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Meet the High School Student Making Algae Biofuel Better

July 29, 2013

Sara Volz, a 17-year-old high school student from Colorado Springs, Colo., was the $100,000 winner of the 2013 Intel Science Talent Search for her work developing algae biofuels, and she was honored by President Obama in a ceremony at the White House. Volz tells PopMech why she’s spent the last four years on making fuel from these organisms, tinkering with their nitrogen supply and genetics to try to make them produce more oil.


How do you describe your work?


Biofuels are alternative energy made from the conversion of natural oils into fuel. The biggest problem with biofuels, however, is where we are getting them. Waste vegetable oil is used, but it’s not a sustainable source. Soybeans aren’t a very efficient fuel because using them that way takes away food and land resources.

Why algae?


[Using] Algae doesn’t require arable land, and they can be grown in a variety of environments. But it’s not economically viable yet. So I’ve been trying to increase the oil content of algae.

How did you develop an interest in biofuels?


I always loved chemistry, and I learned about some neighbors who were making biofuels in their garage.

What are the most important components of your work?


I’m trying to use artificial selection to develop these algae cells with high oil content. [Artificial selection is selective breeding to cause major changes in the features of plants and animals over the course of decades.]

Why do you think your work has gotten so much attention?


Algae produce great biofuel. It’s a good option because it’s a drop-in replacement for diesel fuels. You don’t have to change engines to use it.

How does your work compare with or complement that of others working with algae? Have you had any contact with biofuel companies?


There is a lot of work going on in a wide variety of areas to improve the feasibility of algae biofuel production, with many projects focused on the critical issue of improving oil yields. But according to my knowledge and my reviews of the literature, this work represents a new method for increasing algae oil yields. For several years, I’ve had contact with a small Colorado company working with algae, and more recently, I’ve been contacted by some larger corporations and algae professional organizations, but I have not worked with any of them so far.

The Intel Foundation praised you for your ability to connect the dots across multiple fields. How did you accomplish that?


I wanted to do some molecular biology work—genetic manipulation. I couldn’t do all of that sophisticated stuff, so I thought of alternative ways to conduct my research. I think of science as a process of questioning and wanting to discover more about the world.

Have you ever felt defeated in your research?


In every single project I’ve done, there’s always been a period of time that I thought I was going to fail. For a while, I had algae dying all the time, but I figured it out, and when I’m successful, it makes up for the frustration.

What are your plans for the next decade?


I’m going to MIT in the fall, and in 10 years, I’ll probably be pursuing a post-doctorate or Ph.D. and looking for a teaching position. I want to be a professor and work on my research.

Can you see more work on algae in your future?


I’m pretty proud of my artificial-selection idea to increase algae oil yields. It seems to be working, and I think it’s something new.

Read more: Meet the High School Student Making Algae Biofuel Better – Popular Mechanics

California Rules That Chevy Volt Pollutes More Than VW Diesels

July 17, 2013

This story is brought to you by Gas 2.0

According to the California Air Resources Board (CARB), Chevrolet’s upcoming Volt is an ultra-low emissions vehicle, or ULEV–which is great, until you realize that tailpipe emissions from Volkswagen’s line of TDI diesels, Toyota’s Prius and Honda’s full line of Hybrids are (per CARB) significantly cleaner.

Chevy’s Volt performed well in most categories, but not concerning carbon monoxide. CO limits for SULEV status is 1.0 grams per mile (below) while ULEV is 2.1 g/mi. Volt produces 1.3 g/mi.

To be fair, CARB requires that these tests must be completed with the car’s ICE (internal combustion engine) running, and since the Volt theoretically doesn’t need to burn any gasoline on short drives it doesn’t benefit from its electric-only abilities in this test … although the same could be said of Toyota’s Prius which performed significantly better than the Volt in the same test, earning the Prius a better CARB rating.

There are, I am sure, dozens of ways to interpret this data, but (to me) this news–along with the Cruze’s “reduced” mpg numbers and the Volt’s “outing” as a much more conventional hybrid–seems like another chink in the armor for the new GM.

For those of you who’d like to deep-dive into the mathematics involved, you can CLICK HERE to check out the full CARB report (in PDF format).

