whatsinmywater.co
EPA SDWIS ยท Fresno County, California ยท 704 providers profiled

Fresno County, CA Water Quality Report

Fresno County is served by 704 major public water systems on file with the EPA.

Data current as of July 2026
๐Ÿ”Straight from EPA
๐ŸงชReal Lab Results
๐Ÿ“…Updated Quarterly
๐Ÿ Local Expertise
Results for Fresno County, CA

704 water providers on file for this county, sorted by population served.

Quick answer: Fresno County has 704 water providers profiled, sorted by population served.

Violations on file

Nitrate
Older/archived health-based violation
Found at 21 of 704 providers
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Combined Uranium
Older/archived health-based violation
Found at 4 of 704 providers
A naturally occurring radioactive metal. Long-term exposure above the legal limit is associated with kidney effects and increased cancer risk.
Arsenic
Older/archived health-based violation
Found at 3 of 704 providers
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
TTHM
Older/archived health-based violation
Found at 12 of 704 providers
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.
Coliform (TCR)
Older/archived health-based violation
Found at 18 of 704 providers
Surface Water Treatment Rule
Older/archived health-based violation
Found at 4 of 704 providers
Lead And Copper Rule Revisions
Currently open health violation
Found at 41 of 704 providers
Fluoride
Older/archived health-based violation
Found at 1 of 704 providers
Often added deliberately for dental health; can also occur naturally.
Carbon, Total
Older/archived health-based violation
Found at 1 of 704 providers
Total Haloacetic Acids (HAA5)
Older/archived health-based violation
Found at 6 of 704 providers
1, 2-Dibromo-3-Chloropropane
Older/archived health-based violation
Found at 1 of 704 providers

