San Francisco has gotten kudos from the global press for its efforts to eliminate waste. Mayor Ed Lee has boasted that his city diverts a greater percentage of its waste from the landfill than any other in the country. San Francisco’s environment department, down the street from Twitter and sharing a building with Uber, features art made from reclaimed refuse and a five-bin system for its employees to minimize trash.

But sitting at his desk on a recent weekday, the city’s zero waste manager, Robert Haley, pulled out a piece of paper that contained some troubling stats. After 12 years of consecutive declines, last year the city sent more tons of trash to landfills than it did in 2012: 456,764 tons, or about three pounds per day per resident.

That leaves San Francisco further from what was always an aspirational and probably unattainable goal of zero waste going to landfills or incinerators by 2020.

“I think it’s extremely ambitious,” Haley said of the goal. “It would be hard for me with a straight face to say, ‘In six years, nothing is going to go to the landfill.’ But we want to get as close as we can to that.”

San Francisco’s stall shows that a city’s biggest obstacle to achieving big goals may be the people it serves. No matter how progressive the people are, how long they’ve had to assimilate the mission, how convenient it is to use the freely provided recycling and composting bins, how strong the law is that mandates composting, some city residents just keep tossing items into the trash that they shouldn’t.

Even at the environment department’s office, employees don’t always get the sorting right. As Haley walked around the floor giving me a tour, he stopped to move an item that had been placed in the wrong bin.

“It’s complicated,” Haley said. “We used to say, back in the old days, recycling is simple. Now we’re telling people they have to compost food scraps.” Thousands of items are recyclable — too many to show them all in pictures on or near bins. “Recycling is more complicated. Composting is more complicated. It’s a very complex world.”

Haley thinks the city can cut its landfill totals in half through education and incentives. The owners of single-family homes pay more than 12 times as much each month for a 32-gallon trash bin as they do for recycling and composting bins. And they can save more than $9 per month by switching from a 32-gallon trash bin to a 20-gallon bin. “We don’t need a lot of programs and policies here,” he said. “We need a lot better participation.”

To see the situation for myself, I walked about seven miles on an east-west route covering Potrero Hill, the Mission, the Castro, Cole Valley and Twin Peaks. Most of the oversize bins were for recycling, not trash. I counted over 230 bins of all sizes, the majority of them for composting and recycling. But 77 were trash bins. San Francisco must get that number to zero in six years to achieve its self-assigned mission.

The distraction of diversion rates

Many upbeat articles on the zero-waste project — and Lee himself — don’t stress the tonnage numbers. Instead, they talk about the percentage of waste that is diverted from landfills. In San Francisco, it reached 80 percent in 2010, a figure that continues to be cited to this day.

The only trouble is, San Francisco was using an unconventional method of tallying its diversion rate, one that counted heavy construction waste such as rock and crushed concrete.

Many other cities don’t count this category of construction waste in their diversion rates. Using that method, Samantha MacBride, assistant professor at the Baruch College School of Public Affairs in New York, calculated in an article that San Francisco’s diversion rate is closer to 60 percent than 80 percent.

Recycling managers from other North American cities “have written to me to thank me for writing the piece because they get compared to San Francisco in an unreasonable way,” MacBride said in a telephone interview. Others sent less friendly messages, questioning whether she opposed recycling. She said she has nothing against San Francisco. “One comes across as being an enemy of recycling, a naysayer” for questioning the figures, she said. “San Francisco has this kind of holy status.”

Haley acknowledged that San Francisco included heavy construction debris in its diversion rate. He hasn’t redone the calculation in four years, preferring to focus on reducing tonnage, which is, after all, the subject of the zero-waste target.

The 80 percent figure, Haley said, is “the kind of number that PR people and politicians like to say. I said, ‘I would downplay that,’ because eventually people will start coming at you” — as they have in recent articles in Bloomberg View and the San Francisco Bay Guardian questioning the stat.

