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

The USA national average is 151 mg/L. Coolidge (≈ 120–179 mg/L) is 1 mg/L softer than average.

Coolidge Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

groundwater

pH Level

8.5

neutral = 7.0

Lead

0.006 mg/L

✓ Below action level

TDS

962 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 Coolidge, your appliances are currently losing 20% efficiency due to mineral buildup.

Appliance	In Coolidge	Soft Water City	Efficiency 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 Coolidge compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Coolidge, Arizona	≈ 120–179 mg/L	4.7 ppt	🟠 Hard	groundwater
Florence, Arizona	≈ 120–179 mg/L	94.1 ppt	🟠 Hard	groundwater
San Tan Valley, Arizona	≈ 180+ mg/L	0 ppt	🔴 Very Hard	groundwater
Eloy, Arizona	≈ 180+ mg/L	0 ppt	🔴 Very Hard	groundwater
Casa Grande, Arizona	≈ 180+ mg/L	0 ppt	🔴 Very Hard	groundwater

National Benchmark

How Coolidge compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Coolidge	≈ 120–179 mg/L	🟠 Moderate
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Coolidge's Water Unique?

Local geology and source profile

Source: GroundwaterTDS: 962 mg/LpH: 8.5

The Town of Coolidge Water Department supplies drinking water to residents and businesses throughout Pinal County. This utility draws from a mix of sources, including surface water allocations from the San Pedro River watershed and groundwater from regional aquifers beneath Pinal County. Before reaching homes and businesses, the water undergoes treatment at municipal facilities to ensure it meets the stringent standards set by the EPA's Safe Drinking Water Act.

The water's journey begins in the San Pedro River watershed and regional groundwater aquifers. Geologically, the area is defined by layers of Quaternary alluvial deposits resting atop older Tertiary basin-fill sediments. Deeper still lie the Precambrian crystalline basement rocks. This geological makeup, common in Arizona's Basin and Range province, is rich in dissolved minerals like calcium and magnesium, which are the primary contributors to the water's characteristically hard quality.

Homeowners in Coolidge often encounter the tell-tale signs of hard water. You might notice mineral deposits on fixtures and inside pipes, which can reduce water flow and the efficiency of appliances like dishwashers and washing machines. An increase in the amount of soap and detergent needed for cleaning is also common. To combat these issues and potentially extend the life of your water heater and other appliances, installing a water softener is often recommended. Recent reports confirm the water meets EPA standards for most contaminants, including lead and copper, though a small number of violations have occurred since 2023.

Geology & Source: San Pedro River watershed and regional groundwater aquifers; Quaternary alluvial and Tertiary basin-fill sediments contribute to hard water

Other Arizona Water Reports

Florence

≈ 120–179 mg/L

🟠 Hard

San Tan Valley

≈ 180+ mg/L

🔴 Very Hard

Eloy

≈ 180+ mg/L

🔴 Very Hard

Casa Grande

≈ 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 Coolidge's water safe to drink?

Yes. Coolidge'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 Coolidge?

At ≈ 120–179 mg/L (Hard), Coolidge'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 Coolidge compare to the USA average?

The USA national average is 151 mg/L. Coolidge (≈ 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 Coolidge 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.