Serving roughly 3,500 people in San Francisco County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
🏠Local Expertise
Results for PRESIDIO OF SAN FRANCISCO
1 water provider directly on file, serving roughly 3,500 people in San Francisco County, California.
Quick answer: PRESIDIO OF SAN FRANCISCO has no violations on file. One reading is worth knowing about: Bromodichloromethane was measured at 7.92UG/L, among the highest of the 36 providers on file in this area. It's the most notable figure in this system's record among its 36 local peers.
Lead Summary
PFPEA
PFBA
PFHXS
PFHPA
PFOA
PFHXA
PFBS
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromoform
Bromodichloromethane
Dibromochloromethane
Trichloroaceticacid
Dichloroaceticacid
Monobromoaceticacid
Dibromoaceticacid
Copper, Free
Aggressive Index
Calcium
Alkalinity, Total
Alkalinity, Bicarbonate
Alkalinity, Carbonate
Magnesium
Sodium
Hardness, Total (ASCACO3)
Carbon, Total
TDS
Sulfate
Chloride
Nitrate
Turbidity
pH
Iron
Manganese
Arsenic
Methyltert-Butylether
Conductivity (at 25°C)
Color
Utility PRESIDIO OF SAN FRANCISCOPopulation served 3,500Owner Federal 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: 103 UG/L (ppb)
7/8/2025
Iron
Detected: 2380 UG/L (ppb)
1/7/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Manganese
Detected: 403 UG/L (ppb)
1/7/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Arsenic
Detected: 2 UG/L (ppb)
1/7/2025
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 18.6 UG/L (ppb)
9/9/2025
TTHM
Detected: 43.7 UG/L (ppb)
9/9/2025
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: 16.4 UG/L (ppb)
9/9/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromoform
Detected: 7.63 UG/L (ppb)
9/9/2025
Bromodichloromethane
Detected: 7.92 UG/L (ppb)
9/9/2025
Dibromochloromethane
Detected: 11.8 UG/L (ppb)
9/9/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Sulfate
Detected: 46.2 MG/L (ppm)
1/7/2025
Chloride
Detected: 53.4 MG/L (ppm)
1/7/2025
Nitrate
Detected: 6.41 MG/L (ppm)
7/1/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Minerals
Everyday minerals that mainly affect taste and water hardness
Calcium
Detected: 30 MG/L (ppm)
1/7/2025
Magnesium
Detected: 39 MG/L (ppm)
1/7/2025
Sodium
Detected: 34.3 MG/L (ppm)
1/7/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 238 MG/L (ppm)
1/7/2025
pH
Detected: 8.5 PH
1/7/2025
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
PFPEA
Detected: 0.007 µg/L (ppb)
9/15/2025
PFBA
Detected: 0.0062 µg/L (ppb)
3/11/2025
PFHXS
Detected: 0.0041 µg/L (ppb)
9/15/2025
PFHPA
Detected: 0.0031 µg/L (ppb)
3/11/2025
PFOA
Detected: 0.004 µg/L (ppb)
3/11/2025
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFHXA
Detected: 0.0059 µg/L (ppb)
9/15/2025
PFBS
Detected: 0.0046 µg/L (ppb)
9/15/2025
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 150 MG/L (ppm)
1/7/2025
Alkalinity, Carbonate
Detected: 9 MG/L (ppm)
1/7/2025
Other
Additional substances tested that don't fit neatly into the categories above
Trichloroaceticacid
Detected: 6.34 UG/L (ppb)
9/9/2025
Dichloroaceticacid
Detected: 7.79 UG/L (ppb)
9/9/2025
Monobromoaceticacid
Detected: 1.16 UG/L (ppb)
9/9/2025
Dibromoaceticacid
Detected: 3.35 UG/L (ppb)
9/9/2025
Aggressive Index
Detected: 13 AGGR
1/7/2025
Alkalinity, Total
Detected: 160 MG/L (ppm)
1/7/2025
Carbon, Total
Detected: 1.51 MG/L (ppm)
1/7/2025
TDS
Detected: 369 MG/L (ppm)
1/7/2025
Turbidity
Detected: 2.2 NTU
1/7/2025
A measure of water cloudiness from suspended particles.
Methyltert-Butylether
Detected: 0.58 UG/L (ppb)
10/7/2025
Conductivity (at 25°C)
Detected: 626 UMHO/CM
1/7/2025
Color
Detected: 5 UNITS
1/7/2025
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.