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Water Hardness in 52159

Monona, Iowa · Clayton County

295 PPM
17.3 GPG
Very Hard
0Soft60120180300+
High Confidence — USGS Monitoring

Dataset updated March 9, 2026Matched to 3 water systemsTap readings can vary by utility zone, treatment, and plumbing. Methodology

Source context

How this ZIP reading is built

This ZIP reading is built from 3 matched water systems. When more than one system is matched, the displayed value is weighted toward larger known service populations when that data is available.

Source basis
3 USGS-backed sources
3 matched systems total for this ZIP; USGS monitoring is used where treated-water reports are unavailable.
Water source profile
Primarily groundwater
Groundwater commonly picks up calcium and magnesium after contact with rock and soil. This profile is weighted by known population served across matched systems.
Data recency
March 9, 2026
Dataset rebuilt March 9, 2026; individual utility reporting years can vary.

Hardness is a mineral-content reading, not a drinking-water safety rating. Use it for scale, appliance, and softener decisions; check your utility report or test your tap before sizing treatment equipment. See how we calculate local readings.

Water Systems Serving 52159

These are the systems matched to this ZIP code. The displayed ZIP value is weighted toward larger known service populations when population data is available.

3 water systems
PWSID is the public water system identifier. Data Source shows whether the hardness value comes from a treated-water report, USGS monitoring, or a local estimate; source year is shown when available.
Monona Municipal Water Dept
IA2264095
Very Hard
295 PPMgroundwater1,471 servedHigh Confidence — USGS Monitoring
Farmersburg Waterworks
IA2228037
Very Hard
295 PPMgroundwater276 servedHigh Confidence — USGS Monitoring
Saint Olaf Water Supply
IA2277020
Very Hard
295 PPMgroundwater106 servedHigh Confidence — USGS Monitoring

Nearby Zip Codes

What This Means For You

Recommendations are based on the displayed ZIP hardness reading. Confirm your tap reading before sizing or buying treatment equipment.

Very Hard Water - Treatment Strongly Recommended

Your water is very hard. Without treatment, you can expect significant scale buildup in pipes and appliances, higher energy bills from reduced water heater efficiency, and persistent issues with skin and hair dryness.

Recommended Products

Learn more: Do I Need a Water Softener? | Salt-Based vs Salt-Free | Size Calculator | How to Test Your Water

Know your water hardness?

If you've tested your water or have your utility's CCR report, share your reading to help us improve accuracy for Monona, IA (52159).

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Frequently Asked Questions

Is the water hard in Monona, IA (52159)?

The average water hardness in 52159 is 295 PPM (17.3 GPG), which is classified as very hard.

Do I need a water softener in 52159?

With hardness of 295 PPM, a water softener is recommended for homes in 52159.

Is hard water in 52159 safe to drink?

Water hardness itself is a mineral-content reading, not a drinking-water safety rating. Calcium and magnesium are naturally occurring minerals, but you should check your utility's Consumer Confidence Report for contaminant and compliance information.

How many water systems serve 52159?

Zip code 52159 in Monona, Iowa is served by 3 water systems.

Learn More About Your Water