Where does the water in 64440 come from?

Water for zip code 64440 in De Kalb, Missouri is provided by 2 water systems. Contact your local utility for specific source information, or check our detailed page for your area.

Water Hardness in 64440

De Kalb, Missouri · Buchanan County

200 PPM

11.7 GPG

Hard

0Soft60120180300+

Verified — Annual Water Quality Report

Dataset updated March 9, 2026Matched to 2 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 2 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

1 verified treated-water source

2 matched systems total for this ZIP; 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 Serving 64440

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.

2 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.

Water System	Source	Hardness	Pop. Served	Data Source
Mo American St Joseph MO1010714	groundwater	200 PPM Hard USGS estimate: 284 PPM	89,171	Verified — Annual Water Quality Report
Dekalb Pws MO1011181	groundwater	330 PPM Very Hard	250	Estimated — Nearby Data

Mo American St Joseph

MO1010714

Hard

200 PPMgroundwater89,171 servedVerified — Annual Water Quality Report

Source water: 284 PPM

Dekalb Pws

MO1011181

Very Hard

330 PPMgroundwater250 servedEstimated — Nearby Data

Nearby Zip Codes

64448200 64484203 64504200 64098261 64439260 64401200 64503200 66024406 66002741 64501200 64018260 64507200

What This Means For You

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

Hard Water - Treatment Recommended

Your water is hard. Scale buildup is likely affecting your plumbing and appliances, reducing their lifespan and efficiency. A water softener is recommended to protect your home.

Recommended Products

Salt-Based Water Softener

Our PickAFWFilters Fleck 5600SXT 48K Also GreatWhirlpool WHES40E 40K Also GreatAFWFilters 64K Grain Also GreatAFWFilters Iron Pro 2 64K Also GreatSpringWell Filter + Softener Combo

Salt-Free Water Conditioner

Our PickSpringWell Salt-Free Cartridge

Water Hardness Test Kit

Our PickVarify (150 Strips)Also GreatJNW Direct (150 Strips)

Shower Head Filter

Our PickWeddell Duo Also GreatAquaBliss SF100 Also GreatSprite Pure 7-Setting Also GreatAqua Earth 20-Stage

Water Softener Salt

Our PickMorton Clean & Protect Also GreatDiamond Crystal Bright & Soft

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 De Kalb, MO (64440).

Submit Your Data

Frequently Asked Questions

Is the water hard in De Kalb, MO (64440)?

The average water hardness in 64440 is 200 PPM (11.7 GPG), which is classified as hard.

Do I need a water softener in 64440?

With hardness of 200 PPM, a water softener is recommended for homes in 64440.

Is hard water in 64440 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 64440?

Zip code 64440 in De Kalb, Missouri is served by 2 water systems.