Drinking water quality · 2026
· Verified
What's in Pomona - City, Water Dept., CA tap water
120 contaminants were measured in the Pomona - City, Water Dept., CA water system's 2026 annual report. Each is shown below against its federal limit — 2 sit at or above that limit.
- Reporting year
- 2026
- Contaminants measured
- 120
- Over federal limit
- 2
- Approaching the limit
- 1
- Worst contaminant
- Nitrate Nitrite
- Service area
- CA
1.2× the limit
state-level CCR
At or above the federal limit
Approaching the limit (≥ 80%)
PFAS — EPA UCMR5 (2023–2025)
2 PFAS compounds above EPA limits in Pomona - City, Water Dept., 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.
PFOS (Perfluorooctane sulfonic acid)
● Over EPA limit (4.5×)Measured 18 ng/LEPA limit 4 ng/LSample year 2024Samples 1 detect / 15
near national p90 (19.900000000000006 ng/L across detecting U.S. systems)
PFOA (Perfluorooctanoic acid)
● Over EPA limit (1.8×)Measured 7.1 ng/LEPA limit 4 ng/LSample year 2024Samples 1 detect / 15
near national p90 (13.649999999999999 ng/L across detecting U.S. systems)
PFHxS (Perfluorohexane sulfonic acid)
● Below limitMeasured 7.9 ng/LEPA limit 10 ng/LSample year 2024Samples 1 detect / 15
near national p90 (12.049999999999997 ng/L across detecting U.S. systems)
PFPeA
● Detected (no federal limit)Measured 4.4 ng/LSample year 2024Samples 1 detect / 15
below national p90 (15.95999999999999 ng/L across detecting U.S. systems)
PFBS
● Detected (no federal limit)Measured 3.2 ng/LSample year 2024Samples 1 detect / 15
below national p90 (13.909999999999979 ng/L across detecting U.S. systems)
Lithium
● Detected (no federal limit)Measured 9.3 mg/LSample year 2023Samples 1 detect / 15
below national p90 (76.59999999999991 mg/L across detecting U.S. systems)
PFHxA
● Detected (no federal limit)Measured 4.1 ng/LSample year 2024Samples 1 detect / 15
below national p90 (12.190000000000003 ng/L across detecting U.S. systems)
PWSID CA1910126 · 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
Pomona - City, Water Dept., CA's drinking water comes from ground water, drawn from 23 sources.
Source
23ground water
- WELL · 18
- TUNNEL · 4
- PEDLEY FILTRATION PLANT - RAW
Treatment
18treatment plants
- WELL 03 AIR STRIPPER
- PEDLEY FILTRATION PLANT - TREATED
- ANION EXCHANGE PLANT - 3
- + 15 more
Distribution
22storage units
Also buys water from METROPOLITAN WATER DIST. OF SO. CAL., THREE VALLEYS MWD.
Source: EPA SDWIS facilities inventory. Methodology.
Historical readings · EPA Six-Year Review (2012–2019)
7 contaminants historically over EPA limits in Pomona - City, Water Dept., 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: 2017 | 0.13 mg/L 26.0× | 0.005 mg/L | '12'13'14'15'16'17'18'19 |
DICHLOROETHYLENE 11 worst: 2012 | 0.061 mg/L 8.7× 7.4× the national p90 | 0.007 mg/L | '12'13'14'15'16'17'18'19 |
PCE worst: 2014 | 0.034 mg/L 6.8× | 0.005 mg/L | '12'13'14'15'16'17'18'19 |
NITRATE worst: 2016 | 29 mg/L 2.9× | 10 mg/L | '12'13'14'15'16'17'18'19 |
NITRATE NITRITE worst: 2018 | 22 mg/L 2.2× | 10 mg/L | '16'17'18'19 |
CHROMIUM worst: 2017 | 0.18 mg/L 1.8× 18.0× the national p90 | 0.1 mg/L | '12'13'14'15'16'17'18'19 |
ARSENIC worst: 2015 | 0.011 mg/L 1.1× near national p90 | 0.01 mg/L | '12'13'14'15'16'17'18 |
TTHM worst: 2012 | 0.051 mg/L within | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
THALLIUM worst: 2015 | 0.0012 mg/L within | 0.002 mg/L | '15 |
DBCP worst: 2018 | 0.00011 mg/L within below national p90 | 0.0002 mg/L | '12'15'18 |
HAA5 worst: 2017 | 0.027 mg/L within | 0.06 mg/L | '12'13'14'15'16'17'18'19 |
FLUORIDE worst: 2013 | 0.6 mg/L within | 4 mg/L | '12'13'14'15'16'17'18'19 |
SELENIUM worst: 2018 | 0.0072 mg/L within | 0.05 mg/L | '14'15'18 |
BARIUM worst: 2012 | 0.1 mg/L within below national p90 | 2 mg/L | '12'13'16'18 |
URANIUM worst: 2018 | 0.007 ug/L within below national p90 | 30 ug/L | '12'13'14'15'16'18'19 |
DBAA worst: 2012 | 0.0034 mg/L | — | '12'13'14'15'16'17'18'19 |
DCAA worst: 2012 | 0.0072 mg/L | — | '12'13'14'15'16'17'18'19 |
MBAA worst: 2016 | 0.0024 mg/L | — | '16'17'18 |
TCAA worst: 2012 | 0.0058 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMODICHLOROMETHANE worst: 2012 | 0.013 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMOFORM worst: 2012 | 0.017 mg/L | — | '12'13'14'15'16'17'18'19 |