It’s probably inevitable that some cities would put a positive spin on their diversion numbers, given the expectations of the public and state oversight agencies. Mike Ewall, founder and director of Energy Justice Network, a Philadelphia-based environmental group, says some cities take credit for preventing waste they say would have happened without their interventions. Or they take credit for the interventions themselves. Maryland, for example, gives cities a boost of up to 5 percentage points for its educational programs; Oregon gives up to 6 percentage points for educational programs, promotion of home composting and other activities.

“Comparing within California is tricky,” Haley said. “Comparing with other states is really, really hard.”

A whistleblower questions the stats

But some say San Francisco has gone beyond mere spin. Brian McVeigh, a former employee of Recology, the city’s waste management contractor, accused the company in a whistleblower lawsuit of fudging some numbers in order to receive incentive bonuses. He said he once saw Recology employees jackhammer concrete at a company waste facility, then truck the concrete in to be recycled. “That was pretty brazen, right in everybody’s face,” he said in a telephone interview. He also claims to have seen people walk in with 10 cans and leave with a receipt for $500 in recycled goods, a fraud which he said “absolutely” affected the diversion numbers.

Such practices show that the zero-waste campaign “is a make-me-feel-good thing,” McVeigh said. “We all want to feel good. … There’s good work being done. There’s potential to do better.”

In June, the jury in McVeigh’s suit compelled Recology to repay the city $1.37 million that it undeservedly received as a bonus for meeting a diversion goal.

In a statement, Recology noted the jury cleared the company on four of five counts of false claims to the city, and of all 154 counts of false claims to the state. “We will be appealing the one verdict, as the facts simply do not support it,” company spokesman Sam Singer said.

“Anytime someone accuses Recology or us of something, we take it really seriously,” Haley said. He heard from jurors that many felt Recology wasn’t sharing everything it could with the city. “I’m using that as way to get to Recology to be more forthcoming.”

He’s also assigning staff to go through court documents looking for anything worth following up. “We haven’t found anything substantive so far,” a spokeswoman said. Haley doubts the company would risk its monopoly over the city’s permits, worth roughly $300 million in annual Recology revenue.

Even if the 80 percent figure is accurate, San Francisco would still have 20 percent of the way to go — a figure that amounts to a large and growing pile. “On a recovery percentage basis, we do pretty well,” Haley said. “On a pure generation and consumption basis, we don’t.” Of 34 European countries tracked by Eurostat, the European Commission’s statistical arm, only Cyprus and Malta produced more landfilled or incinerated waste weight per resident than San Francisco did last year.

Haley offered one reason why the city sent more tonnage to the landfill last year than it did the year before. He pointed out that the booming tech economy has made it tough to keep the numbers down. He says the pile at the landfill would have been even higher if not for the progress the city has made.

Still, he’s disappointed. “It’s the first time in many, many years that the number went the wrong way,” he said.

Seattle’s story

Other cities have used the “zero-waste” phrase to describe more attainable numerical targets. Seattle, for instance, is aiming for 60 percent of its waste to be diverted from landfills by next year, and 70 percent in eight years. Those percentages don’t include heavy construction material, so if Seattle meets its goal it will be in line with San Francisco’s success.

“We don’t become students of other people’s numbers,” Timothy Croll, solid waste director for Seattle Public Utilities, said in a telephone interview, “but from what I read in [MacBride’s] article, it doesn’t seem to be apples-to-apples with how we do our numbers.”

Like San Francisco, Seattle is struggling to hold onto earlier gains. The city’s diversion rate barely budged between 2011 and last year, rising just 0.8 percentage points to 56.2 percent.

Croll said Seattle needs bold rule changes to increase recycling and reach the target. “What changes the shape of these graphs is when you do something,” he said. “We don’t expect to magically change the path of the curve unless we do something, but we think we have some tricks up our sleeves.”

In the middle of last decade, Seattle changed the curve by banning disposal of recyclables. Trashing compostables will be a fineable offense in January, if the city council approves it. “We have great hopes for our composting requirement,” Croll said.

Any further gains are unlikely to bring Seattle to absolute zero. “It’s fair to say we view zero waste as an aspiration, just as a doctor might view zero illness as a goal,” Croll said. “We may be stuck with a certain amount of waste, but it’s not a good thing.”

