Serving roughly 110,556 people in Los Angeles County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
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Results for DOWNEY - CITY, WATER DEPT.
1 water provider directly on file, serving roughly 110,556 people in Los Angeles County, California.
Quick answer: DOWNEY - CITY, WATER DEPT. has no violations on file. One reading is worth knowing about: PFHXA was measured at 0.021µg/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
PFBA
PFHXA
PFOA
PFOS
PFBS
PFPEA
PFHXS
PFHPA
Fluoride
Nitrate
Perfluorobutanesulfonicacid (PFBS)
Perfluoroheptanoicacid (PFHPA)
Perfluorohexanesulfonicacid (PFHxS)
Perfluoroctanesulfonicacid (PFOS)
Perfluoroctanoicacid (PFOA)
Perfluorohexanoicacid (PFHXA)
Perfluorobutanoicacid (PFBA)
Perfluoropentanoicacid (PFPEA)
Perfluorononanoicacid (PFNA)
Perfluorodecanoicacid (PFDA)
TTHM
Chloroform
Arsenic
Langelier Index (pH(s))
Langelier Index (Source Temp.)
Magnesium
Potassium
Calcium
Sodium
Hardness, Total (ASCACO3)
Alkalinity, Total
Alkalinity, Bicarbonate
TDS
Chloride
Sulfate
Nitrate-Nitrite
Utility DOWNEY - CITY, WATER DEPT.Population served 110,556Owner Local government
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2023
Arsenic
Detected: 2.2 UG/L (ppb)
2/4/2025
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
TTHM
Detected: 10 UG/L (ppb)
2/4/2025
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: 10 UG/L (ppb)
2/4/2025
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
Fluoride
Detected: 0.32 MG/L (ppm)
2/4/2025
Often added deliberately for dental health; can also occur naturally.
Nitrate
Detected: 3.6 MG/L (ppm)
8/18/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Chloride
Detected: 48 MG/L (ppm)
1/7/2025
Sulfate
Detected: 51 MG/L (ppm)
1/7/2025
Nitrate-Nitrite
Detected: 4.2 MG/L (ppm)
1/7/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 16 MG/L (ppm)
1/7/2025
Potassium
Detected: 4.6 MG/L (ppm)
1/7/2025
Calcium
Detected: 82.8 MG/L (ppm)
1/7/2025
Sodium
Detected: 55 MG/L (ppm)
1/7/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Langelier Index (pH(s))
Detected: 1.02 LANG
1/7/2025
Hardness, Total (ASCACO3)
Detected: 273 MG/L (ppm)
1/7/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
PFBA
Detected: 0.0074 µg/L (ppb)
7/1/2025
PFHXA
Detected: 0.021 µg/L (ppb)
7/1/2025
PFOA
Detected: 0.011 µg/L (ppb)
7/1/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFOS
Detected: 0.014 µg/L (ppb)
7/1/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFBS
Detected: 0.0089 µg/L (ppb)
7/1/2025
PFPEA
Detected: 0.027 µg/L (ppb)
7/1/2025
PFHXS
Detected: 0.0037 µg/L (ppb)
7/1/2025
PFHPA
Detected: 0.0042 µg/L (ppb)
7/1/2025
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 230 MG/L (ppm)
1/7/2025
Other
Additional substances tested that don't fit neatly into the categories above
Perfluorobutanesulfonicacid (PFBS)
Detected: 5.9 NG/L (ppt)
10/21/2025
Perfluoroheptanoicacid (PFHPA)
Detected: 3.9 NG/L (ppt)
10/21/2025
Perfluorohexanesulfonicacid (PFHxS)
Detected: 4.1 NG/L (ppt)
10/21/2025
Perfluoroctanesulfonicacid (PFOS)
Detected: 20 NG/L (ppt)
10/21/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Perfluoroctanoicacid (PFOA)
Detected: 9.9 NG/L (ppt)
9/30/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Perfluorohexanoicacid (PFHXA)
Detected: 17 NG/L (ppt)
9/30/2025
Perfluorobutanoicacid (PFBA)
Detected: 5.5 NG/L (ppt)
9/30/2025
Perfluoropentanoicacid (PFPEA)
Detected: 19 NG/L (ppt)
9/30/2025
Perfluorononanoicacid (PFNA)
Detected: 2.1 NG/L (ppt)
10/21/2025
Perfluorodecanoicacid (PFDA)
Detected: 2.1 NG/L (ppt)
9/30/2025
Langelier Index (Source Temp.)
Detected: 0.447 LANG
1/7/2025
Alkalinity, Total
Detected: 190 MG/L (ppm)
1/7/2025
TDS
Detected: 490 MG/L (ppm)
1/7/2025
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.