I grew up with well water in Northern Wake County and our first well had 0.25 gpm. Yes, my parents dug again, and the second well was about 15 gpm. But at no time the the well diggers claim we were hitting different aquifers. As I understand it well depth and flow are a function of the rocks and sediment, not just the aquifer.
RaleighBoundGeek cited his source,
North Carolina Division of Water Resources . I looked at it. The groundwater mapping he mentioned is here:
Ground Water Database Access Yup, looks like most of Wake County is on the same major aquifer. For all I know there might be minor ones they don't mention, but according to the map it is one. Surfing around a little, I found the page on groundwater particularly interesting.
What is Ground Water?
Check out the section at the end describing how Kinston's well pumping created a saltwater intrusion problem.