How does Sedro-Woolley's water compare to the national average?

The USA national average is 151 mg/L. Sedro-Woolley (≈ 0–59 mg/L) is 121 mg/L softer than average.

Sedro-Woolley Water Hardness & Quality Report (2026)

Water Hardness

soft

~0–59 mg/L

Soft

estimated · not lab-verified

Source

groundwater

pH Level

7.1

neutral = 7.0

Lead

0.008 mg/L

✓ Below action level

TDS

186.5 mg/L

Est. Daily Cost

$0.08

energy & soap waste

Source: See methodology section below · Updated 2026

soft~0–59 mg/LSoft · 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 Sedro-Woolley, your appliances are currently losing 4% efficiency due to mineral buildup.

Appliance	In Sedro-Woolley	Soft Water City	Efficiency Loss
Kettle	8.2 yrs	8.5 yrs	-4%
Washing Machine	11.5 yrs	12 yrs	-4%
Water Heater	14.4 yrs	15 yrs	-4%

Regional Water Comparison

How Sedro-Woolley compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Sedro-Woolley, Washington	≈ 0–59 mg/L	3.2 ppt	🟢 Soft	groundwater
Mount Vernon, Washington	≈ 0–60 mg/L	21.1 ppt	🟢 Soft	reservoir
Arlington, Washington	≈ 120–179 mg/L	9.2 ppt	🟠 Hard	reservoir
Bellingham, Washington	≈ 0–60 mg/L	0 ppt	🟢 Soft	reservoir
Anacortes, Washington	≈ 0–60 mg/L	2.3 ppt	🟢 Soft	reservoir

National Benchmark

How Sedro-Woolley compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Sedro-Woolley	≈ 0–59 mg/L	🟢 None
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Sedro-Woolley's Water Unique?

Local geology and source profile

Source: GroundwaterTDS: 186.5 mg/LpH: 7.1

The City of Sedro-Woolley water utility serves residents in Skagit County, Washington. Their water supply originates from the Skagit River watershed, a significant river system that drains the North Cascades. The utility manages treatment and distribution for the city and its surrounding areas in northwestern Washington. This supply is drawn from the Skagit River watershed, which itself drains glaciated terrain within the Cascade Range.

The region's geology features Quaternary glacial deposits and outwash plains atop Tertiary volcanic and sedimentary bedrock. The bedrock is primarily composed of granitic and metamorphic rocks, and because these rocks contain few carbonate minerals, the water is naturally soft. This is a common characteristic for water found in the foothills of the Cascade Range.

Sedro-Woolley's soft water, measuring around 21.5 ppm, is gentle on plumbing fixtures, water heaters, and appliances, which helps reduce scale buildup and extends their operational life. Homeowners here generally don't need to install extra water softening systems, though some might opt for one based on personal preference. You'll find that soap and detergents work more efficiently, and cleaning tasks often require less product. Residents can find detailed testing results and compliance data in the city's annual Consumer Confidence Report.

Geology & Source: Quaternary glacial deposits over Tertiary bedrock; granitic and metamorphic rocks with low carbonate content yield soft water

Other Washington Water Reports

Mount Vernon

≈ 0–60 mg/L

🟢 Soft

Arlington

≈ 120–179 mg/L

🟠 Hard

Bellingham

≈ 0–60 mg/L

🟢 Soft

Anacortes

≈ 0–60 mg/L

🟢 Soft

Report an Issue

Notice an error or missing data? Help us keep this page accurate. If you spot incorrect water hardness, outdated utility info, or missing details, please let us know.

All reports are reviewed by our team. Thank you for supporting data quality!

Frequently Asked Questions

Is Sedro-Woolley's water safe to drink?

Yes. Sedro-Woolley's water meets all federal safety standards. The hardness is ≈ 0–59 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 Sedro-Woolley?

Sedro-Woolley's water is soft at ≈ 0–59 mg/L. A water softener is generally not necessary, though a carbon filter can improve taste and remove any remaining chlorine.

How does Sedro-Woolley compare to the USA average?

The USA national average is 151 mg/L. Sedro-Woolley (≈ 0–59 mg/L) is 121 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 Sedro-Woolley 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.