A branch drain accepting waste products delivered to it vertically, by gravity, from one or more similar but usually smaller fixtures, and conducting them horizontally to the primary disposal drain.
When the Minuteman III retires, the silos and launch facilities at Malmstrom Air Force Base in Montana, which oversees 150 nuclear ICBMs scattered across a 13,800 square miles, will have been buried for 70 years.
Map: The Nuclear Bombs in Your Backyard. Look up where in the United States the Pentagon keeps its atomic weaponry. The United States currently has 5,113 atomic warheads deployed in silos, bombers, and submarines, mostly in the continental US. That doesn't include thousands of zombies being kept in reserve and a backlog of more than 3,000 warheads awaiting dismantlement.