Drinking water quality · 2023
· Verified
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 — 2 sit at or above that limit.
- Reporting year
- 2023
- Contaminants measured
- 65
- Over federal limit
- 2
- Approaching the limit
- 0
- Worst contaminant
- Chromium, Hexavalent
- Service area
- CA
170.0× the limit
state-level CCR
PFAS — EPA UCMR5 (2023–2025)
1 PFAS compound detected in Pasadena, CA
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
Lithium
● Detected (no federal limit)Measured 64.2 mg/LSample year 2024Samples 5 detect / 7
near national p90 (76.59999999999991 mg/L across detecting U.S. systems)
PWSID CA1910124 · Source: EPA UCMR5. Limits per EPA's April 2024 PFAS National Primary Drinking Water Regulation. PFAS values reported in nanograms per liter (ng/L) — note that 1 ng/L = 1 part per trillion.
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.
Historical readings · EPA Six-Year Review (2012–2019)
4 contaminants historically over EPA limits in Pasadena, CA
Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.
| Contaminant | Worst detection | EPA limit | Years (2012–2019) |
|---|---|---|---|
TCE worst: 2012 | 0.031 mg/L 6.2× | 0.005 mg/L | '12'13'14'15'16'17'18'19 |
PCE worst: 2012 | 0.0138 mg/L 2.8× | 0.005 mg/L | '12'13'14'15'16'17'18'19 |
TTHM worst: 2012 | 0.118 mg/L 1.5× | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
NITRATE worst: 2018 | 13.2 mg/L 1.3× | 10 mg/L | '12'13'14'15'16'17'18'19 |
CARBON TETRACHLORIDE worst: 2012 | 0.00401 mg/L 80% near national p90 | 0.005 mg/L | '12'13'14'15'16'17'18'19 |
DEHP worst: 2012 | 0.0037 mg/L within | 0.006 mg/L | '12 |
HAA5 worst: 2013 | 0.034 mg/L within | 0.06 mg/L | '12'13'14'15'16'17'18'19 |
FLUORIDE worst: 2017 | 1.45 mg/L within | 4 mg/L | '12'13'14'15'16'17'18'19 |
ARSENIC worst: 2014 | 0.003 mg/L within below national p90 | 0.01 mg/L | '14'17 |
CIS DICHLOROETHYLENE 12 worst: 2012 | 0.0207 mg/L within above national p90 | 0.07 mg/L | '12'13'14'15'16'17'18'19 |
NITRATE NITRITE worst: 2016 | 1.6 mg/L within | 10 mg/L | '16 |
DICHLOROETHYLENE 11 worst: 2015 | 0.00091 mg/L within below national p90 | 0.007 mg/L | '15 |
DICHLOROMETHANE worst: 2019 | 0.00054 mg/L within | 0.005 mg/L | '19 |
BARIUM worst: 2014 | 0.17 mg/L within near national p90 | 2 mg/L | '12'13'14'16'17'18'19 |
TRANS DICHLOROETHYLENE 12 worst: 2013 | 0.0042 mg/L within | 0.1 mg/L | '12'13'14 |
URANIUM worst: 2016 | 0.0268 ug/L within above national p90 | 30 ug/L | '12'13'14'15'16'17'18 |
TOLUENE worst: 2015 | 0.0006 mg/L within | 1 mg/L | '15 |
DBAA worst: 2012 | 0.0064 mg/L | — | '12'13'14'15'16'17'18'19 |
DCAA worst: 2012 | 0.016 mg/L | — | '12'13'14'15'16'17'18'19 |
MBAA worst: 2012 | 0.0013 mg/L | — | '12'13'16 |
MCAA worst: 2013 | 0.0032 mg/L | — | '13 |
TCAA worst: 2012 | 0.0096 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMODICHLOROMETHANE worst: 2012 | 0.0379 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMOFORM worst: 2012 | 0.0119 mg/L | — | '12'13'14'15'16'17'18'19 |
CHLOROFORM worst: 2012 | 0.0445 mg/L | — | '12'13'14'15'16'17'18'19 |
DIBROMOCHLOROMETHANE worst: 2012 | 0.0307 mg/L | — | '12'13'14'15'16'17'18'19 |
PWSID CA1910124 · Source: EPA Six-Year Review 4 (2012–2019). Values are the highest detection in each calendar year; non-detect years are omitted. Year tags above show every year with a detection.
