Q says follow the water. I think the same applies to the blood. Adrenechrome, blood sacrifice rituals, trafficking, abortion/PP, etc.. Why would they need to put blood in cement? I think it is worth a dig...
https://patents.google.com/patent/US4203674A/en
??????
Dedicated to the arrogant leftists.
So vain
https://youtu.be/mQZmCJUSC6g