Serving roughly 76,414 people in San Bernardino County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
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Results for CHINO HILLS, CITY OF
1 water provider directly on file, serving roughly 76,414 people in San Bernardino County, California.
Quick answer: CHINO HILLS, CITY OF has no violation currently counted toward its compliance status. EPA's record shows a Nitrate violation dating to 09/01/1984 (42 years ago) — because it's more than five years past its deadline, EPA's policy no longer treats it as part of this system's current standing, though it remains on the public record.
Lead Summary
Totalhaloaceticacids (HAA5)
TTHM
Trichloroaceticacid
Dichloroaceticacid
Dibromoaceticacid
Chloroform
Bromoform
Bromodichloromethane
Dibromochloromethane
Magnesium
Calcium
Potassium
Sodium
Alkalinity, Total
Alkalinity, Bicarbonate
Hardness, Total (ASCACO3)
TDS
Sulfate
Chloride
Fluoride
Nitrate
Nitrate-Nitrite
Turbidity
Combined Uranium
Gross Beta Particle Activity
pH
Vanadium, Total
1, 2, 3-Trichloropropane
Iron
Chromium, Hex
Perchlorate
Chromium
Barium
Arsenic
Conductivity (at 25°C)
Alkalinity, Carbonate
Boron, Total
Utility CHINO HILLS, CITY OFPopulation served 76,414Owner Local government
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2024
Combined Uranium
Detected: 0.287 PCI/L
7/16/2025
A naturally occurring radioactive metal. Long-term exposure above the legal limit is associated with kidney effects and increased cancer risk.
Vanadium, Total
Detected: 48 UG/L (ppb)
7/16/2025
Iron
Detected: 21 UG/L (ppb)
3/4/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Chromium, Hex
Detected: 4.1 UG/L (ppb)
7/16/2025
Chromium
Detected: 11 UG/L (ppb)
3/4/2025
Occurs in two forms — trivalent (an essential nutrient in trace amounts) and hexavalent (linked to increased cancer risk).
Barium
Detected: 7.1 UG/L (ppb)
7/16/2025
Arsenic
Detected: 62 UG/L (ppb)
7/16/2025
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
Totalhaloaceticacids (HAA5)
Detected: 7.8 UG/L (ppb)
5/15/2025
TTHM
Detected: 40 UG/L (ppb)
8/21/2025
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: 12 UG/L (ppb)
8/21/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromoform
Detected: 3.3 UG/L (ppb)
8/21/2025
Bromodichloromethane
Detected: 14 UG/L (ppb)
8/21/2025
Dibromochloromethane
Detected: 11 UG/L (ppb)
8/21/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Sulfate
Detected: 31 MG/L (ppm)
7/16/2025
Chloride
Detected: 15 MG/L (ppm)
7/16/2025
Fluoride
Detected: 0.51 MG/L (ppm)
7/16/2025
Often added deliberately for dental health; can also occur naturally.
Nitrate
Detected: 2.7 MG/L (ppm)
7/16/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Nitrate-Nitrite
Detected: 2.7 MG/L (ppm)
7/16/2025
Boron, Total
Detected: 52 UG/L (ppb)
7/16/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 0.26 MG/L (ppm)
7/16/2025
Calcium
Detected: 5 MG/L (ppm)
7/16/2025
Potassium
Detected: 1.8 MG/L (ppm)
3/4/2025
Sodium
Detected: 58 MG/L (ppm)
7/16/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 14 MG/L (ppm)
7/16/2025
pH
Detected: 8.98 PH
7/16/2025
A measure of how acidic or basic the water is (7 is neutral). Affects taste and plumbing, not a direct health measure.
VOCs (Volatile Organic Compounds)
Industrial solvents and fuel-related chemicals that evaporate easily
1, 2, 3-Trichloropropane
Detected: 0.046 UG/L (ppb)
3/4/2025
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 74 MG/L (ppm)
7/16/2025
Alkalinity, Carbonate
Detected: 8.2 MG/L (ppm)
7/16/2025
Other
Additional substances tested that don't fit neatly into the categories above
Trichloroaceticacid
Detected: 7.8 UG/L (ppb)
5/15/2025
Dichloroaceticacid
Detected: 7.9 UG/L (ppb)
5/15/2025
Dibromoaceticacid
Detected: 4.2 UG/L (ppb)
5/15/2025
Alkalinity, Total
Detected: 74 MG/L (ppm)
7/16/2025
TDS
Detected: 210 MG/L (ppm)
7/16/2025
Turbidity
Detected: 0.12 NTU
3/4/2025
A measure of water cloudiness from suspended particles.
Gross Beta Particle Activity
Detected: 1.42 PCI/L
3/4/2025
Perchlorate
Detected: 3 UG/L (ppb)
3/4/2025
Can occur naturally or from industrial/military sources; may interfere with thyroid function at elevated levels.
Conductivity (at 25°C)
Detected: 310 UMHO/CM
7/16/2025
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.