Drinking water quality · 2025
· Verified
What's in Rialto, City of, CA tap water
123 contaminants were measured in the Rialto, City of, CA water system's 2025 annual report. Each is shown below against its federal limit — 2 sit at or above that limit.
- Reporting year
- 2025
- Contaminants measured
- 123
- Over federal limit
- 2
- Approaching the limit
- 0
- Worst contaminant
- Perchlorate
- Service area
- CA
3.6× the limit
state-level CCR
PFAS — EPA UCMR5 (2023–2025)
1 PFAS compound above EPA limits in Rialto, City of, 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×)Measured 7.3 ng/LEPA limit 4 ng/LSample year 2023Samples 1 detect / 10
near national p90 (13.649999999999999 ng/L across detecting U.S. systems)
PFHxS (Perfluorohexane sulfonic acid)
● Below limitMeasured 3.5 ng/LEPA limit 10 ng/LSample year 2023Samples 1 detect / 10
below national p90 (12.049999999999997 ng/L across detecting U.S. systems)
PFHpA
● Detected (no federal limit)Measured 3.5 ng/LSample year 2023Samples 1 detect / 10
below national p90 (9.309999999999999 ng/L across detecting U.S. systems)
PFBS
● Detected (no federal limit)Measured 4.6 ng/LSample year 2023Samples 1 detect / 10
below national p90 (13.909999999999979 ng/L across detecting U.S. systems)
PFPeA
● Detected (no federal limit)Measured 18 ng/LSample year 2024Samples 1 detect / 9
above national p90 (15.95999999999999 ng/L across detecting U.S. systems)
PFBA
● Detected (no federal limit)Measured 5.7 ng/LSample year 2024Samples 1 detect / 9
below national p90 (18 ng/L across detecting U.S. systems)
PFHxA
● Detected (no federal limit)Measured 17 ng/LSample year 2024Samples 1 detect / 9
above national p90 (12.190000000000003 ng/L across detecting U.S. systems)
PWSID CA3610038 · Source: EPA UCMR5. Limits per EPA's April 2024 PFAS National Primary Drinking Water Regulation. PFAS values reported in nanograms per liter (ng/L) — note that 1 ng/L = 1 part per trillion.
Where your water comes from · EPA SDWIS
Rialto, City of, CA's drinking water comes from ground water, drawn from 9 sources.
Source
9ground water
- CITY · 2
- AIRPORT WELL
- CHINO
- MIRO
- + 4 more
Treatment
8treatment plants
- RIALTO WELL 05 - TREATED
- CEDAR WELL (RIALTO 01) - TREATED (CL2)
- CITY WELL 01 - TREATED (CL2)
- + 5 more
Distribution
0storage units
Also buys water from SAN BERNARDINO VALLEY WD, SAN BERNARDINO CITY, and 3 more.
Source: EPA SDWIS facilities inventory. Methodology.
Historical readings · EPA Six-Year Review (2012–2019)
3 contaminants historically over EPA limits in Rialto, City of, 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 |
PWSID CA3610038 · 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.
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | 21.451794871794874 UG/LAverageSource water | 6 UG/LMCL | At or above the limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| OdorA measure of detectable smell in the water. | 1 TONAverageSource water | 3 TONMCL | Within the limit |
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 228.17073170731706 MG/LAverageSource water | 1000 MG/LMCL | Within the limit |
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 356.6666666666667 UMHO/CMAverageSource water | 1600 UMHO/CMMCL | Within the limit |
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.1375 NTUAverageSource water | 5 NTUMCL | Within the limit |
| ColorA measure of visible tint in the water. | Not detected UNITSHighest single sampleSource water | 15 UNITSMCL | None detected |
| AlkalinityA measure of the water's capacity to neutralize acids. | 154.14414414414415 MG/LAverageEntry point | None set | Detected — no federal limit |
| HardnessA measure of dissolved calcium and magnesium minerals. | 156.66666666666666 MG/LAverageSource water | None set | Detected — no federal limit |
| pHA measure of how acidic or basic the water is. | 7.841666666666666 PHAverageSource water | None set | Detected — no federal limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 1.48 UG/LAverageSource water | 10 UG/LMCL | Within the limit |
| AluminumA common element sometimes used as a treatment coagulant. | Not detected UG/LHighest single sampleSource water | 1000 UG/LMCL | None detected |
| Antimony | Not detected UG/LHighest single sampleSource water | 6 UG/LMCL | None detected |
| Beryllium | Not detected UG/LHighest single sampleSource water | 4 UG/LMCL | None detected |
| BoronA naturally occurring element from rock and soil. | Not detected UG/LHighest single sampleSource water | None set | None detected |
| Cadmium | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| IronA naturally occurring metal common in groundwater. | Not detected UG/LHighest single sampleSource water | 300 UG/LMCL | None detected |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | Not detected UG/LHighest single sampleSource water | None set | None detected |
| ManganeseA naturally occurring metal from soil and rock. | Not detected UG/LHighest single sampleSource water | 50 UG/LMCL | None detected |
| MercuryA toxic metal from erosion of natural deposits and industrial runoff. | Not detected UG/LHighest single sampleSource water | 2 UG/LMCL | None detected |
| NickelA metal from natural deposits and industrial discharge. | Not detected UG/LHighest single sampleSource water | 100 UG/LMCL | None detected |
| SeleniumA trace element from natural deposits and industrial discharge. | Not detected UG/LHighest single sampleSource water | 50 UG/LMCL | None detected |
| Thallium | Not detected UG/LHighest single sampleSource water | 2 UG/LMCL | None detected |
| ZincA naturally occurring metal that can also enter water from corroding pipes. | Not detected UG/LHighest single sampleSource water | 5000 UG/LMCL | None detected |
| CalciumA naturally occurring mineral that contributes to water hardness. | 25.208333333333332 MG/LAverageSource water | None set | Detected — no federal limit |
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 8.691666666666666 MG/LAverageSource water | None set | Detected — no federal limit |
