On the clean side, Salt Lake City is the star, followed by Minneapolis/St. Paul; Portland, Ore.; Denver, and Charleston, S.C.
So, what is it that other cities are doing that we're not? Or are Philadelphians just messier?
Ingrained with grime
Rob Wallace, a spokesman for the nonprofit Keep America Beautiful, said his organization has found three main reasons people litter:
- Trash begets trash. If people see garbage on the streets, they're more likely to toss their own waste to the curb.
- Infrastructure. If trash cans aren't placed frequently enough, people won't hold off on dumping until they find one.
- Ownership of a community. Those most likely to litter are under 30, a group perhaps less likely to be established or property owners. Residents who feel ownership of a community are more likely to see the city as a shared space and more likely to care about what is and isn't acceptable by community standards.
The last, Wallace said, has particular meaning to Philly. The city's infamous inferiority complex plays a part in its appearance.
"It's almost part of the social norm in some circles to think of the city as 'Filthadelphia,' " he said. "It's become ingrained in people."
Deputy Mayor Rina Cutler agreed that the local outlook makes it more difficult to keep the city clean.
"People are disconnected from the fact that littering is very disrespectful to their city," she said. "The biggest difference [between cleaner cities and Philadelphia] is mind-set and attitude."
Some believe that they have the right to litter, said Streets Commissioner Clarena Tolson.
"People think they're actually creating jobs by littering," she said. "These are some of the things we're trying to combat and overcome."
Still, Wallace said, some new programs have promise, like UnLitter Us, a Streets Department campaign that aims to show how disrespectful it is to litter.
"It speaks to the potential of the city," he said. "It gets beyond the perception of what Philadelphians have of themselves."
How do clean cities get - and stay - that way?
In Portland, Ore., population of about 584,000, Mayor Sam Adams has proposed eliminating the distribution of plastic checkout bags at large grocery stores and pharmacies. San Francisco was the first city to enforce such a ban, starting in 2007, and a few dozen cities now outlaw the bags.
In downtown Portland, more than 200 blocks are watched over by the Portland Business Alliance's Clean & Safe program. The program charges property owners between $600 and $100,000 annually for services including daily graffiti removal, sidewalk power-washing and trash pickup - about $4.5 million per year.
"If you took away our Clean & Safe district and put back all those graffiti tags and all the trash and all the cigarette butts, it would be a very different place," said Megan Doern, a spokeswoman for the Portland Business Alliance. "For the past 20 years, we've been able to keep our downtown extremely clean. If there's a graffiti tag one day, it's gone the next."
Another bane of cities? Cigarette butts. A study by Keep America Beautiful found that people who wouldn't ordinarily litter had no problem tossing a butt to the ground.
In 2009, Minneapolis began focusing on cigarette waste, said Angie Brenny, coordinator of Minneapolis' Clean City program. It added cigarette-specific trash receptacles at transitions points, like where someone would catch a bus or enter a business. As a result, cigarette waste reportedly has been reduced by about 50 percent.
The city of about 400,000 even hands out pocket ashtrays.
To prevent illegal dumping, Minneapolis also allows residents to drop off up to 16 tires per year. It will also pick up as many as two used appliances every other week and two pieces of "burnable" furniture every week at no cost.
In Denver, the populace and the government are tuned into the environment and do what they can to keep it a green city, said Meghan Hughes, a spokeswoman for the Denver Department of Environmental Health.
"We have a progressive environmental policy," she said. "We have recycling throughout the city, even in parks. We're not idling our trucks for long periods of time and dirtying the air. We have a composting program."
But the simple fact is that Philadelphia has many programs similar to those used in the cleanest cities: The Center City District spends 45 percent of its $18.7 million budget to keep sidewalks clean over a 233-block stretch. Citywide, burnable furniture can be put out with the regular trash. Weekly streamlined recycling is picking up an increasing percentage of trash.
One city program routinely organizes tire cleanups and pays community groups 50 cents per collected tire, with more than 8,000 tires turned in this year.
But there are continual setbacks. Recently, Deputy Streets Commissioner Carlton Williams went on a ride-along to high-dumping areas. As he approached one, he saw a rented truck dropping about 300 tires onto the ground. He called police, but they were unable to catch the perpetrator.
"While we're making an impact on one end, we're getting hurt on the other," he said.
He also noted that attitude plays a large part in the city's dirtiness. People who accept other negative behaviors accept littering as well.
"If you overlay the crime map with the litter-index map, you'll see similarities between crime and grime," he said.
Not that surveys like Travel + Leisure's, which tallied the votes of people who visited its website, are scientific.
Jeffrey Featherstone, director of Temple University's Center for Sustainable Communities, noted that these opinion-based polls don't take into account a city's population density.
He's seen surveys that analyze the number of food wrappers per acre that list Philadelphia near the top. If the analysis were done per wrapper per person, the outcome would have been better, he said.
"These studies have serious methodological problems," Featherstone said. "We're in the most densely populated area in the United States. . . . It's a more complicated environment here and clearly the density is impacting people's perceptions."
Philadelphia's many narrow streets also contribute to the problem. Another factor that could cloud visitors' views? The view itself as people travel downtown from the airport, catching sight of oil refineries and piles of cars waiting to be compressed.
"We just so happen to be a very industrial city that's very densely populated, and that's why I think we're unfairly considered to be dirty," Featherstone said. "If the visitors were initially shown Kelly Drive or the area along the Schuylkill, the rankings might be very different."