Longmont
Is Longmont tap water safe to drink?
Mostly yes — Longmont scores 99/100. This report aggregates EPA drinking water data across 2 local systems in Longmont. We found 82 total violations (1 unresolved).
Real-Time Environment
Live: 05:45 PM☀️ No active precipitation. Rainfall can impact surface water turbidity and pollutant runoff in Longmont.
Water Quality Impact
🛡️ Home Water Treatment Needs
Should you invest in filtration or softening for your home in Longmont?
Expert Advice
Your water quality is excellent. Standard filtration is optional but can further enhance taste.
Buying a Filter?
Wondering if Longmont tap water needs filtering? We break it down.
Baby Formula Safety
Mixing baby formula with Longmont tap water? Read this first.
Homebuyer's Perspective
If you're house-hunting in Longmont, water quality belongs on your due-diligence checklist alongside schools and crime data. The high safety score (99/100) suggests lower risk for plumbing corrosion and appliance scaling.
Health & Family Safety
Residents should monitor Lead (90th percentile) levels. Pregnant women and families with young children should consult the specific EPA health goals listed below.
View Health Risk Glossary →Compliance Record for Longmont
Based on EPA SDWIS violation records and contaminant test results for all water systems serving Longmont.
Frequently Asked Questions
Is Longmont tap water safe to drink?
Mostly yes — Longmont scores 99/100.
How many water systems serve Longmont?
Longmont is served by 2 public water systems in our latest EPA-backed dataset.
How can I check water quality for my exact address in Longmont?
Use the WaterQ search tool to look up your ZIP code and view nearby systems, contaminant levels, and recent violations for Longmont.
What is the water quality score for Longmont?
The water quality score for Longmont is 99 out of 100, based on EPA contaminant data, violation history, and testing results across the 2 systems serving the city.
What are the top contaminants in Longmont?
The top contaminants detected in Longmont include Lead (90th percentile). View detailed information on our contaminants page.
Longmont Water Quality Summary
Longmont, CO receives a water quality score of 99/100 (Grade A) based on EPA Safe Drinking Water Information System (SDWIS) compliance data for 2 public water systems serving the area.
Longmont's water quality is above the national average, with strong compliance records and low contaminant levels. Residents generally receive clean, safe tap water that meets EPA standards.
Longmont's score of 99 is 17 points above the Colorado state average of 82, and above the nationwide average of roughly 78/100 across all U.S. states.
For residents and home seekers in this mid-size Colorado city, the local municipal systems deliver excellent water quality that draws from high-elevation Mountain West sources. While the surrounding region carries a historic legacy of hardrock mining, Longmont's water infrastructure maintains an exemplary standard of safety and purity. This consistent performance ensures that households throughout the community can trust their tap water for daily use without major quality concerns.
Water quality data is sourced from the U.S. EPA SDWIS database and updated quarterly. Learn about our scoring methodology → Read our Colorado water quality rankings report →
Key Contaminants
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Water Systems Serving Longmont (2)
Check Your Specific Address
Water quality can vary by neighborhood in Longmont.
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