| PotassiumA naturally occurring mineral from rock and soil. | 1.5583333333333333 MG/LAverageSource water | None set | Detected — no federal limit |
| SodiumA naturally occurring salt component. | 12.583333333333334 MG/LAverageSource water | None set | Detected — no federal limit |
| Vanadium | 6.9 UG/LAverageSource water | None set | Detected — no federal limit |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | 0.26739999999999997 PCI/LAverageSource water | 5 PCI/LMCL | Within the limit |
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | Not detected PCI/LHighest single sampleSource water | 15 PCI/LMCL | None detected |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| SulfateA naturally occurring mineral from rock and soil. | 15.013513513513514 MG/LAverageSource water | 500 MG/LMCL | Within the limit |
| ChlorideA naturally occurring salt compound. | 8.9 MG/LAverageDistribution | 500 MG/LMCL | Within the limit |
| Cyanide | Not detected UG/LHighest single sampleSource water | 150 UG/LMCL | None detected |
| NitriteA compound from fertilizer runoff, sewage, and erosion of natural deposits. | Not detected MG/LHighest single sampleSource water | 1 MG/LMCL | None detected |
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 sampleEntry point | 6 UG/LMCL | None detected |
| Deha | Not detected UG/LHighest single sampleSource water | 400 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 |
| Methoxychlor | Not detected UG/LHighest single sampleSource water | 30 UG/LMCL | None detected |
| O Dichlorobenzene | Not detected UG/LHighest single sampleDistribution | 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 sampleSource water | 5 UG/LMCL | None detected |
| Pcb Total | Not detected UG/LHighest single sampleSource water | 0.5 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 |
| Toxaphene | Not detected UG/LHighest single sampleSource water | 3 UG/LMCL | None detected |
| Trans Dichloroethylene 12 | Not detected UG/LHighest single sampleDistribution | 10 UG/LMCL | None detected |
| Trichloroethane 111 | Not detected UG/LHighest single sampleSource water | 200 UG/LMCL | None detected |
| Twofourd | Not detected UG/LHighest single sampleSource water | 70 UG/LMCL | None detected |
| Vinyl Chloride | Not detected UG/LHighest single sampleDistribution | 0.5 UG/LMCL | None detected |
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid, a chlorinated PFAS compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)ADONA, a newer-generation PFAS replacement compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| 4:2 Fluorotelomer sulfonic acid (4:2 FTS)4:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| 6:2 Fluorotelomer sulfonic acid (6:2 FTS)6:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| 8:2 Fluorotelomer sulfonic acid (8:2 FTS)8:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| 9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS)9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid, a chlorinated PFAS compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Hexafluoropropylene oxide dimer acidHFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoro-3-methoxypropanoic acid (PFMPA)Perfluoro-3-methoxypropanoic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoro-4-methoxybutanoic acid (PFMBA)Perfluoro-4-methoxybutanoic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA)Perfluoro(2-ethoxyethane)sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluorodecanoic acid (PFDA)Perfluorodecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluorododecanoic acid (PFDoA)Perfluorododecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoroheptanesulfonic acid (PFHpS)Perfluoroheptanesulfonic acid, a PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluorononanoic acidPerfluorononanoic acid, a PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoropentanesulfonic acid (PFPeS)Perfluoropentanesulfonic acid, a PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoroundecanoic acid (PFUnA)Perfluoroundecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | 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 sampleDistribution | None set | None detected |
| Chloromethane | Not detected UG/LHighest single sampleDistribution | None set | None detected |
| Dalapon | Not detected UG/LHighest single sampleSource water | 200 UG/LMCL | None detected |
| Dichlorodifluoromethane | Not detected UG/LHighest single sampleDistribution | None set | None detected |
| Simazine | Not detected UG/LHighest single sampleSource water | 4 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: Rialto, City of, 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 Rialto, City of, CA's water
+Is Rialto, City of, CA tap water safe to drink in 2025?
The 2025 Consumer Confidence Report for the Rialto, City of, CA water utility lists 2 contaminants at or above the federal limit: Perchlorate and Tce. 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, City of, CA tap water?
123 contaminants were measured in Rialto, City of, CA's 2025 Consumer Confidence Report, spanning other, metals, and pfas ("forever chemicals"). 81 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, City of, CA tap water?
2 contaminants in Rialto, City of, CA's 2025 report sit at or above the federal limit: Perchlorate (3.6× the limit); Tce (1.1× 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, City of, CA tap water?
The contaminant with the highest measured value relative to its federal limit in the 2025 report is Perchlorate, at 3.6× the federal threshold. It belongs to the disinfection byproducts family of contaminants.
+Where does the data on this page come from?
Every value is transcribed from Rialto, City of, 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 Rialto, City of, 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.
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