Drinking water quality · 2022
· Verified
· PWSID CA1910191
What's in Norwalk - City, Water Dept. — Norwalk, Ca, CA tap water
2 contaminants in Norwalk - City, Water Dept. — Norwalk, Ca, CA's water sat at or above a federal limit, led by PFOS at 5.3x the limit.
- !2 contaminants at or above a federal limit — worst is PFOS at 5.3x
- !17 of 27 core regulated contaminants reported — 10 never appear in this report
- ✓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.
- −54 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
- −3 core regulated contaminants never reported (17/27)
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
- PFOS5.3× the federal limit21.1 ng/L · limit 4 ng/L
Linked to cancer, thyroid disease, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
Higher than 85% of CA systems that report it · higher than 85% of U.S. systems
- PFOA1.4× the federal limit5.7 ng/L · limit 4 ng/L
Linked to cancer, liver damage, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
Higher than 70% of CA systems that report it · higher than 75% of U.S. systems
+23 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| Perfluorohexanesulfonic acid | 7.3 ng/L | 10 ng/L |
| TTHM | 51.7 ug/L | 80 ug/L |
| Arsenic | 5.9 ug/L | 10 ug/L |
| Chlorine Total | 1.4 mg/L | 4 mg/L |
| HAA5 | 19.1 ug/L | 60 ug/L |
| Gross Alpha | 4.59 pCi/L | 15 pCi/L |
| Tetrachloroethylene | 1.48 ug/L | 5 ug/L |
| Trichloroethylene | 1.4 ug/L | 5 ug/L |
| Copper | 0.34 mg/L | 1.3 mg/L |
| Benzene | 1.2 ug/L | 5 ug/L |
| Turbidity | 0.2 NTU | 1 NTU |
| Fluoride | 0.7 mg/L | 4 mg/L |
| Nitrate | 1.7 mg/L | 10 mg/L |
| Uranium | 2.42 ug/L | 30 ug/L |
| Barium | 0.07 mg/L | 2 mg/L |
| Chromium | 0.1 ug/L | 100 ug/L |
| Aluminum | 0.11 mg/L | — |
| Lead | 0.0 mg/L | 0.015 mg/L |
| Escherichia coli (E. coli) | 0 % | — |
| Total Coliform | 0.7 % | — |
| Perfluorobutanesulfonic acid | 2.3 ng/L | 500 ng/L |
| Combined Radium | Not detected pCi/L | 5 pCi/L |
| Gross Beta Particle Activity | Not detected | — |
What this report doesn't tell you
10 of the 27 contaminants a community water system normally reports do not appear anywhere in Norwalk - City, Water Dept. — Norwalk, 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 Jan 1999resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