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Water system · PWSID IA7740011

JOHNSTON MUNICIPAL WATER SUPPLY

JOHNSTON, IA · ~24,064 people served

Check your exact address → JOHNSTON overview
100
Excellent
PurityRadar safety score

PWSID

IA7740011

State

Iowa

City

JOHNSTON

Population served

24,064

Primary source

SWP

Score history

No change since tracking began Jun 18, 2026.

Jun 18, 2026 · score 100 Jun 18, 2026 · score 100

2 score updates logged since tracking began Jun 18, 2026. Each future EPA re-score adds a point.

PFAS & contaminant readings

Latest detections from EPA’s UCMR5 monitoring (through Oct 2025). Levels in parts per trillion (ppt).

Lithium

19,000 ppt

limit —

No federal limit

Violations & enforcement

3

Violations on record

0

Unaddressed

1

Health-based

19

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Jul 2013. Official EPA record →

Max contaminant level (MCL) · Total coliform health-based began May 2013 Resolved
Monitoring & reporting · Haloacetic acids (HAA5) began Jan 2006 Resolved
Monitoring & reporting · Total coliform began Sep 2003 Resolved

Recent enforcement actions

  • State action · SIF Jul 2013
  • State action · SOX Jun 2013
  • State action · SFJ May 2013
  • State action · SIE May 2013
  • State action · SIF Oct 2006
  • State action · SIF Oct 2006
  • State action · SOX Aug 2006
  • State action · SOX Aug 2006

Area water-quality monitoring

Environmental monitoring (rivers, wells, intakes) recorded in this system’s service area in the EPA/USGS Water Quality Portal since 2018 — source/ambient water, not finished tap water. Context for the watershed, not a reading from your tap.

ContaminantMedian · max · samples

Nitrate

6 stations · latest May 2026

5 · max 20 mg/L · 137

Copper

1 station · latest Apr 2025

1.4 · max 5.3 ug/L · 61

Fluoride

1 station · latest Sep 2025

0.325 · max 1.56 mg/L · 8

Arsenic

1 station · latest Mar 2020

1.5 · max 1.5 ug/L · 2

Lead

1 station · latest Mar 2020

0.14 · max 0.15 ug/L · 2

Atrazine

1 station · latest Mar 2025

0.3 · max 0.3 ug/L · 1

Source: Water Quality Portal (EPA/USGS/state agencies). Values are as-reported and aren’t health thresholds.

This profile is built from EPA public records for system IA7740011 — SDWIS violations and UCMR5 PFAS sampling. The score is system-level and can’t account for your home’s plumbing (older pipes can add lead at the tap). For health decisions, check your exact address, read the utility’s Consumer Confidence Report, and confirm with your provider.