Drinking water quality · 2024
· Verified
What's in Rialto, CA tap water
34 contaminants were measured in the Rialto, CA water system's 2024 annual report. Each is shown below against its federal limit — 2 sit at or above that limit.
- Reporting year
- 2024
- Contaminants measured
- 34
- Over federal limit
- 2
- Approaching the limit
- 2
- Worst contaminant
- Specific Conductance
- Service area
- CA
PFAS — EPA UCMR5 (2023–2025)
1 PFAS compound above EPA limits in Rialto, 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.
PFOA (Perfluorooctanoic acid)
● Over EPA limit (1.8×)near national p90 (13.649999999999999 ng/L across detecting U.S. systems)
PFHxS (Perfluorohexane sulfonic acid)
● Below limitbelow national p90 (12.049999999999997 ng/L across detecting U.S. systems)
PFHpA
● Detected (no federal limit)below national p90 (9.309999999999999 ng/L across detecting U.S. systems)
PFBS
● Detected (no federal limit)below national p90 (13.909999999999979 ng/L across detecting U.S. systems)
PFPeA
● Detected (no federal limit)above national p90 (15.95999999999999 ng/L across detecting U.S. systems)
PFBA
● Detected (no federal limit)below national p90 (18 ng/L across detecting U.S. systems)
PFHxA
● Detected (no federal limit)above national p90 (12.190000000000003 ng/L across detecting U.S. systems)
Where your water comes from · EPA SDWIS
Rialto, CA's drinking water comes from ground water, drawn from 9 sources.
Source
- CITY · 2
- AIRPORT WELL
- CHINO
- MIRO
- + 4 more
Treatment
- RIALTO WELL 05 - TREATED
- CEDAR WELL (RIALTO 01) - TREATED (CL2)
- CITY WELL 01 - TREATED (CL2)
- + 5 more
Distribution
Also buys water from SAN BERNARDINO VALLEY WD, SAN BERNARDINO CITY, and 3 more.
Historical readings · EPA Six-Year Review (2012–2019)
3 contaminants historically over EPA limits in Rialto, 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) |
|---|---|---|---|
TCE worst: 2016 | 0.01 mg/L 2.0× | 0.005 mg/L | '12'13'14'15'16'17'18'19 |
DEHP worst: 2015 | 0.011 mg/L 1.8× | 0.006 mg/L | '15 |
ARSENIC worst: 2014 | 0.017 mg/L 1.7× above national p90 | 0.01 mg/L | '12'13'14'15'16'17 |
NITRATE worst: 2013 | 9.94 mg/L 99% | 10 mg/L | '12'13'14'15'16'17'18'19 |
DICHLOROMETHANE worst: 2017 | 0.0031 mg/L within | 0.005 mg/L | '17 |
GROSS BETA worst: 2015 | 1.82 mrem/yr within | 4 mrem/yr | '14'15'16 |
TTHM worst: 2019 | 0.035 mg/L within | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
NITRATE NITRITE worst: 2019 | 3.3 mg/L within | 10 mg/L | '16'19 |
PCE worst: 2013 | 0.0015 mg/L within | 0.005 mg/L | '13'14'15'16'17'18'19 |
HAA5 worst: 2014 | 0.016 mg/L within | 0.06 mg/L | '12'13'14'15'16'17'18'19 |
DICHLOROPROPANE 12 worst: 2016 | 0.0012 mg/L within below national p90 | 0.005 mg/L | '13'14'15'16'17'18'19 |
DICHLOROETHANE 12 worst: 2017 | 0.0008 mg/L within below national p90 | 0.005 mg/L | '17 |
TRICHLOROETHANE 112 worst: 2014 | 0.00058 mg/L within below national p90 | 0.005 mg/L | '14 |
DBCP worst: 2017 | 0.000022 mg/L within below national p90 | 0.0002 mg/L | '17 |
FLUORIDE worst: 2012 | 0.4 mg/L within | 4 mg/L | '12'13'14'15'16'17'18'19 |
DICHLOROETHYLENE 11 worst: 2018 | 0.00064 mg/L within below national p90 | 0.007 mg/L | '18'19 |
TOLUENE worst: 2012 | 0.057 mg/L within | 1 mg/L | '12'19 |
STYRENE worst: 2012 | 0.0037 mg/L within | 0.1 mg/L | '12 |
CHROMIUM worst: 2017 | 0.0034 mg/L within below national p90 | 0.1 mg/L | '14'17 |
