Serving roughly 93,692 people in Merced County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
🏠Local Expertise
Results for CITY OF MERCED
1 water provider directly on file, serving roughly 93,692 people in Merced County, California.
Quick answer: CITY OF MERCED has no violations on file. One reading is worth knowing about: Aggressive Index was measured at 12.5AGGR, among the highest of the 237 providers on file in this area. It's the most notable figure in this system's record among its 237 local peers.
Lead Summary
PFOA
PFOS
PFHXS
PFHXA
Aggressive Index
Langelier Index (pH(s))
Alkalinity, Total
Alkalinity, Bicarbonate
Magnesium
Potassium
Sodium
Calcium
Hardness, Total (ASCACO3)
TDS
Chloride
Sulfate
Fluoride
Nitrate-Nitrite
Nitrate
Radium-226
Gross Alpha Particle Activity
pH
TTHM
Lead
Iron
Manganese
Tetrachloroethylene
Chloroform
Bromoform
Bromodichloromethane
Dibromochloromethane
Barium
Arsenic
Copper, Free
Aluminum
Zinc
Conductivity (at 25°C)
Foamingagents (SURFACTANTS)
Utility CITY OF MERCEDPopulation served 93,692Owner Local government
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2024
Lead
Detected: 4 UG/L (ppb)
8/21/2025
A metal that can leach from old pipes, solder, and fixtures. Current medical guidance holds there is no truly safe level of lead exposure, especially for children and pregnant women.
Iron
Detected: 150 UG/L (ppb)
8/21/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Manganese
Detected: 11 UG/L (ppb)
8/21/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Barium
Detected: 480 UG/L (ppb)
8/26/2025
Arsenic
Detected: 3.8 UG/L (ppb)
8/26/2025
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
Copper, Free
Detected: 31 UG/L (ppb)
8/21/2025
Aluminum
Detected: 94 UG/L (ppb)
8/21/2025
Zinc
Detected: 14 UG/L (ppb)
8/21/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
TTHM
Detected: 3 UG/L (ppb)
2/27/2025
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: 0.83 UG/L (ppb)
2/27/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromoform
Detected: 0.59 UG/L (ppb)
2/27/2025
Bromodichloromethane
Detected: 0.79 UG/L (ppb)
2/27/2025
Dibromochloromethane
Detected: 0.81 UG/L (ppb)
2/27/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Chloride
Detected: 13 MG/L (ppm)
8/26/2025
Sulfate
Detected: 10 MG/L (ppm)
8/26/2025
Fluoride
Detected: 0.13 MG/L (ppm)
8/26/2025
Often added deliberately for dental health; can also occur naturally.
Nitrate-Nitrite
Detected: 4.2 MG/L (ppm)
8/26/2025
Nitrate
Detected: 3.7 MG/L (ppm)
10/2/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 21 MG/L (ppm)
8/26/2025
Potassium
Detected: 7.1 MG/L (ppm)
8/26/2025
Sodium
Detected: 35 MG/L (ppm)
8/26/2025
Calcium
Detected: 55 MG/L (ppm)
8/26/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Langelier Index (pH(s))
Detected: 0.44 LANG
8/21/2025
Hardness, Total (ASCACO3)
Detected: 220 MG/L (ppm)
8/26/2025
Gross Alpha Particle Activity
Detected: 10.5 PCI/L
8/26/2025
pH
Detected: 8 PH
8/26/2025
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
PFOA
Detected: 0.0045 µg/L (ppb)
1/30/2024
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFOS
Detected: 0.0065 µg/L (ppb)
1/30/2024
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFHXS
Detected: 0.012 µg/L (ppb)
1/30/2024
PFHXA
Detected: 0.0034 µg/L (ppb)
1/30/2024
VOCs (Volatile Organic Compounds)
Industrial solvents and fuel-related chemicals that evaporate easily
Tetrachloroethylene
Detected: 0.71 UG/L (ppb)
5/21/2025
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 240 MG/L (ppm)
8/26/2025
Other
Additional substances tested that don't fit neatly into the categories above
Aggressive Index
Detected: 12.5 AGGR
8/26/2025
Alkalinity, Total
Detected: 240 MG/L (ppm)
8/26/2025
TDS
Detected: 410 MG/L (ppm)
8/26/2025
Radium-226
Detected: 0.43 PCI/L
8/26/2025
Conductivity (at 25°C)
Detected: 560 UMHO/CM
8/26/2025
Foamingagents (SURFACTANTS)
Detected: 0.088 MG/L (ppm)
8/26/2025
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.