Drinking water quality · 2023
· Verified
What's in Western Hills Water District/diablo Gran — Patterson, Ca, CA tap water
9 contaminants were measured in the Western Hills Water District/diablo Gran — Patterson, Ca, CA water system's 2023 annual report. Each is shown below against its federal limit — 1 sit at or above that limit.
- Reporting year
- 2023
- Contaminants measured
- 9
- Over federal limit
- 1
- Approaching the limit
- 1
- Worst contaminant
- Nitrate
- Service area
- CA
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 0–13 mg/LRangeSystem-wide | 10 mg/LMCL | At or above the limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 9.1–67 ug/LRangeSystem-wide | None set | Approaching the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 0–32 ug/LRangeSystem-wide | None set | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| CopperA metal that enters water from corroding household plumbing. | 0.085 mg/L90th percentileAt the tap | 1.3 mg/LAction level | Within the limit |
| ArsenicA naturally occurring element that also enters water from industry and agriculture. | Not detected ug/LReported levelSystem-wide | None set | None detected |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | Not detected ug/L90th percentileAt the tap | None set | Within the limit |
| ManganeseA naturally occurring metal from soil and rock. | Not detectedReported levelSystem-wide | 500NL | None detected |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals. | 0Highest single sampleNo. of Detections | 0MCLG | None detected |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 1.2–2.8RangeSystem-wide | None set | Detected — no federal limit |
People also ask about Western Hills Water District/diablo Gran — Patterson, Ca, CA's water
+Is Western Hills Water District/diablo Gran — Patterson, Ca, CA tap water safe to drink in 2023?
The 2023 Consumer Confidence Report for the Western Hills Water District/diablo Gran — Patterson, Ca, CA water utility lists 1 contaminant at or above the federal limit: Nitrate. Whether that means the water is "unsafe" depends on which contaminant, how long the exposure, and individual health factors. The table on this page shows the measured value, the federal threshold, and the regulated statistic used for compliance.
+What contaminants are in Western Hills Water District/diablo Gran — Patterson, Ca, CA tap water?
9 contaminants were measured in Western Hills Water District/diablo Gran — Patterson, Ca, CA's 2023 Consumer Confidence Report, spanning metals, disinfection byproducts, and inorganic chemicals. 4 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Which contaminants exceed federal limits in Western Hills Water District/diablo Gran — Patterson, Ca, CA tap water?
One contaminant in Western Hills Water District/diablo Gran — Patterson, Ca, CA's 2023 report sits at or above the federal limit: Nitrate (1.3× the limit). The EPA enforces these limits against the regulated reporting statistic — typically a running annual average or 90th percentile — not a one-off sample spike.
+What is the worst contaminant in Western Hills Water District/diablo Gran — Patterson, Ca, CA tap water?
The contaminant with the highest measured value relative to its federal limit in the 2023 report is Nitrate, at 1.3× the federal threshold. It belongs to the inorganic chemicals family of contaminants.
+Are any contaminants in Western Hills Water District/diablo Gran — Patterson, Ca, CA tap water approaching the federal limit?
One contaminant is between 80% and 100% of the federal limit in this report: TTHM. Approaching means measured but not in violation — a margin that can close quickly if conditions change.
+Where does the data on this page come from?
Every value is transcribed from Western Hills Water District/diablo Gran — Patterson, Ca, CA's 2023 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Western Hills Water District/diablo Gran — Patterson, Ca, CA's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2023 report; a new report will replace it once the utility publishes its next annual update.