In America is it legal to bury dead people on top of each other in the cemetery?

The unidentified and unwanted dead bodies recovered from New York city (1500 a year) are buried several layers deep to conserve space on Hart Island.

Yes it is lega, by law we cemeteries have the right to bury husband on top of wife or child on top of mother etc. As long as the family of the deceased requests and authorizes us to do so yes it is legal