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City water profile

Spearfish water quality

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

Median indexed hardness

511PPM

2 indexed ZIPs

Range 496–525.5 PPM

State comparison
5 PPM below
State hardness rank
#125 of 222
Matched utilities
14
Active health records
1

City summary

What the indexed records say

Spearfish has 2 published ZIP profiles across Lawrence County. The indexed median is 511 PPM, compared with 516 PPM across South Dakota.

Among the 222 South Dakotacities with an indexed median, Spearfish ranks #125from highest to lowest. Across all 246 state ZIP profiles, available estimates run from 20.5to 1330 PPM.

The 496–525.5 PPM range shows how much the available ZIP estimates vary within the city label. At least one estimate is marked low confidence, so observation distance and date deserve extra attention.

Hardness distribution

How local ZIP estimates compare

Soft0 ZIPs
Moderately hard0 ZIPs
Hard0 ZIPs
Very hard2 ZIPs

2 of 2 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.

Evidence quality

Distance, dates, and confidence

Median nearest distance
44.6 miles
Profiles with evidence
2/2

Confidence labels

High: 0Moderate: 0Low: 2

Observation window: May 9, 2016 to Nov 20, 2024.

ZIP directory

Water reports in Spearfish

Open a ZIP for site-level provenance and measurements.

ZIP code

57783

Very Hard

496 PPM

Nearest site
44.6 mi
Confidence
Low

View full ZIP evidence →

ZIP code

57793

Very Hard

525.5 PPM

Nearest site
35.6 mi
Confidence
Low

View full ZIP evidence →

Public water systems

Utilities associated with this city

Spearfish

PWSID SD4600311

Groundwater
System population served
13,803
Last reported
Jun 17, 2026

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

Mountain Plains 2 Homeowners Assoc

PWSID SD4602169

Groundwater
System population served
268
Last reported
Jun 17, 2026

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

Saint Onge Sewer & Water Co

PWSID SD4600287

Groundwater
System population served
255
Last reported
Jun 17, 2026

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

Lantern Estates

PWSID SD4600315

Groundwater
System population served
192
Last reported
Jun 17, 2026

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

Walnut Park

PWSID SD4600316

Groundwater
System population served
180
Last reported
Jun 17, 2026

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

Spearfish Valley Mobile Estates

PWSID SD4600625

Groundwater
System population served
163
Last reported
Jun 17, 2026

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

Country Road Estates

PWSID SD4602204

Groundwater
System population served
112
Last reported
Jun 17, 2026

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

Ken'S Trailer Court

PWSID SD4600314

Groundwater
System population served
110
Last reported
Jun 17, 2026

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

Westfield Addition

PWSID SD4600521

Groundwater
System population served
104
Last reported
Jun 17, 2026

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

Westview Homeowners Association

PWSID SD4600876

Groundwater
System population served
103
Last reported
Jun 17, 2026

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

Whitewood

PWSID SD4600368

Groundwater
System population served
879
Last reported
Jun 17, 2026

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

Rimrock Water Company Llc

PWSID SD4602220

Groundwater
System population served
365
Last reported
Jun 17, 2026

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

Whitewood Forest Acres

PWSID SD4602354

Groundwater
System population served
160
Last reported
Jun 17, 2026

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

Red Water Distribution Llc

PWSID SD4602257

Groundwater
System population served
35
Last reported
Jun 17, 2026

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

Compliance history

What EPA records show

1 unique active health-based record appears among associated systems. This does not mean every contaminant was tested at every tap.

RecordSystemPeriodStatus
Public NoticeSD4602169Dec 13, 2025Unaddressed
Groundwater RuleSD4602169Oct 31, 2025Unaddressed · health-based
Revised Total Coliform RuleSD4602354Sep 1, 2025Archived
Consumer Confidence RuleSD4602169Jul 1, 2025Unaddressed
Revised Total Coliform RuleSD4602331Mar 1, 2025Resolved
Revised Total Coliform RuleSD4602331Feb 1, 2025Resolved
LEAD AND COPPER RULE REVISIONSSD4600316Oct 17, 2024Resolved
LEAD AND COPPER RULE REVISIONSSD4600316Oct 17, 2024Resolved · health-based
LEAD AND COPPER RULE REVISIONSSD4600160Oct 17, 2024Resolved
LEAD AND COPPER RULE REVISIONSSD4600160Oct 17, 2024Resolved · health-based

Practical next steps

Move from index to evidence

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

Questions people ask

About water in Spearfish

Is the water hard?

The indexed city median is 511 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.