Lead in Longmont, CO Drinking Water
Lead data for Longmont, Colorado · 107,385 residents · 4 ZIP codes
Across the water systems that serve Longmont, Colorado, Lead has appeared in EPA compliance samples — standard municipal treatment targets this contaminant, though detections in the compliance record indicate it has reached household taps at measurable levels.
Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-05-14
Lead in Longmont Tap Water
Lead has been detected in Longmont, Colorado drinking water at a maximum level of 1.6 ppb — below the EPA action level of 15 ppb (action level).
This analysis covers 107,385 residents across 4 ZIP codes in Longmont.
Longmont's overall water quality grade is C (62/100).
Is Lead in Longmont Water Safe?
Lead was detected in Longmont water but currently falls within EPA limits. However, some health organizations argue the EPA action level may not be protective enough — the CDC states there is no safe level of lead for children.
If you are concerned, a reverse osmosis or nsf 53 carbon block filter can reduce lead levels further.
Lead Levels by ZIP Code
| ZIP Code | Lead Level | EPA Limit | Status |
|---|---|---|---|
| 80501 | 1.6 ppb | 15 ppb (action level) | OK |
| 80502 | 1.6 ppb | 15 ppb (action level) | OK |
| 80503 | 1.6 ppb | 15 ppb (action level) | OK |
| 80504 | 1.6 ppb | 15 ppb (action level) | OK |
Average lead level across Longmont: 1.6 ppb
Health Effects of Lead
- Brain development delays and reduced IQ in children
- Behavioral problems and learning disabilities
- High blood pressure and kidney damage in adults
- Increased risk of premature birth in pregnant women
Health risk severity: High. Governed by the Lead and Copper Rule Revisions (LCRR/LCRI).
How Lead Gets Into Drinking Water
- Corrosion of lead service lines (pipes connecting water main to home)
- Lead solder in copper plumbing joints (pre-1986 homes)
- Brass fixtures and faucets manufactured before 2014
- Stagnant water that sits in lead-containing pipes overnight
What to Do About Lead in Longmont Water
- Install an NSF 53 or NSF 58 certified filter at kitchen sink
- Run cold water for 30 seconds before using for drinking or cooking
- Use cold water only for cooking and preparing formula
- Consider whole-home reverse osmosis if lead service line is present
Look for filters certified under NSF 53 / NSF 58 for lead removal.