ST. HELENA is served by 4 water providers on file with the EPA.
Data current as of July 2026
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Results for ST. HELENA, CA
4 water providers on file serving this city.
Quick answer: ST. HELENA's water has no violation currently counted toward its compliance status. EPA's record shows a Total Haloacetic Acids (HAA5) violation dating to 10/01/2020 (6 years ago) — because it's more than five years past its deadline, EPA's policy no longer treats it as part of this system's current standing, though it remains on the public record.
Lead Summary
Lithium
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromodichloromethane
Dichloroaceticacid
Trichloroaceticacid
Alkalinity, Total
Alkalinity, Bicarbonate
Carbon, Total
Odor
Iron
Manganese
Color
Aggressive Index
Magnesium
Sodium
Calcium
Hardness, Total (ASCACO3)
TDS
Chloride
Sulfate
Turbidity
pH
Vanadium, Total
Aluminum
Conductivity (at 25°C)
Violations on file
Total Haloacetic Acids (HAA5)
Older/archived health-based violation
Found at 1 of 4 providers
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2023
Iron
Detected: 1600 UG/L (ppb)
9/28/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Manganese
Detected: 86 UG/L (ppb)
9/28/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Vanadium, Total
Detected: 3.2 UG/L (ppb)
2/25/2025
Aluminum
Detected: 530 UG/L (ppb)
2/25/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 69.4 UG/L (ppb)
9/23/2025
TTHM
Detected: 72.52 UG/L (ppb)
9/23/2025
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: 66.55 UG/L (ppb)
9/23/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromodichloromethane
Detected: 5.97 UG/L (ppb)
9/23/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Chloride
Detected: 3.3 MG/L (ppm)
2/25/2025
Sulfate
Detected: 2.8 MG/L (ppm)
2/25/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 1.9 MG/L (ppm)
2/25/2025
Sodium
Detected: 5 MG/L (ppm)
2/25/2025
Calcium
Detected: 4.7 MG/L (ppm)
2/25/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 20 MG/L (ppm)
2/25/2025
pH
Detected: 7.38 PH
2/25/2025
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
Lithium
Detected: 54 µg/L (ppb)
7/12/2023
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: 35 MG/L (ppm)
10/17/2025
Other
Additional substances tested that don't fit neatly into the categories above
Dichloroaceticacid
Detected: 34.1 UG/L (ppb)
9/23/2025
Trichloroaceticacid
Detected: 35.3 UG/L (ppb)
9/23/2025
Alkalinity, Total
Detected: 35 MG/L (ppm)
10/17/2025
Carbon, Total
Detected: 4.85 MG/L (ppm)
9/28/2025
Odor
Detected: 28 TON
2/27/2025
Color
Detected: 6 UNITS
2/27/2025
Aggressive Index
Detected: 10.29 AGGR
2/25/2025
TDS
Detected: 67 MG/L (ppm)
2/25/2025
Turbidity
Detected: 8.2 NTU
2/25/2025
A measure of water cloudiness from suspended particles.
Conductivity (at 25°C)
Detected: 66 UMHO/CM
2/25/2025
Filtration considerations: General system types, not a specific product recommendation.