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City water profile

Oacoma water quality

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

Median indexed hardness

1110PPM

One indexed ZIP

Range 1110–1110 PPM

State comparison
594 PPM above
State hardness rank
#34 of 222
Matched utilities
1
Active health records
0

City summary

What the indexed records say

Oacoma has 1 published ZIP profile across Lyman County. The indexed median is 1110 PPM, compared with 516 PPM across South Dakota.

Among the 222 South Dakotacities with an indexed median, Oacoma ranks #34from 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. 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 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
63.5 miles
Profiles with evidence
1/1

Confidence labels

High: 0Moderate: 0Low: 1

Observation window: Apr 20, 2021 to Aug 6, 2024.

ZIP directory

Water reports in Oacoma

Open a ZIP for site-level provenance and measurements.

ZIP code

57365

Very Hard

1110 PPM

Nearest site
63.5 mi
Confidence
Low

View full ZIP evidence →

Public water systems

Utilities associated with this city

Oacoma

PWSID SD4600229

Surface water
System population served
391
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.

No violation records are included in the current lookback window.

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 Oacoma

Is the water hard?

The indexed city median is 1110 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.