Day 20 of 20: Field trip to the county landfill

What better way to conclude this 20-day challenge than to take the day off from work to tour the local landfill. 

My garbage goes to a county landfill about 10 miles outside of the city. From the highway, I knew I'd found it without seeing the posted sign because of the hawks and other large birds circling in the sky.

Nonetheless, it wasn't entirely what I expected. I thought many months of accumulated garbage would be visible to the eye from great distances, and that the smell would be unbearable. In fact, from the bottom of the hill, I mainly saw a large expanse of wild grasses topped with dirt that was being pushed around by heavy machinery. There was a smell, but I didn't need to use the bandana that I'd brought to cover my nose.

Adam, the person in charge of operations, agreed to give me a tour. The landfill is staffed by just over a dozen people, a fourth of whom are engineers. Adam is a civil engineer himself, and has been with the county landfill operation for 17 years. He asked me if I knew of the sledding hill in one of the city's parks, or the 'duck park' at the convention center. Those sites, he said, are all former landfills, filled to capacity.  The landfill we were standing on is the 'new' one, built in 1985. 

You might wonder what it takes to build a landfill. This too, was not what I expected. Old landfills typically used low-lying ground outside of a town's limits. Once the 'hole' was filled, the landfill was considered 'finished'. According to the American Foundry Society:

"Prior to the implementation of the Resource Conservation and Recovery Act (RCRA) in the 1970’s, most wastes from municipal and industrial sources were dumped in unlined pits with little environmental oversight.  RCRA ushered in the era of the modern sanitary landfill, a repository for “solid waste” materials that allows them to be contained in a controlled environment, with particular attention paid to the potential for groundwater contamination."

My county's landfill was given the 'okay' to be built only after proof of compliance with a list of conditions, including a minimum distance of five miles from any airport. "Garbage attracts birds, which is bad for airplanes," Adam explained.

The construction of a landfill is mathematically complex. Adam explained that it must be ten feet above groundwater, since rainwater that settles in landfill becomes a contaminant called leachate, a highly acidic by-product that then has to be contained. A landfill has many layers, including four feet of compacted clay, a thick plastic liner, a fabric cover to protect the plastic from tearing, and one foot of gravel. While the model below may not be identical to our county's model, it will give you an idea:

From the University of Florida

The plastic liner comes in giant rolls, 23 feet wide by 500 feet long, made of high density polyethylene (HDPE). This is a product of crude oil.

When a landfill is 'finished' (i.e., filled to approved capacity), it must be covered with one foot of soil, two feet of clay, a sheet of plastic, a sheet of fabric, a second two feet of soil, six inches of topsoil, and finally grass seed. Grass prevents erosion.

Adding to the complexity: landfills must have 'slope stability'. Adam explained that for every 100 feet of landfill height, there must be 400 feet of horizontal breadth. This explains the vast expanse of land needed. Stability and safety are critical to landfill management.  
 
Landfills must also prevent greenhouse gasses such as methane (CH4) and carbon dioxide (CO2) from escaping into the atmosphere. These gasses are highly flammable. Adam told me the story of a house in our city that exploded in the 1980's, which prompted the DNR to increase regulation of landfills. (Turns out gas explosions in the 1980's occurred elsewhere too.)

Ultimately, greenhouse gasses need to be 'destroyed', either through conversion to usable fuel which is burned when used, or through simple burning such as in flare towers (which have the tendency to alarm passersby who think that the land is on fire, Adam said). I saw more evidence of the former at this landfill.
 
To transport these gasses safely out of the landfill, 'drilling rigs' are sent from the surface to the bottom of the landfill where gas wells are built out of PVC pipes. 

A small processing plant on-site generates negative pressure which creates suction to draw the gasses out through a network of lateral pipes back to the plant. 

Adam explained that while garbage needs moisture and air to decompose, the gasses produced by decomposing garbage can only be collected in the absence of air, so the drilling rigs and gas wells must account for that. This landfill has 52 gas wells, and each of them must cover a 150-foot "radius of influence".

The captured gas comes out of the ground "moist and hot", which can't be used for fuel, so back at the plant, "drip legs" and "chillers" remove moisture and cool it. The end product is used to power 15 county pick-up trucks, as well as to generate electricity.

"Your trash is my cash." 

The generation of electricity, which the county sold back to the electrical utility, netted 3.5 million dollars in 2013. This is a good thing, since running greenhouse gasses to the energy plant is an extremely costly operation. 

The landfill charges $50 for a ton of garbage and accepts 600 tons of garbage per day. The money for the land and for management of the landfill comes from consumers, either directly by those who drop off waste that isn't collected curbside, or indirectly via property tax payments to the city, which pays the county. (See also day #6.)  Federal and state taxes don't cover landfill, something Adam regularly has to tell trash-haulers who want to dump on demand. 

At the end of every day, what's dumped in the landfill must be covered by six inches of dirt. Heavy machinery works all day, every weekday and half of every Saturday, to spread the garbage out, break it apart and compact it before finally covering it with dirt.

  
My county's landfill is over 99% full, and Adam explained that the landfill is expanding to accommodate our garbage for another 15 years.  

I asked Adam what can be done to help mitigate the effects of increasing amounts of land being used to house our garbage. He responded: 

Buy only what you need, and recycle appropriately. 

For example, the county is able to recover construction waste that is separated correctly, and sends it to another facility where 80% of it is recycled. (Success!)  In the same breath, however, Adam noted that 20% of the landfill's total 'garbage' is paper, which can and should be recycled instead.

During the tour, we saw two television sets that had been dumped in the landfill by someone who didn't want to pay the recovery fee. 

This is an example of an increasing "e-waste" problem.  

"Due to the crude recycling process, many pollutants, such as persistent organic pollutants and heavy metals, are released from e-waste, which can easily accumulate in the human body through the inhalation of contaminated air.

...researchers have now linked e-waste to adverse effects on human health, such as inflammation and oxidative stress – precursors to cardiovascular disease, DNA damage and possibly cancer." - Retrieved from the Institute of Physics

We also saw two teenagers dumping  construction waste, including a sizable stack of large cardboard boxes, which should also be recycled.  

When I asked why they didn't separate it and take it to the bottom on the hill where there's a cardboard recycling drop-off spot, one of the boys said: 

"I pretty much don't want to deal with it."  

When I heard that, I felt hopeless for this world. Adam says it goes with the job. He added that effective landfill management depends on the honesty of its consumers. 

Adam mentioned that he's been to landfills all over the world. In some places, he said, "people go to the landfill to find a meal. Here, we're a prosperous country and people buy more than they need. Consume, consume, consume...."  

Where does it end? 

It ends one person at a time.