BARIUM worst: 2017 | 0.055 mg/L within below national p90 | 2 mg/L | '15'17 |
TRICHLOROBENZENE 124 worst: 2019 | 0.00056 mg/L within below national p90 | 0.07 mg/L | '19 |
ETHYLBENZENE worst: 2012 | 0.0013 mg/L within | 0.7 mg/L | '12 |
URANIUM worst: 2017 | 0.00679 ug/L within below national p90 | 30 ug/L | '14'16'17'19 |
XYLENES TOTAL worst: 2012 | 0.002 mg/L within | 10 mg/L | '12 |
COPPER worst: 2014 | 0.14 mg/L below national p90 | — | '14 |
DBAA worst: 2013 | 0.0012 mg/L | — | '13'15'16'18'19 |
DCAA worst: 2012 | 0.003 mg/L | — | '12'13'16'18'19 |
MBAA worst: 2014 | 0.0017 mg/L | — | '14'19 |
MCAA worst: 2014 | 0.014 mg/L | — | '14'15'17'19 |
TCAA worst: 2012 | 0.0022 mg/L | — | '12'19 |
BROMODICHLOROMETHANE worst: 2012 | 0.0026 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMOFORM worst: 2013 | 0.0021 mg/L | — | '13'14'15'16'17'18'19 |
CHLOROFORM worst: 2012 | 0.004 mg/L | — | '12'13'14'15'16'17'18'19 |
DIBROMOCHLOROMETHANE worst: 2012 | 0.0022 mg/L | — | '12'13'14'15'16'17'18'19 |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 520Reported levelSbvmwd (Blf) | 1MCL | At or above the limit |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 322 mg/LReported levelSbvmwd (Blf) | 1 mg/LMCL | At or above the limit |
+By source (3)— Sbvmwd (Blf), City Of Rialto, Wvwd
| |||
| OdorA measure of detectable smell in the water. | 1Reported levelCity Of Rialto | 3MCL | Within the limit |
+By source (3)— City Of Rialto, Wvwd, Sbvmwd (Blf)
| |||
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.06 ug/LReported levelCity Of Rialto | 5 ug/LMCL | Within the limit |
+By source (3)— City Of Rialto, Sbvmwd (Blf), Wvwd
| |||
| AlkalinityA measure of the water's capacity to neutralize acids. | 190 mg/LReported levelSbvmwd (Blf) | None set | Detected — no federal limit |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
| Bicarbonate | 180 mg/LReported levelCity Of Rialto | None set | Detected — no federal limit |
| HardnessA measure of dissolved calcium and magnesium minerals. | 230 mg/LReported levelSbvmwd (Blf) | None set | Detected — no federal limit |
+By source (3)— Sbvmwd (Blf), City Of Rialto, Wvwd
| |||
| pHA measure of how acidic or basic the water is. | 8Reported levelCity Of Rialto | None set | Detected — no federal limit |
+By source (3)— City Of Rialto, Wvwd, Sbvmwd (Blf)
| |||
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0–12 ug/LReported levelAt the tap | 15 ug/LMCL | Approaching the limit |
| ManganeseA naturally occurring metal from soil and rock. | 9.5 ug/LReported levelCity Of Rialto | 50 ug/LMCL | Within the limit |
+By source (3)— City Of Rialto, Sbvmwd (Blf), Wvwd
| |||
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 1.25 ug/LReported levelCity Of Rialto | 10 ug/LMCL | Within the limit |
+By source (3)— City Of Rialto, Wvwd, Sbvmwd (Blf)
| |||
| AluminumA common element sometimes used as a treatment coagulant. | 80 ug/LReported levelSbvmwd (Blf) | 1000 ug/LMCL | Within the limit |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
| Chromium, TotalTotal chromium — the sum of all chromium forms, from natural deposits and industrial discharge. | 1.3 ug/LReported levelSbvmwd (Blf) | 50 ug/LMCL | Within the limit |
+By source (3)— Sbvmwd (Blf), City Of Rialto, Wvwd
| |||