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 3.4 ug/LAveragePasadena Water System | 0.02 ug/LPublic health goal | At or above the limit |
+By source (2)— Pasadena Water System, MWD Weymouth Plant
| |||
| CopperA metal that enters water from corroding household plumbing. | 0.26 mg/L90th percentilePasadena Water System | 1.3 mg/LAction level | Within the limit |
| IronA naturally occurring metal common in groundwater. | 46 ug/LAveragePasadena Sources | 300 ug/LMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| AluminumA common element sometimes used as a treatment coagulant. | 115 ug/LAverageMWD Weymouth Plant | 1000 ug/LMCL | Within the limit |
+By source (2)— MWD Weymouth Plant, Pasadena Sources
| |||
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | Not detected ug/L90th percentilePasadena Water System | 15 ug/LAction level | None detected |
| 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
| |||
| 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
| |||
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| OdorA measure of detectable smell in the water. | 2AverageMWD Weymouth Plant | 3MCL | Within the limit |
+By source (2)— MWD Weymouth Plant, Pasadena Sources
| |||
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 469 mg/LAveragePasadena Sources | 1000 mg/LMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 733AveragePasadena Sources | 1600MCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| ColorA measure of visible tint in the water. | 1AverageMWD Weymouth Plant | 15MCL | Within the limit |
+By source (2)— MWD Weymouth Plant, Pasadena Sources
| |||
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.3 NTUAveragePasadena Sources | 5 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
| |||
| 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
| |||
| 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
| |||
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | 8AveragePasadena Sources | 15MCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | Not detectedRangeMWD Weymouth Plant | 5MCL | None detected |
+By source (2)— MWD Weymouth Plant, Pasadena Sources
| |||
| Gross Beta Particle ActivityGross beta particle activity — a combined measure of beta-emitting radioactive substances. | Not detectedAverageMWD Weymouth Plant | 50MCL | Within the limit |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 1.4 mg/LAveragePasadena Water System Highest | 4 mg/LMRDL | Within the limit |
+By source (2)— Pasadena Water System, Pasadena Water System Highest
| |||
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | 1.3 ug/LAveragePasadena Sources | 6 ug/LMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| SulfateA naturally occurring mineral from rock and soil. | 102 mg/LAveragePasadena Sources | 500 mg/LMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
| ChlorideA naturally occurring salt compound. | 53 mg/LAveragePasadena Sources | 500 mg/LMCL | Within the limit |
+By source (2)— Pasadena Sources, MWD Weymouth Plant
| |||
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 | 0MCL | 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. | 1.4 %AveragePasadena Water System Highest | None set | Detected — no federal limit |
+By source (2)— Pasadena Water System Highest, Pasadena Water System
| |||
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 ug/LAveragePasadena Water System | 0.005 ug/LMCL | None detected |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)ADONA, a newer-generation PFAS replacement compound. | Not detected ug/LRangePasadena Water System | 0.003 ug/LMCL | None detected |
| 4:2 Fluorotelomer sulfonic acid (4:2 FTS)4:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected ug/LRangePasadena Water System | 0.003 ug/LMCL | None detected |
| 6:2 Fluorotelomer sulfonic acid (6:2 FTS)6:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected ug/LRangePasadena Water System | 0.005 ug/LMCL | None detected |
| 8:2 Fluorotelomer sulfonic acid (8:2 FTS)8:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected ug/LAveragePasadena Water System | 0.005 ug/LMCL | None detected |
| 9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS)9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid, a chlorinated PFAS compound. | Not detected ug/LRangePasadena Water System | 0.002 ug/LMCL | None detected |
| Hexafluoropropylene oxide dimer acidHFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound. | Not detected ug/LAveragePasadena Water System | 0.005 ug/LMCL | None detected |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)N-ethyl perfluorooctanesulfonamidoacetic acid, a PFAS-related compound. | Not detected ug/LRangePasadena Water System | 0.005 ug/LMCL | None detected |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)N-methyl perfluorooctanesulfonamidoacetic acid, a PFAS-related compound. | Not detected ug/LAveragePasadena Water System | 0.006 ug/LMCL | None detected |
