Serving roughly 19,807 people in Humboldt County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
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Results for HUMBOLDT C.S.D.
1 water provider directly on file, serving roughly 19,807 people in Humboldt County, California.
Quick answer: HUMBOLDT C.S.D. has no violations on file and no single reading stands out against its peers (250 other providers in this area). It serves roughly 19,807 people, and the full breakdown below reflects everything EPA and California have on record for it.
Lead Summary
Lithium
Conductivity (at 25°C)
pH
Manganese
Calcium
Chloride
Sulfate
Color
Odor
Fluoride
TDS
Barium
Magnesium
Zinc
Chloroform
Bromodichloromethane
Dibromochloromethane
TTHM
Dichloroaceticacid
Trichloroaceticacid
Totalhaloaceticacids (HAA5)
Copper, Free
Lead
Utility HUMBOLDT C.S.D.Population served 19,807Owner Local government
No violations on file
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0.00205 mg/L (ppm)
12/31/2025
Manganese
Detected: 10 UG/L (ppb)
3/13/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Barium
Detected: 12 UG/L (ppb)
6/26/2025
Zinc
Detected: 24 UG/L (ppb)
6/26/2025
Copper, Free
Detected: 40 UG/L (ppb)
9/9/2025
Lead
Detected: 4 UG/L (ppb)
9/9/2025
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.
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Chloroform
Detected: 8.6 UG/L (ppb)
6/26/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromodichloromethane
Detected: 4.1 UG/L (ppb)
6/26/2025
Dibromochloromethane
Detected: 1.2 UG/L (ppb)
6/26/2025
TTHM
Detected: 14 UG/L (ppb)
6/26/2025
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.
Totalhaloaceticacids (HAA5)
Detected: 6.1 UG/L (ppb)
6/26/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Chloride
Detected: 18 MG/L (ppm)
6/26/2025
Sulfate
Detected: 5.6 MG/L (ppm)
6/26/2025
Fluoride
Detected: 0.11 MG/L (ppm)
6/26/2025
Often added deliberately for dental health; can also occur naturally.
Minerals
Everyday minerals that mainly affect taste and water hardness
Calcium
Detected: 6 MG/L (ppm)
3/13/2025
Magnesium
Detected: 9.2 MG/L (ppm)
6/26/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
pH
Detected: 7.4 PH
6/26/2025
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
Lithium
Detected: 9.48 µg/L (ppb)
9/16/2025
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
Other
Additional substances tested that don't fit neatly into the categories above
Conductivity (at 25°C)
Detected: 170 UMHO/CM
3/5/2025
Color
Detected: 5 UNITS
6/26/2025
Odor
Detected: 2 TON
6/26/2025
TDS
Detected: 100 MG/L (ppm)
6/26/2025
Dichloroaceticacid
Detected: 3.4 UG/L (ppb)
6/26/2025
Trichloroaceticacid
Detected: 2.7 UG/L (ppb)
6/26/2025
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.