CALIFORNIA WATER SERVICE - BEAR GULCH Water Quality Report
Serving roughly 61,431 people in San Mateo County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
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Results for CALIFORNIA WATER SERVICE - BEAR GULCH
1 water provider directly on file, serving roughly 61,431 people in San Mateo County, California.
Quick answer: CALIFORNIA WATER SERVICE - BEAR GULCH has no violations on file. One reading is worth knowing about: Barium was measured at 1400UG/L, among the highest of the 113 providers on file in this area. It's the most notable figure in this system's record among its 113 local peers.
Lead Summary
Perfluoroctanoicacid (PFOA)
Perfluorohexanoicacid (PFHXA)
Aggressive Index
Langelier Index (pH(s))
Magnesium
Calcium
Sodium
Potassium
Alkalinity, Total
Alkalinity, Bicarbonate
Hardness, Total (ASCACO3)
TDS
Chloride
Sulfate
Fluoride
Turbidity
pH, Field
Lithium, Total
Strontium
Iron
Manganese
Chromium, Hex
Barium
Conductivity (at 25°C)
Color
Nitrate
Boron, Total
Zinc
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromodichloromethane
Dibromochloromethane
Dichloroaceticacid
Trichloroaceticacid
Monochloroaceticacid
Utility CALIFORNIA WATER SERVICE - BEAR GULCHPopulation served 61,431Owner Private
No violations on file
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0.004 mg/L (ppm)
12/31/2024
Lithium, Total
Detected: 48 UG/L (ppb)
7/2/2025
Strontium
Detected: 800 UG/L (ppb)
7/2/2025
Iron
Detected: 1100 UG/L (ppb)
7/2/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Manganese
Detected: 170 UG/L (ppb)
7/2/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Chromium, Hex
Detected: 0.02 UG/L (ppb)
2/13/2025
Barium
Detected: 1400 UG/L (ppb)
7/2/2025
Zinc
Detected: 241 UG/L (ppb)
7/8/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 44 UG/L (ppb)
8/13/2025
TTHM
Detected: 42 UG/L (ppb)
8/13/2025
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: 41 UG/L (ppb)
8/13/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromodichloromethane
Detected: 0.74 UG/L (ppb)
8/13/2025
Dibromochloromethane
Detected: 0.56 UG/L (ppb)
5/12/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Chloride
Detected: 36 MG/L (ppm)
7/2/2025
Sulfate
Detected: 64 MG/L (ppm)
7/2/2025
Fluoride
Detected: 0.1 MG/L (ppm)
7/21/2025
Often added deliberately for dental health; can also occur naturally.
Nitrate
Detected: 2.5 MG/L (ppm)
7/21/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Boron, Total
Detected: 82 UG/L (ppb)
7/8/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 18 MG/L (ppm)
7/8/2025
Calcium
Detected: 71 MG/L (ppm)
7/8/2025
Sodium
Detected: 25 MG/L (ppm)
7/8/2025
Potassium
Detected: 1.4 MG/L (ppm)
7/8/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Langelier Index (pH(s))
Detected: 0.12 LANG
7/2/2025
Hardness, Total (ASCACO3)
Detected: 230 MG/L (ppm)
7/2/2025
pH, Field
Detected: 7.6 PH
7/2/2025
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 290 MG/L (ppm)
7/2/2025
Other
Additional substances tested that don't fit neatly into the categories above
Perfluoroctanoicacid (PFOA)
Detected: 3 NG/L (ppt)
8/5/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Perfluorohexanoicacid (PFHXA)
Detected: 2.3 NG/L (ppt)
8/5/2025
Aggressive Index
Detected: 12.3 AGGR
7/2/2025
Alkalinity, Total
Detected: 290 MG/L (ppm)
7/2/2025
TDS
Detected: 490 MG/L (ppm)
7/2/2025
Turbidity
Detected: 3.7 NTU
7/2/2025
A measure of water cloudiness from suspended particles.
Conductivity (at 25°C)
Detected: 800 UMHO/CM
7/2/2025
Color
Detected: 10 UNITS
7/2/2025
Dichloroaceticacid
Detected: 26 UG/L (ppb)
8/13/2025
Trichloroaceticacid
Detected: 15 UG/L (ppb)
8/13/2025
Monochloroaceticacid
Detected: 2.9 UG/L (ppb)
8/13/2025
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.