Drinking water quality · 2025
· Verified
What's in City of Fairfield, CA tap water
102 contaminants were measured in the City of Fairfield, CA water system's 2025 annual report. Each is shown below against its federal limit — 1 sit at or above that limit.
- Reporting year
- 2025
- Contaminants measured
- 102
- Over federal limit
- 1
- Approaching the limit
- 1
- Worst contaminant
- Color
- Service area
- CA
5.2× the limit
state-level CCR
At or above the federal limit
Approaching the limit (≥ 80%)
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
Source: EPA SDWIS facilities inventory. Methodology.
Historical readings · EPA Six-Year Review (2012–2019)
2 contaminants historically over EPA limits in City of Fairfield, CA
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.
| Contaminant | Worst detection | EPA limit | Years (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
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ColorA measure of visible tint in the water. | 78.08333333333333 UNITSAverageSource water | 15 UNITSMCL | At or above the limit |
| TurbidityA measure of cloudiness from suspended particles in the water. | 3.9075 NTUAverageSource water | 5 NTUMCL | Within the limit |
| OdorA measure of detectable smell in the water. | 2.3333333333333335 TONAverageSource water | 3 TONMCL | Within the limit |
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 410 UMHO/CMAverageEntry point | 1600 UMHO/CMMCL | Within the limit |
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 231.25 MG/LAverageEntry point | 1000 MG/LMCL | Within the limit |
| AlkalinityA measure of the water's capacity to neutralize acids. | 109.76875 MG/LAverageEntry point | None set | Detected — no federal limit |
| HardnessA measure of dissolved calcium and magnesium minerals. | 171.25 MG/LAverageEntry point | None set | Detected — no federal limit |
| pHA measure of how acidic or basic the water is. | 8.277083333333334 PHAverageSource water | None set | Detected — no federal limit |
| TemperatureThe measured temperature of the water sample. | 15.5875 CAverageEntry point | None set | Detected — no federal limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| IronA naturally occurring metal common in groundwater. | 242.91666666666666 UG/LAverageSource water | 300 UG/LMCL | Approaching the limit |
| ManganeseA naturally occurring metal from soil and rock. | 20.933333333333334 UG/LAverageSource water | 50 UG/LMCL | Within the limit |
| AluminumA common element sometimes used as a treatment coagulant. | 166.16666666666666 UG/LAverageSource water | 1000 UG/LMCL | Within the limit |
| BariumA metal from erosion of natural deposits and industrial discharge. | 52.083333333333336 UG/LAverageSource water | 1000 UG/LMCL | Within the limit |
| NickelA metal from natural deposits and industrial discharge. | 2.9166666666666665 UG/LAverageSource water | 100 UG/LMCL | Within the limit |
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 0.24350000000000002 UG/LAverageSource water | 10 UG/LMCL | Within the limit |
| ZincA naturally occurring metal that can also enter water from corroding pipes. | 3.0749999999999997 UG/LAverageSource water | 5000 UG/LMCL | Within the limit |
| Antimony | Not detected UG/LHighest single sampleEntry point | 6 UG/LMCL | None detected |
| Beryllium | Not detected UG/LHighest single sampleEntry point | 4 UG/LMCL | None detected |
| MercuryA toxic metal from erosion of natural deposits and industrial runoff. | Not detected UG/LHighest single sampleEntry point | 2 UG/LMCL | None detected |
| SeleniumA trace element from natural deposits and industrial discharge. | Not detected UG/LHighest single sampleEntry point | 50 UG/LMCL | None detected |
| Thallium | Not detected UG/LHighest single sampleSource water | 2 UG/LMCL | None detected |
| CalciumA naturally occurring mineral that contributes to water hardness. | 15.814814814814815 MG/LAverageSource water | None set | Detected — no federal limit |
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 27.375 MG/LAverageEntry point | None set | Detected — no federal limit |