SOURCE: California Air Resource Board, via

Read more: California Rules That Chevy Volt Pollutes More Than VW Diesels – Chevy Volt vs. Diesels – Popular Mechanics

10 Hybrids That Teach Their Drivers to Save Fuel

July 10, 2013

Infiniti M35h Hybrid

This car takes driver coaching to the extreme, with an Eco mode that varies the resistance on the gas pedal to encourage you to accelerate slowly. The M35h will also count and display all the miles that the car has driven on electricity alone. In our test car’s case, it was more than 2000 miles for the life of the car at a time when the Infiniti had been driven 16,000 total miles. That certainly makes you feel good as a driver: It means 1 out of every 8 miles we drove in the Infiniti burned no gasoline. The dash has a graph that displays six 2-minute intervals of fuel-economy performance, showing the driver how he’s driven in the past 12 minutes and how much electricity he’s regenerated, in watt-hours. We averaged around 30.


Honda Will Recycle Rare Earths in New Hybrid Car Motors

July 3, 2013

In just a few months, Honda’s rare earth metal recycling program rapidly morphed from a lab curiosity to a corporate banality (in a good way—when experimental technologies become run-of-the-mill.). Now the Japanese automaker is taking the next step. Today, a little more than three months since Honda announced a plan to salvage those pricey materials from used nickel-metal-hydride batteries, the company says it will repurpose those rare earths in future hybrid vehicle motors.

Announced back in March, Honda’s recovery process—developed in tandem with Japan Minerals & Chemicals Co., Ltd. (JMC)—is reportedly capable of extracting as much as 80 precent of the rare earth metals found within a nickel-metal-hydride battery, resulting in a metal that’s 99 percent pure. Before it developed this extraction prodecure, Honda had been melting down the batteries and using the scrap in stainless steel. Shortly thereafter, the automaker began extracting metals on a commercial scale, reusing the newly-extracted metals in new batteries and “a wide range of Honda products.”

Now, with the help of JMC and TDK Corporation, Honda plans to reuse those same rare-earths in magnetic motors powering future hybrid vehicles. The manufacturing process is already in place—the three companies are just waiting for a larger, more stable supply of used batteries. Honda’s only source of these batteries currently is a voluntary battery donation program, and is actively looking to secure a more robust supply—assumedly through an increase of donations or some sort of arrangement with salvage yards. With a healthy volume of used cells, JMC estimates that at maximum capacity, their plant could produce as much as 400 tons of rare earths per year. By comparison, U.S. rare-earth miner Molycorp produced more than 19,000 metric tons of rare earths by the end of 2012.

Honda is far from the only car manufacturer that’s increasingly conscious of its rare earth use. Last fall, Nissan began implementing new magnets that shaved the use of heat-resistant rare earth dysprosium by 40 percent, while GM demonstrated that Chevy Volt batteries could be reused to provide homes with off-grid back-up power. Given that demand for the rare elements could jump as much as 2600 percent over the next 25 years according to one MIT study—and China now controls 97 percent of the market for these critical elements—companies will need even more innovative ways to keep costs down to keep EVs economical. Otherwise consumers might as well opt for a diesel.

Read more: Honda Will Recycle Rare Earths in New Hybrid Car Motors – Popular Mechanics

Auto Industry Comes to Aid of Oklahoma Storm Victims as Relief Efforts Continue

June 24, 2013
By Auto Remarketing Staff

Hyundai Motor American revealed it is committing $200,000 to Oklahoma tornado relief efforts through a donation to the American Red Cross.

“The massive devastation caused by last week’s tornado in Oklahoma calls for wide-scale recovery efforts and Hyundai pledges to do its part,” said John Krafcik, president and chief executive officer of Hyundai Motor America.

“Our thoughts are with the entire state of Oklahoma and especially those who lost loved ones. We commend everyone on the ground providing tireless efforts to help affected families and we hope this donation will aid in supporting their ongoing work,” he continued.

And VW Credit Inc., the captive finance partner of Volkswagen and Audi in the U.S., and the Volkswagen Credit South Central Region have donated $10,000 to the Automobile Dealers’ Association Car Dealers Care Foundation.

Officials explained this donation will provide direct financial assistance to multiple Volkswagen Group dealer employees impacted by the Oklahoma storm.

“The Car Dealers Care Foundation will provide immediate and tangible benefit to our employees,” said Andrew Stuart, president and CEO, VCI Credit  Inc. “Therefore, we are pleased to be able to donate $10,000 to the foundation to aid in the recovery from these devastating storms.”

On top of the allotment for dealership employees, The Volkswagen of America Foundation made a donation of $250,000 to the American Red Cross and Habitat for Humanity to assist with the disaster relief efforts in Oklahoma.

This donation will help cover costs of shelter, food, recovery and other assistance to families affected by the tornadoes.

