
within
near national p90
0.005 mg/L
'12'13'19
HAA5
worst: 2019
0.024 mg/L
within
0.06 mg/L
'19
FLUORIDE
worst: 2015
1.01 mg/L
within
4 mg/L
'12'13'14'15'16'17'18'19
BROMATE
worst: 2017
0.002 mg/L
within
0.01 mg/L
'16'17
NITRATE
worst: 2012
1.53 mg/L
within
10 mg/L
'12'13'14'17
NITRATE NITRITE
worst: 2017
0.58 mg/L
within
10 mg/L
'17
URANIUM
worst: 2018
0.00283 ug/L
within
below national p90
30 ug/L
'18
COPPER
worst: 2014
0.107 mg/L
below national p90
'14'16'19
LEAD
worst: 2014
0.0064 mg/L
'14'16'18'19
DBAA
worst: 2019
0.0015 mg/L
'19
DCAA
worst: 2019
0.012 mg/L
'19
MCAA
worst: 2019
0.0022 mg/L
'19
TCAA
worst: 2019
0.0093 mg/L
'19
BROMODICHLOROMETHANE
worst: 2012
0.0049 mg/L
'12'13'14'15'16'17'18'19
CHLOROFORM
worst: 2012
0.0063 mg/L
'12'13'14'15'16'17'18'19
DIBROMOCHLOROMETHANE
worst: 2012
0.0032 mg/L
'12'13'14'15'16'17'18'19
PWSID CA4810003 · Source: EPA Six-Year Review 4 (2012–2019). Values are the highest detection in each calendar year; non-detect years are omitted. Year tags above show every year with a detection.

Physical & aggregate

ContaminantMeasuredStatus
ColorA measure of visible tint in the water.276.3333333333333 UNITSAverageSource waterAt or above the limit
TurbidityA measure of cloudiness from suspended particles in the water.17.313333333333336 NTUAverageSource waterAt or above the limit
OdorA measure of detectable smell in the water.2.3333333333333335 TONAverageSource waterWithin the limit
Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts.325 MG/LAverageEntry pointWithin the limit
Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content.518.1 UMHO/CMAverageEntry pointWithin the limit
AlkalinityA measure of the water's capacity to neutralize acids.94 MG/LAverageEntry pointDetected — no federal limit
HardnessA measure of dissolved calcium and magnesium minerals.155 MG/LAverageEntry pointDetected — no federal limit
pHA measure of how acidic or basic the water is.8.2125 PHAverageEntry pointDetected — no federal limit
TemperatureThe measured temperature of the water sample.11.700000000000001 CAverageSource waterDetected — no federal limit

Metals

ContaminantMeasuredStatus
IronA naturally occurring metal common in groundwater.1096.6666666666667 UG/LAverageSource waterAt or above the limit
AluminumA common element sometimes used as a treatment coagulant.1006.6666666666666 UG/LAverageSource waterAt or above the limit
ManganeseA naturally occurring metal from soil and rock.24 UG/LAverageSource waterWithin the limit
BariumA metal from erosion of natural deposits and industrial discharge.59.333333333333336 UG/LAverageSource waterWithin the limit
NickelA metal from natural deposits and industrial discharge.3.6333333333333333 UG/LAverageSource waterWithin the limit
Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium.0.09666666666666668 UG/LAverageSource waterWithin the limit
ZincA naturally occurring metal that can also enter water from corroding pipes.5.333333333333333 UG/LAverageSource waterWithin the limit
AntimonyNot detected UG/LHighest single sampleSource waterNone detected
BerylliumNot detected UG/LHighest single sampleSource waterNone detected
MercuryA toxic metal from erosion of natural deposits and industrial runoff.Not detected UG/LHighest single sampleSource waterNone detected
SeleniumA trace element from natural deposits and industrial discharge.Not detected UG/LHighest single sampleEntry pointNone detected
ThalliumNot detected UG/LHighest single sampleSource waterNone detected
CalciumA naturally occurring mineral that contributes to water hardness.15.25 MG/LAverageEntry pointDetected — no federal limit
MagnesiumA naturally occurring mineral that contributes to water hardness.21 MG/LAverageEntry pointDetected — no federal limit
PotassiumA naturally occurring mineral from rock and soil.3.8000000000000003 MG/LAverageSource waterDetected — no federal limit
SodiumA naturally occurring salt component.44 MG/LAverageEntry pointDetected — no federal limit
Vanadium4.8999999999999995 UG/LAverageSource waterDetected — no federal limit

