# Rio Alto Water District — Cottonwood, Ca, CA — Drinking Water Quality (2023)

> Contaminant levels for the Rio Alto Water District — Cottonwood, Ca, CA public water system from its 2023 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/rio-alto-water-district-cottonwood-ca/2023
- JSON API: https://www.thewatermap.com/api/water/ca/rio-alto-water-district-cottonwood-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: 13
- 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 |
|---|---|---|---|---|---|
| Chloride | Inorganic chemicals | 3 (Reported level) | System-wide | No federal limit | Detected — no federal limit |
| Fluoride | Inorganic chemicals | 0.18 (Reported level) | System-wide | 2 (MCL) | Detected — no federal limit |
| Nitrate | Inorganic chemicals | 1 (Reported level) | System-wide | 10 (MCL) | Detected — no federal limit |
| Sulfate | Inorganic chemicals | 2 (Reported level) | System-wide | No federal limit | Detected — no federal limit |
| Arsenic | Metals | 3 ug/L (Reported level) | System-wide | No federal limit | Within the limit |
| Chromium, Hexavalent | Metals | 4.3 ug/L (Reported level) | System-wide | No federal limit | Detected — no federal limit |
| Copper | Metals | 51 ug/L (90th percentile) | At the tap | No federal limit | Within the limit |
| Lead | Metals | Not detected (90th percentile) | At the tap | No federal limit | None detected |
| Sodium | Metals | 16 (Reported level) | System-wide | No federal limit | Detected — no federal limit |
| Total Coliform | Microbial | 4 (Highest single sample) | No. of Detections | 0 (MCLG) | Detected — no federal limit |
| Chromium | Other | Not detected (Reported level) | System-wide | No federal limit | None detected |
| Hardness | Physical & aggregate | 89 (Reported level) | System-wide | No federal limit | Detected — no federal limit |
| Total Dissolved Solids | Physical & aggregate | 190 (Reported level) | System-wide | No federal limit | Detected — no federal limit |

## What these contaminants are

- **Chloride** — A naturally occurring salt compound. Regulated only as a secondary (cosmetic) standard; high levels cause a salty taste and can corrode pipes.
- **Fluoride** — A mineral often added to drinking water to help prevent tooth decay. Beneficial at low levels, but long-term exposure above the federal limit can cause bone disease and tooth mottling.
- **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.
- **Sulfate** — A naturally occurring mineral from rock and soil. No health-based federal limit; high levels can have a laxative effect and a bitter taste.
- **Arsenic** — A naturally occurring element that also enters water from industry and agriculture. A known human carcinogen; long-term exposure is linked to skin, bladder, and lung cancer.
- **Chromium, Hexavalent** — Hexavalent chromium ('chromium-6') — the more toxic form of chromium. A known carcinogen by inhalation; regulated nationally only within the total-chromium limit, with stricter limits in some states.
- **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.
- **Sodium** — A naturally occurring salt component. Not federally regulated for health; relevant for people on sodium-restricted diets.
- **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.
- **Hardness** — A measure of dissolved calcium and magnesium minerals. Not federally regulated for health; affects scaling, soap use, and taste.
- **Total Dissolved Solids** — Total dissolved solids — the combined content of all dissolved minerals and salts. Regulated only as a secondary (cosmetic) standard; high levels affect taste and hardness.

## 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._