Is tap water safe in Selby?

EPA SDWIS shows no active health-based violation in this profile's reporting window. That is not the same as proving every contaminant is absent, and federal data can lag state and utility records.

How hard is the water in Selby, SD?

Nearby USGS observations produce an estimate of 257 ppm (15 grains per gallon), classified as very hard. This is not a tap measurement.

Do I need a water softener in ZIP code 57472?

At 257 ppm, a correctly sized whole-house softener can reduce scale buildup and hard-water spotting. Treatment for hardness does not remove all health-related contaminants.

City water profile

Selby water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Selby, South Dakota.

Median indexed hardness

257PPM

One indexed ZIP

Range 257–257 PPM

State comparison: 259 PPM below
State hardness rank: #194 of 222
Matched utilities: 1
Active health records: 0

City summary

What the indexed records say

Selby has 1 published ZIP profile across Walworth County. The indexed median is 257 PPM, compared with 516 PPM across South Dakota.

Among the 222 South Dakotacities with an indexed median, Selby ranks #194from highest to lowest. Across all 246 state ZIP profiles, available estimates run from 20.5to 1330 PPM.

Because only one ZIP is represented, the city median and range are the same local estimate. It should not be read as multiple independent samples across the community.

Hardness distribution

How local ZIP estimates compare

Soft0 ZIPs

Moderately hard0 ZIPs

Hard0 ZIPs

Very hard1 ZIP

1 of 1 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.

Evidence quality

Distance, dates, and confidence

Median nearest distance: 18.8 miles
Profiles with evidence: 1/1

Confidence labels

High: 0Moderate: 1Low: 0

Observation window: Jan 8, 2016 to Jan 14, 2026.

ZIP directory

Water reports in Selby

Open a ZIP for site-level provenance and measurements.

ZIP code

57472

Very Hard

257 PPM

Nearest site: 18.8 mi
Confidence: Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

Selby

PWSID SD4600291

Surface water

System population served: 645
Last reported: Jun 17, 2026

EPA SDWIS explicitly lists this ZIP in the system's served geography.

Compliance history

What EPA records show

No active health-based violation appears among the associated systems in the represented EPA reporting quarter. This does not mean every contaminant was tested at every tap.

Record	System	Period	Status
Revised Total Coliform Rule	SD4600291	Oct 1, 2025	Resolved
Revised Total Coliform Rule	SD4600291	Dec 1, 2023	Resolved
Chlorine	SD4600291	Oct 1, 2023	Resolved
Lead and Copper Rule	SD4600291	Oct 1, 2021	Resolved

Practical next steps

Move from index to evidence

1. Open your ZIP. Check distance, dates, confidence, and the associated utility.
2. Read the current CCR. Confirm source water, detections, limits, ranges, and notices.
3. Test the tap when needed. Confirm health concerns or treatment sizing with the right method.

Continue comparing

Other South Dakota communities

Java

Walworth County

253 PPM median

Eureka

Mcpherson County

257 PPM median

Mobridge

Dewey County

257 PPM median

Northville

Spink County

256 PPM median

Bowdle

Edmunds County

253 PPM median

Faulkton

Faulk County

261 PPM median

Search all 234 South Dakota cities →

Questions people ask

About water in Selby

Is the water hard?

The indexed city median is 257 PPM. Open the ZIP report to verify the distance and confidence behind that estimate.

Is the tap water safe?

Compliance history is utility-wide and cannot guarantee conditions at every tap. Check current notices and test when address-specific evidence is needed.

Do I need treatment?

Choose treatment only after confirming the problem at the property. A softener targets hardness; contaminant treatment requires a matching, verified performance claim.