How does Menlo Park's water compare to the national average?

The USA national average is 151 mg/L. Menlo Park (46 mg/L) is 105 mg/L softer than average.

Menlo Park Water Hardness & Quality Report (2026)

Water Hardness

46mg/L

Soft

2.7 grains per gallon

Source

reservoir

pH Level

7.4

neutral = 7.0

Lead

0.003 mg/L

✓ Below action level

TDS

159.2 mg/L

Est. Daily Cost

$0.12

energy & soap waste

Source: See methodology section below · Updated 2026

46mg/L as CaCO₃Soft

0–60

mg/L

Soft

61–120

mg/L

Moderately Hard

121–180

mg/L

Hard

180+

mg/L

Very Hard

Appliance Damage Report

In Menlo Park, your appliances are currently losing 6% efficiency due to mineral buildup.

Appliance	In Menlo Park	Soft Water City	Efficiency Loss
Kettle	8.1 yrs	8.5 yrs	-5%
Washing Machine	11.9 yrs	12 yrs	-1%
Water Heater	13.8 yrs	15 yrs	-8%

Regional Water Comparison

How Menlo Park compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Menlo Park, California	46 mg/L	0 ppt	🟢 Soft	reservoir
North Fair Oaks, California	≈ 0–60 mg/L	4 ppt	🟢 Soft	mixed
Stanford, California	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir
Palo Alto, California	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir
East Palo Alto, California	≈ 120–179 mg/L	0 ppt	🟠 Hard	reservoir

National Benchmark

How Menlo Park compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Menlo Park	46 mg/L	🟢 None
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Menlo Park's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 159.2 mg/LpH: 7.4

Menlo Park Municipal Water, in partnership with the California Water Company (Cal Water) Bear Gulch District, supplies drinking water to approximately 34,000 residents across the city and surrounding neighborhoods including Sharon Heights and West Menlo Park in San Mateo County. Water is purchased from the San Francisco Public Utilities Commission (SFPUC), originating from Hetch Hetchy Reservoir and local Crystal Springs Reservoir. Treatment occurs at SFPUC facilities including the Tesla and Sunol plants, involving filtration, disinfection, and fluoridation before distribution via Menlo Park's infrastructure averaging 2.56 million gallons per day.

The supply derives from the Tuolumne River watershed feeding Hetch Hetchy and the Peninsula Watershed encompassing Crystal Springs, drained by San Andreas Fault-related streams. Geology features Sierra Nevada granites, Paleozoic-Mesozoic metavolcanics of the Franciscan Formation, and scattered chert-limestone outcrops, which dissolve calcium and magnesium during surface runoff and reservoir impoundment. This imparts a moderately mineralised character to the water, with mineral content shaped by the balance of igneous weathering — which has low solubility — and minor carbonate contributions from fault-zone limestones.

As moderately hard water at 46 mg/L, Menlo Park's supply causes moderate scale buildup in water heaters, dishwashers, and coffee makers, reducing efficiency by 20–30% over time and increasing energy costs. Laundry may feel stiff without softeners, and spotting occurs on glassware. Maintenance includes annual descaling of fixtures and vinegar soaks; a water softener is recommended for high-usage households to extend appliance life and improve soap efficiency. The water scores a B+ overall, with no EPA legal limit exceedances but 6 contaminants above health advocacy guidelines, including disinfection byproducts (trihalomethanes, haloacetic acids) and chromium-6; pH is typically 7.5–8.5 from SFPUC reports, with lead/copper rule compliance met via corrosion control.

Geology & Source: Hetch Hetchy Reservoir (Sierra Nevada granites) and Crystal Springs Reservoir (San Andreas Fault zone); Franciscan Complex metavolcanics with minor chert-limestone outcrops — moderately mineralised at 46 mg/L

Other California Water Reports

North Fair Oaks

≈ 0–60 mg/L

🟢 Soft

Stanford

≈ 120–179 mg/L

🟠 Hard

Palo Alto

≈ 120–179 mg/L

🟠 Hard

East Palo Alto

≈ 120–179 mg/L

🟠 Hard

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Frequently Asked Questions

Is Menlo Park's water safe to drink?

Yes. Menlo Park's water meets all federal safety standards. The hardness is 46 mg/L (Soft), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Menlo Park?

Menlo Park's water is soft at 46 mg/L. A water softener is generally not necessary, though a carbon filter can improve taste and remove any remaining chlorine.

How does Menlo Park compare to the USA average?

The USA national average is 151 mg/L. Menlo Park (46 mg/L) is 105 mg/L below the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Menlo Park is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

Water Hardness

Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.

Estimated

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

TDS — Total Dissolved Solids

Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.

Measured

PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances

EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.

Modelled

Lead

Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.

Calculated

Appliance Lifespan

Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.