No municipality that is studying COVID levels in sewage is doing so in any way that could create or maintain a personal poop record. Moreover, using the phrase "sift through" - which is often used when discussing illegal or overbroad searches of personal documents or information - is obviously intended to give your reader a specific idea of how you think about those COVID studies.
Claiming ignorance of the very obvious subtext in your choice of words doesn't make your post come out in a better light. It makes you look like you're trying to avoid engaging in good faith.