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Weekly COVID-19 trends by wastewater treatment facilities

Last updated December 6, 2024

Wastewater treatment facilities participating in the CDPHE Wastewater Surveillance Program submit two samples per week. A statistical time series model is used to determine the trend of SARS-CoV-2 viral concentrations for each individual facility for the date each sample is collected. We review these trends and determine their trend category each week based on the following criteria:  

A steady increase means the viral concentrations of the two most recent samples reflect a statistically significant increase relative to earlier samples from that facility.

A simple increase means the viral concentrations of one out of the two most recent samples reflects a statistically significant increase relative to earlier samples from that facility.

A plateau in the trend means there was no statistically significant change in the viral concentrations of the two most recent samples relative to earlier samples from that facility.

Boulder
Grand Junction - Persigo
Metro WW - NTP
South Platte
Steamboat Springs

A simple decrease means the viral concentrations of one out of the two most recent samples reflects a statistically significant decrease relative to earlier samples from that facility.

Aspen
Durango
La Junta
Upper Blue SD - Breckenridge

A steady decrease means the viral concentrations of the two most recent samples reflect a statistically significant decrease relative to earlier samples from that facility.

Alamosa
Aurora
CO Springs - JD Phillips
CO Springs - Las Vegas
Centennial Water & Sanitation District
Glenwood Springs
Greeley
Metro WW - Clear Creek
Metro WW - Platte/Central
Pueblo
Telluride

Wastewater treatment facilities without two recent samples (within the last 15 days) OR facilities without enough samples to construct a trend model (< 5 samples in 3 weeks) are categorized as insufficient data.

Note: Trends are calculated with the SARS-CoV-2 viral concentration data from each individual facility; raw viral concentration levels cannot be compared between utilities due to the variability in collection time, influent flow rates, and differences in the size and characteristics of resident populations, among other factors.