Contaminants found

Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0.13 mg/L (ppm)
Found at 260 providers
Combined Uranium
Detected: 120 PCI/L
Found at 25 providers
A naturally occurring radioactive metal. Long-term exposure above the legal limit is associated with kidney effects and increased cancer risk.
Chromium, Hex
Detected: 32 UG/L (ppb)
Found at 73 providers
Copper, Free
Detected: 576 UG/L (ppb)
Found at 61 providers
Copper Summary
Detected: 4.6 mg/L (ppm)
Found at 18 providers
Iron
Detected: 2400 UG/L (ppb)
Found at 36 providers
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Manganese
Detected: 190 UG/L (ppb)
Found at 30 providers
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Zinc
Detected: 2000 UG/L (ppb)
Found at 15 providers
Arsenic
Detected: 41 UG/L (ppb)
Found at 61 providers
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
Aluminum
Detected: 250 UG/L (ppb)
Found at 37 providers
Lead
Detected: 37 UG/L (ppb)
Found at 37 providers
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.
Strontium
Detected: 340 UG/L (ppb)
8/14/2025
Barium
Detected: 390 UG/L (ppb)
Found at 35 providers
Selenium
Detected: 7.2 UG/L (ppb)
Found at 6 providers
Manganese, Dissolved
Detected: 44 UG/L (ppb)
7/8/2025
Iron, Dissolved
Detected: 84 UG/L (ppb)
7/8/2025
Nickel
Detected: 11 UG/L (ppb)
Found at 17 providers
Chromium
Detected: 15 UG/L (ppb)
Found at 17 providers
Occurs in two forms โ€” trivalent (an essential nutrient in trace amounts) and hexavalent (linked to increased cancer risk).
Molybdenum, Total
Detected: 6.1 UG/L (ppb)
Found at 2 providers
Vanadium, Total
Detected: 38 UG/L (ppb)
Found at 2 providers
Mercury
Detected: 1.4 UG/L (ppb)
Found at 2 providers
Antimony, Total
Detected: 2.5 UG/L (ppb)
Found at 2 providers
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 67 UG/L (ppb)
Found at 45 providers
TTHM
Detected: 170 UG/L (ppb)
Found at 61 providers
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.
Bromoform
Detected: 71 UG/L (ppb)
Found at 50 providers
Bromodichloromethane
Detected: 66 UG/L (ppb)
Found at 52 providers
Dibromochloromethane
Detected: 71 UG/L (ppb)
Found at 50 providers
Chloroform
Detected: 120 UG/L (ppb)
Found at 49 providers
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
Nitrate
Detected: 21.1 MG/L (ppm)
Found at 205 providers
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Chloride
Detected: 210 MG/L (ppm)
Found at 57 providers
Sulfate
Detected: 1300 MG/L (ppm)
Found at 52 providers
Nitrate-Nitrite
Detected: 19 MG/L (ppm)
Found at 46 providers
Fluoride
Detected: 2.4 MG/L (ppm)
Found at 36 providers
Often added deliberately for dental health; can also occur naturally.
Nitrite
Detected: 0.46 MG/L (ppm)
Found at 2 providers
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 150 MG/L (ppm)
Found at 57 providers
Calcium
Detected: 160 MG/L (ppm)
Found at 62 providers
Potassium
Detected: 9.8 MG/L (ppm)
Found at 32 providers
Sodium
Detected: 230 MG/L (ppm)
Found at 58 providers
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 1000 MG/L (ppm)
Found at 54 providers
Gross Alpha Particle Activity
Detected: 35.8 PCI/L
Found at 52 providers
Langelier Index (pH(s))
Detected: 0.52 LANG
Found at 37 providers
pH
Detected: 8.9 PH
Found at 57 providers
A measure of how acidic or basic the water is (7 is neutral). Affects taste and plumbing, not a direct health measure.
pH, Field
Detected: 7.24 PH
10/28/2025
Orthophosphate
Detected: 0.3 MG/L (ppm)
10/14/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
PFOA
Detected: 0.018 ยตg/L (ppb)
Found at 6 providers
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFOS
Detected: 0.041 ยตg/L (ppb)
Found at 5 providers
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFBS
Detected: 0.013 ยตg/L (ppb)
Found at 5 providers
PFPEA
Detected: 0.016 ยตg/L (ppb)
Found at 5 providers
PFBA
Detected: 0.0081 ยตg/L (ppb)
