More on cisterns... And their role in serving the public need for water as compared to an individual's need. So can a cistern really be dug on Chol HaMoed or not? Which leaves us with the "Anatomy of the Psak" on this. Also, the marking of graves, and the need to be careful with regard to tumah and taharah. Different parts of the body were specifically marked, for this practical halakhic consideration. Plus, Beit HaPras, the field strewn with bones.