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Water Hardness in 83821

Coolin, Idaho · Bonner County

103 PPM
6 GPG
Slightly Hard
0Soft60120180300+
High Confidence - USGS Monitoring

Dataset updated March 9, 2026Matched to 5 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 5 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
4 USGS-backed sources
5 matched systems total for this ZIP; USGS monitoring is used where treated-water reports are unavailable.
Water source profile
Primarily surface water
Surface-water hardness can shift with reservoirs, runoff, season, and treatment. 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 83821

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.

5 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.
Sandpoint Public Works Dept
ID1090121
Slightly Hard
106 PPMsurface water12,284 servedHigh Confidence - USGS Monitoring
Dover City Of
ID1090193
Slightly Hard
78 PPMsurface water865 servedHigh Confidence - USGS Monitoring
Sagle Valley Water Dist
ID1090118
Slightly Hard
106 PPMgroundwater708 servedEstimated - County Avg
Huckleberry Bay Water System
ID1090209
Soft
60 PPMgroundwater362 servedHigh Confidence - USGS Monitoring
Cougar Creek Water Assn
ID1090030
Soft
60 PPMgroundwater270 servedHigh Confidence - USGS Monitoring

Nearby Zip Codes

8385694838481048386410583852104838479783841104991197999139738382210483805709918018183860101

What This Means For You

Use this ZIP reading as a local planning estimate, not a final treatment specification. Hardness can vary by utility zone, seasonal blend, private well, and building plumbing. Confirm your tap reading with a utility report or home hardness test before sizing equipment.

MethodologyData sourcesHow 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 Coolin, ID (83821).

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Frequently Asked Questions

Is the water hard in Coolin, ID (83821)?

The average water hardness in 83821 is 103 PPM (6 GPG), which is classified as slightly hard.

Do I need a water softener in 83821?

At 103 PPM, your water is relatively soft. A water softener is generally not necessary.

Is hard water in 83821 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 83821?

Zip code 83821 in Coolin, Idaho is served by 5 water systems.

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