# Town of Yountville — Yountville, Ca, CA — Drinking Water Quality (2022)

> Contaminant levels for the Town of Yountville — Yountville, Ca, CA public water system from its 2022 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/yountville-yountville-ca/2022
- JSON API: https://www.thewatermap.com/api/water/ca/yountville-yountville-ca/2022
- 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: 2022
- Contaminants measured: 5
- Contaminants with a federal limit: 2
- 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 |
|---|---|---|---|---|---|
| HAA5 | Disinfection byproducts | 16 ug/L (Running annual avg) | System-wide | No federal limit | Within the limit |
| TTHM | Disinfection byproducts | 40.96 ug/L (Running annual avg) | System-wide | No federal limit | Within the limit |
| Copper | Metals | 0.13 mg/L (90th percentile) | At the tap | 1.3 mg/L (Action level) | Within the limit |
| Lead | Metals | 0.005 mg/L (90th percentile) | At the tap | 0.015 mg/L (Action level) | Within the limit |
| Escherichia coli (E. coli) | Microbial | 0 (Reported level) | System-wide | No federal limit | None detected |

## What these contaminants are

- **HAA5** — Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. Long-term exposure above the federal limit is associated with an increased cancer risk.
- **TTHM** — Total trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. Long-term exposure above the federal limit is linked to liver, kidney, and central-nervous-system effects and increased cancer risk.
- **Copper** — A metal that enters water from corroding household plumbing. Short-term exposure causes stomach distress; long-term exposure can damage the liver and kidneys.
- **Lead** — A toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. There is no safe level of lead; it harms brain development in children and raises blood pressure in adults. The EPA sets an action level, not a health goal above zero.
- **Escherichia coli (E. coli)** — Escherichia coli — bacteria found in the gut of humans and animals. Its presence in drinking water indicates fecal contamination and a real risk of waterborne illness.

## 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 2026-06-04 from thewatermap.com._