Serving roughly 1,039,920 people in Santa Clara County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
🏠Local Expertise
Results for SAN JOSE WATER
1 water provider directly on file, serving roughly 1,039,920 people in Santa Clara County, California.
Quick answer: SAN JOSE WATER has no violations on file. One reading is worth knowing about: Aggressive Index was measured at 12.66AGGR, among the highest of the 320 providers on file in this area. It's the most notable figure in this system's record among its 320 local peers.
Lead Summary
PFHXS
Lithium
PFOS
Aggressive Index
Langelier Index (Source Temp.)
Magnesium
Potassium
Sodium
Calcium
Alkalinity, Total
Alkalinity, Bicarbonate
Hardness, Total (ASCACO3)
TDS
Chloride
Sulfate
Fluoride
Nitrate
Nitrate-Nitrite
Perfluorohexanesulfonicacid (PFHxS)
Perfluoroctanesulfonicacid (PFOS)
Perfluorobutanesulfonicacid (PFBS)
Perfluorohexanoicacid (PFHXA)
Perfluorobutanoicacid (PFBA)
Perfluoropentanoicacid (PFPEA)
Gross Alpha Particle Activity
Carbondioxide
Iron
Barium
Conductivity (at 25°C)
Color
Carbon, Total
Chromium, Hex
Utility SAN JOSE WATERPopulation served 1,039,920Owner Private
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
Iron
Detected: 110 UG/L (ppb)
7/9/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Barium
Detected: 130 UG/L (ppb)
1/6/2025
Chromium, Hex
Detected: 0.45 UG/L (ppb)
2/20/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Chloride
Detected: 16 MG/L (ppm)
3/25/2025
Sulfate
Detected: 36 MG/L (ppm)
3/25/2025
Fluoride
Detected: 0.14 MG/L (ppm)
3/25/2025
Often added deliberately for dental health; can also occur naturally.
Nitrate
Detected: 4.6 MG/L (ppm)
10/9/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Nitrate-Nitrite
Detected: 1.1 MG/L (ppm)
2/19/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 10 MG/L (ppm)
3/25/2025
Potassium
Detected: 1.3 MG/L (ppm)
3/11/2025
Sodium
Detected: 18 MG/L (ppm)
3/25/2025
Calcium
Detected: 41 MG/L (ppm)
3/25/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 145 MG/L (ppm)
3/25/2025
Gross Alpha Particle Activity
Detected: 2.76 PCI/L
2/19/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
PFHXS
Detected: 0.0032 µg/L (ppb)
8/23/2023
Lithium
Detected: 9.11 µg/L (ppb)
8/22/2023
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
PFOS
Detected: 0.0062 µg/L (ppb)
8/16/2023
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: 140 MG/L (ppm)
7/11/2025
Other
Additional substances tested that don't fit neatly into the categories above
Aggressive Index
Detected: 12.66 AGGR
3/25/2025
Langelier Index (Source Temp.)
Detected: 0.5 LANG
3/25/2025
Alkalinity, Total
Detected: 140 MG/L (ppm)
7/11/2025
TDS
Detected: 180 MG/L (ppm)
7/11/2025
Perfluorohexanesulfonicacid (PFHxS)
Detected: 3.7 NG/L (ppt)
10/9/2025
Perfluoroctanesulfonicacid (PFOS)
Detected: 3 NG/L (ppt)
2/19/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Perfluorobutanesulfonicacid (PFBS)
Detected: 2 NG/L (ppt)
1/6/2025
Perfluorohexanoicacid (PFHXA)
Detected: 2.4 NG/L (ppt)
1/6/2025
Perfluorobutanoicacid (PFBA)
Detected: 2.1 NG/L (ppt)
1/6/2025
Perfluoropentanoicacid (PFPEA)
Detected: 2.1 NG/L (ppt)
1/6/2025
Carbondioxide
Detected: 5000 UG/L (ppb)
3/25/2025
Conductivity (at 25°C)
Detected: 370 UMHO/CM
3/25/2025
Color
Detected: 5 UNITS
2/19/2025
Carbon, Total
Detected: 1.38 MG/L (ppm)
9/24/2025
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.