| PotassiumA naturally occurring mineral from rock and soil. | 1.9416666666666667 MG/LAverageSource water | None set | Detected — no federal limit |
| SodiumA naturally occurring salt component. | 24.375 MG/LAverageEntry point | None set | Detected — no federal limit |
| Vanadium | 3.5749999999999997 UG/LAverageSource water | None set | Detected — no federal limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| SulfateA naturally occurring mineral from rock and soil. | 46.125 MG/LAverageEntry point | 500 MG/LMCL | Within the limit |
| ChlorideA naturally occurring salt compound. | 15.4 MG/LAverageSource water | 500 MG/LMCL | Within the limit |
| Cyanide | 2.9 UG/LAverageEntry point | 150 UG/LMCL | Within the limit |
| NitriteA compound from fertilizer runoff, sewage, and erosion of natural deposits. | Not detected MG/LHighest single sampleSource water | 1 MG/LMCL | None detected |
| Ammonia | 0.0235 MG/LAverageEntry point | None set | Detected — no federal limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | Not detected UG/LHighest single sampleEntry point | 6 UG/LMCL | None detected |
| BromoformA trihalomethane disinfection byproduct. | 0.2703125 UG/LAverageDistribution | None set | Detected — no federal limit |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Carbofuran | Not detected UG/LHighest single sampleSource water | 18 UG/LMCL | None detected |
| Carbon Tetrachloride | Not detected UG/LHighest single sampleEntry point | 0.5 UG/LMCL | None detected |
| Chlordane | Not detected UG/LHighest single sampleSource water | 0.1 UG/LMCL | None detected |
| Chlorobenzene | Not detected UG/LHighest single sampleSource water | 70 UG/LMCL | None detected |
| Cis Dichloroethylene 12 | Not detected UG/LHighest single sampleSource water | 6 UG/LMCL | None detected |
| Deha | Not detected UG/LHighest single sampleSource water | 400 UG/LMCL | None detected |
| Dehp | Not detected UG/LHighest single sampleSource water | 4 UG/LMCL | None detected |
| Dichloroethane 12 | Not detected UG/LHighest single sampleEntry point | 0.5 UG/LMCL | None detected |
| Dichloroethylene 11 | Not detected UG/LHighest single sampleSource water | 6 UG/LMCL | None detected |
| Dichloropropane 12 | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Dinoseb | Not detected UG/LHighest single sampleSource water | 7 UG/LMCL | None detected |
| Diquat | Not detected UG/LHighest single sampleSource water | 20 UG/LMCL | None detected |
| Edb | Not detected UG/LHighest single sampleSource water | 0.05 UG/LMCL | None detected |
| Endothall | Not detected UG/LHighest single sampleSource water | 100 UG/LMCL | None detected |
| Endrin | Not detected UG/LHighest single sampleSource water | 2 UG/LMCL | None detected |
| Glyphosate | Not detected UG/LHighest single sampleSource water | 700 UG/LMCL | None detected |
| Heptachlor | Not detected UG/LHighest single sampleSource water | 0.01 UG/LMCL | None detected |
| Heptachlor Epoxide | Not detected UG/LHighest single sampleSource water | 0.01 UG/LMCL | None detected |
| Hexachlorobenzene | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| Hexachlorocyclopentadiene | Not detected UG/LHighest single sampleSource water | 50 UG/LMCL | None detected |
| Mbaa | Not detected UG/LHighest single sampleDistribution | None set | None detected |
| Methoxychlor | Not detected UG/LHighest single sampleSource water | 30 UG/LMCL | None detected |
| O Dichlorobenzene | Not detected UG/LHighest single sampleEntry point | 600 UG/LMCL | None detected |
| Oxamyl | Not detected UG/LHighest single sampleSource water | 50 UG/LMCL | None detected |
| P Dichlorobenzene | Not detected UG/LHighest single sampleEntry point | 5 UG/LMCL | None detected |
| Pcb Total | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
| Pce | Not detected UG/LHighest single sampleEntry point | 5 UG/LMCL | None detected |
| Pentachlorophenol | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| Picloram | Not detected UG/LHighest single sampleSource water | 500 UG/LMCL | None detected |
