Drinking water quality · 2023
· Verified
What's in Gswc-south Arcadia — San Dimas, Ca, CA tap water
18 contaminants were measured in the Gswc-south Arcadia — San Dimas, Ca, CA water system's 2023 annual report. Each is shown below against its federal limit — 1 sit at or above that limit.
- Reporting year
- 2023
- Contaminants measured
- 18
- Over federal limit
- 1
- Approaching the limit
- 0
- Worst contaminant
- PFOS
- Service area
- CA
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PFOSPerfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. | 5.4 ng/LAverageSystem-wide | 6.5 ng/LNL | At or above the limit |
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | Not detected ng/LAverageSystem-wide | 3 ng/LNL | Within the limit |
| PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. | Not detected ng/LAverageSystem-wide | 5.1 ng/LNL | Within the limit |
| PFBAPerfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' | 1.2 ng/LAverageSystem-wide | None set | Detected — no federal limit |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 1.5 mg/LAverageSystem-wide | 4 mg/LMCL | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| CopperA metal that enters water from corroding household plumbing. | 0.28 mg/L90th percentileAt the tap | 1.3 mg/LAction level | Within the limit |
| Chromium, TotalTotal chromium — the sum of all chromium forms, from natural deposits and industrial discharge. | Not detected ug/LAverageSystem-wide | None set | Within the limit |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | Not detected ug/L90th percentileAt the tap | None set | None detected |
| AluminumA common element sometimes used as a treatment coagulant. | Not detected mg/LAverageSystem-wide | None set | Detected — no federal limit |
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 4.2 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. | 1.6 mg/LAverageSystem-wide | 10 mg/LMCL | Within the limit |
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.6 mg/LAverageSystem-wide | 4 mg/LMCL | Within the limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 5.3 ug/LAverageSystem-wide | None set | Within the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | Not detected ug/LAverageSystem-wide | None set | Within the limit |
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | Not detected ug/LAverageSystem-wide | None set | Detected — no federal limit |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Pce | Not detected ug/LAverageSystem-wide | None set | Within the limit |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | Not detected pCi/LAverageSystem-wide | 15 pCi/LMCL | Within the limit |
| UraniumA naturally occurring radioactive metal from erosion of natural deposits. | 1.8 pCi/LAverageSystem-wide | 20 pCi/LMCL | Detected — no federal limit |
People also ask about Gswc-south Arcadia — San Dimas, Ca, CA's water
+Is Gswc-south Arcadia — San Dimas, Ca, CA tap water safe to drink in 2023?
The 2023 Consumer Confidence Report for the Gswc-south Arcadia — San Dimas, Ca, CA water utility lists 1 contaminant at or above the federal limit: PFOS. 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 Gswc-south Arcadia — San Dimas, Ca, CA tap water?
18 contaminants were measured in Gswc-south Arcadia — San Dimas, Ca, CA's 2023 Consumer Confidence Report, spanning metals, pfas ("forever chemicals"), and disinfection byproducts. 9 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 Gswc-south Arcadia — San Dimas, Ca, CA tap water?
One contaminant in Gswc-south Arcadia — San Dimas, Ca, CA's 2023 report sits at or above the federal limit: PFOS (1.4× 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 Gswc-south Arcadia — San Dimas, Ca, CA tap water?
The contaminant with the highest measured value relative to its federal limit in the 2023 report is PFOS, at 1.4× the federal threshold. It belongs to the pfas ("forever chemicals") family of contaminants.
+Where does the data on this page come from?
Every value is transcribed from Gswc-south Arcadia — San Dimas, Ca, CA's 2023 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 Gswc-south Arcadia — San Dimas, Ca, 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 2023 report; a new report will replace it once the utility publishes its next annual update.