Running Low on the 510

510 — the East Bay’s area code. Rappers sing about it, people get it tattooed on their bodies, and it shows up on store signs all over Alameda County. But the East Bay is running out of the 510 area code, and soon, a new one is coming to town. The process for adding a new area code — well — that’s not as simple as you might think. Ariel Plotnick has the story.