Pleistocene bones abound beneath the Fairmead landfill near Chowchilla. See them at the Fossil Discovery Center of Madera County. Photos by Andrew Alden

My previous side trips from I-5 have involved rocks, but that's not all there is to geology. This suggested route, an alternative to taking I-5 straight south to Los Angeles, will expose you to the southern Great Valley's hydrology and many excellent, recently excavated fossils.

Start by exiting at Santa Nella — not to patronize the garish set of businesses there, but to take state route 152 east. You'll go all the way across the valley to Route 99, then south from there to the "Grapevine".

The first thing you'll notice, if you haven't already, is the profusion of canals in the Valley. They come in all sizes, ranging from the Edmund G. Brown Aqueduct (that's the first one you cross) down to uncountable numbers of field ditches. There are natural streams, but most of the water you'll see is in canals. This one runs parallel to the San Joaquin River about 6 miles west of Dos Palos Y.

Right next to it, the river that gave its name to the San Joaquin Valley was a sandy ditch in March during the rainy season. In good weather you'll be able to see mountains wherever you are, either the Coast Range on the west or the Sierra Nevada on the east (as seen here). I believe that there is no place in California where mountains are not visible if the air is clear.

The far end of route 152 meets Route 99. I recommend the old-timey charm of Chowchilla just north of here for a road stop, but otherwise you'll turn south on 99 and take the very first exit to the Fossil Discovery Center of Madera County.

Photo courtesy Tsing Bardin

The center is across the road from a sanitary landfill, and for a good reason: in 1996, diggers at the new Fairmead landfill uncovered a complete mammoth tusk. Soon it was realized that the site contained a world-class Irvingtonian fossil fauna dating from the mid-Pleistocene about half a million years ago. (There's a Bay Area connection here: the Irvingtonian is named for the wonderful bone beds unearthed in the East Bay's Irvington district during freeway construction in the 1940s.)

A paleontological foundation was set up and scientific ties established at nearby Cal State Fresno. Whenever the landfill operators open up a new pit, fossil scientists are on hand to harvest what they can. Bones of mammoths, wolves, sabertooth cats, horses, camels, ground sloths and many smaller creatures are stockpiled and studied at leisure between digs. The Fossil Discovery Center opened its doors in late 2010 and makes an excellent visit whatever your level of interest or expertise. Its outdoor "Pleistocene Water Source" exhibit makes it easy to imagine the lush scene in ancient times.

You can sit out back, next to the fossil washing station, and cast your eye over the surrounding land. I was told that the center has options on some of this acreage, where thousands more fossils surely lie in wait.

Eventually you'll need to return to 99 and resume your journey. Another stop you should consider is in Bakersfield, where less than 5 miles east of the road on Stockdale Highway is the city's gracious new Riverwalk Park on the Kern River, which is still a vigorous stream here.

Bakersfield has a lot going on. Another spot to consider visiting is the Buena Vista Museum of Natural History, home of superb fossils from nearby Sharktooth Hill.

Landfills, like this one at Hunter’s Point, produce methane, which can be used for electricity and fuel. Photo: kqedquest.

Trash that ends up at a landfill is the ugly stepsister of hipper, cooler compostable kitchen scraps and recyclable bottles and cans. But landfill trash has more of a future than you might think. As garbage decomposes, it gives off methane. Methane, when floating around in the atmosphere, is a harmful greenhouse gas; it traps 20 times more heat than CO2. But methane’s other moniker is natural gas, and is an important energy source. Methane from landfills can be captured and used to generate power and fuel vehicles—often the very same garbage trucks that brought the trash to the landfill in the first place.

Landfills are not just giant heaps of rotting trash. At the base and sides of a landfill, the trash is separated from the natural world by thick plastic liner, which prevents the effluvia from decomposing garbage from entering the environment and contaminating the groundwater. The trash itself is strategically stacked in layers of cells—landfills can be hundreds of feet deep. Within the landfill, different microbes break down the trash via anaerobic digestion. The microbes produce methane gas as a waste product. There are other gases produced too; this mix of gases produced by anaerobic microbes is called biogas.

Old landfills are punctuated by pipes that collect the biogas, which is then burned to prevent the gas from entering the atmosphere (and prevent the neighbors from smelling the stink). Open flares are just what they sound like—little burning flames of methane. Closed flares filter out the contaminants before the smoke is released. Flaring the biogas at the landfill is probably the most common way of dealing with it. But it is an unfortunate waste of a potentially valuable fuel source.