| Styrene | Not detected UG/LHighest single sampleEntry point | 100 UG/LMCL | None detected |
| Tce | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Toxaphene | Not detected UG/LHighest single sampleSource water | 3 UG/LMCL | None detected |
| Trans Dichloroethylene 12 | Not detected UG/LHighest single sampleSource water | 10 UG/LMCL | None detected |
| Trichlorobenzene 124 | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Trichloroethane 111 | Not detected UG/LHighest single sampleSource water | 200 UG/LMCL | None detected |
| Trichloroethane 112 | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Twofourd | Not detected UG/LHighest single sampleSource water | 70 UG/LMCL | None detected |
| Vinyl Chloride | Not detected UG/LHighest single sampleEntry point | 0.5 UG/LMCL | None detected |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| 1,2,3-TCP | Not detected UG/LHighest single sampleSource water | 0.005 UG/LMCL | None detected |
| AtrazineA widely used agricultural herbicide that reaches water through runoff. | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| Benzene | Not detected UG/LHighest single sampleEntry point | 1 UG/LMCL | None detected |
| Benzo(a)pyrene | Not detected UG/LHighest single sampleSource water | 0.2 UG/LMCL | None detected |
| ChloroethaneA volatile organic compound used in some industrial processes. | Not detected UG/LHighest single sampleSource water | None set | None detected |
| Chloromethane | Not detected UG/LHighest single sampleSource water | None set | None detected |
| Dalapon | Not detected UG/LHighest single sampleSource water | 200 UG/LMCL | None detected |
| Dichlorodifluoromethane | Not detected UG/LHighest single sampleSource water | None set | None detected |
| Dichloromethane | Not detected UG/LHighest single sampleEntry point | 5 UG/LMCL | None detected |
| Ethylbenzene | Not detected UG/LHighest single sampleEntry point | 300 UG/LMCL | None detected |
| Simazine | Not detected UG/LHighest single sampleSource water | 4 UG/LMCL | None detected |
| Toluene | Not detected UG/LHighest single sampleSource water | 150 UG/LMCL | None detected |
| XylenesA group of industrial solvents found in gasoline and paint. | Not detected UG/LHighest single sampleSource water | 1750 UG/LMCL | None detected |
Source: City of Fairfield, CA's 2025 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 2025?
The 2025 Consumer Confidence Report for the City of Fairfield, CA water utility lists 1 contaminant at or above the federal limit: Color. 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?
102 contaminants were measured in City of Fairfield, CA's 2025 Consumer Confidence Report, spanning other, metals, and vocs & pesticides. 79 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?
One contaminant in City of Fairfield, CA's 2025 report sits at or above the federal limit: Color (5.2× 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 2025 report is Color, at 5.2× the federal threshold. It belongs to the physical & aggregate family of contaminants.
+Are any contaminants in City of Fairfield, CA tap water approaching the federal limit?
One contaminant is between 80% and 100% of the federal limit in this report: Iron. Approaching means measured but not in violation — a margin that can close quickly if conditions change.
+Where does the data on this page come from?
Every value is transcribed from City of Fairfield, CA's 2025 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 2025 report; a new report will replace it once the utility publishes its next annual update.
More water systems in CA
City of FairfieldCity of FairfieldFairfieldCity of VacavilleCity of VacavilleCity of VacavilleVacavilleGolden State Water CompanyGolden State Water Company - Los OsosGolden State Water Company - Los OsosGolden State Water Company - Los OsosCity of MartinezCity of MartinezCity of MartinezCity of MartinezCity of VallejoCity of VallejoCity of VallejoVallejoCity of PittsburgCity of PittsburgCity of PittsburgCity of PittsburgConcordAll water systems →