Drinking water quality · 2024
· Verified
What's in Chico, CA tap water
41 contaminants were measured in the Chico, CA water system's 2024 annual report. Each is shown below against its federal limit.
- Reporting year
- 2024
- Contaminants measured
- 41
- Over federal limit
- 0
- Approaching the limit
- 1
- Service area
- CA
PFAS — EPA UCMR5 (2023–2025)
3 PFAS compounds above EPA limits in Chico, CA
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFOS (Perfluorooctane sulfonic acid)
● Over EPA limit (5.6×)above national p90 (19.900000000000006 ng/L across detecting U.S. systems)
PFHxS (Perfluorohexane sulfonic acid)
● Over EPA limit (2.2×)above national p90 (12.049999999999997 ng/L across detecting U.S. systems)
PFOA (Perfluorooctanoic acid)
● Over EPA limit (1.7×)below national p90 (13.649999999999999 ng/L across detecting U.S. systems)
PFBS
● Detected (no federal limit)near national p90 (13.909999999999979 ng/L across detecting U.S. systems)
Lithium
● Detected (no federal limit)below national p90 (76.59999999999991 mg/L across detecting U.S. systems)
PFHxA
● Detected (no federal limit)below national p90 (12.190000000000003 ng/L across detecting U.S. systems)
PFPeA
● Detected (no federal limit)below national p90 (15.95999999999999 ng/L across detecting U.S. systems)
Where your water comes from · EPA SDWIS
Chico, CA's drinking water comes from ground water, drawn from 54 sources.
Source
- WELL 20-01
- WELL 75-01
- WELL 21-01
- WELL 24-01 - STANDBY
- + 50 more
Treatment
- WELL 50-01 - CHLORINATED XCLD
- WELL 62-01 - CHLORINATED XCLD
- WELL 37-01 - CHLORINATED XCLD
- + 62 more
Distribution
Historical readings · EPA Six-Year Review (2012–2019)
2 contaminants historically over EPA limits in Chico, 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) |
|---|---|---|---|
PCE worst: 2016 | 0.22 mg/L 44.0× | 0.005 mg/L | '12'13'16'17'18'19 |
NITRATE worst: 2012 | 13.5 mg/L 1.4× | 10 mg/L | '12'13'14'15'16'17'18'19 |
NITRATE NITRITE worst: 2018 | 6.9 mg/L within | 10 mg/L | '16'17'18'19 |
ARSENIC worst: 2012 | 0.0025 mg/L within below national p90 | 0.01 mg/L | '12'13'14'15 |
TCE worst: 2012 | 0.00118 mg/L within | 0.005 mg/L | '12'13'14'15'16 |
NITRITE worst: 2013 | 0.195 mg/L within | 1 mg/L | '13 |
DICHLOROMETHANE worst: 2017 | 0.00085 mg/L within | 0.005 mg/L | '17 |
TTHM worst: 2013 | 0.0118 mg/L within | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
CARBON TETRACHLORIDE worst: 2017 | 0.00072 mg/L within below national p90 | 0.005 mg/L | '17 |
CIS DICHLOROETHYLENE 12 worst: 2015 | 0.0091 mg/L within near national p90 | 0.07 mg/L | '12'13'14'15'16'17'18'19 |
CHROMIUM worst: 2013 | 0.012 mg/L within above national p90 | 0.1 mg/L | '12'13'14 |
DICHLOROETHYLENE 11 worst: 2012 | 0.00058 mg/L within below national p90 | 0.007 mg/L | '12 |
FLUORIDE worst: 2017 | 0.11 mg/L within | 4 mg/L | '12'17 |
BARIUM worst: 2015 | 0.0424 mg/L within below national p90 | 2 mg/L | '14'15'19 |
STYRENE worst: 2014 | 0.0019 mg/L within | 0.1 mg/L | '14'15 |
SELENIUM worst: 2015 | 0.000217 mg/L within | 0.05 mg/L | '14'15 |
ANTIMONY worst: 2015 | 0.000021 mg/L within below national p90 | 0.006 mg/L | '14'15 |
CADMIUM worst: 2015 | 0.000012 mg/L within below national p90 | 0.005 mg/L | '15 |
TOLUENE worst: 2015 | 0.0022 mg/L within | 1 mg/L | '15'18 |
ETHYLBENZENE worst: 2015 | 0.0012 mg/L within | 0.7 mg/L | '15 |
XYLENES TOTAL worst: 2015 | 0.0094 mg/L within | 10 mg/L | '13'15 |
BERYLLIUM worst: 2015 | 0.000002 mg/L within below national p90 | 0.004 mg/L | '15 |
URANIUM worst: 2015 | 0.00108 ug/L within below national p90 | 30 ug/L | '14'15 |
COPPER worst: 2014 | 0.000394 mg/L below national p90 | — | '14'15 |
LEAD worst: 2014 | 0.000051 mg/L | — | '14'15 |
DCAA worst: 2016 | 0.0012 mg/L | — | '16 |
BROMODICHLOROMETHANE worst: 2013 | 0.00308 mg/L | — | '13'15'16'17'18'19 |
BROMOFORM worst: 2013 | 0.00127 mg/L | — | '13 |
CHLOROFORM worst: 2012 | 0.00194 mg/L | — | '12'13'14'15'16'17'18'19 |
DIBROMOCHLOROMETHANE worst: 2013 | 0.00275 mg/L | — | '13'15'16'17'18'19 |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Vanadium | 14 ug/LAverageGroundwater | 50 ug/LNL | Within the limit |
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 2.5 ug/LAverageSystem-wide | 10 ug/LMCL | Within the limit |
