The Wastewater Surveillance Program is transitioning to a new laboratory instrument to test wastewater samples. Due to this change in methodology, trend classifications for the viral concentration of SARS-CoV-2 will not be calculated and posted until we have enough data to classify trends. Throughout the transition, the viral concentration will be posted to the public wastewater monitoring dashboard as usual.
Last updated: 12/8/2023
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 classify the trend category for utilities each week. The count of utilities is listed next to each trend category, which is determined based on the criteria described within each expandable section.
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 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.
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.
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.
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.