Drinking water quality · 2024
What's in Rancho Cucamonga, CA tap water
16 contaminants were measured in the Rancho Cucamonga, CA water system's 2024 annual report. Each is shown below against its federal limit.
- Reporting year
- 2024
- Contaminants measured
- 16
- Over federal limit
- 0
- Approaching the limit
- 0
- Service area
- CA
Where your water comes from · EPA SDWIS
Rancho Cucamonga, CA's drinking water comes from ground water, drawn from 4 sources.
Source
- WELL · 4
Treatment
- WELL 08 DISINFECTION
- NITRATAX BLENDING MONITOR
- WELL 12 DISINFECTION
Distribution
Also buys water from YUIMA MUNICIPAL WATER DISTRICT.
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-based10 violations on record · most recent Apr 2018resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 30.53 ug/LAverageSystem-wide | None set | Within the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 4.39 ug/LAverageSystem-wide | None set | Within the limit |
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | 0.86 ug/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. | 3.68 mg/LAverageSystem-wide | 10 mg/LMCL | Within the limit |
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.25 mg/LAverageSystem-wide | 4 mg/LMCL | Within the 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/LMCL | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| CopperA metal that enters water from corroding household plumbing. | 0.13 mg/L90th percentileSystem-wide | None set | Within the limit |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0 ug/L90th percentileSystem-wide | None set | None detected |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | 0.38 pCi/LAverageSystem-wide | 5 pCi/LMCL | Within the limit |
| UraniumA naturally occurring radioactive metal from erosion of natural deposits. | 0.73 pCi/LAverageSystem-wide | 20 pCi/LMCL | Detected — no federal limit |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| DBCP1,2-dibromo-3-chloropropane — a banned soil fumigant pesticide. | 5.6 ng/LAverageSystem-wide | None set | Within the limit |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chromium | 2.56 ug/LAverageSystem-wide | None set | Within the limit |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals. | 0RangeSystem-wide | None set | None detected |
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 0 %AverageSystem-wide | 0 %Public health goal | Detected — no federal limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 1.65 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.08AverageSystem-wide | None set | Detected — no federal limit |
People also ask about Rancho Cucamonga, CA's water
+Is Rancho Cucamonga, CA tap water safe to drink in 2024?
Every one of the 16 contaminants measured in Rancho Cucamonga, 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 Rancho Cucamonga, CA tap water?
16 contaminants were measured in Rancho Cucamonga, CA's 2024 Consumer Confidence Report, spanning disinfection byproducts, inorganic chemicals, and metals. 6 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 Rancho Cucamonga, 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 Rancho Cucamonga, 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.