Serving roughly 218,771 people in Stanislaus County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
🏠Local Expertise
Results for MODESTO, CITY OF
1 water provider directly on file, serving roughly 218,771 people in Stanislaus County, California.
Quick answer: MODESTO, CITY OF has no violations on file. One reading is worth knowing about: Lead Summary was measured at 0.012mg/L, among the highest of the 442 providers on file in this area. It's the most notable figure in this system's record among its 442 local peers.
Lead Summary
PFOS
PFHXS
PFOA
PFHXA
Lithium
PFPEA
PFHPA
PFBS
Nitrate
Chromium, Hex
Arsenic
Aggressive Index
TDS
Sulfate
Chloride
Magnesium
Calcium
Sodium
Potassium
Hardness, Total (ASCACO3)
Alkalinity, Total
Alkalinity, Bicarbonate
Fluoride
Perfluorobutanesulfonicacid (PFBS)
Perfluorohexanoicacid (PFHXA)
Perfluoropentanoicacid (PFPEA)
Perfluorohexanesulfonicacid (PFHxS)
Perfluoroctanesulfonicacid (PFOS)
Perfluoroctanoicacid (PFOA)
Adsorbableorganicfluorine
Perfluoroheptanoicacid (PFHPA)
Perfluorobutanoicacid (PFBA)
Perfluoropentanesulfonicacid (PFPES)
Perfluorononanoicacid (PFNA)
Combined Uranium
Utility MODESTO, CITY OFPopulation served 218,771Owner Local government
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0.012 mg/L (ppm)
12/31/2027
Chromium, Hex
Detected: 0.236 UG/L (ppb)
3/26/2025
Arsenic
Detected: 8.2 UG/L (ppb)
10/8/2025
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
Combined Uranium
Detected: 14 PCI/L
10/8/2025
A naturally occurring radioactive metal. Long-term exposure above the legal limit is associated with kidney effects and increased cancer risk.
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Nitrate
Detected: 8.2 MG/L (ppm)
10/15/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Sulfate
Detected: 23 MG/L (ppm)
5/21/2025
Chloride
Detected: 17 MG/L (ppm)
5/21/2025
Fluoride
Detected: 0.12 MG/L (ppm)
5/21/2025
Often added deliberately for dental health; can also occur naturally.
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 4.7 MG/L (ppm)
5/21/2025
Calcium
Detected: 23 MG/L (ppm)
5/21/2025
Sodium
Detected: 13 MG/L (ppm)
5/21/2025
Potassium
Detected: 1.5 MG/L (ppm)
5/21/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 77 MG/L (ppm)
5/21/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
PFOS
Detected: 0.0046 µg/L (ppb)
9/12/2024
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFHXS
Detected: 0.0069 µg/L (ppb)
9/12/2024
PFOA
Detected: 0.0041 µg/L (ppb)
9/12/2024
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFHXA
Detected: 0.0039 µg/L (ppb)
9/12/2024
Lithium
Detected: 12 µg/L (ppb)
5/16/2024
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
PFPEA
Detected: 0.0046 µg/L (ppb)
9/12/2024
PFHPA
Detected: 0.0036 µg/L (ppb)
8/28/2024
PFBS
Detected: 0.0034 µg/L (ppb)
9/12/2024
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 180 MG/L (ppm)
5/21/2025
Other
Additional substances tested that don't fit neatly into the categories above
Aggressive Index
Detected: 11.79 AGGR
5/21/2025
TDS
Detected: 290 MG/L (ppm)
5/21/2025
Alkalinity, Total
Detected: 180 MG/L (ppm)
5/21/2025
Perfluorobutanesulfonicacid (PFBS)
Detected: 4.9 NG/L (ppt)
9/25/2025
Perfluorohexanoicacid (PFHXA)
Detected: 4.5 NG/L (ppt)
9/25/2025
Perfluoropentanoicacid (PFPEA)
Detected: 5.2 NG/L (ppt)
9/25/2025
Perfluorohexanesulfonicacid (PFHxS)
Detected: 8.4 NG/L (ppt)
9/25/2025
Perfluoroctanesulfonicacid (PFOS)
Detected: 5.3 NG/L (ppt)
9/25/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Perfluoroctanoicacid (PFOA)
Detected: 5.2 NG/L (ppt)
9/25/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Adsorbableorganicfluorine
Detected: 3300 NG/L (ppt)
6/17/2025
Perfluoroheptanoicacid (PFHPA)
Detected: 2.2 NG/L (ppt)
6/17/2025
Perfluorobutanoicacid (PFBA)
Detected: 2.7 NG/L (ppt)
6/17/2025
Perfluoropentanesulfonicacid (PFPES)
Detected: 1.8 NG/L (ppt)
6/17/2025
Perfluorononanoicacid (PFNA)
Detected: 2.1 NG/L (ppt)
6/16/2025
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.