cremevax, 5 months ago

Hi, it’s the weekly #washingtonstate #kingcounty (that is, #seattle and environs) #COVID #COVID19 #wastewater toots.

Yay, we got some data this week.

Let's start with the West Point sewage treatment plant. The latest reading, done on 12/12, shows much improved numbers for the Sars-CoV-2 concentrations 7 day rolling average from the crazy rise of two weeks ago. But it also shows backfilled data for 12/5 and 12/10 of ... 0?? I ... I have questions.

Theory: they didn't have data for 12/5 and the zero reading is a placeholder value. Then they did get valid sample data on 12/10 (you can find it in the download file) but since they didn't have 12/5 they couldn't do the seven-day rolling average, so they left that as a placeholder value too. My inclination is to mentally draw a line from 12/3 to 12/12 and be happy that the trendline is good.

You can find overviews, individual sewershed results, and a breakdown of variants for the state wastewater surveillance program, along with other metrics like case counts and hospitalizations for Covid-19 and other respiratory illnesses, at https://doh.wa.gov/data-and-statistical-reports/diseases-and-chronic-conditions/communicable-disease-surveillance-data/respiratory-illness-data-dashboard#WasteWater. WSPT is one of three King County(-ish) sewersheds in this dataset. The dashboard gets updated every Wednesday (generally).

Note: when the state switched over to new data providers in September, they also removed the previous historical data from the graphical interface. That's because the two providers used different methodologies that made direct comparisons difficult. Unfortunately, it also removed valuable context for interpreting the results. So, keep in mind we're just seeing what happened in September 2023 until now.