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Water system · PWSID IA9778054

SIOUX CITY WATER SUPPLY

SIOUX CITY, IA · ~85,791 people served

Check your exact address → SIOUX CITY overview
42
Action needed
PurityRadar safety score

PWSID

IA9778054

State

Iowa

City

SIOUX CITY

Population served

85,791

Primary source

GU

Score history

▼ 58 points — the score moved from 100 to 42 on Jun 18, 2026, as newly published EPA data was incorporated.

Jun 18, 2026 · score 100 Jun 18, 2026 · score 42

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 Jul 2024). Levels in parts per trillion (ppt).

PFHxS

Perfluorohexanesulfonic acid

29 ppt

limit 10 ppt

Above EPA limit · 2.9×

PFOA

Perfluorooctanoic acid

5.4 ppt

limit 4 ppt

Above EPA limit · 1.4×

PFOS

Perfluorooctanesulfonic acid

4.1 ppt

limit 4 ppt

Above EPA limit · 1.0×

Lithium

140,000 ppt

limit —

No federal limit

PFHxA

28 ppt

limit —

No federal limit

PFPeA

18 ppt

limit —

No federal limit

PFBS

17 ppt

limit —

No federal limit

PFPeS

11 ppt

limit —

No federal limit

PFBA

9.2 ppt

limit —

No federal limit

PFHpA

4.3 ppt

limit —

No federal limit

Violations & enforcement

32

Violations on record

0

Unaddressed

12

Health-based

131

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement May 2025. Official EPA record →

Monitoring & reporting · Total trihalomethanes (TTHM) began May 2024 Resolved
Monitoring & reporting · Haloacetic acids (HAA5) began May 2024 Resolved
Max contaminant level (MCL) · Total trihalomethanes (TTHM) health-based began Oct 2019 Resolved
Max contaminant level (MCL) · Total trihalomethanes (TTHM) health-based began Jul 2019 Resolved
Treatment technique · EPA contaminant 2257 health-based began Mar 2017 Resolved
Treatment technique · EPA contaminant 2257 health-based began Nov 2016 Resolved
Treatment technique · EPA contaminant 2257 health-based began May 2016 Resolved
Monitoring & reporting · EPA contaminant 0300 began May 2015 Resolved
Monitoring & reporting · EPA contaminant 0200 began Jul 2012 Resolved
Monitoring & reporting · EPA contaminant 0200 began Jun 2012 Resolved
Treatment technique · EPA contaminant 0200 health-based began Apr 2012 Resolved
Monitoring & reporting · Nitrate began Jul 2007 Resolved

Recent enforcement actions

  • State action · SIF May 2025
  • State action · SIF May 2025
  • State action · SOX Aug 2024
  • State action · SOX Aug 2024
  • State action · SIE Jul 2024
  • State action · SIE Jul 2024
  • State action · SFJ Jul 2024
  • State action · SFJ Jul 2024

This profile is built from EPA public records for system IA9778054 — 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.