Serving roughly 66,600 people in Orange County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
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Results for CITY OF TUSTIN
1 water provider directly on file, serving roughly 66,600 people in Orange County, California.
Quick answer: CITY OF TUSTIN has no violation currently counted toward its compliance status. EPA's record shows a Nitrate violation dating to 10/30/1979 (47 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
Lithium
PFHXS
PFOS
PFPEA
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromoform
Bromodichloromethane
Dibromochloromethane
Dichloroaceticacid
Trichloroaceticacid
Dibromoaceticacid
TDS
Nitrate
Magnesium
Potassium
Sodium
Calcium
Hardness, Total (ASCACO3)
Bromide
Alkalinity, Total
Carbon, Total
Sulfate
Chloride
Nitrite
Nitrate-Nitrite
Utility CITY OF TUSTINPopulation served 66,600Owner 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
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 5.6 UG/L (ppb)
9/2/2025
TTHM
Detected: 26.6 UG/L (ppb)
9/2/2025
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: 7.3 UG/L (ppb)
9/2/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromoform
Detected: 2.4 UG/L (ppb)
9/2/2025
Bromodichloromethane
Detected: 8.2 UG/L (ppb)
9/2/2025
Dibromochloromethane
Detected: 8.7 UG/L (ppb)
9/2/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Nitrate
Detected: 3.8 MG/L (ppm)
9/24/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Sulfate
Detected: 83.8 MG/L (ppm)
7/29/2025
Chloride
Detected: 235 MG/L (ppm)
7/29/2025
Nitrite
Detected: 0.007 MG/L (ppm)
8/12/2025
Nitrate-Nitrite
Detected: 2.92 MG/L (ppm)
10/15/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 8.3 MG/L (ppm)
4/22/2025
Potassium
Detected: 1 MG/L (ppm)
4/22/2025
Sodium
Detected: 38.3 MG/L (ppm)
4/22/2025
Calcium
Detected: 27.6 MG/L (ppm)
4/22/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 103 MG/L (ppm)
4/22/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
Lithium
Detected: 10.8517 µg/L (ppb)
11/20/2025
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
PFHXS
Detected: 0.0035 µg/L (ppb)
4/22/2025
PFOS
Detected: 0.0042 µg/L (ppb)
4/22/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFPEA
Detected: 0.0037 µg/L (ppb)
11/20/2025
VOCs (Volatile Organic Compounds)
Industrial solvents and fuel-related chemicals that evaporate easily
Bromide
Detected: 0.02 MG/L (ppm)
4/22/2025
Other
Additional substances tested that don't fit neatly into the categories above
Dichloroaceticacid
Detected: 3.7 UG/L (ppb)
9/2/2025
Trichloroaceticacid
Detected: 1.9 UG/L (ppb)
9/2/2025
Dibromoaceticacid
Detected: 1.1 UG/L (ppb)
6/3/2025
TDS
Detected: 184 MG/L (ppm)
10/15/2025
Alkalinity, Total
Detected: 224 MG/L (ppm)
7/29/2025
Carbon, Total
Detected: 0.15 MG/L (ppm)
7/29/2025
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.