Larimer County, Colorado: drinking water report. Larimer County stretches from the Front Range suburbs of Fort Collins and Loveland into Rocky Mountain…
Larimer County stretches from the Front Range suburbs of Fort Collins and Loveland into Rocky Mountain National Park, with a population of about 360,000. Fort Collins Utilities and the City of Loveland each operate their own water systems, drawing from the Cache la Poudre River, Horsetooth Reservoir (Colorado-Big Thompson Project), and local treatment plants. The 2012 High Park Fire and 2020 Cameron Peak Fire both burned significant portions of the county's water supply watersheds, creating lasting impacts on source water quality.
Post-fire watershed degradation is the dominant water quality story in Larimer County. When forest burns, it strips the ground of vegetation that holds soil in place and absorbs rainfall. For years afterward, storms wash ash, sediment, and dissolved organic matter into reservoirs at rates far above pre-fire levels. According to Fort Collins Utilities' 2024 water quality report, turbidity spikes in the Poudre River following summer storms have been three to five times higher than pre-fire baselines, forcing the treatment plant to use more chemicals – which produces more disinfection byproducts.
The EPA's UCMR5 data shows PFAS detections at low levels in Fort Collins' system. A 2024 CDPHE assessment documented one public water system in the county with PFAS above detection limits. The Northern Colorado Regional Airport in Loveland has used AFFF foam, creating a localized contamination concern.
Fire-impacted watersheds take a decade or more to stabilize, and Larimer County is still in that recovery window. Heavy summer storms can temporarily degrade source water quality in ways that ripple through the treatment process.
Check your water for the latest monitoring data. A carbon block filter reduces disinfection byproducts and taste/odor compounds. For PFAS, reverse osmosis is more thorough. Our water filter guide covers both scenarios. Get your detailed report for trend data, and visit our Colorado page for statewide context.