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City water profile

Potosi water quality

Compare local ZIP estimates, evidence quality, associated public systems, and compliance history for Potosi, Wisconsin.

Median indexed hardness

268PPM

One indexed ZIP

Range 268–268 PPM

State comparison
20 PPM below
State hardness rank
#339 of 479
Matched utilities
3
Active health records
0

City summary

What the indexed records say

Potosi has 1 published ZIP profile across Grant County. The indexed median is 268 PPM, compared with 288 PPM across Wisconsin.

Among the 479 Wisconsincities with an indexed median, Potosi ranks #339from highest to lowest. Across all 556 state ZIP profiles, available estimates run from 41.3to 467 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
23.9 miles
Profiles with evidence
1/1

Confidence labels

High: 0Moderate: 1Low: 0

Observation window: Feb 9, 2016 to Mar 3, 2026.

ZIP directory

Water reports in Potosi

Open a ZIP for site-level provenance and measurements.

ZIP code

53820

Very Hard

268 PPM

Nearest site
23.9 mi
Confidence
Moderate

View full ZIP evidence →

Public water systems

Utilities associated with this city

Potosi Waterworks

PWSID WI1220117

Groundwater
System population served
718
Last reported
May 29, 2026

The system names this served city; Census place overlap links the city to this ZCTA.

Tennyson Waterworks

PWSID WI1220120

Groundwater
System population served
367
Last reported
May 29, 2026

The system names this served city; Census place overlap links the city to this ZCTA.

River Vista Estates Llc

PWSID WI1220121

Groundwater
System population served
30
Last reported
May 29, 2026

The system names this served city; Census place overlap links the city to this ZCTA.

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.

RecordSystemPeriodStatus
LEAD AND COPPER RULE REVISIONSWI1220121Jul 2, 2025Resolved
Lead and Copper RuleWI1220120Jan 1, 2025Resolved
Lead and Copper RuleWI1220121Jan 1, 2025Resolved
Stage 1 Disinfectants and Disinfection Byproducts RuleWI1220117Mar 1, 2024Resolved · health-based
Stage 1 Disinfectants and Disinfection Byproducts RuleWI1220120Mar 1, 2024Resolved · health-based
Lead and Copper RuleWI1220117Jan 1, 2024Resolved
Lead and Copper RuleWI1220120Jan 1, 2024Resolved
Lead and Copper RuleWI1220120Jun 1, 2023Resolved
Revised Total Coliform RuleWI1220121Jan 1, 2021Resolved

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 Potosi

Is the water hard?

The indexed city median is 268 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.