Inorganic chemicals

ContaminantMeasuredStatus
SulfateA naturally occurring mineral from rock and soil.97.5 MG/LAverageEntry pointWithin the limit
ChlorideA naturally occurring salt compound.21.333333333333332 MG/LAverageSource waterWithin the limit
CyanideNot detected UG/LHighest single sampleSource waterNone detected
NitriteA compound from fertilizer runoff, sewage, and erosion of natural deposits.Not detected MG/LHighest single sampleSource waterNone detected
Ammonia0.0585 MG/LAverageEntry pointDetected — no federal limit

Other

ContaminantMeasuredStatus
Carbon TetrachlorideNot detected UG/LHighest single sampleEntry pointNone detected
ChlorobenzeneNot detected UG/LHighest single sampleEntry pointNone detected
Cis Dichloroethylene 12Not detected UG/LHighest single sampleSource waterNone detected
Dichloroethane 12Not detected UG/LHighest single sampleEntry pointNone detected
Dichloroethylene 11Not detected UG/LHighest single sampleEntry pointNone detected
Dichloropropane 12Not detected UG/LHighest single sampleSource waterNone detected
MbaaNot detected UG/LHighest single sampleDistributionNone detected
O DichlorobenzeneNot detected UG/LHighest single sampleSource waterNone detected
P DichlorobenzeneNot detected UG/LHighest single sampleEntry pointNone detected
PceNot detected UG/LHighest single sampleEntry pointNone detected
StyreneNot detected UG/LHighest single sampleSource waterNone detected
TceNot detected UG/LHighest single sampleEntry pointNone detected
Trans Dichloroethylene 12Not detected UG/LHighest single sampleSource waterNone detected
Trichlorobenzene 124Not detected UG/LHighest single sampleEntry pointNone detected
Trichloroethane 111Not detected UG/LHighest single sampleEntry pointNone detected
Trichloroethane 112Not detected UG/LHighest single sampleEntry pointNone detected
Vinyl ChlorideNot detected UG/LHighest single sampleEntry pointNone detected

PFAS ("forever chemicals")

ContaminantMeasuredStatus
Hexafluoropropylene oxide dimer acidHFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound.Not detected NG/LHighest single sampleSource waterNone detected
Perfluorononanoic acidPerfluorononanoic acid, a PFAS 'forever chemical.'Not detected NG/LHighest single sampleSource waterNone detected

VOCs & pesticides

ContaminantMeasuredStatus
BenzeneNot detected UG/LHighest single sampleSource waterNone detected
ChloroethaneA volatile organic compound used in some industrial processes.Not detected UG/LHighest single sampleSource waterNone detected
ChloromethaneNot detected UG/LHighest single sampleSource waterNone detected
DichlorodifluoromethaneNot detected UG/LHighest single sampleSource waterNone detected
DichloromethaneNot detected UG/LHighest single sampleEntry pointNone detected
EthylbenzeneNot detected UG/LHighest single sampleSource waterNone detected
TolueneNot detected UG/LHighest single sampleSource waterNone detected
XylenesA group of industrial solvents found in gasoline and paint.Not detected UG/LHighest single sampleSource waterNone detected

Disinfection byproducts

ContaminantMeasuredStatus
BromoformA trihalomethane disinfection byproduct.0.93875 UG/LAverageDistributionDetected — no federal limit
Source: City of Fairfield, CA's 2026 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.

People also ask about City of Fairfield, CA's water

+Is City of Fairfield, CA tap water safe to drink in 2026?

The 2026 Consumer Confidence Report for the City of Fairfield, CA water utility lists 4 contaminants at or above the federal limit: Color, Iron, Turbidity, and Aluminum. Whether that means the water is "unsafe" depends on which contaminant, how long the exposure, and individual health factors. The table on this page shows the measured value, the federal threshold, and the regulated statistic used for compliance.

+What contaminants are in City of Fairfield, CA tap water?

78 contaminants were measured in City of Fairfield, CA's 2026 Consumer Confidence Report, spanning other, metals, and physical & aggregate. 53 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.

+Which contaminants exceed federal limits in City of Fairfield, CA tap water?

4 contaminants in City of Fairfield, CA's 2026 report sit at or above the federal limit: Color (18.4× the limit); Iron (3.7× the limit); Turbidity (3.5× the limit); Aluminum (1.0× the limit). The EPA enforces these limits against the regulated reporting statistic — typically a running annual average or 90th percentile — not a one-off sample spike.

+What is the worst contaminant in City of Fairfield, CA tap water?

The contaminant with the highest measured value relative to its federal limit in the 2026 report is Color, at 18.4× the federal threshold. It belongs to the physical & aggregate family of contaminants.

+Where does the data on this page come from?

Every value is transcribed from City of Fairfield, CA's 2026 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.

+How often is City of Fairfield, CA's water quality data updated?

Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2026 report; a new report will replace it once the utility publishes its next annual update.

More water systems in CA