Serving roughly 110,000 people in Orange County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
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Results for MESA WATER DISTRICT
1 water provider directly on file, serving roughly 110,000 people in Orange County, California.
Quick answer: MESA WATER DISTRICT has no violations on file. One reading is worth knowing about: Odor was measured at 240TON, among the highest of the 167 providers on file in this area. It's the most notable figure in this system's record among its 167 local peers.
Lead Summary
Lithium
TTHM
Dibromoaceticacid
Dichloroaceticacid
Chloroform
Bromoform
Bromodichloromethane
Dibromochloromethane
Turbidity
Odor
Color
Magnesium
Potassium
Sodium
Calcium
Hardness, Total (ASCACO3)
Bromide
Alkalinity, Bicarbonate
Alkalinity, Total
Carbon, Total
TDS
Sulfate
Chloride
Alkalinity, Carbonate
Utility MESA WATER DISTRICTPopulation served 110,000Owner Local government
No violations on file
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2023
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
TTHM
Detected: 7.2 UG/L (ppb)
8/12/2025
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: 1.3 UG/L (ppb)
8/12/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromoform
Detected: 3.5 UG/L (ppb)
8/12/2025
Bromodichloromethane
Detected: 1 UG/L (ppb)
8/12/2025
Dibromochloromethane
Detected: 1.3 UG/L (ppb)
8/12/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Sulfate
Detected: 15.9 MG/L (ppm)
8/14/2025
Chloride
Detected: 12.8 MG/L (ppm)
8/14/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 3.9 MG/L (ppm)
8/14/2025
Potassium
Detected: 1.6 MG/L (ppm)
8/14/2025
Sodium
Detected: 25.6 MG/L (ppm)
8/14/2025
Calcium
Detected: 22 MG/L (ppm)
8/14/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 71.3 MG/L (ppm)
8/14/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
Lithium
Detected: 28.9887 µg/L (ppb)
12/6/2023
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
VOCs (Volatile Organic Compounds)
Industrial solvents and fuel-related chemicals that evaporate easily
Bromide
Detected: 0.03 MG/L (ppm)
8/14/2025
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 105 MG/L (ppm)
8/14/2025
Alkalinity, Carbonate
Detected: 11.2 MG/L (ppm)
2/6/2025
Other
Additional substances tested that don't fit neatly into the categories above
Dibromoaceticacid
Detected: 1.4 UG/L (ppb)
8/12/2025
Dichloroaceticacid
Detected: 1.5 UG/L (ppb)
8/12/2025
Turbidity
Detected: 0.22 NTU
9/8/2025
A measure of water cloudiness from suspended particles.
Odor
Detected: 240 TON
9/3/2025
Color
Detected: 200 UNITS
9/3/2025
Alkalinity, Total
Detected: 86.2 MG/L (ppm)
8/14/2025
Carbon, Total
Detected: 0.08 MG/L (ppm)
8/14/2025
TDS
Detected: 150 MG/L (ppm)
8/14/2025
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.