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

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

Marshalltown 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

405 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 Marshalltown, your appliances are currently losing 45% efficiency due to mineral buildup.

Appliance	In Marshalltown	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 Marshalltown compares to its nearest neighbours

City	Hardness	Risk	Source
▶ Marshalltown, Iowa	≈ 180+ mg/L	🔴 Very Hard	groundwater
Newton, Iowa	≈ 120–179 mg/L	🟠 Hard	groundwater
Pella, Iowa	≈ 120–179 mg/L	🟠 Hard	groundwater
Cedar Falls, Iowa	≈ 120–179 mg/L	🟠 Hard	groundwater
Altoona, Iowa	≈ 120–179 mg/L	🟠 Hard	groundwater

National Benchmark

How Marshalltown compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Marshalltown	≈ 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 Marshalltown's Water Unique?

Local geology and source profile

Source: GroundwaterTDS: 405 mg/LpH: 8.2

Marshalltown Water Works has served the community for over 140 years, providing drinking water to Marshalltown in Marshall County, Iowa (ZIP 50158). The utility operates a groundwater-based supply, drawing from Mississippian-age aquifers via production wells distributed across the service area. No surface reservoirs or rivers are used as primary sources. Treatment and distribution infrastructure serves Marshalltown and the surrounding service territory, with annual compliance documented in the Consumer Confidence Report available from the utility at (641) 753-7913.

The Iowa River watershed in central Iowa is characterized by Mississippian-age limestone and dolomite formations at depth. These carbonate rock layers dissolve readily as groundwater flows through them, releasing substantial dissolved calcium and magnesium into the supply. The Mississippian aquifers are relatively protected from surface contamination due to their depth and geological setting, though the utility monitors potential pathways such as abandoned or poorly maintained wells that could compromise water quality.

Marshalltown's supply is very hard, making severe scale buildup in pipes, water heaters, dishwashers, and washing machines a significant concern. Residents and businesses will experience reduced efficiency in hot water systems, increased soap and detergent consumption, and potential appliance damage over time. A water softener is strongly recommended for households and commercial users to protect plumbing infrastructure and extend appliance lifespan. The utility maintains compliance with Safe Drinking Water Act standards; specific pH, lead/copper, and treatment details are documented in the annual Consumer Confidence Report.

Geology & Source: Iowa River watershed, central Iowa — Mississippian-age limestone and dolomite aquifers; carbonate bedrock dissolves calcium and magnesium as groundwater percolates through, producing very hard water typical of eastern and central Iowa

Other Iowa Water Reports

Newton

≈ 120–179 mg/L

🟠 Hard

Pella

≈ 120–179 mg/L

🟠 Hard

Cedar Falls

≈ 120–179 mg/L

🟠 Hard

Altoona

≈ 120–179 mg/L

🟠 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 Marshalltown's water safe to drink?

Yes. Marshalltown'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 Marshalltown?

At ≈ 180+ mg/L (Very Hard), Marshalltown'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 Marshalltown compare to the USA average?

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