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Fairfax Station Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

reservoir

pH Level

7.2

neutral = 7.0

Lead

0.003 mg/L

✓ Below action level

TDS

195.5 mg/L

Est. Daily Cost

$0.40

energy & soap waste

Source: See methodology section below · Updated 2026

hard~120–179 mg/LHard · est.

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 Fairfax Station, your appliances are currently losing 20% efficiency due to mineral buildup.

ApplianceIn Fairfax StationSoft Water CityEfficiency Loss
Kettle
6.8 yrs
8.5 yrs-20%
Washing Machine
9.6 yrs
12 yrs-20%
Water Heater
12 yrs
15 yrs-20%

Regional Water Comparison

How Fairfax Station compares to its nearest neighbours

CityHardnessPFAS (ppt)RiskSource
Fairfax Station, Virginia≈ 120–179 mg/L5.5 ppt🟠 Hardreservoir
Kings Park West, Virginia≈ 120–179 mg/L6.1 ppt🟠 Hardreservoir
Fairfax, Virginia≈ 120–179 mg/L5.3 ppt🟠 Hardreservoir
Burke, Virginia≈ 120–179 mg/L4.5 ppt🟠 Hardgroundwater
Oakton, Virginia≈ 120–179 mg/L7.6 ppt🟠 Hardreservoir

National Benchmark

How Fairfax Station compares to the USA average

BenchmarkHardnessAppliance Risk
Fairfax Station≈ 120–179 mg/L🟠 Moderate
USA National Avg151 mg/L🟠 Moderate
Scarsdale Top Rated0.02 mg/L🟢 None

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What Makes Fairfax Station's Water Unique?

Local geology and source profile

Source: ReservoirTDS: 195.5 mg/LpH: 7.2

Fairfax Water is the main provider for Fairfax Station, Virginia, supplying treated water to more than 2 million residents across Fairfax County, Prince William County, and parts of Loudoun County. Their supply originates from the Potomac River and Occoquan Reservoir, which is fed by the Occoquan River. Water undergoes advanced treatment at four facilities: Frederick P. Griffith Jr. on the Occoquan Reservoir, and James J. Corbalis Jr., McMillan, and Dalecarlia on the Potomac River. This treated water flows through an interconnected system, with Prince William Water also drawing from the Griffith plant for nearby areas. The watershed spans the Potomac River basin and the Occoquan Reservoir catchment in the Piedmont region.

Geologically, the area is characterized by Paleozoic and Mesozoic sedimentary rocks and Quaternary alluvial deposits. Key formations include limestone and dolomite outcrops, particularly within the Piedmont physiographic province. As these carbonate-rich rocks weather, they release calcium and magnesium into the surface water. This natural process, influenced by regional karst features, is the primary reason for the supply's hard water characteristics, making it moderately mineralized.

This hard water can lead to scale buildup in household plumbing, water heaters, dishwashers, and washing machines, potentially shortening their lifespan and reducing efficiency. You might also notice reduced soap lathering and spots on glassware after washing. To manage scale, regularly descale fixtures and consider using vinegar for cleaning items like tea kettles. For persistent issues and to help appliances last longer, installing a water softener is often recommended. While Fairfax Water meets stringent quality standards, testing your home's plumbing for lead is advisable if it was installed before 1986.

Geology & Source: Paleozoic and Mesozoic sedimentary rocks, including limestone and dolomite; carbonate-rich formations cause hard water.

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Frequently Asked Questions

Is Fairfax Station's water safe to drink?
Yes. Fairfax Station's water meets all federal safety standards. The hardness is ≈ 120–179 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.
Do I need a water softener in Fairfax Station?
At ≈ 120–179 mg/L (Hard), Fairfax Station's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 20%.
How does Fairfax Station compare to the USA average?
The USA national average is 151 mg/L. Fairfax Station (≈ 120–179 mg/L) is 1 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 Fairfax Station 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

pH

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.