# City of Cupertino, CA — Drinking Water Quality (2023)

> Contaminant levels for the City of Cupertino, CA public water system from its 2023 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/cupertino/2023
- JSON API: https://www.thewatermap.com/api/water/ca/cupertino/2023
- Source: the utility's annual Consumer Confidence Report (CCR)
- Verification: transcribed by a model, cross-checked by a second model, approved before publishing
- Reporting year: 2023
- Contaminants measured: 68
- Contaminants with a federal limit: 48
- Contaminants at or above the federal limit: 0
- Part of The Water Map — https://www.thewatermap.com

## Contaminants measured

| Contaminant | Category | Measured level | Sampling context | Federal limit | Status |
|---|---|---|---|---|---|
| Nitrate | Inorganic chemicals | 3.9000000000000004 MG/L (Average) | Source water | 10 MG/L (MCL) | Within the limit |
| Carbofuran | Other | Not detected UG/L (Highest single sample) | Source water | 18 UG/L (MCL) | None detected |
| Carbon Tetrachloride | Other | Not detected UG/L (Highest single sample) | Source water | 0.5 UG/L (MCL) | None detected |
| Chlordane | Other | Not detected UG/L (Highest single sample) | Source water | 0.1 UG/L (MCL) | None detected |
| Chlorobenzene | Other | Not detected UG/L (Highest single sample) | Source water | 70 UG/L (MCL) | None detected |
| Cis Dichloroethylene 12 | Other | Not detected UG/L (Highest single sample) | Source water | 6 UG/L (MCL) | None detected |
| Deha | Other | Not detected UG/L (Highest single sample) | Source water | 400 UG/L (MCL) | None detected |
| Dehp | Other | Not detected UG/L (Highest single sample) | Source water | 4 UG/L (MCL) | None detected |
| Dichloroethane 12 | Other | Not detected UG/L (Highest single sample) | Source water | 0.5 UG/L (MCL) | None detected |
| Dichloroethylene 11 | Other | Not detected UG/L (Highest single sample) | Source water | 6 UG/L (MCL) | None detected |
| Dichloropropane 12 | Other | Not detected UG/L (Highest single sample) | Source water | 5 UG/L (MCL) | None detected |
| Dinoseb | Other | Not detected UG/L (Highest single sample) | Source water | 7 UG/L (MCL) | None detected |
| Diquat | Other | Not detected UG/L (Highest single sample) | Source water | 20 UG/L (MCL) | None detected |
| Edb | Other | Not detected UG/L (Highest single sample) | Source water | 0.05 UG/L (MCL) | None detected |
| Endothall | Other | Not detected UG/L (Highest single sample) | Source water | 100 UG/L (MCL) | None detected |
| Endrin | Other | Not detected UG/L (Highest single sample) | Source water | 2 UG/L (MCL) | None detected |
| Glyphosate | Other | Not detected UG/L (Highest single sample) | Source water | 700 UG/L (MCL) | None detected |
| Heptachlor | Other | Not detected UG/L (Highest single sample) | Source water | 0.01 UG/L (MCL) | None detected |
| Heptachlor Epoxide | Other | Not detected UG/L (Highest single sample) | Source water | 0.01 UG/L (MCL) | None detected |
| Hexachlorobenzene | Other | Not detected UG/L (Highest single sample) | Source water | 1 UG/L (MCL) | None detected |
| Hexachlorocyclopentadiene | Other | Not detected UG/L (Highest single sample) | Source water | 50 UG/L (MCL) | None detected |
| Methoxychlor | Other | Not detected UG/L (Highest single sample) | Source water | 30 UG/L (MCL) | None detected |
| O Dichlorobenzene | Other | Not detected UG/L (Highest single sample) | Source water | 600 UG/L (MCL) | None detected |
| Oxamyl | Other | Not detected UG/L (Highest single sample) | Source water | 50 UG/L (MCL) | None detected |
| P Dichlorobenzene | Other | Not detected UG/L (Highest single sample) | Source water | 5 UG/L (MCL) | None detected |
| Pcb Total | Other | Not detected UG/L (Highest single sample) | Source water | 0.5 UG/L (MCL) | None detected |
| Pce | Other | Not detected UG/L (Highest single sample) | Source water | 5 UG/L (MCL) | None detected |
| Pentachlorophenol | Other | Not detected UG/L (Highest single sample) | Source water | 1 UG/L (MCL) | None detected |
| Picloram | Other | Not detected UG/L (Highest single sample) | Source water | 500 UG/L (MCL) | None detected |
| Styrene | Other | Not detected UG/L (Highest single sample) | Source water | 100 UG/L (MCL) | None detected |
| Tce | Other | Not detected UG/L (Highest single sample) | Source water | 5 UG/L (MCL) | None detected |
| Toxaphene | Other | Not detected UG/L (Highest single sample) | Source water | 3 UG/L (MCL) | None detected |
| Trans Dichloroethylene 12 | Other | Not detected UG/L (Highest single sample) | Source water | 10 UG/L (MCL) | None detected |
| Trichlorobenzene 124 | Other | Not detected UG/L (Highest single sample) | Source water | 5 UG/L (MCL) | None detected |
| Trichloroethane 111 | Other | Not detected UG/L (Highest single sample) | Source water | 200 UG/L (MCL) | None detected |
| Trichloroethane 112 | Other | Not detected UG/L (Highest single sample) | Source water | 5 UG/L (MCL) | None detected |
| Twofourd | Other | Not detected UG/L (Highest single sample) | Source water | 70 UG/L (MCL) | None detected |
| Vinyl Chloride | Other | Not detected UG/L (Highest single sample) | Source water | 0.5 UG/L (MCL) | None detected |
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| 4:2 Fluorotelomer sulfonic acid (4:2 FTS) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| 6:2 Fluorotelomer sulfonic acid (6:2 FTS) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| 8:2 Fluorotelomer sulfonic acid (8:2 FTS) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| 9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Hexafluoropropylene oxide dimer acid | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluorodecanoic acid (PFDA) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluorododecanoic acid (PFDoA) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluoroheptanesulfonic acid (PFHpS) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluoroheptanoic acid | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluorohexanoic acid | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluorononanoic acid | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluoropentanesulfonic acid (PFPeS) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluoropentanoic acid | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| Perfluoroundecanoic acid (PFUnA) | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| PFBA | PFAS ("forever chemicals") | Not detected NG/L (Highest single sample) | Source water | No federal limit | None detected |
| 1,2,3-TCP | VOCs & pesticides | Not detected UG/L (Highest single sample) | Source water | 0.005 UG/L (MCL) | None detected |
| Atrazine | VOCs & pesticides | Not detected UG/L (Highest single sample) | Source water | 1 UG/L (MCL) | None detected |
| Benzene | VOCs & pesticides | Not detected UG/L (Highest single sample) | Source water | 1 UG/L (MCL) | None detected |
| Benzo(a)pyrene | VOCs & pesticides | Not detected UG/L (Highest single sample) | Source water | 0.2 UG/L (MCL) | None detected |
| Dalapon | VOCs & pesticides | Not detected UG/L (Highest single sample) | Source water | 200 UG/L (MCL) | None detected |
| Dichloromethane | VOCs & pesticides | Not detected UG/L (Highest single sample) | Source water | 5 UG/L (MCL) | None detected |
| Ethylbenzene | VOCs & pesticides | Not detected UG/L (Highest single sample) | Source water | 300 UG/L (MCL) | None detected |
| Simazine | VOCs & pesticides | Not detected UG/L (Highest single sample) | Source water | 4 UG/L (MCL) | None detected |
| Toluene | VOCs & pesticides | Not detected UG/L (Highest single sample) | Source water | 150 UG/L (MCL) | None detected |
| Xylenes | VOCs & pesticides | Not detected UG/L (Highest single sample) | Source water | 1750 UG/L (MCL) | None detected |