VW of America is also matching funds  to any employee donations made to the American Red Cross, Habitat for Humanity or the organization of their choosing.

Lastly, dealer solution company HookLogic is offering discounts and help for dealers in affected areas whose businesses were damaged by the tornadoes.

The company explained they will offset the monthly fees and incentives for the next three months for these parties.

“If your Oklahoma-based dealership isn’t directly affected, you can pass these savings along to the most appropriate local charity that needs it the most,” officials added.

“We know how greatly this tragedy is impacting our customers and industry friends. We commend those that have stepped up to help those impacted by the tornadoes, and hope that this support effort proves helpful to those of you that may have been affected,” they continued.

Read more: Autoremarketing | Auto Industry Comes to Aid of Oklahoma Storm Victims as Relief Efforts Continue

Used Wholesale Prices Drop to 3-Year Low

June 17, 2013
By Staff Writer Sarah Rubenoff


Kelley Blue Book has reported that used-car auction values have reached a three-year low. After the 2008 recession and the consequential drop in off-lease supply, news like this has been a long time coming for dealers.

In fact, KBB senior market analyst for automotive insights Alec Gutierrez said, “This year started at a three-year high, but with no strong appreciation in Q1, auction values began an early decline in April and since have declined below levels seen in 2012 and 2011.”

But since there have been lulls in the strength of auction prices before during the past few years only to rise again, Gutierrez offered some good news for dealers regarding the rest of 2013.

“We expect this depreciation to continue through the remainder of the year, with year-end values no more than 3 to 5 percent below where they ended in 2012,” he said.

And as we approach June, only a few segments “are maintaining a positive value for the year,” KBB shared.

First, since the housing market is improving and construction is on the rise, midsize pickup trucks are a bit pricier in the lanes, Gutierrez reported. This segment saw a 2.2-percent increase in auction prices this month.

Also, as a seasonal trend and summer approaches, the sports car segment “remains ahead of the curve” for auction prices, rising by 2.9 percent in May.

The warmer weather is “making coupes and convertibles more attractive to summer buyers,” Gutierrez said.

As 2013 got underway, gas prices were high, and consumers were bracing themselves for rates of $4 per gallon and higher.

But now, the tides have turned.

“Hybrid vehicles have fallen the most year-to-date, with a nearly 9 percent decline from where the segment started in January,” Gutierrez said. “This drop can be attributed to the fairly stable fuel prices seen in the first quarter.”

Hybrid prices have dropped 8.9 percent this month as gas prices stabilize.

Editor’s Note: For more analysis on May auction price trends, see Monday’s Auto Remarketing Today e-newsletter.

Read more: Autoremarketing | Used Wholesale Prices Drop to 3-Year Low

Saab Automobile Parts North America Added to eBay Motors Seller Program

June 10, 2013

Although new models no longer are being manufactured, eBay Motors recently added Saab Automobile Parts North America to its seller program so genuine parts, accessories, technical support and repair service will be available “for years to come,” according to site officials.

The site highlighted that the addition of SPNA continues to bolster eBay Motors’ continually growing parts and accessories business.

Through the SPNA eBay store, Saab owners have an option for genuine accessories, hard to find, and limited availability parts.

“Whether you’re searching for interior parts to a classic 1986 900 convertible, 1995 9000 suspension components, or side moldings for a newer 2011 9-5, the store will provide everything Saab owners need to keep their cars running and looking as the factory intended,” eBay Motors officials said.

And as SPNA chief executive officer Tim Colbeck told the eBay Motors Blog, “Our eBay partnership provides a great parts resource for those who own, repair and restore Saab vehicles.”

Read more: Autoremarketing | Saab Automobile Parts North America Added to eBay Motors Seller Program

Which Vehicles Avoid Downward Price Impact Amid Heavy Lease-Return Volume?

June 3, 2013
By Auto Remarketing Editor Joe Overby

The rising tide of off-lease volumes looks like it will stick around for the next few years, and the influx of supply has already been downwardly impacting used-vehicle values in the opening half of 2013, according to’s Trade-In Marketplace.

That is, with one huge exception.

Putting values on an estimated 8,000 to 10,000 used units each day, data analysis from Trade-In Marketplace indicates that TIM Instant Cash Offers have dropped hundreds of dollars this year.

(The TIM Instant Cash Offer is a guaranteed price given to the consumer for his or her trade that’s good for 72 hours;  the shopper can use this offer to put toward buying a vehicle or simply take home in a check)

More specifically, since Jan. 1, there has been average decline of $700 on these offers, according to a report provided by Trade-In Marketplace director of operations Juan Flores. The year-over-year drop is even steeper at $1,100.

