The question is at what point do you have to worry about your genetics flooding the area around you to the point of inbreeding?

I live in an area that I think is fairly isolated colony wise. I also believe that there is very little as far as managed and or "wild" populations in this area.

Assume in a few years when I have more hive and am rearing my own queens. Is there a rule of thumb as far as how many hives I can manage versus the population around me before I have to be concerned about my genetics spreading and dominating the surrounding population to the point that inbreeding is an issue.