Piles of trash remain after marathon runners disposed of water cups on the ground in Park Slope. Photo by Lauren Gerber

Piles of trash remain after marathon runners disposed of water cups on the ground in Park Slope. Photo by Lauren Gerber

Marathoners know how to run, but they also know how to leave behind a mess. Fortunately, cleanup teams know how to get rid of it.

Early Sunday afternoon, there was little sign that 42,000 runners had stomped through Park Slope, Brooklyn, four hours earlier. Fourth Avenue, near the eight-mile mark, was left with a few dozen trash bags lumped in piles and some cardboard boxes strewn along the sidewalks. Other than that, the neighborhood looked, and felt, untouched.

At Fourth Avenue near Atlantic Avenue, the last runners came through at 11 a.m., and the area was expected to be clean by 2 p.m.

This turnaround doesn’t happen miraculously. Cleanup teams are sent to neighborhoods with water stops, such as Park Slope. These areas are the most littered because runners chuck away cups as they go, but cleanup teams follow an organized system to dispose of the trash.

“These guys are used to it,” said Jason Shankle, 36, of Queens, an operations manager for Royal Waste Services. “This city has it down to a science.”

Volunteers who gave out water throw away the cups into garbage bags and leave them on the sidewalk. Royal Waste Services, a contracted private company, has three or four employees at each water stop, throwing the bags into company trucks. The New York City Department of Sanitation employees then come through on “sweeper” trucks with circular turning brooms that rake up any excess pieces of trash. And like that, the road looks as if it was freshly plowed after a snowstorm.

“It’s really these guys here,” said Shankle, pointing to the Department of Sanitation trucks. “They’re not gonna take the time to talk to you. They have supervisors running up and down the street making sure they stay on schedule. They have to get the street open at a certain time.”

If they didn’t, Park Slope’s traffic would be delayed, as would the city’s clean-up schedule. The Department of Sanitation is responsible to clean up every water stop and make sure the streets are re-opened to traffic by a specific time.

But in Park Slope, even if city traffic is halted, those on Atlantic Avenue are getting on with their lazy Sunday like any other. Young couples walked their babies in strollers, 20-somethings carried six-packs of beers and teenagers flooded out of Target.

Even if some did watch the race, they seemed to have new finish lines on their minds. And the cleanup teams helped them get there, fast.

“Well, it’s not the South,” said Shankle. “This is the city.”