How does Washington's water compare to the national average?

The USA national average is 151 mg/L. Washington (≈ 180+ mg/L) is 189 mg/L harder than average.

Washington Water Hardness & Quality Report (2026)

Water Hardness

very hard

180+ mg/L

Very Hard

estimated · not lab-verified

Source

groundwater

pH Level

8.2

neutral = 7.0

Lead

0.003 mg/L

✓ Below action level

TDS

272.5 mg/L

Est. Daily Cost

$0.91

energy & soap waste

Source: See methodology section below · Updated 2026

very hard180+ mg/LVery Hard · 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 Washington, your appliances are currently losing 45% efficiency due to mineral buildup.

Appliance	In Washington	Soft Water City	Efficiency Loss
Kettle	4.7 yrs	8.5 yrs	-45%
Washing Machine	6.6 yrs	12 yrs	-45%
Water Heater	8.3 yrs	15 yrs	-45%

Regional Water Comparison

How Washington compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Washington, Illinois	≈ 180+ mg/L	0 ppt	🔴 Very Hard	groundwater
Morton, Illinois	128.5 mg/L	0 ppt	🟠 Hard	groundwater
East Peoria, Illinois	≈ 180+ mg/L	44.3 ppt	🔴 Very Hard	groundwater
North Peoria, Illinois	≈ 180+ mg/L	8.5 ppt	🔴 Very Hard	river
Peoria, Illinois	≈ 180+ mg/L	56 ppt	🔴 Very Hard	groundwater

National Benchmark

How Washington compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Washington	≈ 180+ mg/L	🔴 High
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Washington's Water Unique?

Local geology and source profile

Source: GroundwaterTDS: 272.5 mg/LpH: 8.2

The Washington Municipal Water Company serves around 13,458 residents in Washington, Illinois, drawing water from local groundwater reserves via wells, with no specified treatment plant. The supply comes from the Mahomet Aquifer system, part of the glacial drift and bedrock aquifers in the Illinois Basin. You can contact the utility at 309-444-3196 or 2453 Washington Rd, Washington, IL 61571 for more information.

The geology underlying the Mahomet Aquifer is characterized by Paleozoic bedrock, including Pennsylvanian-age sandstones, shales, and limestones, which contribute dissolved minerals to the water. Overlying Pleistocene glacial deposits enhance mineral leaching, resulting in a hard water supply with elevated mineral content. The Illinois Basin's limestone formations, rich in calcium and magnesium-bearing minerals, also play a role in the water's hardness.

Homeowners may notice the effects of this hard water, from scale buildup in pipes and appliances to reduced soap lathering and white deposits on fixtures. To mitigate these effects, regular maintenance like descaling appliances and flushing water heaters is a good idea. A whole-house water softener is also strongly recommended to protect plumbing and reduce the risk of damage. Additionally, residents should be aware of potential contaminants in the groundwater supply, including Radium, Di(2-ethylhexyl) adipate, and Atrazine, and check the annual Consumer Confidence Reports for compliance details and information on water treatment.

Geology & Source: Mahomet Aquifer; glacial drift aquifers - Paleozoic bedrock; Pennsylvanian sandstone and limestone formations; calcium and magnesium-bearing minerals

Other Illinois Water Reports

Morton

128.5 mg/L

🟠 Hard

East Peoria

≈ 180+ mg/L

🔴 Very Hard

North Peoria

≈ 180+ mg/L

🔴 Very Hard

Peoria

≈ 180+ mg/L

🔴 Very Hard

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 Washington's water safe to drink?

Yes. Washington's water meets all federal safety standards. The hardness is ≈ 180+ mg/L (Very Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Washington?

At ≈ 180+ mg/L (Very Hard), Washington'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 45%.

How does Washington compare to the USA average?

The USA national average is 151 mg/L. Washington (≈ 180+ mg/L) is 189 mg/L above the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Washington 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.