I lived in Washington, D.C. for the first two years after college, and I would often take weekend trips down to North Carolina with my girlfriend and one of my best pals in DC, who was originally from North Carolina. We always joked about Saturday being “Trash Burning Day” down there, because we saw people on several occasions burning trash in piles in the countryside. Obviously, this kind of thing happens all over, but we liked to poke fun at North Carolina to amuse ourselves. Burning trash is very common, although it can be dangerous to burn some things if you’re exposed to the chemicals that are released. My younger brother deployed to Afghanistan during that time, and told me afterward about how marines would burn all of the waste in the Forward Operating Bases in pits with diesel fuel for logistical and security reasons. In recent years, President Biden drew a link between his son’s fatal brain cancer and the harmful exposure to which veterans have been subjected by this practice.
At the same time that I was becoming familiar with the beautiful countryside and quaint towns of eastern North Carolina, I was leading a “Category Review” of wastewater discharges from the Waste Combustion Industry. The Environmental Protection Agency (EPA) had directed my company to review these discharges under Section 304(m) of the Clean Water Act. This section of the statute requires EPA to periodically review industrial sectors that discharge potentially harmful wastewater, to determine whether existing environmental regulations are sufficient to protect the environment – and public health – from evolving industries. The concern centered around companies that incinerate hazardous wastes. Although some hazardous wastes can be burned for their value as fuel (e.g., contaminated gasoline) in waste-to-energy plants or cement kilns, these wastes can vary greatly in their value as a fuel. Many of these wastes can release very dangerous emissions, including some dioxin congeners which top the list of the most toxic chemicals known to be routinely released by industrial facilities.
Waste incineration facilities in the U.S. usually use wet scrubbers to “clean” their emissions prior to venting them to the atmosphere. A wet scrubber basically works by passing an industrial emission upward through a tower filled with an inert media, and water flows downward over the media against the current of the air emissions to “scrub” the toxins out of the gas phase and into the water phase. Because of the difficulty of destroying dioxin compounds and other toxins, many such environmental controls work by removing the toxins from one phase (gas in this case) and concentrating them into another phase (water in this case). As a side note, air strippers clean contaminated water in a process that is almost exactly the reverse. The dirty effluent from these wet scrubbers is typically recycled, and the equipment is configured with a bleed stream to balance the dioxin removal efficiency against the need to minimize the wastewater generated. The bleed stream is the wastewater that must ultimately be disposed of, and it is heavily regulated because of the potential hazards. These companies often spray this water on top of hazardous waste landfills, which have special liners and leachate recovery systems underneath them to protect the groundwater. The idea is to ultimately deposit the dioxins and other toxic constituents within the landfill, which is capped with a very low permeability liner upon closure.
This process may seem rather ugly to the uninitiated, but it represents the current state of the science for economically feasible treatment of these wastes. Although it’s technically feasible to treat the water to remove these toxins, further treatment is generally so expensive that EPA believes it is not an economically viable option for waste management.
Another form of slightly more benign waste incineration that is common in some places is to incinerate nonhazardous, combustible wastes to reduce the need for landfill space. It’s interesting to note that several European countries which are generally regarded as more environmentally progressive than the U.S. allow or even require this type of waste management to reduce the need for landfills. For example, since the year 2000, it has been technically illegal to landfill combustible, nonrecyclable waste in Switzerland. Sweden sends only one percent of its trash to landfills, and nearly all of the rest is either recycled or incinerated. Both of these countries generate electricity from the heat released by the incineration. Nonrecyclable plastics are a large part of this waste stream. It seems likely, at least when comparing Switzerland to the U.S., that part of the reason for the difference in waste management strategies is the availability of land nearby for landfills.
While it would be nice to save real estate in the U.S. from the ignominious fate of becoming a future landfill, people are generally concerned about the carbon footprint of the incineration process. After all, even though electricity can be generated from the incineration, the carbon dioxide released per unit of electricity is much higher than the ratio you would see for natural gas or even coal. The relative fraction of its total electricity that Switzerland generates from carbon-neutral nuclear power (insert footnote about carbon dioxide associated with plant construction and the age of Swiss power plants) is twice that of the U.S., so I doubt that the Swiss are losing much sleep over the carbon footprint from waste incineration.
Landfills create other environmental impacts beyond the space that they require (e.g., groundwater contamination, emissions from earth moving equipment). As environmental management practices in the U.S. continue to evolve, perhaps we will decide that we, too, should begin incinerating more of our wastes. Bjorn Lomborg, a heterodox Danish author and vocal opponent of popular climate activism, has advocated for increasing the practice of waste incineration to reduce ocean plastics, microplastic pollution, and other waste management issues. It is my hope that more environmental professionals will analyze waste management practices in the future to properly balance climate change risks against the need to reduce litter. I sincerely believe that we can achieve our climate goals at the same time that we cleaning up our oceans.