What’s more, since April 1 alone, there has been an average drop of $500 on TIM Instant Cash Offers. The report from Flores details some of reasons for this decline.

Among those he listed are as follows: the fact that dealers have been able to take care of their inventory needs via upstream channels; the sales rates for off-lease or program vehicles at auction has stayed below 40 percent; projections are for off-lease values to stay low; near-luxury (down $600) and luxury (down $1,200) segments are underperforming the market.

But there’s that one exception to these declines: fully equipped models coming off lease.

Specifically, the analysis indicates, these lease returns with amenities like technology packages, navigation, premium sound, leather and V6 engines are the ones bucking the trend.

Trade-In Marketplace has noticed fully equipped lease-returns have notched sales rates between 70 percent and 80 percent. What’s more, TIM Instant Cash Offers for these vehicles have climbed $200 on average, since April 1.

Conversely, standard-equipped editions of the same models have fallen $800 in the same time period. To illustrate this more concretely, Trade-In Marketplace provided the table below, which breaks it down model by model.

And in what’s great news for dealers, Flores said this TIM Instant Cash Offer increase “completely translates” to the retail sales side. In other words, dealers aren’t the only ones paying more for these cars – consumers will, too.

Read more: Autoremarketing | Which Vehicles Avoid Downward Price Impact Amid Heavy Lease-Return Volume?

Recycling Helps, but It’s Not All You Can Do for the Environment

May 28, 2013

Michael Stravato for The New York Times

A lone recycling bin alongside trash cans on a street in Houston, which recycles only about 3 percent of its trash.


LIKE most households, we recycle pretty religiously. It’s easy, though, because our town in suburban New York allows us to throw pretty much everything into one bin, and it gets picked up at the curb.

Recycling has become so automatic that if we’re out and there’s no place to recycle that soda can or bottle, it feels slightly illicit to just drop it in the trash. It’s like littering. You just don’t do it.

Lately, however, I started wondering — are we really doing anything with all this recycling besides feeling better about the stuff we buy?

Much of the discussion has focused on the economic impact. That issue has been batted back and forth with mixed results, although most experts now agree that cities have become more experienced and more effective — and therefore made it more cost-efficient — to recycle most products rather than dump them in landfills.

I’m more curious about what impact it has on other environmental behavior. And when I started looking at that more closely, I discovered that there’s an intense debate going on about this issue.

Recycling “is good civic behavior,” said Samantha MacBride, an assistant professor of public affairs at Baruch College, City University of New York, but it’s oversold as a panacea to a whole host of environmental ills, from overflowing landfills to global warming. “I wouldn’t say that people who do recycling feel they’ve done everything they can by participating, but they think there’s a lot more being achieved than there actually is,” she said. Nationally, said Professor MacBride, who is the author of “Recycling Reconsidered” (MIT Press, 2011), recycling prevents only about one-third of all trash from ending up in landfills.

Partly, she said, that is because people are not recycling everything they can. Partly it’s because the recycling model in most municipalities of picking up a bin with all the recyclables mixed together, especially the plastics, doesn’t work well.

“There’s a huge range of plastic materials and hundreds of different resins,” Professor MacBride said. “We need markets and processes to route them back into production and for the most part, those processes don’t exist.”

So some plastics are sent in bales to China and developing countries, and some are disposed of in landfills.

The emphasis, she said, has to be much more on regulating and recycling waste from manufacturers rather than consumer waste.

The other problem is that while “recycling is a wonderful thing to do if we’re comparing it to throwing stuff away, it has become a reward for consumption,” said Michael Maniates, a professor of environmental science at Allegheny College in Pennsylvania.

Gernot Wagner, an economist with the Environmental Defense Fund and author of “But Will the Planet Notice: How Smart Economics Can Save the World,” (Hill and Wang, 2011), agrees. “There’s a well-documented phenomenon known as single-action bias, where people do one thing and move on,” he said. “People don’t explicitly think, ‘I’ve recycled a cup and solved global warming,’ but rather once they’ve done an action like recycling, they feel consciously or subconsciously like they’ve done their part.”

Or as the Center for Research on Environmental Decisions, which is affiliated with the Earth Institute at Columbia University, says on its Web site: “Although recycling is important, it should be but one activity in a series of behavior changes aimed at reducing climate change. Switching to wind or other renewable energies, consuming less meat, conserving daily energy use and eating locally grown food are other effective ways to mitigate climate change, to name but a few. However, if individuals and institutions participate in recycling programs, they may be prone to the single-action bias and feel like they are already doing enough to protect the environment.”

