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Water Quality Lookup / California / Sonoma County / CALIFORNIA-AMERICAN LARKFIELD (PUC)
EPA SDWIS · Sonoma County, California

CALIFORNIA-AMERICAN LARKFIELD (PUC) Water Quality Report

Serving roughly 7,913 people in Sonoma County, California.

Data current as of July 2026
🔍Straight from EPA
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Results for CALIFORNIA-AMERICAN LARKFIELD (PUC)

1 water provider directly on file, serving roughly 7,913 people in Sonoma County, California.

Quick answer: CALIFORNIA-AMERICAN LARKFIELD (PUC) has no violations on file. One reading is worth knowing about: Lead was measured at 20UG/L, among the highest of the 756 providers on file in this area. It's the most notable figure in this system's record among its 756 local peers.
Utility CALIFORNIA-AMERICAN LARKFIELD (PUC) Population served 7,913 Owner Private
No violations on file

Contaminants found

Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0.006 mg/L (ppm)
12/31/2025
Lead
Detected: 20 UG/L (ppb)
8/29/2025
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.
Copper, Free
Detected: 398 UG/L (ppb)
8/29/2025
Arsenic
Detected: 5 UG/L (ppb)
9/23/2025
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
Manganese
Detected: 927 UG/L (ppb)
9/23/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Iron
Detected: 330 UG/L (ppb)
7/15/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 5.4 UG/L (ppb)
8/12/2025
TTHM
Detected: 13.9 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: 3.1 UG/L (ppb)
8/12/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromoform
Detected: 1.3 UG/L (ppb)
8/12/2025
Bromodichloromethane
Detected: 4.3 UG/L (ppb)
8/12/2025
Dibromochloromethane
Detected: 5.2 UG/L (ppb)
8/12/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Chloride
Detected: 19 MG/L (ppm)
6/10/2025
Sulfate
Detected: 11 MG/L (ppm)
6/10/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 16 MG/L (ppm)
6/10/2025
Calcium
Detected: 20 MG/L (ppm)
6/10/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 116 MG/L (ppm)
6/10/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
Lithium
Detected: 10 µg/L (ppb)
10/4/2023
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 160 MG/L (ppm)
6/10/2025
Other
Additional substances tested that don't fit neatly into the categories above
Dichloroaceticacid
Detected: 2.5 UG/L (ppb)
8/12/2025
Trichloroaceticacid
Detected: 1.2 UG/L (ppb)
8/12/2025
Dibromoaceticacid
Detected: 1.6 UG/L (ppb)
8/12/2025
Aggressive Index
Detected: 11.71 AGGR
6/10/2025
Alkalinity, Total
Detected: 160 MG/L (ppm)
6/10/2025
TDS
Detected: 240 MG/L (ppm)
6/10/2025
Odor
Detected: 7.1 TON
10/14/2025
Conductivity (at 25°C)
Detected: 370 UMHO/CM
6/10/2025
Color
Detected: 6 UNITS
6/10/2025
Perfluorobutanesulfonicacid (PFBS)
Detected: 3.2 NG/L (ppt)
1/14/2025
Perfluorohexanesulfonicacid (PFHxS)
Detected: 7.4 NG/L (ppt)
7/15/2025
Perfluoroctanesulfonicacid (PFOS)
Detected: 6.5 NG/L (ppt)
1/14/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
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.
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
LeadPartialYesPartial
ArsenicPartialYesPartial
Chromium-6 (Hexavalent)PartialYesPartial
CopperPartialYesPartial
Combined UraniumPartialYesPartial
PFOAPartialYes*Partial
PFOSPartialYes*Partial
NitratePartialYesPartial
Combined RadiumPartialYesPartial
LithiumPartialYes*Partial
DichloroaceticacidPartialYesPartial
TrichloroaceticacidPartialYesPartial
DibromoaceticacidPartialYesPartial
Copper, FreePartialYesPartial
Aggressive IndexPartialYesPartial
Alkalinity, TotalPartialYesPartial
TDSPartialYesPartial
ChloridePartialYesPartial
SulfatePartialYesPartial
OdorPartialYesPartial
Conductivity (at 25°C)PartialYesPartial
ColorPartialYesPartial
Perfluorobutanesulfonicacid (PFBS)PartialYesPartial
Perfluorohexanesulfonicacid (PFHxS)PartialYesPartial
Perfluoroctanesulfonicacid (PFOS)PartialYesPartial
ManganesePartialYesPartial
IronPartialYesPartial
Coliform Bacteria (indicator)NoYesNo
MagnesiumNoPartialNo
CalciumNoPartialNo
Alkalinity, BicarbonateNoNoNo
Hardness, Total (ASCACO3)NoNoNo

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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?