Earthsky Interviews
Private: How long would it take to fill the Grand Canyon with trash?
02-20-2004 - Uncategorized
_DB:_ Well, if you add up all the non-hazardous waste from homes and businesses in the U.S. – all the used paper, food scraps, bottles, appliances, packing materials and so on – it amounts to about 230 million tons each year. That’s according to the U.S. Environmental Protection Agency. Some of the waste is recycled, composted or burned. But a little more than half goes straight into landfills.
_JB:_ To estimate how quickly we’d fill up the Grand Canyon, you have to make several assumptions – including the average height of the canyon and the average density of the waste. Experts at the U.S. Geological Survey conservatively put the canyon’s volume at about 40 billion cubic meters – or 52 billion cubic yards. Landfill experts say that in the U.S., we fill about a third of a percent of that volume in a year. So if we started throwing all of our trash into the Grand Canyon tomorrow – it would take about 300 years to fill it up.
_DB:_ In reality, the trash would settle and decompose over time, so it might take more like 400 years. No one knows for sure – there’s never been a landfill this deep. Four hundred years might sound like a pretty long time. But consider that it took several million years to create the Grand Canyon.
_JB:_ To see how we came up with the numbers, come to today’s show at earthsky.org. We’re Block and Byrd for Earth and Sky.
Calculations
Step 1: Determine the weight of waste that is landfilled each year in the U.S. To do so, begin with the weight of waste generated (229.2 million tons) and multiply by the fraction of waste that actually goes into landfills (0.557). (See source #1)
229.2 million tons X 0.557 = 127.664 million tons
Step 2: Convert the weight from tons to pounds. To do so, multiply the annual landfilled weight by 2,000 pounds/ton.
127.664 million tons X 2,000 pounds/ton = 255.329 billion pounds
Step 3: Determine the volume of waste landfilled in the U.S. each year. To do so, divide the weight of landfilled waste (255.329 billion pounds) by the average density of landfilled waste. That density can vary widely, but an average of 1500 pounds per cubic yard is assumed. This average density will increase over time as older waste is compressed by newer waste above. (See sources #2, 3 & 4)
255.329 billion pounds / 1500 pounds per cubic yard = 170.219 million cubic yards
Step 4: Determine the number of years to fill the Grand Canyon. To do so, take the volume of the canyon (52 billion cubic yards) and divide by the rate of landfill use (170.219 million cubic yards/year). (See source #5)
52 billion cubic yards / 170.219 million cubic yards/year = 305 years
Sources of data:
1. “Municipal Solid Waste in The United States: 2001 Facts and Figures,” by the U.S. EPA and Franklin Associates.
2. Jeremy O’Brien, Director of Applied Research at the Solid Waste Association of North America (SWANA).
3. Don Neller, Assistant Department Head, Los Angeles County Sanitation Districts, Whittier, CA.
4. Ray Huitric, Division Engineer, Los Angeles County Sanitation Districts, Whittier, CA.
5. U.S. Geological Survey. The information was relayed by Dennis Fenn, Center Director for the USGS Southwest Biological Science Center in Flagstaff, AZ.
What is “Waste”?
According to “Municipal Solid Waste in The United States: 2001 Facts and Figures,” by the U.S. EPA and Franklin Associates, “MSW – otherwise known as trash or garbage – consists of everyday items such as product packaging, grass clippings, furniture, clothing, bottles, food scraps, newspapers, appliances, and batteries. Not included are materials that also may be disposed in landfills, but are not generally considered MSW, such as construction and demolition debris, municipal wastewater treatment sludges, and non-hazardous industrial wastes.”
According to the EPA’s Office of Solid Waste, “Municipal Solid Waste (MSW) ? more commonly known as trash or garbage ? consists of everyday items such as product packaging, grass clippings, furniture, clothing, bottles, food scraps, newspapers, appliances, paint, and batteries.”
According to the National Solid Wastes Management Association, “Municipal solid waste (MSW), also known as garbage, trash, refuse and rubbish, is simply what is left of the products that we have used and no longer need. Whether it is yesterday’s newspaper, a banana peel, an empty beer bottle, or an old computer, our trash is just the effluence of our affluence. The United States Environmental Protection Agency (U.S. EPA) regulates the land disposal of MSW through the Resource Conservation and Recovery Act’s Subtitle D regulations. MSW does not include construction and demolition debris, hazardous, medical, and radioactive wastes, or other non-household and non-business refuse; therefore, this profile does not include those items.”
Rate of Waste & Dumping
According to “Municipal Solid Waste in The United States: 2001 Facts and Figures,” by the U.S. EPA and Franklin Associates, “During 2001, about 55.7 percent of MSW was landfilled, down somewhat from 56.3 percent in 2000.” (See page 14) The report also says, “In the United States, we generated approximately 229.2 million tons of MSW in 2001?a decrease of 2.8 million tons from 2000.” Therefore, the amount of MSW put into landfills in 2001 was 127.6644 million tons (or about 255 billion pounds).