CHLOROFORM worst: 2012 | 0.015 mg/L | — | '12'13'14'15'16'17'18'19 |
DIBROMOCHLOROMETHANE worst: 2012 | 0.019 mg/L | — | '12'13'14'15'16'17'18'19 |
PWSID CA1910126 · 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.
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | 5.65 UG/LAverageSource water | 6 UG/LMCL | Approaching the limit |
| NDMA | Not detected UG/LHighest single sampleEntry point | None set | None detected |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 7.294 UG/LAverageSource water | 10 UG/LMCL | Within the limit |
| IronA naturally occurring metal common in groundwater. | 38.6 UG/LAverageSource water | 300 UG/LMCL | Within the limit |
| AluminumA common element sometimes used as a treatment coagulant. | 80.71428571428571 UG/LAverageEntry point | 1000 UG/LMCL | Within the limit |
| ManganeseA naturally occurring metal from soil and rock. | 1.5 UG/LAverageSource water | 50 UG/LMCL | Within the limit |
| CopperA metal that enters water from corroding household plumbing. | 5.34 UG/LAverageEntry point | 1000 UG/LMCL | Within the limit |
| ZincA naturally occurring metal that can also enter water from corroding pipes. | 5.82 UG/LAverageEntry point | 5000 UG/LMCL | Within the limit |
| Antimony | Not detected UG/LHighest single sampleSource water | 6 UG/LMCL | None detected |
| Beryllium | Not detected UG/LHighest single sampleSource water | 4 UG/LMCL | None detected |
| Cadmium | Not detected UG/LHighest single sampleEntry point | 5 UG/LMCL | None detected |
| MercuryA toxic metal from erosion of natural deposits and industrial runoff. | Not detected UG/LHighest single sampleSource water | 2 UG/LMCL | None detected |
| NickelA metal from natural deposits and industrial discharge. | Not detected UG/LHighest single sampleEntry point | 100 UG/LMCL | None detected |
| CalciumA naturally occurring mineral that contributes to water hardness. | 24.583333333333332 MG/LAverageSource water | None set | Detected — no federal limit |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | 0.31799999999999995 UG/LAverageEntry point | None set | Detected — no federal limit |
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 11.28 MG/LAverageEntry point | None set | Detected — no federal limit |
| PotassiumA naturally occurring mineral from rock and soil. | 1.98 MG/LAverageEntry point | None set | Detected — no federal limit |
| SodiumA naturally occurring salt component. | 22.72 MG/LAverageEntry point | None set | Detected — no federal limit |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| 1,2,3-TCP | 0.0031142857142857144 UG/LAverageSource water | 0.005 UG/LMCL | Within the limit |
| AtrazineA widely used agricultural herbicide that reaches water through runoff. | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| Benzene | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| Benzo(a)pyrene | Not detected UG/LHighest single sampleSource water | 0.2 UG/LMCL | None detected |
| Dalapon | Not detected UG/LHighest single sampleSource water | 200 UG/LMCL | None detected |
| Dichloromethane | Not detected UG/LHighest single sampleEntry point | 5 UG/LMCL | None detected |
| Ethylbenzene | Not detected UG/LHighest single sampleEntry point | 300 UG/LMCL | None detected |
| Simazine | Not detected UG/LHighest single sampleSource water | 4 UG/LMCL | None detected |
| Toluene | Not detected UG/LHighest single sampleSource water | 150 UG/LMCL | None detected |
| XylenesA group of industrial solvents found in gasoline and paint. | Not detected UG/LHighest single sampleSource water | 1750 UG/LMCL | None detected |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 588.125 UMHO/CMAverageEntry point | 1600 UMHO/CMMCL | Within the limit |
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 304 MG/LAverageEntry point | 1000 MG/LMCL | Within the limit |
| OdorA measure of detectable smell in the water. | 0.8 TONAverageEntry point | 3 TONMCL | Within the limit |
| TurbidityA measure of cloudiness from suspended particles in the water. | 1.2100000000000002 NTUAverageSource water | 5 NTUMCL | Within the limit |
| ColorA measure of visible tint in the water. | 1.2 UNITSAverageSource water | 15 UNITSMCL | Within the limit |
