It’s not often that a stock hits a 30-year low, but AT&T (NYSE: T) did just that last summer when it was revealed that “toxic” lead-coated cables left underground and underwater by the company decades ago could cost it billions of dollars to remove and properly dispose of.

The lead cable problem was the latest embarrassment to befall the telecommunications giant after years of underperformance that included a failed bid to buy Sprint, loss of market share to more nimble competitors like T-Mobile, and a series of failed acquisitions including DirecTV and Time Warner that wiped out tens of billions of dollars in market value.

Just when it seemed things couldn’t get any worse for AT&T, however, the company began to turn around. Since July 17, when the stock bottomed out at $13.43 following a Wall Street Journal investigation into lead-coated cables, AT&T’s stock price has surged 24%, outperforming the S&P 500 index.