Newer landfills are built with methane collection in mind from the early stages of construction. Pipes can be buried in the landfill as it is filled with trash. Pipes can also be placed in wells drilled through the trash after the landfill has begun to be filled. A vacuum system collects the gas as the microbes produce it. The amount of gas a landfill produces depends on the volume of trash and the age of the landfill; eventually, the gas production will peak and then begin to taper off. Today’s big landfills, however, can produce biogas for decades.

The methane collected from landfills can generate electricity via a turbine or internal combustion engine. Often some of the electricity is used at the landfill to run equipment, and the rest is sold to the local utility.

Methane from biogas can be converted to compressed natural gas, which can be used as fuel for vehicles. In some areas, regulations stipulate that large fleets of vehicles (with more than about 50 trucks) are required to run on clean fuel. When biogas is converted to compressed natural gas, the vehicles can refuel at the landfill. Building a system that converts biogas into compressed natural gas is a big investment, but the fleet saves on fuel costs for decades. These kinds of biogas systems can be installed at anaerobic waste digesters at places like wastewater treatment plants, not just landfills.

Altamont Landfill has taken things a step further, converting landfill biogas into liquefied natural gas. First, impurities are removed, and then the gas is cooled down to a liquid state. This liquefied natural gas is used to fuel Waste Management’s garbage trucks. Altamont Landfill’s liquid natural gas system is the largest in the world.

Obviously, we should buy only what we need, recycle what we can, and be careful to compost everything that’s compostable. But it’s nice to know that something useful can come from plain old trash.

A Gold Rush-era ship is excavated from historical fill at a San Francisco construction site in 2005. Photo by Andrew Alden.

Humans have been making land for thousands of years. Lately we have gotten better at it, but nature has a head start of a few billion years, and we don't work with nature's infinite care.

On the largest scale, land grows because volcanoes and tectonic movements elevate rocks above sea level. The Bay Area has no volcanoes at present, and the basic framework of our terrain is tectonism organized around the San Andreas fault system. On the scale of human history, that's too slow to be relevant. For growing new land, erosion and deposition matter more to us.

New land grows naturally around the Bay as wetlands capture sediment washed in with the seawater. Unfortunately for builders, it's soft black mud and it's barely at sea level. And unfortunately for shippers, "bay mud" bars vessels from approaching the shore almost everywhere except around steep bodies of bedrock, like Yerba Buena and Alcatraz Islands. When Gold Rush settlers came here to stay, making bay mud into useful land—reclamation—was one of their chief concerns.

In San Francisco there were so many abandoned ships in the harbor that many were simply scuttled and buried in fill—dredged sand and mud from the Bay, mostly, along with waste rock and debris. We dig up the old ships occasionally while building around the Financial District.

More land was made elsewhere simply by diking off sections of the Bay, letting it dry out, and putting it to use growing crops or harvesting sea salt. (Today the salt ponds of the South Bay are carefully being restored to working wetland.) In San Mateo County, levees were built to create Brewer's Island around the turn of the last century. The dry bay mud served as hayfields and salt ponds until T. Jack Foster set out to turn Brewer's Island into a complete planned city. The creation of Foster City in the 1960s was overseen by geotechnical engineers, but the basic method was age-old: dredge, dump, drain.

The U.S. Geological Survey has mapped artificial land along with all the other geologic units around the Bay. The majority of this reclaimed land is in the central Bay, in San Francisco and Oakland.

Major land reclamation areas of the central Bay are shown in purple, marked afbm for artificial fill on bay mud. Map from USGS Open-File 00-444. Click to view it at full size.

Reclaimed land shows its weakness in earthquakes. In the 1906 quake it was widely noted that buildings placed on "made land" were prone to failure. Nonetheless the city's rubble was used for fill at the site of the 1915 Pan Pacific Exposition, which later became developed as the Marina district. In the 1989 Loma Prieta quake the Marina had the deadliest damage in the city. Likewise, the Cypress section of Interstate 880, in west Oakland, failed where it crossed old fill. In San Francisco the notorious Embarcadero Freeway, also built upon old fill, was torn down shortly after Loma Prieta, before it could fail. Our areas of fill, old and new, will continue to be tested by earthquakes while our reclamation practices continue to improve.

For geology enthusiasts, Oakland's reclaimed land has given us an unexpected treat, seen in the new Middle Harbor Park.

A replica seawall recycles rock from an early land reclamation project: the port of Oakland. Photo by Andrew Alden.

