Drinking water quality · 2024
What's in Chico, CA tap water
42 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
- 42
- Over federal limit
- 0
- Approaching the limit
- 0
- 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×)PFHxS (Perfluorohexane sulfonic acid)
● Over EPA limit (2.2×)PFOA (Perfluorooctanoic acid)
● Over EPA limit (1.7×)PFBS
● Detected (no federal limit)PFHxA
● Detected (no federal limit)PFPeA
● Detected (no federal limit)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
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Maximum contaminant level exceededHealth-based5 violations on record · most recent Sep 2002resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.21 NTUAverageSystem-wide | 1 NTUMCL | Within the limit |
| AlkalinityA measure of the water's capacity to neutralize acids. | 131 mg/LAverageGroundwater | None set | Detected — no federal limit |
| ColorA measure of visible tint in the water. | 1.8AverageSystem-wide | 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 |
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 296AverageSystem-wide | None set | Detected — no federal limit |
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 219 mg/LAverageSystem-wide | None set | Detected — no federal limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 1.7 mg/LAverageSystem-wide | 10 mg/LMCL | Within the limit |
| FluorideA mineral often added to drinking water to help prevent tooth decay. | Not detected mg/LAverageSystem-wide | 4 mg/LMCL | Within the limit |
| ChlorideA naturally occurring salt compound. | 11 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| SulfateA naturally occurring mineral from rock and soil. | 6.2 mg/LAverageSystem-wide | None set | Detected — no federal limit |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chlorine Free | 0.59 mg/LAverageSystem-wide | 4 mg/LMCL | Within the limit |
| Chromium | Not detected ug/LAverageSystem-wide | None set | Within the limit |
| Cis Dichloroethylene 12 | Not detected ug/LAverageSystem-wide | None set | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| CopperA metal that enters water from corroding household plumbing. | 0.18 mg/L90th percentileAt the tap | 1.3 mg/LAction level | Within the limit |
| ArsenicA naturally occurring element that also enters water from industry and agriculture. | Not detected ug/LAverageSystem-wide | None set | Within the limit |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | Not detected ug/L90th percentileAt the tap | None set | None detected |
| AluminumA common element sometimes used as a treatment coagulant. | 1.1 ug/LAverageSystem-wide | None set | Detected — no federal limit |
| CalciumA naturally occurring mineral that contributes to water hardness. | 24 mg/LAverageGroundwater | None set | Detected — no federal limit |
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 2.5 ug/LAverageSystem-wide | None set | Detected — no federal limit |
| IronA naturally occurring metal common in groundwater. | Not detected ug/LAverageSystem-wide | None set | Detected — no federal limit |
| LithiumA naturally occurring element found in some groundwater. | Not detected ug/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 |
| Vanadium | 14 ug/LAverageGroundwater | 50 ug/LNL | Detected — no federal limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 1.5 ug/LAverageAnnual Average | None set | Within the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | Not detected ug/LRangeSystem-wide | None set | None detected |
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | Not detected ug/LAverageGroundwater | 6 ug/LNL | Detected — no federal limit |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals. | 0MaximumMonthly | None set | 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 42 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?
42 contaminants were measured in Chico, CA's 2024 Consumer Confidence Report, spanning metals, pfas ("forever chemicals"), and physical & aggregate. 14 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+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.