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Tap water quality report

Longmont City of

EPA monitoring tested this supplier for 107 contaminants and detected 14. A detection doesn't automatically mean the water is unsafe — the level and EPA source for each is below.

107
contaminants tested
14
detected
104,178
people served
2
health-based violations
Colorado rankingsLead in ColoradoPFAS in Colorado
Water source
Surface water
Ownership
Local government
Counties served
Boulder

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

2
health-based violations
77
violations on file
0
still open
ViolationTypeStatusPeriod
TT Health-based Resolved 1995-06-01 → 1995-06-30
TT Health-based Resolved 1995-06-01 → 1995-06-30
MR Monitoring Resolved 2022-07-01 → 2022-09-30
MR Monitoring Resolved 2022-07-01 → 2022-09-30
MR Monitoring Resolved 2022-07-01 → 2022-09-30
MR Monitoring Resolved 2022-07-01 → 2022-09-30
MR Monitoring Resolved 2022-07-01 → 2022-09-30
MR Monitoring Resolved 2022-07-01 → 2022-09-30
MR Monitoring Resolved 2005-01-01 → 2007-12-31
MR Monitoring Resolved 2005-01-01 → 2007-12-31

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of this system's samples — over 100% is worth reading, but is not by itself a violation. Where a single sample came in higher than that percentile, it is noted under the bar. Formal violations are listed separately.
ContaminantLevel vs EPA limitDetection rateSourcePeriod
TTHM
41.45 µg/L 52%
of the EPA limit 80 µg/L
worst single sample: 48.4 µg/L
251/251 SYR4 2012–2019
Total Haloacetic Acids (HAA5)
28.975 µg/L 48%
of the EPA limit 60 µg/L
worst single sample: 36.5 µg/L
250/250 SYR4 2012–2019
Lead
0.0016 mg/L 11%
of the EPA limit 0.0150 mg/L
 20/20 LCR 2025
Bromodichloromethane
2.714 µg/L
No EPA limit set
worst single sample: 2.79 µg/L
9/9 SYR4 2012–2018
Chloroform
35.94 µg/L
No EPA limit set
worst single sample: 36.5 µg/L
9/9 SYR4 2012–2018
Dichloroacetic Acid
9.4035 µg/L
No EPA limit set
worst single sample: 9.54 µg/L
8/8 SYR4 2018
Trichloroacetic Acid
12.525 µg/L
No EPA limit set
worst single sample: 12.7 µg/L
8/8 SYR4 2018
Nitrate
110 µg/L 1.1%
of the EPA limit 10000 µg/L
 6/16 SYR4 2012–2019
Fluoride
670 µg/L 17%
of the EPA limit 4000 µg/L
worst single sample: 680 µg/L
5/5 SYR4 2012–2018
Di(2-ethylhexyl) Phthalate
1.456 µg/L 24%
of the EPA limit 6 µg/L
worst single sample: 1.5 µg/L
2/14 SYR4 2012–2019
Nitrate-Nitrite
88.652 µg/L 0.9%
of the EPA limit 10000 µg/L
worst single sample: 91.16 µg/L
2/3 SYR4 2012–2014
Barium
10.4 µg/L 0.5%
of the EPA limit 2000 µg/L
 1/1 SYR4 2012
Combined Radium (-226 And -228)
0.2000 pCi/L 4%
of the EPA limit 5 pCi/L
 1/1 SYR4 2012
Gross Alpha, Excl. Radon And U
0.6000 pCi/L 4%
of the EPA limit 15 pCi/L
 1/1 SYR4 2012
93 contaminants tested, none detected
1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-DIBROMO-3-CHLOROPROPANE1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalArsenicAtrazineBhc-GammaBenzeneBenzo(A)PyreneBeryllium, TotalBromoformChlorobenzeneCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumCombined UraniumDichloromethaneDalaponDi(2-ethylhexyl) AdipateDibromoacetic AcidDibromochloromethaneDinosebDiquatEthylene DibromideEndothallEndrinEthylbenzeneHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorMonobromoacetic AcidMonochloroacetic AcidNetfosaaNfdhaNmefosaaNitriteOxamylPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroethyleneVinyl ChlorideXylenes, Totalcis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

Utility contact

Contact
HUFFER, CHRIS
Phone
303-651-8351
Email
[email protected]

Frequently asked questions about Longmont City of

Is Longmont City of tap water safe to drink?

EPA monitoring detected 14 contaminants in Longmont City of's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in Longmont City of's water?

EPA monitoring detected TTHM, Total Haloacetic Acids (HAA5), Lead, Bromodichloromethane, Chloroform, and others. The full list with the level and data source for each is above.

How many people does Longmont City of serve?

Longmont City of reports serving 104,178 people in Colorado, per its EPA record.

Has Longmont City of had any water quality violations?

The EPA has 77 violations on file for Longmont City of, of which 2 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.