| CalciumA naturally occurring mineral that contributes to water hardness. | 72 mg/LReported levelSbvmwd (Blf) | None set | Detected — no federal limit |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 13 mg/LReported levelSbvmwd (Blf) | None set | Detected — no federal limit |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
| PotassiumA naturally occurring mineral from rock and soil. | 2.4 mg/LReported levelWvwd | None set | Detected — no federal limit |
+By source (2)— Wvwd, City Of Rialto
| |||
| SodiumA naturally occurring salt component. | 30 mg/LReported levelWvwd | None set | Detected — no federal limit |
+By source (3)— Wvwd, Sbvmwd (Blf), City Of Rialto
| |||
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | 2.4 pCi/LReported levelSbvmwd (Blf) | 5 pCi/LMCL | Within the limit |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | 3.09 pCi/LReported levelSbvmwd (Blf) | 15 pCi/LMCL | Within the limit |
+By source (3)— Sbvmwd (Blf), City Of Rialto, Wvwd
| |||
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 1.4 mg/LReported levelSbvmwd (Blf) | 4 mg/LMRDL | Within the limit |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TetrachloroethyleneAn industrial solvent (PCE) used in dry cleaning and degreasing. | 0.73 ug/LReported levelSbvmwd (Blf) | 5 ug/LMCL | Within the limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| SulfateA naturally occurring mineral from rock and soil. | 48 mg/LReported levelSbvmwd (Blf) | 500 mg/LMCL | Within the limit |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
| ChlorideA naturally occurring salt compound. | 22.5 mg/LReported levelWvwd | 500 mg/LMCL | Within the limit |
+By source (3)— Wvwd, Sbvmwd (Blf), City Of Rialto
| |||
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | Not detected ug/LReported levelSbvmwd (Blf) | 6 ug/LMCL | None detected |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals. | 0RangeSystem-wide | 0Public health goal | None detected |
+By source (3)— Sbvmwd (Blf), Wvwd, City of Rialto
| |||
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 0–6RangeSystem-wide | 0Public health goal | Detected — no federal limit |
+By source (3)— City of Rialto, Wvwd, Sbvmwd (Blf)
| |||
People also ask about Rialto, CA's water
+Is Rialto, CA tap water safe to drink in 2024?
The 2024 Consumer Confidence Report for the Rialto, CA water utility lists 2 contaminants at or above the federal limit: Specific Conductance and Total Dissolved Solids. 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 Rialto, CA tap water?
34 contaminants were measured in Rialto, CA's 2024 Consumer Confidence Report, spanning metals, physical & aggregate, and inorganic chemicals. 24 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 Rialto, CA tap water?
2 contaminants in Rialto, CA's 2024 report sit at or above the federal limit: Specific Conductance (520.0× the limit); Total Dissolved Solids (322.0× 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 Rialto, CA tap water?
The contaminant with the highest measured value relative to its federal limit in the 2024 report is Specific Conductance, at 520.0× the federal threshold. It belongs to the physical & aggregate family of contaminants.
+Are any contaminants in Rialto, CA tap water approaching the federal limit?
2 contaminants are between 80% and 100% of the federal limit in this report: Uranium and Lead. 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 Rialto, 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 Rialto, 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.