Drinking water quality · 2023
· Verified
What's in Coastside County Water District — Half Moon Bay, Ca, CA tap water
11 contaminants were measured in the Coastside County Water District — Half Moon Bay, Ca, CA water system's 2023 annual report. Each is shown below against its federal limit.
- Reporting year
- 2023
- Contaminants measured
- 11
- Over federal limit
- 0
- Approaching the limit
- 0
- Service area
- CA
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Maximum contaminant level exceededHealth-based4 violations on record · most recent Jan 2004resolved
- Treatment technique violationHealth-based2 violations on record · most recent Apr 2008resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 60 ug/LRunning annual avgLocation RAA | None set | Within the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 27 ug/LRunning annual avgLocation RAA | None set | Within the limit |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 0.84 mg/LAverageSystem-wide | None set | Within the limit |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 1.7 ug/L90th percentileAt the tap | None set | Within the limit |
| CopperA metal that enters water from corroding household plumbing. | 0.08 mg/L90th percentileAt the tap | 1.3 mg/LAction level | Within the limit |
| BoronA naturally occurring element from rock and soil. | Not detected ug/LAverageNunes WTP | 1000 ug/LNL | None detected |
+By source (2)— Nunes WTP, Denniston WTP
| |||
| AluminumA common element sometimes used as a treatment coagulant. | Not detected mg/LAverageNunes WTP | None set | Detected — no federal limit |
+By source (2)— Nunes WTP, Denniston WTP
| |||
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.2 mg/LAverageDenniston WTP | 4 mg/LMCL | Within the limit |
+By source (2)— Nunes WTP, Denniston WTP
| |||
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 0.4 mg/LAverageNunes WTP | 10 mg/LMCL | Within the limit |
+By source (2)— Nunes WTP, Denniston WTP
| |||
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.025 NTUAverageNunes WTP | None set | Within the limit |
+By source (2)— Nunes WTP, Denniston WTP
| |||
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 1.2 mg/LAverageNunes WTP | None set | Detected — no federal limit |
+By source (2)— Nunes WTP, Denniston WTP
| |||
People also ask about Coastside County Water District — Half Moon Bay, Ca, CA's water
+Is Coastside County Water District — Half Moon Bay, Ca, CA tap water safe to drink in 2023?
Every one of the 11 contaminants measured in Coastside County Water District — Half Moon Bay, Ca, CA's 2023 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in Coastside County Water District — Half Moon Bay, Ca, CA tap water?
11 contaminants were measured in Coastside County Water District — Half Moon Bay, 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.
+Where does the data on this page come from?
Every value is transcribed from Coastside County Water District — Half Moon Bay, 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 Coastside County Water District — Half Moon Bay, 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.