Drinking water quality · 2022
What's in Norwalk - City, Water Dept. — Norwalk, Ca, CA tap water
25 contaminants were measured in the Norwalk - City, Water Dept. — Norwalk, Ca, CA water system's 2022 annual report. Each is shown below against its federal limit — 2 sit at or above that limit.
- Reporting year
- 2022
- Contaminants measured
- 25
- Over federal limit
- 2
- Approaching the limit
- 0
- Worst contaminant
- PFOS
- 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-based1 violation on record · most recent Jan 1999resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PFOSPerfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. | 21.1 ng/LAverageSystem-wide | 6.5 ng/LNL | At or above the limit |
| PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. | 5.7 ng/LAverageSystem-wide | 5.1 ng/LNL | At or above the limit |
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | 7.3 ng/LAverageSystem-wide | 3 ng/LNL | Within the limit |
| Perfluorobutanesulfonic acidPerfluorobutanesulfonic acid, a shorter-chain PFAS 'forever chemical.' | 2.3 ng/LAverageSystem-wide | 500 ng/LNL | Detected — no federal 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. | 51.7 ug/LRunning annual avgDistribution System Highest Running | None set | Within the limit |
+By source (2)— Distribution System, Distribution System Highest Running
| |||
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 19.1 ug/LRunning annual avgDistribution System Highest Running | None set | Within the limit |
+By source (2)— Distribution System, Distribution System Highest Running
| |||
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ArsenicA naturally occurring element that also enters water from industry and agriculture. | 5.9 ug/LAverageGroundwater | None set | Within the limit |
+By source (2)— Groundwater, MWD's Surface Water
| |||
| CopperA metal that enters water from corroding household plumbing. | 0.34 mg/L90th percentileDistribution System | 1.3 mg/LAction level | Within the limit |
| BariumA metal from erosion of natural deposits and industrial discharge. | 0.07 mg/LAverageGroundwater | 2 mg/LMCL | Within the limit |
+By source (2)— Groundwater, MWD's Surface Water
| |||
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0.0 mg/L90th percentileAt the tap | 0.015 mg/LAction level | None detected |
| AluminumA common element sometimes used as a treatment coagulant. | 0.11 mg/LAverageMWD's Surface Water | None set | Detected — no federal limit |
+By source (2)— MWD's Surface Water, Groundwater
| |||
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chlorine Total | 1.4 mg/LRunning annual avgDistribution System Highest Running | 4 mg/LMCL | Within the limit |
+By source (2)— Distribution System, Distribution System Highest Running
| |||
| Chromium | 0.1 ug/LAverageGroundwater | None set | Within the limit |
+By source (2)— Groundwater, MWD's Surface Water
| |||
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | 4.59 pCi/LAverageGroundwater | 15 pCi/LMCL | Within the limit |
+By source (2)— MWD's Surface Water, Groundwater
| |||
| UraniumA naturally occurring radioactive metal from erosion of natural deposits. | 2.42 ug/LAverageGroundwater | 30 ug/LMCL | Within the limit |
+By source (2)— Groundwater, MWD's Surface Water
| |||
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | Not detected pCi/LAverageGroundwater | 5 pCi/LMCL | None detected |
+By source (2)— Groundwater, MWD's Surface Water
| |||
| Gross Beta Particle ActivityGross beta particle activity — a combined measure of beta-emitting radioactive substances. | Not detectedAverageMWD's Surface Water | None set | Detected — no federal limit |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TetrachloroethyleneAn industrial solvent (PCE) used in dry cleaning and degreasing. | 1.48 ug/LAverageGroundwater | 5 ug/LMCL | Within the limit |
+By source (2)— Groundwater, MWD's Surface Water
| |||
| TrichloroethyleneAn industrial solvent (TCE) used in metal degreasing. | 1.4 ug/LAverageGroundwater | 5 ug/LMCL | Within the limit |
+By source (2)— Groundwater, MWD's Surface Water
| |||
| Benzene | 1.2 ug/LAverageGroundwater | None set | Within the limit |
+By source (2)— Groundwater, MWD's Surface Water
| |||
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.2 NTUAverageDistribution System | None set | Within the limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.7 mg/LAverageMWD's Surface Water | 4 mg/LMCL | Within the limit |
+By source (2)— MWD's Surface Water, Groundwater
| |||
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 1.7 mg/LAverageGroundwater | None set | Within the limit |
+By source (2)— Groundwater, MWD's Surface Water
| |||
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals. | 0 %AverageDistribution System Average % Positive | None set | None detected |
+By source (2)— Distribution System Average % Positive, Distribution System Range % Positive
| |||
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 0.7 %AverageDistribution System Average % Positive | None set | Detected — no federal limit |
+By source (2)— Distribution System Range % Positive, Distribution System Average % Positive
| |||
People also ask about Norwalk - City, Water Dept. — Norwalk, Ca, CA's water
+Is Norwalk - City, Water Dept. — Norwalk, Ca, CA tap water safe to drink in 2022?
The 2022 Consumer Confidence Report for the Norwalk - City, Water Dept. — Norwalk, Ca, CA water utility lists 2 contaminants at or above the federal limit: PFOS and PFOA. 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 Norwalk - City, Water Dept. — Norwalk, Ca, CA tap water?
25 contaminants were measured in Norwalk - City, Water Dept. — Norwalk, Ca, CA's 2022 Consumer Confidence Report, spanning metals, pfas ("forever chemicals"), and radionuclides. 14 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 Norwalk - City, Water Dept. — Norwalk, Ca, CA tap water?
2 contaminants in Norwalk - City, Water Dept. — Norwalk, Ca, CA's 2022 report sit at or above the federal limit: PFOS (5.3× the limit); PFOA (1.4× 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 Norwalk - City, Water Dept. — Norwalk, Ca, CA tap water?
The contaminant with the highest measured value relative to its federal limit in the 2022 report is PFOS, at 5.3× the federal threshold. It belongs to the pfas ("forever chemicals") family of contaminants.
+Where does the data on this page come from?
Every value is transcribed from Norwalk - City, Water Dept. — Norwalk, Ca, CA's 2022 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 Norwalk - City, Water Dept. — Norwalk, 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 2022 report; a new report will replace it once the utility publishes its next annual update.