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Arlington Heights Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

river

pH Level

8.5

neutral = 7.0

Lead

0.008 mg/L

✓ Below action level

TDS

664.4 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 Arlington Heights, your appliances are currently losing 20% efficiency due to mineral buildup.

ApplianceIn Arlington HeightsSoft 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 Arlington Heights compares to its nearest neighbours

CityHardnessPFAS (ppt)RiskSource
Arlington Heights, Illinois≈ 120–179 mg/L0 ppt🟠 Hardriver
Rolling Meadows, Illinois≈ 120–179 mg/L0 ppt🟠 Hardriver
Prospect Heights, Illinois≈ 120–179 mg/L9.3 ppt🟠 Hardriver
Mount Prospect, Illinois≈ 120–179 mg/L0 ppt🟠 Hardriver
Palatine, Illinois≈ 120–179 mg/L0 ppt🟠 Hardriver

National Benchmark

How Arlington Heights compares to the USA average

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

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What Makes Arlington Heights's Water Unique?

Local geology and source profile

Source: RiverTDS: 664.4 mg/LpH: 8.5

The Village of Arlington Heights Public Water Utility serves approximately 79,000 residents across Arlington Heights in Cook County, Illinois. Water is sourced exclusively from surface water purchased from the City of Evanston, ultimately originating from Lake Michigan. There are no local treatment plants; the utility receives conventionally treated and chlorinated water via interconnection with Evanston's system. The utility can be reached at 847-368-5250, Village of Arlington Heights, 33 South Arlington Heights Road, Arlington Heights, IL 60005. Water quality is rated 80/100 with no EPA violations noted.

The Lake Michigan watershed spans multiple states, fed by rivers traversing glacial till and Paleozoic bedrock dominated by Ordovician and Silurian limestone and dolomite formations. Pleistocene glacial deposits overlay these bedrock units, influencing recharge to the lake. Prolonged contact with carbonate-rich formations dissolves calcium and magnesium-bearing minerals, imparting a characteristically hard water quality to the supply — typical of Great Lakes region surface waters influenced by carbonate geology.

Hard water in Arlington Heights causes scale buildup in water heaters, dishwashers, washing machines, and pipes, reducing efficiency and lifespan while increasing energy costs. Soap scum forms readily, causing spots on glassware and drier laundry. Regular descaling of appliances and fixtures is recommended; a water softener is advised to mitigate these effects and protect plumbing. Treatment by Evanston involves conventional filtration and chlorine disinfection; no specific pH, lead/copper, or PFAS data was available in the source material.

Geology & Source: Lake Michigan via City of Evanston; Paleozoic Ordovician and Silurian limestone and dolomite bedrock under glacial drift — calcium and magnesium dissolution produces hard water

Other Illinois Water Reports

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Frequently Asked Questions

Is Arlington Heights's water safe to drink?
Yes. Arlington Heights'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 Arlington Heights?
At ≈ 120–179 mg/L (Hard), Arlington Heights'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 Arlington Heights compare to the USA average?
The USA national average is 151 mg/L. Arlington Heights (≈ 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 Arlington Heights 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.