Is Longmont, CO tap water safe?
The short answer
None of the 8 utilities serving Longmont has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and Colorado’s records.
City of Longmont, which serves the most people here, has 1 result above the health goal. The worst: Lead at 1.6 ppb, above the health goal. Health goals are stricter than legal limits and are not enforced.
A town can be served by more than one utility, and some homes are on private wells. The name on your water bill tells you which is yours, and your ZIP code narrows it down. They are listed by how many people each serves in Longmont’s ZIP codes, from EPA’s estimates.
- Open report
City of Longmont
Colorado · serves 104,178 people · about 41,200 in Longmont
1 result above the health goal. The worst: Lead at 1.6 ppb, above the health goal.
No health-based violations since 2016
- Open report
Left Hand WD
Colorado · serves 20,280 people · about 1,600 in Longmont
1 result above the health goal. The worst: Lead at 1.0 ppb, above the health goal.
No health-based violations since 2016
- Open report
Town of Firestone
Colorado · serves 27,798 people · about 1,200 in Longmont
1 result above the health goal. The worst: Lead at 3.6 ppb, above the health goal.
No health-based violations since 2016
- Open report
Town of Frederick
Colorado · serves 17,173 people · about 600 in Longmont
1 result above the health goal. The worst: Lead at 2.9 ppb, above the health goal.
No health-based violations since 2016
- Open report
Central Weld Cnty WD
Colorado · serves 7,662 people · about 460 in Longmont
1 result above the health goal. The worst: Lead at 6.0 ppb, above the health goal.
No health-based violations since 2016
- Open report
Longs Peak WD
Colorado · serves 3,200 people · under 100 in Longmont
1 result above the health goal. The worst: Lead at 2.0 ppb, above the health goal.
No health-based violations since 2016
- Open report
Countryside of Longmont
Colorado · serves 775 people · lists Longmont among the places it serves
Nothing in its records is above a health goal. Hardness: soft, typically 16 mg/L (0.9 grains per gallon).
No health-based violations since 2016
- Open report
St Vrain MHP LLC
Colorado · serves 544 people · lists Longmont among the places it serves
Nothing in its records is above a health goal. Hardness: soft, typically 21 mg/L (1.2 grains per gallon).
No health-based violations since 2016
What handles it
Each of these is certified, on a certifier’s listing, for a result above a line in City of Longmont’s water, which serves the most people here. Another utility’s report names what handles its own results.
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Brita Tahoe Pitcher with Elite Filter (OB60, OB06)
Pitcher
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 13, 2026
- IAPMO listing:NSF/ANSI 53checked Oct. 13, 2026
Certified for: Lead
Brita Everyday Pitcher with Elite Filter (OB46, OB06)
Pitcher
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 13, 2026
Certified for: Lead
PUR PLUS 11-Cup Pitcher (PPT111W)
Pitcher
- NSF listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 4, 2026
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 4, 2026
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 4, 2026
Certified for: Lead
Water testing near Longmont
The 3 labs Colorado certifies closest to Longmont, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Murray-Brown Laboratories, LLC.
Northglenn, CO · about 20 miles
Certified for bacteria
EAnalytics Laboratory
Loveland, CO · about 20 miles
Certified for bacteria
Colorado Analytical Laboratory - Commerce City
Commerce City, CO · about 23 miles
Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts, PFAS, radioactivity
Which ZIP codes are in Longmont: Census 2020 relationship files. Which utilities serve them, and how many people: EPA SDWIS and EPA’s service area map. Each utility’s results: EPA UCMR 5, EPA SDWIS, and EPA’s and the state’s compliance monitoring, as its report lists them. How they are measured: methodology. Certified labs: CDPHE certified drinking water laboratories; distances from the Census 2020 ZIP code tabulation area gazetteer.
Near Longmont
Other towns in Boulder County with a page of their own.
What to do next
- Read City of Longmont’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- Filters for LeadRanked by certification and what they cost over five years.The best water filters for lead, ranked
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water