Two sinks

 Igros Moshe (YD I #42) Question Washing dishes in the sink.  Is a single  sink permitted? Answer: Even if you want to claim that a Bal Nefesh should be strict and not wash dishes in a single sink this is not the normative halacha to a person who only wants to do the minimum because most sinks can not actually be prohibited and thus it is not prohibited even to a Bal Nefesh. Also most times the dishes are not actually touching the sink but rest on a racks  which are separate for meat and milk. Even if occasionally that the sink water rises to touch the dishes. This is only a concern lechatchilah but bedieved it is not a problem even for a Bal Nefesh. Thus even though the custom is to have separate sinks  it is not prohibited to have a single sin