Drinking water quality · 2023
· Verified
· PWSID CA4110011
What's in Coastside County Water District — Half Moon Bay, Ca, CA tap water
Only 8 of 27 core regulated contaminants were reported for Coastside County Water District — Half Moon Bay, Ca, CA. What was measured is clean — but most of the picture is missing.
- !8 of 27 core regulated contaminants reported — 19 never appear in this report
- ✓Nothing over a federal limit
- ✓No open federal violations
+How this score is calculated
Every system starts at 100. Points come off for measured levels, for the federal violation record, and for how much of the core regulated set the utility actually reported. All three inputs are the utility's own published numbers and EPA's own records.
- −0 contaminants at or above a federal limit
- −0 contaminants within 20% of a limit
- −0 open health-based violations
- −0 open monitoring / reporting violations
- −0 health-based violations resolved in the last 5 years
- −17 core regulated contaminants never reported (8/27)
A 90–100 · B 80–89 · C 70–79 · D 60–69 · F below 60. A system reporting under a third of the core set is capped at C however clean its numbers look — a short report is not a clean bill of health.
Full grading methodology, constant for constant →+11 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| TTHM | 60 ug/L | 80 ug/L |
| HAA5 | 27 ug/L | 60 ug/L |
| Chlorine | 0.84 mg/L | 4 mg/L |
| Lead | 1.7 ug/L | 15 ug/L |
| Copper | 0.08 mg/L | 1.3 mg/L |
| Fluoride | 0.2 mg/L | 4 mg/L |
| Nitrate | 0.4 mg/L | 10 mg/L |
| Turbidity | 0.025 NTU | 1 NTU |
| Aluminum | Not detected mg/L | — |
| Boron | Not detected ug/L | 1000 ug/L |
| TOC | 1.2 mg/L | — |
What this report doesn't tell you
19 of the 27 contaminants a community water system normally reports do not appear anywhere in Coastside County Water District — Half Moon Bay, Ca, CA's data. Absent is not the same as absent-from-the-water — it means nobody published a number.
+Full detail: PFAS testing, water source, historical monitoring, and the federal violation record
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 Dec 2003resolved
- Treatment technique violationHealth-based2 violations on record · most recent Mar 2008resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