Portland, Ore., has its own zero-waste goal, but like Seattle it is aiming for a more attainable intermediate target. The city wants to get its diversion rate up to 75 percent by the end of next year — counting a 6 percentage point credit it gets from the state for education programs and for home composting. The city has been stuck at a recovery rate — its term for diversion rate — of between 67 percent and 71 percent since 2008. To reach the target, Portland must increase rates for recycling and composting by businesses, which have lagged residential rates, said Bruce Walker, manager of the city’s solid waste and recycling program.

For many places, “zero waste” is a rallying cry and a branding exercise but not a real goal, Ewall said. Anything else would be naïve. “The idea of zero waste is not to get to absolute zero,” he said. “It’s to drive home the point: If you’re not for zero waste, how much waste are you for? Don’t just sit back and get satisfied once you hit a certain goal post.”

The compost imperative

Recology’s compost facility in Vacaville, California, halfway between San Francisco and Sacramento, shows composting’s potential to drive waste down toward zero, and what it would take to achieve that potential. The Jepson Prairie Organics composting facility is down the road from Travis Air Force Base, and adjacent to a Recology landfill. Waste trucks hauling solids bound for either destination crowd the farm-lined road, fittingly called Hay Road.

Jepson turns food scraps and yard trimmings into a fine powder of fertile, soil-boosting compost through a multistage, two-month process. The food arrives between 10 p.m. and 2 a.m., to avoid daytime heat and to suppress odor. I visited Jepson in the morning, so I saw how yard trimmings get processed. First they’re fed into a grinder to reduce them to a manageable size. The pieces pass through a trommel — a screened, spinning cylinder that sorts them by size. The bigger pieces enter a conveyor belt, which feeds them past workers who pick out any trash that got mixed in. What they let pass gets ground once more, and then piled and exposed to the sun and to atmospheric microorganisms. Methane and other gases they emit get sucked out and can be used as fuel. The piles get turned and watered, to give the microorganisms sustenance as they break the nutrients into smaller pieces that can more effectively enrich soil.

This process normally plays out over several months. Like a cooking show where foods in different stages of a recipe have been pre-prepared, a tour of the Vacaville facility shows compost in each stage of development, in reverse order. As I entered the facility, the first thing I saw were piles of finished compost, alongside soil amendments — additives such as redwood sawdust — that Recology buys to mix in for custom blends designed to match the nutritional needs of customers’ soil. Recology sells the finished products to local farmers for about $12 per cubic yard, and often the supply can’t keep up with the demand, Recology spokesman Robert Reed said.

Part of Recology’s supply problem is that roughly half of San Francisco’s trash could be composted. Put another way, most of what can be composted isn’t going into green bins and getting to facilities like Jepson, reducing San Francisco’s share of the potential environmental benefits from composting. Daily composting tonnage from San Francisco has increased by 62 percent since 2008, the year before composting became mandatory, but it has much further to go.

Another composting challenge stems from what goes in the green bins, but shouldn’t. Two years ago, San Francisco banned from stores all plastic bags that can be used just once. But the city isn’t stopping people with bags at the borders, and workers and visitors leave plenty behind, some of them in green bins. The statewide ban passed by California lawmakers in August wouldn’t take full effect until 2016, if Gov. Jerry Brown signs it. Jepson’s trommel was lined with shredded plastic bags, and the piles of compost in their early stages contained bits of them. Eventually, most get filtered out, Reed said. Still, removal adds to the cost, and if any plastic gets left behind, it could contaminate the compost.

“Nothing is perfect on this planet,” Reed said during the tour. “It’s an imperfect business.”

CORRECTION (Sept. 4, 2:27 p.m.): An earlier version if this post indicated that a statewide ban on plastic bags in California would take effect in 2016, but the legislation still awaits the governor’s signature.

CORRECTION (Sept. 4, 6:32 p.m): Most of what can be composted in San Francisco isn’t going into green bins and getting to facilities like Jepson. This post originally said most of what can be composted is going into green bins.

CORRECTION (Sept. 4, 11:54 p.m): An earlier version of this article misspelled the last name of Samantha MacBride, assistant professor at the Baruch College School of Public Affairs in New York.