When trash burns wrong, part 1

To take Zygomatica beyond the realm of academic speculation, I have decided to hitch myself to a concrete issue which I have little competence in. A municipal solid-waste incinerator is being planned in Turku, quite near where I live. In any human activity, things can always go haywire. How can things go wrong with the incinerator, and how can we prepare for them?  [Click here for Finnish version]

This first blog is simply a summary of what I have learned in some days of browsing. I think I have most of the facts right.  Concretely, I am a member of the Turku section of the Finnish Association for Nature Conservation, and have helped comment the Environmental Impact Assessment of the planned incinerator. Being a member of the Association helps find information, but also allows me to affect things rather than just theorizing about them. All views and opinions expressed here are absolutely my own, however.

Trash incineration is a difficult issue politically, ethically, environmentally, and technically. I don’t actually know my opinion yet. I live quite close to the planned incinerator, but am not automatically against it. In this series I will take a laser focus which is the same whether I end up being for or against the incinerator: I will focus on the possibility of major accidents, how to prepare for them, how to inform the population, and how to  recover from them. My essential interest is in the finding and disseminating of information.

In one sentence: an incinerator is a huge furnace. The waste from trucks is dumped into silos and fed into the incinerator (Figure 1). The temperature needs to be at least 800 degrees in order to break up the toxic materials. The process can generate both heat and electricity. The burning produces flue gases which need to be cleaned (Figure 2). The clean-up residue (5% or the original mass) is considered toxic waste. The bottom ash weighs about 15% of the original mass. If the incineration was successful, the bottom ash can be used for example in landfills and construction.

Figure 1: The furnace system. (Source: TSJ:n YVA-dokumentti).

Figure 2: The cleaning system. (Source: TSJ:n YVA-dokumentti).

In Turku, the planned amount of waste would be 150,00 tons per year (one dump truck an hour). About 8,000 tons of toxic waste will be produced (one dump truck per day), and 25,000 tons of non-toxic bottom ash (a few dump trucks per day).

Before the 1980’s, little attention was paid to environmental matters. Incinerators produced significant amounts of dioxins and toxic heavy metals. When reality struck, incinerators disappeared from Finland; for many years, Turku had the only functioning incinerator in the country. In new incinerators, the emission levels have been set lower than for other energy-producing plants. If everything works correctly, the emission levels are considered acceptable (whether they really are acceptable is an issue which I will not get into here).

However, one thing is pure common sense: if a plant operates for thirty years, everything will not work correctly all the time. Something will happen: fires, failures of the filtering system, industrial actions, accidental contamination by toxic wastes, unexpected chemical reactions, failed maintenance, human errors…. If an accident can happen, it will happen, somewhere, eventually.

This common sense should ideally be supported by facts. And there is the catch: facts are hard to come by, at least from easily available public sources. Manufacturers and operators do not report malfunctions automatically. Accident reports can occasionally be found, but not systematically. That, then, is the theme of this series. Based on the limited information that is available, I will try to determine what can go wrong in an incinerator, and how the locals can deal with such malfunctions.

I feel no hysteria. Even if a fire is set off, it will end when there is nothing more left to burn. An explosion like the Flixborough disaster is not possible. Even in the (theoretical) case of an explosion, the shock wave is not an issue. The release of hazardous substances is the core issue; right now, I have no real idea how much and what types of materials might be released.

It is certainly possible that I will find nothing dramatic. In that case, I will report that nothing dramatic was found. Time will tell.