Drinking water quality · 2024
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.
- Reporting year
- 2024
- Contaminants measured
- 34
- Over federal limit
- 0
- Approaching the limit
- 0
- Service area
- CA
state-level CCR
Where your water comes from · EPA SDWIS
Rialto, 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.
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-based2 violations on record · most recent Aug 1993resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ArsenicA naturally occurring element that also enters water from industry and agriculture. | 5.53 ug/LReported levelCity Of Rialto | None set | Within the limit |
+By source (3)— City Of Rialto, Wvwd, Sbvmwd (Blf)
| |||
| CopperA metal that enters water from corroding household plumbing. | 0.14 mg/L90th percentileAt the tap | 1.3 mg/LAction level | Within the limit |
| BariumA metal from erosion of natural deposits and industrial discharge. | 0.057 mg/LReported levelSbvmwd (Blf) | 2 mg/LMCL | Within the limit |
+By source (3)— Sbvmwd (Blf), City Of Rialto, Wvwd
| |||
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0 mg/L90th percentileAt the tap | 0.015 mg/LAction level | None detected |
| AluminumA common element sometimes used as a treatment coagulant. | 80 ug/LReported levelSbvmwd (Blf) | None set | Detected — no federal limit |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
| 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), City Of Rialto, Wvwd
| |||
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 1.25 ug/LReported levelCity Of Rialto | None set | Detected — no federal limit |
+By source (3)— City Of Rialto, Wvwd, Sbvmwd (Blf)
| |||
| 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
| |||
| ManganeseA naturally occurring metal from soil and rock. | 9.5 ug/LReported levelCity Of Rialto | None set | Detected — no federal limit |
+By source (3)— City Of Rialto, Sbvmwd (Blf), Wvwd
| |||
| 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
| |||
| UraniumA naturally occurring radioactive metal from erosion of natural deposits. | 17 pCi/LReported levelWvwd | 20 pCi/LMCL | Detected — no federal limit |
+By source (3)— Wvwd, Sbvmwd (Blf), City Of Rialto
| |||
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 3.8 mg/LReported levelSbvmwd (Blf) | 10 mg/LMCL | Within the limit |
+By source (3)— Sbvmwd (Blf), City Of Rialto, Wvwd
| |||
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.34 mg/LReported levelSbvmwd (Blf) | 4 mg/LMCL | Within the limit |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
| ChlorideA naturally occurring salt compound. | 22.5 mg/LReported levelWvwd | None set | Detected — no federal limit |
+By source (3)— Wvwd, Sbvmwd (Blf), City Of Rialto
| |||
| SulfateA naturally occurring mineral from rock and soil. | 48 mg/LReported levelSbvmwd (Blf) | None set | Detected — no federal limit |
+By source (3)— Sbvmwd (Blf), Wvwd, City Of Rialto
| |||
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/LMCL | 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 |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chromium | 1.3 ug/LReported levelSbvmwd (Blf) | None set | Within the limit |
+By source (3)— Sbvmwd (Blf), City Of Rialto, Wvwd
| |||
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 0.62 ug/LReported levelCity Of Rialto | None set | Within the limit |
+By source (3)— City Of Rialto, Wvwd, Sbvmwd (Blf)
| |||
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | Not detected ug/LReported levelCity Of Rialto | None set | None detected |
+By source (3)— City Of Rialto, Wvwd, Sbvmwd (Blf)
| |||
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 18Reported levelWvwd | None set | Detected — no federal limit |
+By source (3)— City Of Rialto, Sbvmwd (Blf), Wvwd
| |||
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)— City of Rialto, Wvwd, Sbvmwd (Blf)
| |||
| 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)
| |||
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| 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
| |||
| OdorA measure of detectable smell in the water. | 1Reported levelCity Of Rialto | None set | Detected — no federal limit |
+By source (3)— City Of Rialto, Wvwd, Sbvmwd (Blf)
| |||
| 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)
| |||
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 520Reported levelSbvmwd (Blf) | None set | Detected — no federal 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) | None set | Detected — no federal limit |
+By source (3)— Sbvmwd (Blf), City Of Rialto, Wvwd
| |||
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.06 ug/LReported levelCity Of Rialto | 5 ug/LMCL | Detected — no federal limit |
+By source (3)— City Of Rialto, Wvwd, Sbvmwd (Blf)
| |||
Source: Rialto, CA's 2024 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, CA's water
+Is Rialto, CA tap water safe to drink in 2024?
Every one of the 34 contaminants measured in Rialto, 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 Rialto, CA tap water?
34 contaminants were measured in Rialto, CA's 2024 Consumer Confidence Report, spanning metals, physical & aggregate, and inorganic chemicals. 13 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 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.
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