# Rincon Del Diablo MWD (id-1), CA — Drinking Water Quality (2025)

> Contaminant levels for the Rincon Del Diablo MWD (id-1), CA public water system from its 2025 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/rincon-del-diablo-mwd-id-1/2025
- JSON API: https://www.thewatermap.com/api/water/ca/rincon-del-diablo-mwd-id-1/2025
- 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: 2025
- Contaminants measured: 15
- Contaminants with a federal limit: 3
- 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 |
|---|---|---|---|---|---|
| Bromodichloromethane | Disinfection byproducts | 6.7375 UG/L (Average) | Distribution | No federal limit | Detected — no federal limit |
| Bromoform | Disinfection byproducts | 1.90625 UG/L (Average) | Distribution | No federal limit | Detected — no federal limit |
| Chloroform | Disinfection byproducts | 5.4625 UG/L (Average) | Distribution | No federal limit | Detected — no federal limit |
| Dibromochloromethane | Disinfection byproducts | 6.45625 UG/L (Average) | Distribution | No federal limit | Detected — no federal limit |
| HAA5 | Disinfection byproducts | 4.93125 UG/L (Average) | Distribution | 60 UG/L (MCL) | Within the limit |
| TTHM | Disinfection byproducts | 20.5625 UG/L (Average) | Distribution | 80 UG/L (MCL) | Within the limit |
| Copper | Metals | 401 UG/L (90th percentile) | Distribution | 1300 UG/L (Al) | Within the limit |
| Lead | Metals | 1.5366666666666666 UG/L (Average) | Distribution | No federal limit | Detected — no federal limit |
| Lithium | Metals | 43 mg/L (Highest single sample) | Entry point | No federal limit | Detected — no federal limit |
| Dbaa | Other | 1.15625 UG/L (Average) | Distribution | No federal limit | Detected — no federal limit |
| Dcaa | Other | 3.4875 UG/L (Average) | Distribution | No federal limit | Detected — no federal limit |
| Mbaa | Other | Not detected UG/L (Highest single sample) | Distribution | No federal limit | None detected |
| Mcaa | Other | Not detected UG/L (Highest single sample) | Distribution | No federal limit | None detected |
| Tcaa | Other | 1.7 UG/L (Average) | Distribution | No federal limit | Detected — no federal limit |
| PFBA | PFAS ("forever chemicals") | 10 ng/L (Highest single sample) | Entry point | No federal limit | Detected — no federal limit |

## What these contaminants are

- **Bromodichloromethane** — A trihalomethane disinfection byproduct. Counted within regulated total trihalomethanes; long-term exposure is associated with cancer and reproductive effects.
- **Bromoform** — A trihalomethane disinfection byproduct. Counted within regulated total trihalomethanes; long-term exposure is associated with liver and kidney effects.
- **Chloroform** — A trihalomethane formed when chlorine reacts with organic matter in water. A component of regulated total trihalomethanes; long-term exposure is linked to liver and kidney effects.
- **Dibromochloromethane** — A trihalomethane disinfection byproduct. Part of regulated total trihalomethanes; long-term exposure is linked to nervous-system, liver, and kidney effects.
- **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.
- **Lithium** — A naturally occurring element found in some groundwater. No enforceable federal limit; on the EPA contaminant candidate list for further study.
- **PFBA** — Perfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment and the human body.

## 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._