| Nonafluoro-3,6-dioxaheptanoic acidNonafluoro-3,6-dioxaheptanoic acid, a PFAS-related compound. | Not detectedAveragePasadena Water System | 0.02MCL | None detected |
| Perfluoro-3-methoxypropanoic acid (PFMPA)Perfluoro-3-methoxypropanoic acid, a PFAS-related compound. | Not detected ug/LRangePasadena Water System | 0.004 ug/LMCL | None detected |
| Perfluoro-4-methoxybutanoic acid (PFMBA)Perfluoro-4-methoxybutanoic acid, a PFAS-related compound. | Not detected ug/LRangePasadena Water System | 0.003 ug/LMCL | None detected |
| Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA)Perfluoro(2-ethoxyethane)sulfonic acid, a PFAS-related compound. | Not detected ug/LRangePasadena Water System | 0.003 ug/LMCL | None detected |
| Perfluorobutanesulfonic acidPerfluorobutanesulfonic acid, a shorter-chain PFAS 'forever chemical.' | Not detected ug/LRangePasadena Water System | 0.003 ug/LMCL | None detected |
| Perfluorodecanoic acid (PFDA)Perfluorodecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected ug/LRangePasadena Water System | 0.003 ug/LMCL | None detected |
| Perfluorododecanoic acid (PFDoA)Perfluorododecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected ug/LRangePasadena Water System | 0.003 ug/LMCL | None detected |
| Perfluoroheptanesulfonic acid (PFHpS)Perfluoroheptanesulfonic acid, a PFAS 'forever chemical.' | Not detected ug/LAveragePasadena Water System | 0.003 ug/LMCL | None detected |
| Perfluoroheptanoic acidPerfluoroheptanoic acid, a PFAS 'forever chemical.' | Not detected ug/LRangePasadena Water System | 0.003 ug/LMCL | None detected |
| Perfluorohexanesulfonic acidPerfluorohexanesulfonic acid, a PFAS 'forever chemical.' | Not detected ug/LRangePasadena Water System | 0.003 ug/LMCL | None detected |
| Perfluorohexanoic acidPerfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.' | Not detected ug/LAveragePasadena Water System | 0.003 ug/LMCL | None detected |
| Perfluorononanoic acidPerfluorononanoic acid, a PFAS 'forever chemical.' | Not detected ug/LRangePasadena Water System | 0.004 ug/LMCL | None detected |
| Perfluoropentanesulfonic acid (PFPeS)Perfluoropentanesulfonic acid, a PFAS 'forever chemical.' | Not detected ug/LAveragePasadena Water System | 0.004 ug/LMCL | None detected |
| Perfluoropentanoic acidPerfluoropentanoic acid, a shorter-chain PFAS 'forever chemical.' | Not detected ug/LRangePasadena Water System | 0.003 ug/LMCL | None detected |
| Perfluorotetradecanoic acid (PFTeDA)Perfluorotetradecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected ug/LRangePasadena Water System | 0.008 ug/LMCL | None detected |
| Perfluorotridecanoic acid (PFTrDA)Perfluorotridecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected ug/LAveragePasadena Water System | 0.007 ug/LMCL | None detected |
| Perfluoroundecanoic acid (PFUnA)Perfluoroundecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected ug/LAveragePasadena Water System | 0.002 ug/LMCL | None detected |
| PFBAPerfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' | Not detected ug/LAveragePasadena Water System | 0.005 ug/LMCL | None detected |
| PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. | Not detected ug/LRangePasadena Water System | 0.004 ug/LMCL | None detected |
| PFOSPerfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. | Not detected ug/LAveragePasadena Water System | 0.004 ug/LMCL | None detected |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TetrachloroethyleneAn industrial solvent (PCE) used in dry cleaning and degreasing. | Not detected ug/LAverageMWD Weymouth Plant | 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?
The 2023 Consumer Confidence Report for the Pasadena, CA water utility lists 2 contaminants at or above the federal limit: Chromium, Hexavalent and Lithium. 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 Pasadena, CA tap water?
65 contaminants were measured in Pasadena, CA's 2023 Consumer Confidence Report, spanning pfas ("forever chemicals"), metals, and physical & aggregate. 57 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 Pasadena, CA tap water?
2 contaminants in Pasadena, CA's 2023 report sit at or above the federal limit: Chromium, Hexavalent (170.0× the limit); Lithium (1.8× 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 Pasadena, CA tap water?
The contaminant with the highest measured value relative to its federal limit in the 2023 report is Chromium, Hexavalent, at 170.0× the federal threshold. It belongs to the metals family of contaminants.
+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.