This: Is it okay for a city to track what’s in your poop? – Macleans.ca, is a provocative question that headlines a good article.
Now for most people, the answer would be a loud “no!”. But as you can see in the article, smarter cities lead to municipal governments gathering more information about you. Certainly in the case of smart meters, the government agency can tell alot about you just from when you use power. Digital technology and the need to better manage government resources can lead to further tracking, including to what is in your waste water. Expect to see more such tracking in the future.
Ideally for any information being gathered about you, there would be strict control over who has access to the information and what they can do with it. As well, there would be some accountability with regards to that information. I would expect there is a mixed record for much of that information, but the fact that I can only speculate tells me there is more work to be done with regards to accountability.
Read the article. It helps to be informed about such tracking so you can know how you can be tracked and how you can ask questions about such tracking to government officials and elected politicians.