WH

Water Hardness in Nampa, ID

Idaho · 3 zip codes · 37 matched water systems

150 PPM
8.8 GPG
Moderately Hard
0Soft60120180300+
Verified — Annual Water Quality Report

City avg (weighted): 150 PPM

Dataset updated March 9, 202637 matched water systems in the city rollupIndividual systems and ZIPs can differ. Methodology

System used for this reading
Nampa City Of
ID3140080
Water source: groundwater
Serves: 100,200
USGS environmental estimate: 196 PPM
Source context

How this city reading is built

This city reading is a weighted rollup across 37 matched water systems and 3 ZIP codes. Citywide readings are useful for comparison, but individual utility zones and ZIPs can differ.

Source basis
37 verified treated-water sources
37 matched systems total for this city; treated-water reports are prioritized when available.
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 in Nampa

These systems are matched to Nampa, ID. Citywide readings are useful for comparison, but the system serving a specific address may differ from the city average.

37 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.
Nampa City Of
ID3140080
Moderately Hard
150 PPMgroundwater100,200 servedVerified — Annual Water Quality Report
Source water: 196 PPM
Caldwell City Of
ID3140013
Moderately Hard
150 PPMgroundwater74,000 servedVerified — Annual Water Quality Report
Source water: 196 PPM
Middleton City Of
ID3140074
Moderately Hard
150 PPMgroundwater13,190 servedVerified — Annual Water Quality Report
Source water: 110 PPM
Belle Aire Acres 2
ID3140009
Moderately Hard
150 PPMgroundwater350 servedVerified — Annual Water Quality Report
Source water: 198 PPM
Evergreen Mobile Park
ID3140035
Moderately Hard
150 PPMgroundwater284 servedVerified — Annual Water Quality Report
Source water: 196 PPM
Showing the first 5 systems. Expand to review all matched systems.

Zip Codes in Nampa, ID

What This Means For You

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

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 Nampa, ID.

Submit Your Data

Frequently Asked Questions

How hard is the water in Nampa, ID?

The citywide weighted average water hardness in Nampa, ID is 150 PPM (8.8 GPG), classified as moderately hard. This is based on 37 matched water systems.

Do I need a water softener in Nampa, ID?

With a citywide average hardness of 150 PPM, a water softener is worth considering for homes in Nampa. Confirm your tap reading before sizing equipment.

Is hard water in Nampa, ID 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 Nampa, ID?

Nampa, Idaho is served by 37 matched water systems across 3 zip codes.

Learn More About Your Water