# Hilmar County Water District — Hilmar, Ca, CA — Drinking Water Quality (2023)

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

- Page: https://www.thewatermap.com/water/ca/hilmar-county-water-district-hilmar-ca/2023
- JSON API: https://www.thewatermap.com/api/water/ca/hilmar-county-water-district-hilmar-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: 11
- Contaminants with a federal limit: 5
- Contaminants at or above the federal limit: 2
- Part of The Water Map — https://www.thewatermap.com

## Contaminants measured

| Contaminant | Category | Measured level | Sampling context | Federal limit | Status |
|---|---|---|---|---|---|
| Chlorine | Disinfectants | 0.48–0.73 mg/L (Range) | System-wide | 4 mg/L (MCL) | Within the limit |
| Fluoride | Inorganic chemicals | 0.1–0.13 mg/L (Range) | System-wide | 4 mg/L (MCL) | Within the limit |
| Nitrate | Inorganic chemicals | 1–34.3 mg/L (Range) | System-wide | 10 mg/L (MCL) | At or above the limit |
| Arsenic | Metals | 1.02–13.2 ug/L (Range) | System-wide | No federal limit | At or above the limit |
| Barium | Metals | 60–135 ug/L (Range) | System-wide | No federal limit | Within the limit |
| Copper | Metals | 0.172 mg/L (90th percentile) | At the tap | 1.3 mg/L (Action level) | Within the limit |
| Lead | Metals | 0 ug/L (90th percentile) | At the tap | No federal limit | Within the limit |
| Nickel | Metals | 9.2 ug/L (Reported level) | System-wide | No federal limit | Detected — no federal limit |
| Selenium | Metals | 1.7 ug/L (Range) | System-wide | No federal limit | Within the limit |
| Escherichia coli (E. coli) | Microbial | 0 (Reported level) | Total No. of Detections | No federal limit | None detected |
| Turbidity | Physical & aggregate | 0.2–0.8 NTU (Range) | System-wide | 1 NTU (MCL) | Approaching 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.
- **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.
- **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.
- **Barium** — A metal from erosion of natural deposits and industrial discharge. Long-term exposure above the federal limit can raise blood pressure.
- **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.
- **Nickel** — A metal from natural deposits and industrial discharge. Long-term exposure can cause skin and other effects; monitored under EPA rules.
- **Selenium** — A trace element from natural deposits and industrial discharge. Essential in tiny amounts, but long-term exposure above the federal limit can cause hair and fingernail loss and circulatory problems.
- **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.
- **Turbidity** — A measure of cloudiness from suspended particles in the water. High turbidity can shelter microbes from disinfection; the EPA enforces it through a treatment-technique standard.

## 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._