According to the EPA’s Office of Solid Waste, “In 2001, U.S. residents, businesses, and institutions produced more than 229 million tons of MSW, which is approximately 4.4 pounds of waste per person per day, up from 2.7 pounds per person per day in 1960. … Currently, in the United States, 30 percent [of MSW] is recovered and recycled or composted, 15 percent is burned at combustion facilities, and the remaining 56 percent is disposed of in landfills.”
According to the National Solid Wastes Management Association, “323,812,000 cubic yards of MSW was landfilled in 1997.”
Density of Waste
According to the National Solid Wastes Management Association, “By volume, corrugated boxes, clothing and footwear, yard waste, food waste, wood packaging and newspapers occupy the most space in landfills. Aluminum cans and plastic bottles have the lowest landfill density (pounds per cubic yard). Glass bottles and food waste have the highest landfill density. An “average” pound of trash has a landfill density of 739 pounds per cubic yard.”
But other sources suggest that what goes into landfills is usually much denser than that. Jeremy O’Brien, Director of Applied Research at SWANA, says that the trucks that gather trash on city streets usually compact the trash to about 1,000 pounds per cubic yard in transit. Then, when the truck arrives at the landfill, it’s often compacted even more – sometimes to 1200 or 1400 pounds per cubic yard – before being dumped. Don Neller, Assistant Department Head, Los Angeles County Sanitation Districts, told me that most landfills end up with an average density of about 1,500 pounds per cubic yard and that at the bottom of some landfills, densities might approach 2,000 pounds per cubic yard.
So in our show, we started with the assumption that the density of landfilled waste begins at 1,000 pounds per cubic yard and that over time, it would compress and might eventually reach twice that density.
Grand Canyon Age
According to the Grand Canyon National Park web site, the canyon has “formed only in the past five or six million years.”
Grand Canyon Volume
The volume of the Grand Canyon is about 52 billion cubic yards or 40 billion cubic meters.
According to Dennis Fenn, Director of the USGS Southwest Biological Science Center in Flagstaff, Arizona, “As you can imagine, the response to this question depends a lot on certain assumptions. Our GIS folks took on this challenge this afternoon and determined that if one uses a 1400m elevation line for the top of your hypothetical “fill”, which is considerably below the North Rim elevation, but would assure that there was no spillage anywhere along the length of the canyon, then they calculate a Grand Canyon volume of about 52 Billion cubic yards. This would represent a conservative minimum volume measure for the Grand Canyon. If one assumes a higher elevation for the top of your theoretical “fill”, and thus did not worry that there would be some spillage in a few places along the canyon, then the calculated Grand Canyon volume would be even higher.”
Existing Canyon Landfills
By the way, the whole idea of a Grand Canyon landfill might sound far-fetched, but there are already small-scale versions being used today. For example, if you live in Glendale or Pasadena, California, your trash may go to Scholl Canyon Landfill. Since the 1950s, Los Angeles County has used several urban canyons as landfills. But in recent years, residents have opposed opening new canyons for landfills. Instead, they plan to build a rail system that will carry LA trash to remote desert sites over two hundred miles away.
More Resources:
“Municipal Solid Waste – Basic Facts”:http://www.epa.gov/epaoswer/non-hw/muncpl/facts.htm (U.S. EPA)
“Grand Canyon National Park”:http://www.nps.gov/grca/grandcanyon/ (National Park Service)
“How Old is the Grand Canyon?”:http://www.nps.gov/grca/grandcanyon/faq.htm#3 (National Park Service)
“SWANA (Solid Waste Association of North American)”:http://www.swana.org/
“Franklin Associates”:http://www.fal.com/ (a private company that is contracted by the EPA to do annual evaluations of solid waste in the U.S.)
“Municipal Solid Waste – Characterization Report”:http://www.epa.gov/epaoswer/non-hw/muncpl/msw99.htm (U.S. EPA)
“Scholl Canyon Landfill”:http://www.lacsd.org/swaste/Facilities/Open/schlcnyn.htm (Sanitation Districts of Los Angeles County)
“Rubbish! The Archaeology of Garbage”:http://www.uapress.arizona.edu/books/bid1369.htm (U. of Arizona Press)
“Use Less Stuff”:http://www.gristmagazine.com/grist/books/lilienfeld043099.stm (Grist Magazine)
“Are We History?”:http://www.zerowaste.ca/articles/column24.html (Review of Use Less Stuff by Toenail Environmental Services)
The following individuals were interviewed for today’s show. Our thanks to:
Dennis (Denny) Fenn
Center Director
USGS Southwest Biological Science Center
Flagstaff, AZ
Jeremy O’Brien
Director of Applied Research
Solid Waste Association of North America (SWANA)
Silver Spring, MD (although he works mostly from his home in Charlottesville, NC)
Ray Huitric
Division Engineer
Los Angeles County Sanitation Districts (a government entity)
Whittier, CA
Don Neller
Asst. Department Head (headed up the planning and permitting efforts for landfills)
Los Angeles County Sanitation Districts (a government entity)
Whittier, CA