## What these contaminants are

- **Nitrate** — A compound from fertilizer runoff, septic systems, and erosion of natural deposits. Levels above the federal limit can cause 'blue baby syndrome,' a serious oxygen-transport condition in infants.
- **11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)** — 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid, a chlorinated PFAS compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **4,8-Dioxa-3H-perfluorononanoic acid (ADONA)** — ADONA, a newer-generation PFAS replacement compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **4:2 Fluorotelomer sulfonic acid (4:2 FTS)** — 4:2 fluorotelomer sulfonic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **6:2 Fluorotelomer sulfonic acid (6:2 FTS)** — 6:2 fluorotelomer sulfonic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **8:2 Fluorotelomer sulfonic acid (8:2 FTS)** — 8:2 fluorotelomer sulfonic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS)** — 9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid, a chlorinated PFAS compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **Hexafluoropropylene oxide dimer acid** — HFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound. Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
- **Perfluoro-3-methoxypropanoic acid (PFMPA)** — Perfluoro-3-methoxypropanoic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **Perfluoro-4-methoxybutanoic acid (PFMBA)** — Perfluoro-4-methoxybutanoic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA)** — Perfluoro(2-ethoxyethane)sulfonic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **Perfluorodecanoic acid (PFDA)** — Perfluorodecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **Perfluorododecanoic acid (PFDoA)** — Perfluorododecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **Perfluoroheptanesulfonic acid (PFHpS)** — Perfluoroheptanesulfonic acid, a PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
- **Perfluoroheptanoic acid** — Perfluoroheptanoic acid, a PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
- **Perfluorohexanoic acid** — Perfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and widely detected.
- **Perfluorononanoic acid** — Perfluorononanoic acid, a PFAS 'forever chemical.' Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
- **Perfluoropentanesulfonic acid (PFPeS)** — Perfluoropentanesulfonic acid, a PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
- **Perfluoropentanoic acid** — Perfluoropentanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
- **Perfluoroundecanoic acid (PFUnA)** — Perfluoroundecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **PFBA** — Perfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment and the human body.
- **Atrazine** — A widely used agricultural herbicide that reaches water through runoff. Long-term exposure above the federal limit can affect the cardiovascular and reproductive systems.
- **Xylenes** — A group of industrial solvents found in gasoline and paint. Long-term exposure above the federal limit can damage the nervous system.

## How to read this

- A water-quality report covers an entire service area, not a single address.
- 'Federal limit' is the EPA standard (MCL, action level, treatment technique, etc.) that the measured level is compared against.
- 'At or above the federal limit' means the utility's own reported figure met or exceeded that standard.

_Figures are the utility's own published numbers. Generated 2026-05-26 from thewatermap.com._