Drinking water quality · 2023
What's in Pasadena, CA tap water
65 contaminants were measured in the Pasadena, CA water system's 2023 annual report. Each is shown below against its federal limit.
- Reporting year
- 2023
- Contaminants measured
- 65
- Over federal limit
- 0
- Approaching the limit
- 1
- Service area
- CA
state-level CCR
Approaching the limit (≥ 80%)
Where your water comes from · EPA SDWIS
Pasadena, CA's drinking water comes from ground water, drawn from 11 sources.
Source
11ground water
- WELL
- WOODBURY
- BANGHAM WELL
- TWOMBLY WELL
- + 7 more
Treatment
12treatment plants
- EASTSIDE CENTRL CHLORAMINE @ JONES RES.
- JONES RES. NO3 & CLO4 BLEND COMPLIANCE
- SUNSET-TANK #2-NO3,CLO4,123TCP,VOC BLEND
- + 9 more
Distribution
16storage units
Also buys water from METROPOLITAN WATER DIST. OF SO. CAL., KINNELOA IRRIGATION DIST., and 3 more.
Source: EPA SDWIS facilities inventory. Methodology.
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-based2 violations on record · most recent Jan 1999resolved
- Treatment technique violationHealth-based1 violation on record · most recent Jun 1993resolved
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. | 6–66 ug/LRangePasadena Water System | None set | Approaching the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 3–36 ug/LRangePasadena Water System | None set | Within the limit |
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | 1.3 ug/LAveragePasadena Sources | None set | Detected — no federal limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chlorine Total | 0–3 mg/LRangePasadena Water System | 4 mg/LMCL | Within the limit |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | 8 pCi/LAveragePasadena Sources | 15 pCi/LMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| UraniumA naturally occurring radioactive metal from erosion of natural deposits. | 8.7 ug/LAveragePasadena Sources | 30 ug/LMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | Not detected pCi/LRangePasadena Sources | 5 pCi/LMCL | None detected |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| Gross Beta Particle ActivityGross beta particle activity — a combined measure of beta-emitting radioactive substances. | Not detectedAverageMWD Weymouth Plant | None set | Detected — no federal limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 4.6 mg/LAveragePasadena Sources | 10 mg/LMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.8 mg/LAveragePasadena Sources | 4 mg/LMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| ChlorideA naturally occurring salt compound. | 53 mg/LAveragePasadena Sources | None set | Detected — no federal limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| SulfateA naturally occurring mineral from rock and soil. | 102 mg/LAveragePasadena Sources | None set | Detected — no federal limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.3 NTUAveragePasadena Sources | 1 NTUMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| AlkalinityA measure of the water's capacity to neutralize acids. | 173 mg/LAveragePasadena Sources | None set | Detected — no federal limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| ColorA measure of visible tint in the water. | 1AverageMWD Weymouth Plant | None set | Detected — no federal limit |
+By source (2)— MWD Weymouth Plant, Pasadena Sources
| |||
| HardnessA measure of dissolved calcium and magnesium minerals. | 290 mg/LAveragePasadena Sources | None set | Detected — no federal limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| OdorA measure of detectable smell in the water. | 2AverageMWD Weymouth Plant | None set | Detected — no federal limit |
+By source (2)— MWD Weymouth Plant, Pasadena Sources
| |||
| pHA measure of how acidic or basic the water is. | 8.6AverageMWD Weymouth Plant | None set | Detected — no federal limit |
+By source (2)— MWD Weymouth Plant, Pasadena Sources
| |||
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 733AveragePasadena Sources | None set | Detected — no federal limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 469 mg/LAveragePasadena Sources | None set | Detected — no federal limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| CopperA metal that enters water from corroding household plumbing. | 0.26 mg/L90th percentilePasadena Water System | 1.3 mg/LAction level | Within the limit |
| ArsenicA naturally occurring element that also enters water from industry and agriculture. | Not detected ug/LAveragePasadena Sources | None set | None detected |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| BariumA metal from erosion of natural deposits and industrial discharge. | Not detected ug/LAveragePasadena Sources | None set | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| 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. | Not detected ug/LAveragePasadena Sources | None set | Detected — no federal limit |
+By source (2)— MWD Weymouth Plant, Pasadena Sources
| |||
| CalciumA naturally occurring mineral that contributes to water hardness. | 82 mg/LAveragePasadena Sources | None set | Detected — no federal limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 3.4 ug/LAveragePasadena Water System | 0.02 ug/LPublic health goal | Detected — no federal limit |
+By source (2)— Pasadena Water System, MWD Weymouth Plant
| |||
| IronA naturally occurring metal common in groundwater. | 46 ug/LAveragePasadena Sources | None set | Detected — no federal limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| LithiumA naturally occurring element found in some groundwater. | 16 ug/LAveragePasadena Water System | None set | Detected — no federal limit |
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 24 mg/LAveragePasadena Sources | None set | Detected — no federal limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| PotassiumA naturally occurring mineral from rock and soil. | 2.8 mg/LAverageMWD Weymouth Plant | None set | Detected — no federal limit |
+By source (2)— MWD Weymouth Plant, Pasadena Sources
| |||
| SodiumA naturally occurring salt component. | 47 mg/LAverageMWD Weymouth Plant | None set | Detected — no federal limit |