In the 1880s, early in the creation of Oakland's harbor, a pair of "training walls" was built to guide the tides into scouring the ship channel clean. The project required lots of large boulders, and every quarry along the Bay Area shoreline was recruited to supply the stones. When the old north training wall was demolished in 2001, some of the best rocks were set aside. These were made into a replica pier, nicely laid down in drystone masonry, that displays excellent specimens of Bay Area rock types.

In California, 82 percent of cans and bottles are recycled.

Monet Coleman, I think it’s fair to say, is not your average dyed-in-the-wool, tree-hugging environmentalist. She says until recently, “I never thought to recycle. Ever.”

But a couple months ago, Coleman ran out of gas money and was late to her classes at nursing school. She wasn’t finding part time work. And that’s when she started getting a lot more enthusiastic about garbage. A few weeks ago, she made eighty dollars collecting cans and bottles from family members’ homes and around her complex, and bringing them to Alliance Recycling, a buy-back center in Emeryville.

“Recycling is making the way for me now,” she says. “I guess it’s my job.”

That’s true of a lot more people than it used to be, says Jay Anast, who owns Alliance Recycling. A few years ago, the only people who came in here were were pushing shopping carts. Now, he’s seeing late model Toyotas.

“Since the economy burst,” says Anast, “we’ve seen more of your middle-class types. We’re getting quite a bit of that now.”

A lot of this stuff would have been put out on the curbside and recycled anyway. But some of it wouldn’t have, which is one reason that recycling rates across the country have soared, according to Jerry Powell, who edits Resource Recycling Magazine, based in Portland, Oregon.

Powell says nationwide, 58 percent of aluminum cans are recycled, the highest rate in 11 years. Soon, he predicts, more cans will be recycled than ever before.

Here in California, the rates are even higher, thanks in part to the state’s bottle bill, which puts a five-cent redemption value on every aluminum, glass, and plastic beverage container, from soda cans to water bottles. (You can see which 11 states in the US have bottle bills on this map.) Last year, 82 percent of cans and bottles sold in California were recycled. That’s up from 55 percent in 2003.

People are recycling vastly more than they used to. It’s a big shift. Recycling was once the icing. Now, it’s the cake. And no where is this change as stark as it is in San Francisco, where the city now recycles or composts almost 80 percent of its waste, sending 30 percent to the landfill. “Fifteen years ago, it was completely the opposite,” says Powell.

As a result of both high recycling rates, and increasing scarcity of natural resources, recycling is a bigger part of our economy than it has ever been before. Entire industries, here, and abroad, literally can’t survive without those bottles, cans, and cardboard boxes you put on the curb, or bring to a recycling center.

“If the total recycling industry said ‘stop,’, says Powell, “ you wouldn’t have an American car made. They’re mainly made out of recycled steel. You wouldn’t have beverages as we have today. You’d have half the newspaper, because you could only get half the paper. Recycling is now just part of the normal economic order.”

But when people start recycling even more and throwing away less, there are growing pains.

For example, Berkeley. For years, the city billed residents for garbage pick-up. Recycling was free, as a way of encouraging people to do more of it. But when people started throwing away less garbage, the city’s revenues dropped. The city has raised garbage rates three times in as many years.

And then, consider the landfills.

Under a baking blue sky at Altamont Landfill, near Livermore, a bulldozer rakes over the days’ trash. It’s been trucked up here from San Francisco and Alameda County and is now being crushed into the hillside.

Ken Lewis, area director for this landfill, and I stand on a massive pile of old garbage. It contains almost every scrap of trash tossed by San Francisco residents for the past 30 years.

In the industry, it’s called “municipal solid waste,” says Lewis, “paper, organic materials, plastics, film plastic bottles, a lot of materials you’d find in any household that’s been thrown out over the last years.”

But times have changed. Almost every one of those things is now recyclable, which means, more and more, they aren’t ending up here. Add the fact that, in a recession people buy less stuff, and you have a landfill that’s taking in about two thirds of what it accepted in 2000, says Lewis. He says volumes are way down from San Francisco, Alameda County, and virtually every other jurisdiction as well.

Once upon a time, California’s politicians warned about a landfill crisis. Now, the state finds itself with enough existing landfill space to last nearly 50 years.

But it also means that, as garbage sent to landfills, decreases, the companies that run the landfills must find ways to diversify their businesses. They must find ways to make a profit off of not throwing stuff away.

