Serving roughly 5,610 people in Napa County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
🏠Local Expertise
Results for CALISTOGA, CITY OF
1 water provider directly on file, serving roughly 5,610 people in Napa County, California.
Quick answer: CALISTOGA, CITY OF has no violations on file. One reading is worth knowing about: Odor was measured at 14TON, among the highest of the 358 providers on file in this area. It's the most notable figure in this system's record among its 358 local peers.
Lead Summary
PFHXA
PFPEA
PFOS
PFOA
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromodichloromethane
Dibromochloromethane
Dichloroaceticacid
Trichloroaceticacid
Monobromoaceticacid
Dibromoaceticacid
Copper, Free
Carbon, Total
Odor
Iron
Manganese
Color
Aggressive Index
Magnesium
Sodium
Calcium
Alkalinity, Total
Alkalinity, Bicarbonate
Hardness, Total (ASCACO3)
TDS
Chloride
Sulfate
Turbidity
pH
Aluminum
Conductivity (at 25°C)
Utility CALISTOGA, CITY OFPopulation served 5,610Owner Local government
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2022
Copper, Free
Detected: 120 UG/L (ppb)
4/30/2025
Iron
Detected: 480 UG/L (ppb)
4/8/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Manganese
Detected: 100 UG/L (ppb)
4/8/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Aluminum
Detected: 440 UG/L (ppb)
4/8/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 31.2 UG/L (ppb)
7/15/2025
TTHM
Detected: 29.36 UG/L (ppb)
7/15/2025
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: 25.75 UG/L (ppb)
7/15/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromodichloromethane
Detected: 3.61 UG/L (ppb)
7/15/2025
Dibromochloromethane
Detected: 2.02 UG/L (ppb)
7/15/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Chloride
Detected: 2.7 MG/L (ppm)
4/8/2025
Sulfate
Detected: 13 MG/L (ppm)
4/8/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 9.1 MG/L (ppm)
4/8/2025
Sodium
Detected: 4.2 MG/L (ppm)
4/8/2025
Calcium
Detected: 11 MG/L (ppm)
4/8/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 65 MG/L (ppm)
4/8/2025
pH
Detected: 7.57 PH
4/8/2025
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
PFHXA
Detected: 0.0032 µg/L (ppb)
6/4/2024
PFPEA
Detected: 0.0042 µg/L (ppb)
6/4/2024
PFOS
Detected: 0.0122 µg/L (ppb)
6/4/2024
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFOA
Detected: 0.0064 µg/L (ppb)
6/4/2024
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 120 MG/L (ppm)
10/17/2025
Other
Additional substances tested that don't fit neatly into the categories above
Dichloroaceticacid
Detected: 14.7 UG/L (ppb)
7/15/2025
Trichloroaceticacid
Detected: 16.5 UG/L (ppb)
7/15/2025
Monobromoaceticacid
Detected: 1.9 UG/L (ppb)
1/13/2025
Dibromoaceticacid
Detected: 1.1 UG/L (ppb)
4/8/2025
Carbon, Total
Detected: 1.95 MG/L (ppm)
10/17/2025
Odor
Detected: 14 TON
10/7/2025
Color
Detected: 10 UNITS
10/7/2025
Aggressive Index
Detected: 10.81 AGGR
4/8/2025
Alkalinity, Total
Detected: 120 MG/L (ppm)
10/17/2025
TDS
Detected: 130 MG/L (ppm)
4/8/2025
Turbidity
Detected: 24 NTU
4/8/2025
A measure of water cloudiness from suspended particles.
Conductivity (at 25°C)
Detected: 160 UMHO/CM
4/8/2025
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.