# Great Oaks Wc Inc — San Jose, Ca, CA — Drinking Water Quality (2023)

> Contaminant levels for the Great Oaks Wc Inc — San Jose, Ca, CA public water system from its 2023 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/great-oaks-wc-inc-san-jose-ca/2023
- JSON API: https://www.thewatermap.com/api/water/ca/great-oaks-wc-inc-san-jose-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: 20
- Contaminants with a federal limit: 8
- 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 |
|---|---|---|---|---|---|
| HAA5 | Disinfection byproducts | 2.8 ug/L (Average) | System-wide | No federal limit | Within the limit |
| TTHM | Disinfection byproducts | 14.74 ug/L (Reported level) | Calero Pressure Zone | No federal limit | Within the limit |
| Asbestos | Inorganic chemicals | 0–0.19 MFL (Range) | System-wide | 7 MFL (MCL) | Within the limit |
| Bromide | Inorganic chemicals | 9.7 ug/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| Bromochloroacetic acid | Inorganic chemicals | 0.51 ug/L (Average) | System-wide | No federal limit | Within the limit |
| Chlorodibromoacetic acid | Inorganic chemicals | 0.52 ug/L (Average) | System-wide | No federal limit | Within the limit |
| Dibromoacetic acid | Inorganic chemicals | 1.8 ug/L (Average) | System-wide | No federal limit | Within the limit |
| Fluoride | Inorganic chemicals | 0.11–0.21 mg/L (Range) | System-wide | 4 mg/L (MCL) | Within the limit |
| Nitrate | Inorganic chemicals | 0.79–7.4 mg/L (Range) | System-wide | 10 mg/L (MCL) | Within the limit |
| Arsenic | Metals | 0–2.4 ug/L (Range) | System-wide | No federal limit | Within the limit |
| Barium | Metals | 0–0.18 mg/L (Range) | System-wide | 2 mg/L (MCL) | Within the limit |
| Chromium, Total | Metals | 0–8.5 ug/L (Range) | System-wide | No federal limit | Within the limit |
| Copper | Metals | 0.38 mg/L (Reported level) | At the tap | 1.3 mg/L (Action level) | Within the limit |
| Lead | Metals | Not detected mg/L (Reported level) | At the tap | 0.015 mg/L (Action level) | None detected |
| Manganese | Metals | 0.04 ug/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| Total Coliform | Microbial | 0–1 % (Range) | System-wide | No federal limit | Detected — no federal limit |
| Nitrate Nitrite | Other | 0.44–7.1 mg/L (Range) | System-wide | 10 mg/L (MCL) | Within the limit |
| TOC | Physical & aggregate | 0.32 mg/L (Average) | System-wide | No federal limit | Detected — no federal limit |
| Gross Alpha | Radionuclides | 0–1.7 pCi/L (Range) | System-wide | 15 pCi/L (MCL) | Within the limit |
| Dichlorodifluoromethane | VOCs & pesticides | 0–3.5 ug/L (Range) | System-wide | No federal limit | Detected — no federal limit |

## What these contaminants are

- **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.
- **Bromide** — A naturally occurring salt found in source water. Not directly regulated, but a precursor that increases formation of brominated disinfection byproducts.
- **Bromochloroacetic acid** — A mixed-halogen haloacetic acid disinfection byproduct. Part of the broader HAA9 group; monitored without its own enforceable limit.
- **Chlorodibromoacetic acid** — A brominated haloacetic acid disinfection byproduct. Part of the broader HAA9 group; monitored but without its own enforceable federal limit.
- **Dibromoacetic acid** — A brominated haloacetic acid disinfection byproduct. Part of the broader HAA9 group; monitored without its own enforceable limit.
- **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.
- **Chromium, Total** — Total chromium — the sum of all chromium forms, from natural deposits and industrial discharge. Long-term exposure above the federal limit can cause allergic dermatitis; includes hexavalent chromium.
- **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.
- **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.
- **TOC** — Total organic carbon — a measure of organic material dissolved in the water. Not harmful itself, but it is the raw material that forms disinfection byproducts; removal is a treatment requirement.
- **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._