+By source (2)— MWD Weymouth Plant, Pasadena Sources
| |||
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Escherichia coli (E. coli)Escherichia coli — bacteria found in the gut of humans and animals. | 0AveragePasadena Water System Highest | None set | None detected |
+By source (2)— Pasadena Water System Highest, Pasadena Water System
| |||
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 0–1.4 %RangePasadena Water System | None set | Detected — no federal limit |
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid, a chlorinated PFAS compound. | Not detected ng/LAveragePasadena Water System | None set | None detected |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)ADONA, a newer-generation PFAS replacement compound. | Not detected ng/LAveragePasadena Water System | None set | None detected |
| 4:2 Fluorotelomer sulfonic acid (4:2 FTS)4:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected ng/LRangePasadena Water System | None set | None detected |
| 6:2 Fluorotelomer sulfonic acid (6:2 FTS)6:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected ng/LAveragePasadena Water System | None set | None detected |
| 8:2 Fluorotelomer sulfonic acid (8:2 FTS)8:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected ng/LRangePasadena Water System | None set | None detected |
| 9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS)9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid, a chlorinated PFAS compound. | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Hexafluoropropylene oxide dimer acidHFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound. | Not detected ng/LAveragePasadena Water System | 10 ng/LMCL | None detected |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)N-ethyl perfluorooctanesulfonamidoacetic acid, a PFAS-related compound. | Not detected ng/LAveragePasadena Water System | None set | None detected |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)N-methyl perfluorooctanesulfonamidoacetic acid, a PFAS-related compound. | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Nonafluoro-3,6-dioxaheptanoic acidNonafluoro-3,6-dioxaheptanoic acid, a PFAS-related compound. | Not detectedAveragePasadena Water System | None set | None detected |
| Perfluoro-3-methoxypropanoic acid (PFMPA)Perfluoro-3-methoxypropanoic acid, a PFAS-related compound. | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluoro-4-methoxybutanoic acid (PFMBA)Perfluoro-4-methoxybutanoic acid, a PFAS-related compound. | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA)Perfluoro(2-ethoxyethane)sulfonic acid, a PFAS-related compound. | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluorobutanesulfonic acidPerfluorobutanesulfonic acid, a shorter-chain PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluorodecanoic acid (PFDA)Perfluorodecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluorododecanoic acid (PFDoA)Perfluorododecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluoroheptanesulfonic acid (PFHpS)Perfluoroheptanesulfonic acid, a PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluoroheptanoic acidPerfluoroheptanoic acid, a PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | 10 ng/LMCL | None detected |
| Perfluorohexanoic acidPerfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluorononanoic acidPerfluorononanoic acid, a PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | 10 ng/LMCL | None detected |
| Perfluoropentanesulfonic acid (PFPeS)Perfluoropentanesulfonic acid, a PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluoropentanoic acidPerfluoropentanoic acid, a shorter-chain PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluorotetradecanoic acid (PFTeDA)Perfluorotetradecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluorotridecanoic acid (PFTrDA)Perfluorotridecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| Perfluoroundecanoic acid (PFUnA)Perfluoroundecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| PFBAPerfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' | Not detected ng/LAveragePasadena Water System | None set | None detected |
| PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. | Not detected ng/LAveragePasadena Water System | 4 ng/LMCL | None detected |
| PFOSPerfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. | Not detected ng/LAveragePasadena Water System | 4 ng/LMCL | None detected |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TetrachloroethyleneAn industrial solvent (PCE) used in dry cleaning and degreasing. | Not detected ug/LAveragePasadena Sources | 5 ug/LMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| TrichloroethyleneAn industrial solvent (TCE) used in metal degreasing. | Not detected ug/LAveragePasadena Sources | 5 ug/LMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
Source: Pasadena, CA's 2023 Consumer Confidence Report — the annual drinking-water report every U.S. utility is required to publish. The numbers on this page are the utility's own. A water-quality report covers an entire service area, not a single address.
People also ask about Pasadena, CA's water
+Is Pasadena, CA tap water safe to drink in 2023?
Every one of the 65 contaminants measured in Pasadena, 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 Pasadena, CA tap water?
65 contaminants were measured in Pasadena, CA's 2023 Consumer Confidence Report, spanning pfas ("forever chemicals"), metals, and physical & aggregate. 17 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Are any contaminants in Pasadena, CA tap water approaching the federal limit?
One contaminant is between 80% and 100% of the federal limit in this report: TTHM. Approaching means measured but not in violation — a margin that can close quickly if conditions change.
+Where does the data on this page come from?
Every value is transcribed from Pasadena, 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 Pasadena, 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.
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