# Rio Dell, City of — Rio Dell, Ca, CA — Drinking Water Quality (2023)

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

- Page: https://www.thewatermap.com/water/ca/rio-dell-rio-dell-ca/2023
- JSON API: https://www.thewatermap.com/api/water/ca/rio-dell-rio-dell-ca/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: 6
- 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 |
|---|---|---|---|---|---|
| Chlorine | Disinfectants | 1.9 mg/L (Average) | System-wide | No federal limit | Within the limit |
| HAA5 | Disinfection byproducts | 11 ug/L (Average) | System-wide | No federal limit | Within the limit |
| TTHM | Disinfection byproducts | 26 ug/L (Average) | System-wide | No federal limit | Within the limit |
| Escherichia coli (E. coli) | Microbial | 0 (Highest single sample) | Highest # Of Detections | 0 (MCLG) | None detected |
| Total Coliform | Microbial | 0 (Highest single sample) | Highest # Of Detections | No federal limit | None detected |
| Gross Alpha | Radionuclides | 0.17 pCi/L (Average) | System-wide | 15 pCi/L (MCL) | Within the limit |

## What these contaminants are

- **Chlorine** — A disinfectant added to drinking water to kill bacteria and viruses. Effective and necessary, but high residual levels can cause taste and odor issues; the EPA caps the residual disinfectant level.
- **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.
- **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.
- **Total Coliform** — A group of bacteria used as an indicator of overall water-system sanitation. Coliforms themselves are usually harmless, but their presence signals that disease-causing organisms could enter the system.
- **Gross Alpha** — Gross alpha particle activity — a combined measure of alpha-emitting radioactive substances. Long-term exposure above the federal limit increases cancer risk.

## 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._