Must A Kosher Home Have Two Sinks?

Rabbi Marc B. Shapiro writes: Among my children’s generation, many kids believe that there is a halakhic requirement to have two sinks. Some of these kids have literally never been to a kosher home which doesn’t have this. If they saw such a home, they would probably assume that there must be a heter for one sink, but only for those who can’t afford to redo their kitchens.