Found at 4 providers
PFHXA
Detected: 0.014 ยตg/L (ppb)
Found at 5 providers
PFHXS
Detected: 0.0072 ยตg/L (ppb)
Found at 3 providers
PFHPA
Detected: 0.013 ยตg/L (ppb)
Found at 4 providers
Lithium
Detected: 41.3 ยตg/L (ppb)
Found at 2 providers
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
Pfda
Detected: 0.003 ยตg/L (ppb)
11/3/2023
PFNA
Detected: 0.0069 ยตg/L (ppb)
Found at 2 providers
6:2 Fts
Detected: 0.0053 ยตg/L (ppb)
7/24/2023
Pfpes
Detected: 0.0047 ยตg/L (ppb)
9/8/2023
VOCs (Volatile Organic Compounds)
Industrial solvents and fuel-related chemicals that evaporate easily
1, 2, 3-Trichloropropane
Detected: 0.15 UG/L (ppb)
Found at 27 providers
Tetrachloroethylene
Detected: 2.1 UG/L (ppb)
Found at 3 providers
Trichloroethylene
Detected: 1.5 UG/L (ppb)
10/9/2025
Dichloromethane
Detected: 1.1 UG/L (ppb)
Found at 2 providers
Petroleum Compounds
Substances associated with fuel or petroleum contamination
Benzene
Detected: 2 UG/L (ppb)
10/3/2025
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 280 MG/L (ppm)
Found at 58 providers
Alkalinity, Carbonate
Detected: 30 MG/L (ppm)
Found at 9 providers
Other
Additional substances tested that don't fit neatly into the categories above
Chlorite
Detected: 0.0089 MG/L (ppm)
7/3/2025
Dichloroaceticacid
Detected: 45 UG/L (ppb)
Found at 38 providers
Trichloroaceticacid
Detected: 30.8 UG/L (ppb)
Found at 34 providers
Radium-228
Detected: 0.625 PCI/L
Found at 7 providers
Aggressive Index
Detected: 12.6 AGGR
Found at 37 providers
Alkalinity, Total
Detected: 310 MG/L (ppm)
Found at 61 providers
TDS
Detected: 5400 MG/L (ppm)
Found at 59 providers
Conductivity (at 25ยฐC)
Detected: 2600 UMHO/CM
Found at 74 providers
Dibromoaceticacid
Detected: 35 UG/L (ppb)
Found at 37 providers
Turbidity
Detected: 16 NTU
Found at 38 providers
A measure of water cloudiness from suspended particles.
Monochloroaceticacid
Detected: 8.1 UG/L (ppb)
Found at 25 providers
Carbon, Total
Detected: 2.3 MG/L (ppm)
Found at 8 providers
Color
Detected: 50 UNITS
Found at 39 providers
Silica
Detected: 58 MG/L (ppm)
Found at 2 providers
Foamingagents (SURFACTANTS)
Detected: 0.14 MG/L (ppm)
Found at 13 providers
1, 2-Dibromo-3-Chloropropane
Detected: 0.32 UG/L (ppb)
Found at 27 providers
Trichlorotrifluoroethane
Detected: 9.9 UG/L (ppb)
7/18/2025
Perfluorobutanesulfonicacid (PFBS)
Detected: 10 NG/L (ppt)
Found at 8 providers
Perfluorononanoicacid (PFNA)
Detected: 6.8 NG/L (ppt)
Found at 3 providers
Perfluoroctanesulfonicacid (PFOS)
Detected: 48 NG/L (ppt)
Found at 9 providers
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Perfluoroctanoicacid (PFOA)
Detected: 15 NG/L (ppt)
Found at 10 providers
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Perfluorohexanoicacid (PFHXA)
Detected: 9.9 NG/L (ppt)
Found at 8 providers
Perfluorobutanoicacid (PFBA)
Detected: 7.2 NG/L (ppt)
Found at 7 providers
Perfluoropentanoicacid (PFPEA)
Detected: 14 NG/L (ppt)
Found at 8 providers
Perfluoroheptanoicacid (PFHPA)
Detected: 13 NG/L (ppt)
Found at 6 providers
Perfluorohexanesulfonicacid (PFHxS)
Detected: 11 NG/L (ppt)
Found at 6 providers
Odor
Detected: 4 TON
Found at 18 providers
Perchlorate
Detected: 2.5 UG/L (ppb)
Found at 5 providers
Can occur naturally or from industrial/military sources; may interfere with thyroid function at elevated levels.
Monobromoaceticacid
Detected: 4.1 UG/L (ppb)
Found at 26 providers
Adsorbableorganicfluorine
Detected: 3700 NG/L (ppt)
Found at 4 providers
Perfluorodecanoicacid (PFDA)
Detected: 3.2 NG/L (ppt)
10/16/2025
Temperature (CENTIGRADE)
Detected: 25 C
Found at 5 providers
Combined Radium (-226 & -228)
Detected: 0.429 PCI/L
4/17/2025
A naturally occurring radioactive element found in some groundwater.
Gross Beta Particle Activity
Detected: 11.5 PCI/L
4/17/2025
Asbestos
Detected: 3.8 MFL
1/17/2025
Filtration considerations: General system types, not a specific product recommendation.