Hold on there, said Allen Hershkowitz, senior scientist and director of the solid waste project at the environmental organization the Natural Resources Defense Council. “I’ve never dealt with a person or company who said, ‘We recycle so we don’t have to do anything else.’ It’s, ‘We recycle, what else can we do?’ ”

In his role as an adviser to the National Hockey League, Major League Baseball and the National Basketball Association, among others, he said he found that recycling was “an entry activity that leads to other activities such as buying recycled, energy effectiveness and fan education.”

Juliet Schor, a professor of sociology at Boston College, said that a number of European studies had demonstrated that people who bought green products or did some sort of similar “conscious consumerism” didn’t stop there, but continued on with other types of environmental activism.

A study conducted by Professor Schor and a graduate student, Margaret Willis, and published recently in The Annals of the American Academy of Political and Social Science, called “Does Changing Light Bulbs Lead to Changing the World? Political Action and the Conscious Consumer” looked at the concern that “individual action substitutes or ‘crowds out’ civic and collective action.”

Part of the study included 2,271 survey responses from people identified as being “conscious consumers” through an ecologically oriented nonprofit organization the Center for a New American dream. These respondents, largely white, female and highly educated, were asked questions like how often (ranging from “never” to “very consistently”) they engaged in such activities as choosing to drive less, contacting government representatives to express an opinion and buying local or green goods.

While the study didn’t look at recycling in particular, it found that those who chose to do individual green actions were also more involved in other broader political activism.

But Professor Schor said she was troubled that recycling “is what they’re teaching kids in school is going to save the world.”

And that was the point Professor MacBride wanted to emphasize.

“We don’t want to hear the bad side of recycling,” Professor MacBride said. “That’s a child’s view of the world. It’s time to grow up.”

So what can we do? Remember that there’s two other Rs — reduce and reuse — that are far too often ignored.

“As it has turned out ‘reuse’ is something that our kids learn in school as part of the ‘three Rs,’” Professor Maniates said. “But it has no resonance or meaning in mainstream or popular environmental politics and living. I brought my hangers to the dry cleaner and said, ‘Maybe you can reuse these’ and they said, ‘Sure, we’ll recycle them.’ ”

David N. Pellow, a professor of sociology at the University of Minnesota, offered a similar perspective. “I would urge people to buy fewer things, buy higher quality, fix things when they’re broken. I would encourage people to recycle as a last stage after they’ve done all these other things.”

And remember not to buy into single-action bias. As Mr. Hershkowitz said: “We are dealing with a gigantic problem and there is no one large undertaking that any individual or business or country can do to solve our ecological problems. It will take billions of people making highly intelligent ecological choices.”

Full article

A version of this article appeared in print on October 20, 2012, on page B5 of the New York edition with the headline: Recycling Helps, but It’s Not All You Can Do for the Environment.

Cities Get So Close to Recycling Ideal, They Can Smell It

May 20, 2013

PORTLAND, Ore. — Stephanie and Matt Murphy plan on using cloth diapers instead of disposable ones once their first baby arrives next month. They want to be good environmental citizens and reduce what they send to landfills, but there is another incentive, too.

“It’ll be nice not to have it sitting out there in the trash,” Ms. Murphy said. “That’s the main reason we’re doing it: to improve the odor of Portland.”

Just when their infant girl is due to arrive, Portland will be experiencing its first summer of biweekly garbage pickup. The change to every other week, introduced in cool weather last fall along with a weekly collection for food scraps, has reduced the amount of garbage that this progressive city is shipping to landfills by 44 percent.

The experience has not been entirely smooth. Since the garbage pickups were spaced out, the city’s main recycling company has complained that more garbage — disposable diapers included — is showing up in recycling bins. Residents complain about strong smells from garbage that has stewed for two weeks in the driveway.

Yet while some grumble, many say the inconveniences, and occasional startling whiff, are prices they are willing to pay to live on the leading edge of recycling.

“It was fuller and stinkier, but for the overall sake of the mission, we were willing to deal,” Penelope Miller, a resident with a 2-year-old daughter, said of her trash can.

Pioneers like Portland, Seattle and San Francisco have become so good at waste diversion that it is becoming harder to get much better. San Francisco reuses a whopping 78 percent of what enters its waste stream, compared with the national average of 34 percent.

