NORTH COAST COUNTY WATER DIST Water Quality Report
Serving roughly 38,546 people in San Mateo County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
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Results for NORTH COAST COUNTY WATER DIST
1 water provider directly on file, serving roughly 38,546 people in San Mateo County, California.
Quick answer: NORTH COAST COUNTY WATER DIST has no violations on file and no single reading stands out against its peers (113 other providers in this area). It serves roughly 38,546 people, and the full breakdown below reflects everything EPA and California have on record for it.
Lead Summary
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromodichloromethane
Dibromochloromethane
Dichloroaceticacid
Trichloroaceticacid
Copper, Free
Utility NORTH COAST COUNTY WATER DISTPopulation served 38,546Owner Local government
No violations on file
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2025
Copper, Free
Detected: 587 UG/L (ppb)
7/24/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 8.04 UG/L (ppb)
8/4/2025
TTHM
Detected: 21 UG/L (ppb)
8/4/2025
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: 9.64 UG/L (ppb)
8/4/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromodichloromethane
Detected: 6.83 UG/L (ppb)
8/4/2025
Dibromochloromethane
Detected: 4.58 UG/L (ppb)
8/4/2025
Other
Additional substances tested that don't fit neatly into the categories above
Dichloroaceticacid
Detected: 5.91 UG/L (ppb)
8/4/2025
Trichloroaceticacid
Detected: 2.13 UG/L (ppb)
8/4/2025
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.