| AlkalinityA measure of the water's capacity to neutralize acids. | 99.23809523809524 MG/LAverageSource water | None set | Detected — no federal limit |
| HardnessA measure of dissolved calcium and magnesium minerals. | 196 MG/LAverageEntry point | None set | Detected — no federal limit |
| pHA measure of how acidic or basic the water is. | 8.0875 PHAverageEntry point | None set | Detected — no federal limit |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | 4.71 PCI/LAverageSource water | 15 PCI/LMCL | Within the limit |
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | Not detected PCI/LHighest single sampleSource water | 5 PCI/LMCL | None detected |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorideA naturally occurring salt compound. | 74.85499999999999 MG/LAverageEntry point | 500 MG/LMCL | Within the limit |
| SulfateA naturally occurring mineral from rock and soil. | 29.939999999999998 MG/LAverageEntry point | 500 MG/LMCL | Within the limit |
| Asbestos | Not detected MFLHighest single sampleSource water | 7 MFLMCL | None detected |
| Cyanide | Not detected UG/LHighest single sampleEntry point | 150 UG/LMCL | None detected |
| NitriteA compound from fertilizer runoff, sewage, and erosion of natural deposits. | Not detected MG/LHighest single sampleOther | 1 MG/LMCL | None detected |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Carbofuran | Not detected UG/LHighest single sampleSource water | 18 UG/LMCL | None detected |
| Carbon Tetrachloride | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
| Chlordane | Not detected UG/LHighest single sampleSource water | 0.1 UG/LMCL | None detected |
| Chlorobenzene | Not detected UG/LHighest single sampleEntry point | 70 UG/LMCL | None detected |
| Cis Dichloroethylene 12 | Not detected UG/LHighest single sampleEntry point | 6 UG/LMCL | None detected |
| Deha | Not detected UG/LHighest single sampleSource water | 400 UG/LMCL | None detected |
| Dehp | Not detected UG/LHighest single sampleSource water | 4 UG/LMCL | None detected |
| Dichloroethane 12 | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
| Dichloropropane 12 | Not detected UG/LHighest single sampleEntry point | 5 UG/LMCL | None detected |
| Dinoseb | Not detected UG/LHighest single sampleSource water | 7 UG/LMCL | None detected |
| Diquat | Not detected UG/LHighest single sampleSource water | 20 UG/LMCL | None detected |
| Edb | Not detected UG/LHighest single sampleSource water | 0.05 UG/LMCL | None detected |
| Endothall | Not detected UG/LHighest single sampleSource water | 100 UG/LMCL | None detected |
| Endrin | Not detected UG/LHighest single sampleSource water | 2 UG/LMCL | None detected |
| Glyphosate | Not detected UG/LHighest single sampleSource water | 700 UG/LMCL | None detected |
| Heptachlor | Not detected UG/LHighest single sampleSource water | 0.01 UG/LMCL | None detected |
| Heptachlor Epoxide | Not detected UG/LHighest single sampleSource water | 0.01 UG/LMCL | None detected |
| Hexachlorobenzene | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| Hexachlorocyclopentadiene | Not detected UG/LHighest single sampleSource water | 50 UG/LMCL | None detected |
| Mcaa | Not detected UG/LHighest single sampleDistribution | None set | None detected |
| Methoxychlor | Not detected UG/LHighest single sampleSource water | 30 UG/LMCL | None detected |
| O Dichlorobenzene | Not detected UG/LHighest single sampleSource water | 600 UG/LMCL | None detected |
| Oxamyl | Not detected UG/LHighest single sampleSource water | 50 UG/LMCL | None detected |
| P Dichlorobenzene | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Pcb Total | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
| Pentachlorophenol | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| Picloram | Not detected UG/LHighest single sampleSource water | 500 UG/LMCL | None detected |
| Styrene | Not detected UG/LHighest single sampleSource water | 100 UG/LMCL | None detected |
| Toxaphene | Not detected UG/LHighest single sampleSource water | 3 UG/LMCL | None detected |
| Trans Dichloroethylene 12 | Not detected UG/LHighest single sampleEntry point | 10 UG/LMCL | None detected |
| Trichlorobenzene 124 | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Trichloroethane 111 | Not detected UG/LHighest single sampleEntry point | 200 UG/LMCL | None detected |