Houston-based Waste Management, which owns the Altamont landfill, is a good example. Over the last few years, the company has been buying up composting facilities across the country. It runs more recycling operations than any other single company.

And a couple years ago this landfill took a step ahead of any other such site in the country. It opened up the first landfill-gas-to-liquid-natural-gas facility in the country. This way, the company can benefit from all those rotting banana peels inside the landfill. As the garbage decomposes, it lets off natural gas, including methane. The landfill has built a facility to suck these gasses out of the landfill, and send them to a processing facility, where they’re converted into liquid natural gas.

This gas now fuels Waste Management’s trucks.

37.6818745 -121.7680088

Here's one silver lining to a slow economy: High recycling rates. Americans are wasting far less, and recycling far more. Nowhere is the trend as strong as in California. As Amy Standen reports, this change is sending ripple effects throughout the economy.

Monet Coleman, I think it’s fair to say, is not your average dyed-in-the-wool, tree-hugging environmentalist. She says until recently, “I never thought to recycle. Ever.”

But a couple months ago, Coleman ran out of gas money and was late to her classes at nursing school. She wasn’t finding part time work. And that’s when she started getting a lot more enthusiastic about garbage. A few weeks ago, she made eighty dollars collecting cans and bottles from family members’ homes and around her complex, and bringing them to Alliance Recycling, a buy-back center in Emeryville.

“Recycling is making the way for me now,” she says. “I guess it’s my job.”

That’s true of a lot more people than it used to be, says Jay Anast, who owns Alliance Recycling. A few years ago, the only people who came in here were were pushing shopping carts. Now, he’s seeing late model Toyotas.

“Since the economy burst,” says Anast, “we’ve seen more of your middle-class types. We’re getting quite a bit of that now.”

A lot of this stuff would have been put out on the curbside and recycled anyway. But some of it wouldn’t have, which is one reason that recycling rates across the country have soared, according to Jerry Powell, who edits Resource Recycling Magazine, based in Portland, Oregon.

Powell says nationwide, 58 percent of aluminum cans are recycled, the highest rate in 11 years. Soon, he predicts, more cans will be recycled than ever before.

Here in California, the rates are even higher, thanks in part to the state’s bottle bill, which puts a five-cent redemption value on every aluminum, glass, and plastic beverage container, from soda cans to water bottles. (You can see which 11 states in the US have bottle bills on this map.) Last year, 82 percent of cans and bottles sold in California were recycled. That’s up from 55 percent in 2003.

People are recycling vastly more than they used to. It’s a big shift. Recycling was once the icing. Now, it’s the cake. And no where is this change as stark as it is in San Francisco, where the city now recycles or composts almost 80 percent of its waste, sending 30 percent to the landfill. “Fifteen years ago, it was completely the opposite,” says Powell.

As a result of both high recycling rates, and increasing scarcity of natural resources, recycling is a bigger part of our economy than it has ever been before. Entire industries, here, and abroad, literally can’t survive without those bottles, cans, and cardboard boxes you put on the curb, or bring to a recycling center.

“If the total recycling industry said ‘stop,’, says Powell, “ you wouldn’t have an American car made. They’re mainly made out of recycled steel. You wouldn’t have beverages as we have today. You’d have half the newspaper, because you could only get half the paper. Recycling is now just part of the normal economic order.”

But when people start recycling even more and throwing away less, there are growing pains.

For example, Berkeley. For years, the city billed residents for garbage pick-up. Recycling was free, as a way of encouraging people to do more of it. But when people started throwing away less garbage, the city’s revenues dropped. The city has raised garbage rates three times in as many years.

And then, consider the landfills.

Under a baking blue sky at Altamont Landfill, near Livermore, a bulldozer rakes over the days’ trash. It’s been trucked up here from San Francisco and Alameda County and is now being crushed into the hillside.

Ken Lewis, area director for this landfill, and I stand on a massive pile of old garbage. It contains almost every scrap of trash tossed by San Francisco residents for the past 30 years.

In the industry, it’s called “municipal solid waste,” says Lewis, “paper, organic materials, plastics, film plastic bottles, a lot of materials you’d find in any household that’s been thrown out over the last years.”

But times have changed. Almost every one of those things is now recyclable, which means, more and more, they aren’t ending up here. Add the fact that, in a recession people buy less stuff, and you have a landfill that’s taking in about two thirds of what it accepted in 2000, says Lewis. He says volumes are way down from San Francisco, Alameda County, and virtually every other jurisdiction as well.

