# O'connor Tract Co-operative Water Co. — Palo Alto, Ca, CA — Drinking Water Quality (2023)

> Contaminant levels for the O'connor Tract Co-operative Water Co. — Palo Alto, Ca, CA public water system from its 2023 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/o-connor-tract-co-operative-water-co-palo-alto-ca/2023
- JSON API: https://www.thewatermap.com/api/water/ca/o-connor-tract-co-operative-water-co-palo-alto-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: 9
- Contaminants with a federal limit: 5
- 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 | 0.28–0.64 mg/L (Average) | And Range | No federal limit | Within the limit |
| Fluoride | Inorganic chemicals | 0.2 mg/L (Reported level) | Well 1 | 4 mg/L (MCL) | Within the limit |
| Nitrate | Inorganic chemicals | 0.8 mg/L (Reported level) | Well 1 | 10 mg/L (MCL) | Within the limit |
| Barium | Metals | 0.1 mg/L (Reported level) | Well 2 | 2 mg/L (MCL) | Within the limit |
| Copper | Metals | 0.16 mg/L (90th percentile) | At the tap | 1.3 mg/L (Action level) | Within the limit |
| Lead | Metals | 7 ug/L (90th percentile) | At the tap | No federal limit | Within the limit |
| Manganese | Metals | 10–23 ug/L (Average) | And Range | No federal limit | Detected — no federal limit |
| Selenium | Metals | 7.5 ug/L (Reported level) | Well 2 | No federal limit | Within the limit |
| Gross Alpha | Radionuclides | 3.07 pCi/L (Reported level) | Well 2 | 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.
- **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.
- **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.
- **Manganese** — A naturally occurring metal from soil and rock. No enforceable federal limit; high levels stain fixtures and laundry and can affect taste, with a health advisory for infants.
- **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.
- **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._