Serving roughly 22,362 people in San Mateo County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
🏠Local Expertise
Results for MENLO PARK MUNICIPAL WATER
1 water provider directly on file, serving roughly 22,362 people in San Mateo County, California.
Quick answer: MENLO PARK MUNICIPAL WATER has no violations on file. One reading is worth knowing about: Sodium was measured at 120MG/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
Magnesium
Sodium
Hardness, Total (ASCACO3)
Calcium
Alkalinity, Total
Alkalinity, Bicarbonate
TDS
Sulfate
Chloride
Fluoride
Nitrate-Nitrite
Nitrate
Turbidity
Gross Alpha Particle Activity
Gross Beta Particle Activity
pH
Manganese
Chromium, Hex
Barium
Color
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromodichloromethane
Dibromochloromethane
Dichloroaceticacid
Trichloroaceticacid
Utility MENLO PARK MUNICIPAL WATERPopulation served 22,362Owner Local government
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0.0031 mg/L (ppm)
12/31/2024
Manganese
Detected: 57 UG/L (ppb)
3/4/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Chromium, Hex
Detected: 0.056 UG/L (ppb)
3/4/2025
Barium
Detected: 100 UG/L (ppb)
3/4/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 37.5 UG/L (ppb)
7/8/2025
TTHM
Detected: 63.3 UG/L (ppb)
7/8/2025
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: 62.1 UG/L (ppb)
7/8/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromodichloromethane
Detected: 1.22 UG/L (ppb)
7/8/2025
Dibromochloromethane
Detected: 1.24 UG/L (ppb)
1/14/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Sulfate
Detected: 37 MG/L (ppm)
3/4/2025
Chloride
Detected: 110 MG/L (ppm)
3/4/2025
Fluoride
Detected: 0.21 MG/L (ppm)
3/4/2025
Often added deliberately for dental health; can also occur naturally.
Nitrate-Nitrite
Detected: 1.1 MG/L (ppm)
3/4/2025
Nitrate
Detected: 1.1 MG/L (ppm)
3/4/2025
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
Magnesium
Detected: 13 MG/L (ppm)
3/4/2025
Sodium
Detected: 120 MG/L (ppm)
3/4/2025
Calcium
Detected: 46 MG/L (ppm)
3/4/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 170 MG/L (ppm)
3/4/2025
Gross Alpha Particle Activity
Detected: 2.12 PCI/L
3/4/2025
pH
Detected: 7.86 PH
3/4/2025
A measure of how acidic or basic the water is (7 is neutral). Affects taste and plumbing, not a direct health measure.
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 219 MG/L (ppm)
3/4/2025
Other
Additional substances tested that don't fit neatly into the categories above
Alkalinity, Total
Detected: 219 MG/L (ppm)
3/4/2025
TDS
Detected: 372 MG/L (ppm)
3/4/2025
Turbidity
Detected: 0.57 NTU
3/4/2025
A measure of water cloudiness from suspended particles.
Gross Beta Particle Activity
Detected: 3.68 PCI/L
3/4/2025
Color
Detected: 2 UNITS
3/4/2025
Dichloroaceticacid
Detected: 19.3 UG/L (ppb)
7/8/2025
Trichloroaceticacid
Detected: 18.2 UG/L (ppb)
7/8/2025
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.