Once upon a time, California’s politicians warned about a landfill crisis. Now, the state finds itself with enough existing landfill space to last nearly 50 years.

But it also means that, as garbage sent to landfills, decreases, the companies that run the landfills must find ways to diversify their businesses. They must find ways to make a profit off of not throwing stuff away.

Houston-based Waste Management, which owns the Altamont landfill, is a good example. Over the last few years, the company has been buying up composting facilities across the country. It runs more recycling operations than any other single company.

And a couple years ago this landfill took a step ahead of any other such site in the country. It opened up the first landfill-gas-to-liquid-natural-gas facility in the country. This way, the company can benefit from all those rotting banana peels inside the landfill. As the garbage decomposes, it lets off natural gas, including methane. The landfill has built a facility to suck these gasses out of the landfill, and send them to a processing facility, where they’re converted into liquid natural gas.

This gas now fuels Waste Management’s trucks.

Slideshow Producer: Kate Szrom

According to Sunset Scavenger Spokesman Robert Reed, San Francisco residents should have nothing but "film plastics" (like plastic bags from stores and dry cleaners) and polystyrene, aka Styrofoam.

But the life of a recycling ascetic ain't easy. First of all, it means learning the rules of your particular community, since recycling practices vary depending on where you live. Probably, It means forgoing juice boxes, disposable diapers, complicated, multi-material packaging. It means you've scraped out your cat food cans ("contaminated" recyclables are often tossed). If you're a paper shredder, you've put all the scraps into a paper bag labeled "shredded paper." (Tiny pieces of paper are too hard to collect – sorters usually landfill them.) In short, you've earned a PhD in recycling. (And if you think that's complicated, consider the Japanese.)

Some experts have argued that this is all too much trouble – that instead of aiming for zero waste, we should accept a certain amount of landfilling. Others say that the more citizens recycle, the more efficient the program becomes – hence the movement toward mandatory recycling. One point that nearly everyone seems to agree on is that products on the shelves must be designed to be more easily recyclable than they are today.

Is This Recyclable?

On that note, we interviewed two recycling experts: Mark Murray, director of Californians Against Waste, and Kurt Standen (no relation, amazingly to both of us), general manager of the Sacramento Recycling and Transfer Station. We came armed with six recycling stumpers, including a rubber boot, a juice box, and that much-maligned item of transport, the plastic bag. See what Standen and Murray had to say by clicking on the images below.

Listen to the Getting to Zero Waste radio report online.

37.741125 -122.375949

Humans produce 500 billion plastic bags annually.

In China, they recently banned it. Australia, Bangladesh, Ireland, Italy, South Africa,Taiwan, Mumbai and India have either banned it or discouraged its use by raising taxes. And on March 27, 2007, San Francisco became the first city in the USA to ban it from large grocery stores.

More people are ditching plastic bags on a local and national level with good reason: we produce about 500 billion plastic bags world-wide, and less than one percent of that is recycled.

A recent QUEST report shows that plastic bottles are straining our environment, too: each year the USA alone produces 50 billion plastic bottles. Some would say to switch from plastic to paper bags – but reports show that paper bags aren't the most sustainable solution.

Plastic can have a longer shelf-live than humans do: it can persist in the environment for anywhere between 20 to 1,000 years. But a 16-year-old from Waterloo, Canada figured out to decompose it in only six weeks.

Daniel Burd, a student at Waterloo Collegiate Institute, discovered the key to decomposing plastic bags for a school science fair. Needless to say, he won.

"Almost every week I have to do chores and when I open the closet door, I have this avalanche of plastic bags falling on top of me," said Burd to The Record, a Waterloo newspaper. "One day, I got tired of it and wanted to know what other people are doing with these plastic bags."

First, Burd decided to isolate the microbes that break down plastic in polyethelene plastic bags. Burd ground plastic bags into powder and created a solution to break it down using tap water and yeast. Six weeks later, he found that the plastic weighed 17 percent less than the control group.

Burd then isolated the effective strains that caused the degradation – Sphingomonas and Pseudomonas – and tried the experiment again, adding sodium acecate.

Six weeks later – as opposed to 1,000 years – the plastic decomposed by 43 percent.

For his final report, Plastic Not Fantastic, Burd wrote that his process of polyethylene degradation can be used for large-scale plastic bag biodegradation.

"As a result, this would save the lives of millions of wildlife species and save space in landfills," wrote Burd.

37.762611 -122.409719