Mei'la/ Middot 36: Draining Sacrificial Blood from the Temple

We are introduced to new Mishnayot today, each focusing on the Temple and the Altar.  One Mishna teaches that at the south-western corner of the base of the altar there were two holes like two fine nostrils.  The sacrificial blood was poured on the western side of the foundation and it flowed until it met blood flowing from the southern side.  From there they flowed out to the brook of Kidron.  Below that corner, there was a cubit square covered by a marble slab with a ring fixed in it.  It was used to go down into the pit to clean it out.

After the sprinkling of the blood, the rest of the blood would go down a drain built into the foundation of the altar.  The blood would mix in with the plumbing pipes of the Temple with the blood poured into another drain in the outer altar.  The blood would flow together to the Kidron Valey and their remains would be sold as fertilizer.  

We learn that the Kidron Valley ran to the east of the Temple Mount.  It is the natural run off point for sewage from the Temple.  The walls of the Temple Mount stand at the edge of the Shiloach, which is dry until the spring.  Steinsaltz reminds us that we learned in Massechet Sukka (49) that only once every seventy years would the congealed blood be cleaned.  Not just that, but the Meiri believed that because those remains were removed and burned at the altar, the cleaning would only go as deep as the young priests could reach using tools.