WH

Water Hardness in 66618

Topeka, Kansas · Shawnee County

200 PPM
11.7 GPG
Hard
0Soft60120180300+
Verified — Annual Water Quality Report

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
5 verified treated-water sources
5 matched systems total for this ZIP; treated-water reports are prioritized when available.
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 66618

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.
Topeka, City Of
KS2017701
Hard
200 PPMsurface water125,963 servedVerified — Annual Water Quality Report
Source water: 237 PPM
Shawnee Co Rwd 4C
KS2017718
Hard
200 PPMsurface water12,000 servedVerified — Annual Water Quality Report
Source water: 237 PPM
Shawnee Co Rwd 3C
KS2017717
Hard
200 PPMsurface water2,675 servedVerified — Annual Water Quality Report
Source water: 237 PPM
Shawnee Co Rwd 2C
KS2017713
Hard
200 PPMsurface water700 servedVerified — Annual Water Quality Report
Source water: 237 PPM
Metro Topeka Airport Authority
KS2117703
Hard
200 PPMsurface water500 servedVerified — Annual Water Quality Report
Source water: 237 PPM

Nearby Zip Codes

665392016660620066608200666172006660320066604200666122006661620066611200666072006644029966615200

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 48KAlso GreatWhirlpool WHES40E 40KAlso GreatAFWFilters 64K GrainAlso GreatAFWFilters Iron Pro 2 64KAlso 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 DuoAlso GreatAquaBliss SF100Also GreatSprite Pure 7-SettingAlso GreatAqua Earth 20-Stage
Water Softener Salt
Our PickMorton Clean & ProtectAlso 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 Topeka, KS (66618).

Submit Your Data

Frequently Asked Questions

Is the water hard in Topeka, KS (66618)?

The average water hardness in 66618 is 200 PPM (11.7 GPG), which is classified as hard.

Do I need a water softener in 66618?

With hardness of 200 PPM, a water softener is recommended for homes in 66618.

Is hard water in 66618 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 66618?

Zip code 66618 in Topeka, Kansas is served by 5 water systems.

Learn More About Your Water

Best Water Softeners 2026: Top Picks for Every Budget

We compared salt-based, salt-free, and portable water softeners. Here are our top picks based on water hardness level, home size, and budget.

12 min read

Water Softener Size Calculator: What Grain Capacity Do You Need?

Calculate the right water softener size for your home. Enter your household size and water hardness to get a grain capacity recommendation.

7 min read

Hard Water and Hair: Effects, Damage Signs & What Actually Helps

How mineral buildup affects your hair - and what to do about it based on your actual water hardness level.

10 min read