As some press toward a goal of “zero waste,” the challenge is asking residents to conquer what officials call “the ick factor” of organic waste, endure fewer garbage pickups, become more sophisticated sorters and live without things like plastic grocery bags and polystyrene containers for their takeout food.

At the same time, the cities are exploring novel solutions for recycling challenging materials that take up relatively far more space at the dump than they did before recycling took hold. Those targets include construction debris from small haulers, complex plastics, polystyrene foam and the smelliest of the smelly: cat litter, dog poop and diapers.

“We have the infrastructure in place that could theoretically take us to 85 percent,” said David Assmann, the deputy director of San Francisco’s Department of the Environment. “The challenge is going to be that last 15 percent. We don’t have a blueprint yet that says exactly how we’re going to get to zero.”

The march to this moment has taken more than three decades. It began with newspaper and cardboard recycling in the 1970s; expanded to glass, aluminum, plastics and other materials; and is now conquering the last relatively easy-to-divert target: food scraps and yard debris that can be turned into compost. In some cases, the compost it creates is sold or given right back to the residents who threw it out.

The West Coast became a leader in part because it has easier access to markets in Asia that buy recyclable materials like paper and plastic. It also has significantly higher landfill costs than many other regions.

The leading cities have long traditions of environmental progressivism and are relatively small, with 800,000 or fewer residents apiece. Portland and Seattle in particular have many single-family houses, where the most responsible recycling takes place.

This summer, Seattle is opening a mammoth new transfer station in an industrial area south of downtown. With a far larger floor area, it will be able to sort waste more thoroughly, including construction debris.

The building puts a bright face on what some people might otherwise deem a dirty industrial endeavor. Old street signs decorate its entrance, a former drawbridge is a sculpture out front, the landscaping is irrigated with captured rainwater, and waste is misted to keep odors down. Windows allow abundant natural light.

“People who have had a hard time finding their transfer station aren’t going to have a hard time now,” said Juwan Williams, a scale attendant for 18 years at the gritty old South Transfer Station. “You can see this place from space.”

Seattle requires composting as well as recycling. Dick’s Drive-In, a beloved local burger chain that has been around since 1954, provides multiple bins with photographs clarifying for customers which piece of waste goes where.

“A shake is all three,” said Eli Hays, who works at the restaurant’s Wallingford neighborhood location. “The lid is recyclable, the straw is garbage, and the cup is compostable.”

Not everyone supports the mandates.

Chris Baldwin, a Dick’s regular, said he had “issues with being told I have to recycle.” Turning to three colleagues who had joined him for a late lunch spread across the bed of a pickup truck, he said, “We wait until Seattle police go by, and we throw it all in the garbage.”

Next month, Seattle will begin a pilot program for biweekly garbage pickup. By 2018, it wants to provide some neighborhoods with a fourth curbside bin for diapers and pet waste. The feces would be placed in anaerobic digesters to produce power.

“It doesn’t look any weirder now than collecting food waste looked weird to us 12 years ago,” said Tim Croll, the head of the solid waste division of Seattle Public Utilities.

Still, there are aggravations for trash handlers.

In Portland, the move to collecting food scraps added to a problem with sea gulls at one of the city’s main transfer stations. In January, a falconer was hired to patrol the site with three falcons to deter the gulls.

“When we started, there were about 400 birds,” said the falconer, Kort Clayton. “Today, the average is less than a few each day.”

Mr. Clayton noted that the gulls had easy pickings in the piles of food scraps but flocked to the garbage as well — evidence that some residents and businesses are not separating their waste. “There’s still food in the garbage,” he said.

And the week after Portland switched to biweekly garbage collection on Oct. 31, Far West Fibers, which handles more than 70 percent of the city’s recyclables sorting, saw a 50 percent increase in the amount of garbage in the weekly recycling loads, said the company’s president, Keith Ristau.

While dirty diapers make up only a small amount of the contamination, he said, “that doesn’t make it any less disgusting” for workers at the recycling plant.

“They have to stop the line and pull the diaper off,” Mr. Ristau said. “You can’t really grab it when it’s going 150 feet a minute on the conveyor belt.”

For Joe Gatto, a driver for Portland Disposal and Recycling for the past 13 years, the new nemesis on his biweekly garbage route is the steep rise in cat litter.

“It smells really bad,” he said. “And you get the added negative that it’s really heavy.”

Full article

A version of this article appeared in print on June 28, 2012, on page A14 of the New York edition with the headline: Cities Get So Close To Recycling Ideal, They Can Smell It.