| AluminumA common element sometimes used as a treatment coagulant. | 1.1 ug/LAverageSystem-wide | 200 ug/LMCL | Within the limit |
| Chromium, TotalTotal chromium — the sum of all chromium forms, from natural deposits and industrial discharge. | Not detected ug/LAverageSystem-wide | 50 ug/LMCL | Within the limit |
| IronA naturally occurring metal common in groundwater. | Not detected ug/LAverageSystem-wide | 300 ug/LMCL | Within the limit |
| CalciumA naturally occurring mineral that contributes to water hardness. | 24 mg/LAverageGroundwater | None set | Detected — no federal limit |
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 15 mg/LAverageGroundwater | None set | Detected — no federal limit |
| PotassiumA naturally occurring mineral from rock and soil. | 0.55 mg/LAverageGroundwater | None set | Detected — no federal limit |
| SodiumA naturally occurring salt component. | 14 mg/LAverageGroundwater | None set | Detected — no federal limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 219 mg/LAverageSystem-wide | 1000 mg/LMCL | Within the limit |
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 296AverageSystem-wide | 1600MCL | Within the limit |
| ColorA measure of visible tint in the water. | 1.8AverageSystem-wide | 15MCL | Within the limit |
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.21 NTUAverageSystem-wide | 5 NTUMCL | Within the limit |
| AlkalinityA measure of the water's capacity to neutralize acids. | 131 mg/LAverageGroundwater | None set | Detected — no federal limit |
| HardnessA measure of dissolved calcium and magnesium minerals. | 122 mg/LAverageGroundwater | None set | Detected — no federal limit |
| pHA measure of how acidic or basic the water is. | 7.4AverageGroundwater | None set | Detected — no federal limit |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 0.59 mg/LAverageSystem-wide | 4 mg/LMRDL | Within the limit |
Inorganic chemicals
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | Not detected ug/LAverageAnnual Average | 60 ug/LMCL | None detected |
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | Not detected ug/LAverageGroundwater | 6 ug/LNL | Within the limit |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals. | 0MaximumMonthly | 0MCL | None detected |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | Not detected pCi/LAverageSystem-wide | 0.019 pCi/LPublic health goal | Within the limit |
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | Not detected pCi/LAverageSystem-wide | 15 pCi/LMCL | Within the limit |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TetrachloroethyleneAn industrial solvent (PCE) used in dry cleaning and degreasing. | Not detected ug/LAverageSystem-wide | 5 ug/LMCL | Within the limit |
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Perfluoroheptanoic acidPerfluoroheptanoic acid, a PFAS 'forever chemical.' | 0.08 ng/LAverageGroundwater | None set | Detected — no federal limit |
| Perfluoropentanesulfonic acid (PFPeS)Perfluoropentanesulfonic acid, a PFAS 'forever chemical.' | 0.12 ng/LAverageGroundwater | None set | Detected — no federal limit |
| PFBAPerfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' | 0.05 ng/LAverageGroundwater | None set | Detected — no federal limit |
People also ask about Chico, CA's water
+Is Chico, CA tap water safe to drink in 2024?
Every one of the 41 contaminants measured in Chico, CA's 2024 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in Chico, CA tap water?
41 contaminants were measured in Chico, CA's 2024 Consumer Confidence Report, spanning metals, pfas ("forever chemicals"), and physical & aggregate. 28 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Are any contaminants in Chico, CA tap water approaching the federal limit?
One contaminant is between 80% and 100% of the federal limit in this report: Perfluorohexanesulfonic acid. 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 Chico, CA's 2024 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 Chico, 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 2024 report; a new report will replace it once the utility publishes its next annual update.