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Water system · PWSID CO0107485

LONGMONT CITY OF

LONGMONT, CO · ~102,866 people served

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

PWSID

CO0107485

State

Colorado

City

LONGMONT

Population served

102,866

Primary source

Surface water

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

No PFAS detections are on record for this system from EPA’s UCMR5 monitoring (2023–25). Absence of a detection isn’t a guarantee — not every system was sampled, and this dataset doesn’t cover other contaminants.

Violations & enforcement

41

Violations on record

0

Unaddressed

1

Health-based

9

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Oct 2022. Official EPA record →

Monitoring & reporting · Total trihalomethanes (TTHM) began Jul 2022 Resolved
Monitoring & reporting · Haloacetic acids (HAA5) began Jul 2022 Resolved
Monitoring & reporting · EPA contaminant 2037 began Jan 2005 Resolved
Monitoring & reporting · EPA contaminant 2032 began Jan 2005 Resolved
Monitoring & reporting · EPA contaminant 2035 began Jan 2005 Resolved
Monitoring & reporting · EPA contaminant 2036 began Jan 2005 Resolved
Monitoring & reporting · EPA contaminant 2005 began Jan 2005 Resolved
Monitoring & reporting · EPA contaminant 2031 began Jan 2005 Resolved
Monitoring & reporting · EPA contaminant 2010 began Jan 2005 Resolved
Monitoring & reporting · EPA contaminant 2015 began Jan 2005 Resolved
Monitoring & reporting · EPA contaminant 2020 began Jan 2005 Resolved
Monitoring & reporting · EPA contaminant 2033 began Jan 2005 Resolved

Recent enforcement actions

  • State action · SOX Oct 2022
  • State action · SIA Oct 2022
  • State action · SIE Oct 2022
  • State action · SOX Sep 2009
  • State action · SIA Feb 2008
  • State action · SOX Feb 2007
  • State action · SFJ Jul 1995
  • State action · SOX May 1991

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

1 station · latest Dec 2024

10.1 · max 10.9 mg/L · 10

Arsenic

1 station · latest Jun 2022

1.17 · max 1.95 ug/L · 4

Fluoride

1 station · latest Jun 2022

1.14 · max 1.64 mg/L · 2

Lead

1 station · latest Jun 2022

0.684 · max 1.25 ug/L · 2

Manganese

1 station · latest Jun 2022

34.6 · max 40.8 ug/L · 2

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 CO0107485 — 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.