| Trichloroethane 112 | Not detected UG/LHighest single sampleEntry point | 5 UG/LMCL | None detected |
| Twofourd | Not detected UG/LHighest single sampleSource water | 70 UG/LMCL | None detected |
| Vinyl Chloride | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
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/LHighest single sampleSource water | None set | None detected |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)ADONA, a newer-generation PFAS replacement compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| 4:2 Fluorotelomer sulfonic acid (4:2 FTS)4:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleEntry point | None set | None detected |
| 6:2 Fluorotelomer sulfonic acid (6:2 FTS)6:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleEntry point | None set | None detected |
| 8:2 Fluorotelomer sulfonic acid (8:2 FTS)8:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | 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/LHighest single sampleSource water | None set | None detected |
| Hexafluoropropylene oxide dimer acidHFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound. | Not detected NG/LHighest single sampleEntry point | None set | None detected |
| Perfluoro-3-methoxypropanoic acid (PFMPA)Perfluoro-3-methoxypropanoic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleEntry point | None set | None detected |
| Perfluoro-4-methoxybutanoic acid (PFMBA)Perfluoro-4-methoxybutanoic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA)Perfluoro(2-ethoxyethane)sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluorodecanoic acid (PFDA)Perfluorodecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected NG/LHighest single sampleEntry point | None set | None detected |
| Perfluorododecanoic acid (PFDoA)Perfluorododecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoroheptanesulfonic acid (PFHpS)Perfluoroheptanesulfonic acid, a PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoroheptanoic acidPerfluoroheptanoic acid, a PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluorononanoic acidPerfluorononanoic acid, a PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoropentanesulfonic acid (PFPeS)Perfluoropentanesulfonic acid, a PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoroundecanoic acid (PFUnA)Perfluoroundecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected NG/LHighest single sampleEntry point | None set | None detected |
| PFBAPerfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
Source: Pomona - City, Water Dept., CA's 2026 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 Pomona - City, Water Dept., CA's water
+Is Pomona - City, Water Dept., CA tap water safe to drink in 2026?
The 2026 Consumer Confidence Report for the Pomona - City, Water Dept., CA water utility lists 2 contaminants at or above the federal limit: Nitrate Nitrite and Nitrate. 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 Pomona - City, Water Dept., CA tap water?
120 contaminants were measured in Pomona - City, Water Dept., CA's 2026 Consumer Confidence Report, spanning other, metals, and pfas ("forever chemicals"). 82 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 Pomona - City, Water Dept., CA tap water?
2 contaminants in Pomona - City, Water Dept., CA's 2026 report sit at or above the federal limit: Nitrate Nitrite (1.2× the limit); Nitrate (1.2× 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 Pomona - City, Water Dept., CA tap water?
The contaminant with the highest measured value relative to its federal limit in the 2026 report is Nitrate Nitrite, at 1.2× the federal threshold. It belongs to the other family of contaminants.
+Are any contaminants in Pomona - City, Water Dept., CA tap water approaching the federal limit?
One contaminant is between 80% and 100% of the federal limit in this report: Perchlorate. 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 Pomona - City, Water Dept., CA's 2026 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 Pomona - City, Water Dept., 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 2026 report; a new report will replace it once the utility publishes its next annual update.
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