Serving roughly 151,713 people in Los Angeles County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
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Results for POMONA - CITY, WATER DEPT.
1 water provider directly on file, serving roughly 151,713 people in Los Angeles County, California.
Quick answer: POMONA - CITY, WATER DEPT. has no violations on file. One reading is worth knowing about: Nitrate was measured at 20MG/L, among the highest of the 601 providers on file in this area. It's the most notable figure in this system's record among its 601 local peers.
Lead Summary
Lithium
PFPEA
PFHXA
PFOA
PFOS
PFHXS
PFBS
Aggressive Index
Langelier Index (pH(s))
Langelier Index (Source Temp.)
Magnesium
Potassium
Sodium
Calcium
Alkalinity, Total
Alkalinity, Bicarbonate
Hardness, Total (ASCACO3)
Orthophosphate
TDS
Sulfate
Chloride
Fluoride
Nitrate
Nitrate-Nitrite
Perfluorobutanesulfonicacid (PFBS)
Perfluoroheptanoicacid (PFHPA)
Perfluorohexanesulfonicacid (PFHxS)
Perfluoroctanesulfonicacid (PFOS)
Perfluoroctanoicacid (PFOA)
Perfluorohexanoicacid (PFHXA)
Perfluoropentanoicacid (PFPEA)
Perfluorobutanoicacid (PFBA)
Turbidity
Combined Uranium
Gross Alpha Particle Activity
pH
1, 2, 3-Trichloropropane
TTHM
Iron
Chromium, Hex
Trichloroethylene
Tetrachloroethylene
1, 1-Dichloroethylene
Perchlorate
Chloroform
Utility POMONA - CITY, WATER DEPT.Population served 151,713Owner Local government
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0.0021 mg/L (ppm)
12/31/2025
Combined Uranium
Detected: 1.3 PCI/L
9/17/2025
A naturally occurring radioactive metal. Long-term exposure above the legal limit is associated with kidney effects and increased cancer risk.
Iron
Detected: 22 UG/L (ppb)
8/27/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Chromium, Hex
Detected: 9 UG/L (ppb)
10/28/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
TTHM
Detected: 0.52 UG/L (ppb)
1/15/2025
A group of disinfection byproducts formed when chlorine reacts with organic matter. Long-term exposure above the legal limit has been linked to increased cancer risk in some studies.
Chloroform
Detected: 1.4 UG/L (ppb)
8/13/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Sulfate
Detected: 42 MG/L (ppm)
8/27/2025
Chloride
Detected: 35 MG/L (ppm)
8/27/2025
Fluoride
Detected: 0.24 MG/L (ppm)
8/27/2025
Often added deliberately for dental health; can also occur naturally.
Nitrate
Detected: 20 MG/L (ppm)
10/28/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Nitrate-Nitrite
Detected: 20 MG/L (ppm)
10/28/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 13 MG/L (ppm)
8/27/2025
Potassium
Detected: 1.7 MG/L (ppm)
8/27/2025
Sodium
Detected: 10 MG/L (ppm)
8/27/2025
Calcium
Detected: 68 MG/L (ppm)
8/27/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Langelier Index (pH(s))
Detected: 1.1 LANG
8/27/2025
Hardness, Total (ASCACO3)
Detected: 220 MG/L (ppm)
8/27/2025
Orthophosphate
Detected: 0.016 MG/L (ppm)
8/27/2025
Gross Alpha Particle Activity
Detected: 2.66 PCI/L
9/17/2025
pH
Detected: 8 PH
8/27/2025
A measure of how acidic or basic the water is (7 is neutral). Affects taste and plumbing, not a direct health measure.
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
Lithium
Detected: 9.3 µg/L (ppb)
8/23/2023
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
PFPEA
Detected: 0.0044 µg/L (ppb)
4/25/2024
PFHXA
Detected: 0.0041 µg/L (ppb)
4/25/2024
PFOA
Detected: 0.0071 µg/L (ppb)
4/25/2024
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFOS
Detected: 0.018 µg/L (ppb)
4/25/2024
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFHXS
Detected: 0.0079 µg/L (ppb)
4/25/2024
PFBS
Detected: 0.0032 µg/L (ppb)
4/25/2024
VOCs (Volatile Organic Compounds)
Industrial solvents and fuel-related chemicals that evaporate easily
1, 2, 3-Trichloropropane
Detected: 0.016 UG/L (ppb)
10/28/2025
Trichloroethylene
Detected: 2.8 UG/L (ppb)
10/28/2025
Tetrachloroethylene
Detected: 0.51 UG/L (ppb)
10/14/2025
1, 1-Dichloroethylene
Detected: 1.8 UG/L (ppb)
10/28/2025
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 140 MG/L (ppm)
8/27/2025
Other
Additional substances tested that don't fit neatly into the categories above
Aggressive Index
Detected: 12 AGGR
8/27/2025
Langelier Index (Source Temp.)
Detected: 0.53 LANG
8/27/2025
Alkalinity, Total
Detected: 140 MG/L (ppm)
8/27/2025
TDS
Detected: 310 MG/L (ppm)
8/27/2025
Perfluorobutanesulfonicacid (PFBS)
Detected: 3 NG/L (ppt)
9/25/2025
Perfluoroheptanoicacid (PFHPA)
Detected: 2.1 NG/L (ppt)
9/25/2025
Perfluorohexanesulfonicacid (PFHxS)
Detected: 5.5 NG/L (ppt)
9/25/2025
Perfluoroctanesulfonicacid (PFOS)
Detected: 8.5 NG/L (ppt)
9/25/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Perfluoroctanoicacid (PFOA)
Detected: 4.9 NG/L (ppt)
9/25/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Perfluorohexanoicacid (PFHXA)
Detected: 4.1 NG/L (ppt)
9/25/2025
Perfluoropentanoicacid (PFPEA)
Detected: 4.1 NG/L (ppt)
9/25/2025
Perfluorobutanoicacid (PFBA)
Detected: 2.9 NG/L (ppt)
2/27/2025
Turbidity
Detected: 0.55 NTU
8/27/2025
A measure of water cloudiness from suspended particles.
Perchlorate
Detected: 12 UG/L (ppb)
10/28/2025
Can occur naturally or from industrial/military sources; may interfere with thyroid function at elevated levels.
Filtration considerations: See the table below for how whole-house carbon, under-sink reverse osmosis, and under-sink carbon systems compare against what's actually on file here. These are general system types, not a specific product recommendation.