Contaminant Whole-House Carbon Under-Sink RO Under-Sink Carbon
Total Trihalomethanes (TTHM)YesYesYes
Haloacetic Acids (HAA5)YesYesYes
ChloroformYesYesYes
Chlorine / TasteYesYesYes
Sediment / TurbidityYesYesYes
TrichloroethyleneYesYesYes
TetrachloroethyleneYesYesYes
cis-1,2-DichloroethyleneYesYesYes
1,1-DichloroethyleneYesYesYes
BromoformYesYesYes
BromodichloromethaneYesYesYes
DibromochloromethaneYesYesYes
1,1,2-TrichloroethaneYesYesYes
Vinyl ChlorideYesYesYes
Carbon TetrachlorideYesYesYes
BenzeneYesYesYes
TolueneYesYesYes
XyleneYesYesYes
Totalhaloaceticacids (HAA5)YesYesYes
1, 2, 3-TrichloropropaneYesYesYes
DichloromethaneYesYesYes
LeadPartialYesPartial
ArsenicPartialYesPartial
Chromium-6 (Hexavalent)PartialYesPartial
CopperPartialYesPartial
Combined UraniumPartialYesPartial
PFOAPartialYes*Partial
PFOSPartialYes*Partial
NitratePartialYesPartial
Combined RadiumPartialYesPartial
ChloritePartialYesPartial
DichloroaceticacidPartialYesPartial
TrichloroaceticacidPartialYesPartial
Combined UraniumPartialYesPartial
Chromium, HexPartialYesPartial
Copper, FreePartialYesPartial
Aggressive IndexPartialYesPartial
Alkalinity, TotalPartialYesPartial
TDSPartialYesPartial
ChloridePartialYesPartial
SulfatePartialYesPartial
Conductivity (at 25ยฐC)PartialYesPartial
PFBSPartialYes*Partial
Nitrate-NitritePartialYesPartial
DibromoaceticacidPartialYesPartial
IronPartialYesPartial
ManganesePartialYesPartial
ZincPartialYesPartial
MonochloroaceticacidPartialYesPartial
Carbon, TotalPartialYesPartial
AluminumPartialYesPartial
ColorPartialYesPartial
SilicaPartialYesPartial
StrontiumPartialYesPartial
BariumPartialYesPartial
Foamingagents (SURFACTANTS)PartialYesPartial
FluoridePartialYesPartial
1, 2-Dibromo-3-ChloropropanePartialYesPartial
TrichlorotrifluoroethanePartialYesPartial
PFPEAPartialYes*Partial
PFBAPartialYes*Partial
PFHXAPartialYes*Partial
PFHXSPartialYes*Partial
PFHPAPartialYes*Partial
Perfluorobutanesulfonicacid (PFBS)PartialYesPartial
Perfluorononanoicacid (PFNA)PartialYesPartial
Perfluoroctanesulfonicacid (PFOS)PartialYesPartial
Perfluoroctanoicacid (PFOA)PartialYesPartial
Perfluorohexanoicacid (PFHXA)PartialYesPartial
Perfluorobutanoicacid (PFBA)PartialYesPartial
Perfluoropentanoicacid (PFPEA)PartialYesPartial
Perfluoroheptanoicacid (PFHPA)PartialYesPartial
Perfluorohexanesulfonicacid (PFHxS)PartialYesPartial
OdorPartialYesPartial
PerchloratePartialYesPartial
SeleniumPartialYesPartial
LithiumPartialYes*Partial
Manganese, DissolvedPartialYesPartial
Iron, DissolvedPartialYesPartial
MonobromoaceticacidPartialYesPartial
NickelPartialYesPartial
ChromiumPartialYesPartial
Molybdenum, TotalPartialYesPartial
Vanadium, TotalPartialYesPartial
MercuryPartialYesPartial
AdsorbableorganicfluorinePartialYesPartial
PfdaPartialYes*Partial
PFNAPartialYes*Partial
Perfluorodecanoicacid (PFDA)PartialYesPartial
6:2 FtsPartialYes*Partial
PfpesPartialYes*Partial
Temperature (CENTIGRADE)PartialYesPartial
Antimony, TotalPartialYesPartial
NitritePartialYesPartial
Combined Radium (-226 & -228)PartialYesPartial
Gross Beta Particle ActivityPartialYesPartial
AsbestosPartialYesPartial
Coliform Bacteria (indicator)NoYesNo
MagnesiumNoPartialNo
CalciumNoPartialNo
Hardness, Total (ASCACO3)NoNoNo
Gross Alpha Particle ActivityNoNoNo
Langelier Index (pH(s))NoNoNo
PotassiumNoPartialNo
SodiumNoPartialNo
Alkalinity, BicarbonateNoNoNo
pHNoNoNo
Alkalinity, CarbonateNoNoNo
pH, FieldNoNoNo
OrthophosphateNoNoNo

Browse by city

Individual water providers

Want a different ZIP, city, or address?
Look up your water quality โ†’
Learn more
What is TTHM? Understanding EPA Violation Status Is Chromium-6 Dangerous? Whole-House vs. Under-Sink Filtration Lead and Copper in Drinking Water What is PFAS? Arsenic and Uranium Explained Nitrate and Fluoride Explained Water Hardness, pH, and Turbidity What is Coliform Bacteria?