Why A Landfill is Not Like a Dump

A dump is *nothing* like a landfill. A dump is just a pile of stuff, like what you see at a transfer station.

A landfill is a very specific creation that is more like geology than anything else. There are wet landfills and dry landfills, each with their own serious cons, and very little pros. But our trash has to go somewhere, right?

Here are the basics I learned from visiting the Gray Wolf Landfill in Arizona, owned by Waste Management, Inc:

First an area of land is scooped out into subsoil ‘cells’. Landfills have very expensive linings (geomembrane), followed by more super expensive linings (geotextile), followed by layers of clay, then gravel, followed by compacted soil, followed by a layer of trash. Then more soil, more gravel, more trash. This system continues until the cell is filled.

When the area is ‘filled’ to the point where the angle of repose is reached (the spot where things cannot be piled up anymore without tumbling down), then that cell is capped. The capping requires more layers of compacted soil and gravel and then of geotextile and geomembrane. Then another set of geotextile and geomembrane. Followed by more soil and then some kind of earth-stabilizing seeding (like grasses) that keeps the soil from eroding right off and exposing the geoplastic to the elements.

There are runnels made throughout the entire strata to contain the leachate, that runs to leachate ponds, and continual testing is mandated to ensure leachate does not enter the water table in any measurable way. There are also constant testings mandated by government to ensure toxic outgassing stays within certain levels. Water has to be sprayed on every layer of soil to ensure dust levels are minimized (or else the companies get huge fines). One ounce of mercury could shut down an entire cell of the landfill. So, more testing. It is a very complicated system. It’s not like a dump in any way.

A landfill, done correctly, is not a threat to the environment while it’s in active use. It’s when the landfill closes and the companies have moved on…and the linings crack (because of faults and earth shifts), that the interior leachate and outgassing turn the area into a Superfund site. According to Garbage Land, by Elizabeth Royte,  this is considered an inevitability for each capped dry landfill.

This is where the government drops the ball, because the capped landfill is no longer the waste business’ problem, and the government does not have the money to keep monitoring the area. And even if the government continued monitoring these sites, there isn’t much you can do once the landfill linings crack.

From my tour, I was impressed with Waste Management’s attention to detail, safety and environmental concern. They are a business and are in it to make money, yet are using solar panels to power the site, and are proud to report they have gone more than eleven years without a single work-related accident.

I have no quarrel with Waste Management in any way. I wish there was a system in place to remove the the salvage items, the recyclables, and also the green wastes (landscaping materials) for mulching. This is something that would probably need to come from the government, since setting up systems for this would cost more than a waste company would see returned in profit.

All we can do is try to remove as much as possible from the waste stream on our end.

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