According to PhillyVoice on August 31st:
Philly’s infrastructure problem may be even worse than you think. There have been 2019 sinkholes reported this year – around one for every mile of road Philadelphia has, one city official said.
Newsworks talked to Streets Commissioner David Perri, who attributed the nearly 20 percent increase in sinkholes over last year to “extreme bouts of cold weather.”
Water froze under the roads during the winter, leaving space that can collapse in on itself when the ice thaws. Geological forces that that city can’t control also contribute to the number of sinkholes each year.
One thing that the city can control is its water system. Philadelphia’s sewer system dates back to the 1800s in some sections. Last week, for example, a massive sinkhole in Kensington was linked back to a broken water main constructed in 1886.
The city’s water department replaces about 22 miles in its 3,100-mile network of pipes each year. Meanwhile, the department is working toward its goal of replacing all pipes more than a century old.
Until then, drive carefully and watch your step.