Science and Technology Blog
This blog contains articles about science, technology and a life of faith.  Written by the rector of Grace, these articles first appeared as the trailer articles in the Weekly Grace email newsletter.

Garbage by the Numbers

In 1971 while in college, I helped create a community-wide recycling center (paper, glass, metals) for Rolla Missouri. We used a donated, abandoned grocery store and we repurposed donated agricultural conveyors and other equipment. Trash compactors were rebuilt and cleaned to use for paper and aluminum can compaction. I have recycled my household trash ever since.

The average American generates 1,600 pounds of trash per year. This means that in my adult life to date, my household as a typical American household would have discarded 135 tons of trash or about 10 full garbage trucks. This volume would fill a two bedroom apartment floor to ceiling with compacted trash. I estimate that we have recycled more than half of our household trash for more than forty years.

Residential trash contains materials that could easily be recycled by those in the household. This amounts to roughly 60% of the trash volume. The amount that American residential households ACTUALLY recycle is 13%. By contrast, Europeans recycle 50-64% of their residential trash. We have a long way to go.

Here’s a more vivid image – If you took the 72 million tons of Municipal Solid Waste that goes to the landfill every year across our land, the garbage trucks to transport that waste would be lined up bumper to bumper from here to the moon. We could shrink that by 60% if we only cared enough about future generations to do so.

On top of the recyclable trash, about half of our domestic food waste can be composted. This saves energy, reduces investment in sewage infrastructure and provides useful gardening soil. Studies vary in their measurements but 20-28% of American households actually compost some or all of the 36 million pounds of food waste they send to the dump each year.

It takes 20 times the amount of energy to create new aluminum from its ore (bauxite) than it does to melt an aluminum can and recycle it. For glass the number is about 3. For plastic it is about 1.6. Here are some more tangible ways to look at it: The energy saved in recycling ONE aluminum can could run a 14 watt CFL light bulb for 20 hours or power your desktop computer for 3 hours. Five 2 liter recycled PET bottles (mainly soft drink bottles), produces enough fiberfill to make a ski jacket. The energy saved recycling one glass bottle would run a 14 watt CFL bulb for 28 hours. Broken glass in the environment takes 1 million years to break down.

Manufacturing one ton of office paper products with recycled paper saves between 3,000-4,000 kilowatt hours of energy or about the entire output of the Muskogee power plant for one hour. Grace uses a ton of paper products every two years (most of which gets recycled).

If we really care about the “unborn” or those who come after us, we might ponder these numbers in prayer and resolve to do what we can about it. The future is literally in your hands.


Sometimes the bad comes with the good

Nobel Prize (chemistry) winner, Linus Pauling, once hailed the [economically feasible] development of synthetic fertilizer in the early 20th century as the most important technology of the 20th  century.  That is not an overstatement.  Affordable, synthetic fertilizer made with fossil-fuel generated energy forestalled the inevitable collision of population and food resources.  Demographers and biologists predicted a food catastrophe sometime in the late 20th century that never happened.  The reason – fertilizer.  US crop yields outstripped farms in the rest of the world by a factor of 10 to 20!  But there is a cost that we are beginning to pay for this chemical blessing.

Let me admit that in late January and February when I am tired of a brown landscape, the sight of luxuriant green winter wheat makes my heart leap and I look forward to the colors of life in a resurrected spring time.  Unfortunately, much of that lovely green color comes from various forms of nitrate (NO3) applied to the fields.

In the past few years, peer-reviewed studies throughout the Mississippi basin have shown that excessive amounts of fertilizer have been applied to agricultural fields and much of that excess has been accumulating in the soil.  No big deal right?

When excessive nitrogen is applied, the plants do not take it up and use it.  So the nitrate dissolves in water and runs off the field.  Here’s what happens next.

  • Mississippi basin runoff all goes into the Gulf of Mexico which now has a “dead zone” of 6,500 square miles (the size of Connecticut and Rhode Island combined) located off the coast of Louisiana and Mississippi. No fish can live in the dead zone because the nitrate causes a bloom in algae which then consumes all the oxygen in the water.  The technical term for this is hypoxia.  The economic term for this is no fishing industry.
  • Des Moines, Iowa and other towns in the Mississippi basin have been forced to spend millions of dollars upgrading their water treatment plants to reduce nitrate levels in drinking water to safe standards. (Remember Flint Michigan and lead?  This is just as bad.)
  • The same Des Moines water company is suing three upstream counties for failing to address harmful surface-water nitrate levels that are more than twice the US federal drinking water standard.
  • Nitrates are being found below the “top plow zone” which is one to three feet below the surface. We now know they will persist there for decades while slowly leaching into agricultural runoff water.
  • People who live in the Mississippi basin and who depend upon shallow, improperly constructed or improperly located water wells often have nitrate levels exceeding safe levels. This leads to a potentially fatal blood disorder in infants under six months called methemoglobinemia or “blue-baby” syndrome; in which there is a reduction in the oxygen-carrying capacity of blood.  The symptoms can be confused with other diseases and except in extreme cases (where the baby is actually blue), the disorder can be difficult to diagnose.  Many state public health agencies have not added this disease to their “reportable disease” index so accurate incidence records are difficult to find now.  Nonetheless many counties have information about this disease on their websites.
  • This last item is a chemistry argument of mine, but NO3 is pretty high on the electromotive force table. That means it will outcompete other trace elements (in their anionic forms) in the uptake by plants.  Long term this displacement of other important elements for human life could lead to various types of malnutrition like scurvy in 18th century British sailors (which was solved by adding citrus fruit to their diet).

Linus Pauling was certainly right in his assessment of an important technology.  But that was in the 1960s. Today we need to be smarter about our use of technologies of all kinds.  That would include taking the long term perspective and not just blindly label things universally good before we truly understand all sides of the issue.