Drinking water quality · 2023
· Verified
· PWSID CA4010009
What's in San Luis Obispo Water Department — San Luis Obispo, Ca, CA tap water
Every one of the 10 core regulated contaminants reported for San Luis Obispo Water Department — San Luis Obispo, Ca, CA came in below its federal limit.
- !2 contaminants within 20% of a limit
- !10 of 27 core regulated contaminants reported — 17 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
- −8 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
- −14 core regulated contaminants never reported (10/27)
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 →What to worry about
- TTHM94% of the federal limit27–75 ug/L · limit 80 ug/L
Long-term exposure above the federal limit is linked to liver, kidney, and central-nervous-system effects and increased cancer risk.
Higher than 95% of CA systems that report it · higher than 90% of U.S. systems
- HAA582% of the federal limit21–49 ug/L · limit 60 ug/L
Long-term exposure above the federal limit is associated with an increased cancer risk.
Higher than 95% of CA systems that report it · higher than 90% of U.S. systems
+13 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| Chlorine | 0.09–1.9 mg/L | 4 mg/L |
| Chromium, Total | 24 ug/L | 100 ug/L |
| Fluoride | 0–0.9 mg/L | 4 mg/L |
| Arsenic | 2 ug/L | 10 ug/L |
| Turbidity | 0.18 NTU | 1 NTU |
| Selenium | 6 ug/L | 50 ug/L |
| Copper | 0.15 mg/L | 1.3 mg/L |
| Gross Alpha | 0.735 pCi/L | 15 pCi/L |
| Aluminum | 0.05–0.15 mg/L | — |
| Lithium | 10 ug/L | — |
| Sodium | 32 mg/L | — |
| Hardness | 126–317 mg/L | — |
| TOC | 26–43 | — |
What this report doesn't tell you
17 of the 27 contaminants a community water system normally reports do not appear anywhere in San Luis Obispo Water Department — San Luis Obispo, 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-based1 violation on record · most recent Apr 2015resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