Drinking water quality · 2024
· Verified
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.
Historical readings · EPA Six-Year Review (2012–2019)
3 contaminants historically over EPA limits in Rancho Cucamonga, 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) |
|---|---|---|---|
THALLIUM worst: 2012 | 0.038 mg/L 19.0× | 0.002 mg/L | '12 |
NITRATE worst: 2019 | 17 mg/L 1.7× | 10 mg/L | '12'13'14'15'16'17'18'19 |
ANTIMONY worst: 2014 | 0.0065 mg/L 1.1× above national p90 | 0.006 mg/L | '12'14 |
SELENIUM worst: 2012 | 0.04 mg/L within | 0.05 mg/L | '12'17'18 |
ARSENIC worst: 2012 | 0.0071 mg/L within near national p90 | 0.01 mg/L | '12'17'18 |
FLUORIDE worst: 2014 | 0.85 mg/L within | 4 mg/L | '12'14'17'18 |
BARIUM worst: 2014 | 0.084 mg/L within below national p90 | 2 mg/L | '12'14'17'18 |
URANIUM worst: 2019 | 0.116 ug/L within 5.5× the national p90 | 30 ug/L | '13'16'17'18'19 |
TOLUENE worst: 2017 | 0.0036 mg/L within | 1 mg/L | '17 |
LEAD worst: 2012 | 0.18 mg/L | — | '12 |
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 | 80 ug/LMCL | Within the limit |
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | 0.86 ug/LAverageSystem-wide | 6 ug/LMCL | Within the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 4.39 ug/LAverageSystem-wide | 60 ug/LMCL | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chromium, TotalTotal chromium — the sum of all chromium forms, from natural deposits and industrial discharge. | 2.56 ug/LAverageSystem-wide | 10 ug/LMCL | Within the limit |
| CopperA metal that enters water from corroding household plumbing. | 0.13 mg/LRangeSystem-wide | 1.3 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 |
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 |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| DBCP1,2-dibromo-3-chloropropane — a banned soil fumigant pesticide. | 5.6 ng/LAverageSystem-wide | 200 ng/LMCL | 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 | 0MCL | 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, metals, and inorganic chemicals. 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 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.