What’s the problem with burning trash?

Back in 2009, when I got involved in the public consultations on Metro Vancouver’s Integrated Solid Waste and Resource Management Plan (ISWRMP), I spent a lot of time thinking about the merits and costs of trash incineration, which is euphemistically called Waste-to-Energy, or WTE. In the end, I took a position against WTE, but not for the reasons that many others oppose it. With this subject coming up again locally with recent action at the Urban Woodwaste site, I thought I would clarify where my position is coming form.

Right off the bat, we should define some terms. WTE can mean a lot of things, including the use of heat from domestic sewage to make power, or extracting water heat from cooling towers at industrial sites, or using flare gas from a sewage plant to turn a turbine, to replacing fuel in a gas-fired boiler with wood scraps… most of my comments on this post will limit the WTE definition to burning domestic garbage to produce steam or electricity, as proposed in “Goal 3” of the ISWRMP.

This creates the distinction between the Metro Vancouver waste incinerator in Burnaby and the introduction of wood waste gasification plants at facilities like Kruger’s paper plant in New Westminster. In the former, an amalgam of biomass and fossil fuels mixed with non-consumables are burned to produce electricity to sell to BC Hydro, or steam to sell to neighbouring businesses. In the latter, a business is replacing the fossil fuel going into the boilers it needs to operate with locally sourced non-fossil carbon. The first is designed to make money burning fossil fuels; the second is designed to make money reducing the burning of fossil fuels. Big difference.

Metro Vancouver (and apparently, our Mayor) are bullish on WTE facilities. Although the public consultation showed a strong distaste for them, and the Fraser Valley Regional District was vociferous about Vancouver’s trash being added to its airshed along with Vancouver’s exhaust, the final ISWRMP included WTE (notably, that plan was not passed by the former Minister of Environment, who hails from the Fraser Valley, and is still on the desk of the current Minister, who hails from a riding much closer to the Cache Creek Landfill).

The arguments for WTE are almost all made in contrast to landfilling. Proponents argue that WTE is safe, is popular in Europe, has a lower GHG footprint, and turns the economics of waste from costing us money to bringing us profits. Opponents worry about air quality, the reality of the GHG equations, and about creating a “market” for trash that will need to be filled. There is also a healthy dose of NIMBYism in some of the arguments against: who wants 300 trucks a day dumping trash into an industrial site in their backyard? As always, I can opine on all of these points.

Much to the chagrin of many of my “green” friends and colleagues, I don’t worry about the safety of these plants. I think that the air quality impacts are measurable, and regulations exist to manage them. A well designed and property managed WTE facility should not put out any dioxins or furans (the carbons are heated high enough and the oxygen content is high enough in the combustion that the problematic volatiles like fluorine, chlorine and bromine will not form complex carbon compounds). Things like trace metals and fly ash can be managed effectively. There are less certain risks related to “nanoparticles”, but the science is up in the air (sorry) on that, and at the very least, they are not as dangerous as the Polycyclic Aromatic Hydrocarbons we pump into the air every day in automobile exhaust. An incinerator will never be “zero emission”, but it is likely to be no worse than any other point source in the City, and arguing against this point source on safety concerns seems to me a little disingenuous.

The same goes for landfills. WTE proponents will be quick to point out that this is not a “burning pile of trash”, but an advanced piece of technology that first heats materials to vaporization in an oxygen-poor environment, then combusts them with oxygen at a controlled rate to assure complete and clean combustion. Then they will refer to a landfill as “the dump”, like it is a pile of rotting garbage. A modern, well-designed and well-managed landfill is just as advanced a piece of technology as a modern WTE plant. There are engineered systems to separate the groundwater from the fill material, to first reduce, then control and trap any landfill gasses, and to trap and treat effluents. Much like the WTE, most of the negatives we associate with landfills are related to poorly designed or run landfills.

In summary, both landfills and WTE have negative impacts on the greater environment, both of which can be mitigated very effectively using technology and engineering know-how, along with the application of large sums of taxpayers money.

The next topic is greenhouse gas emissions. Depending on whom you ask (and how you ask), solid waste represents about 10% of the greenhouse gas emissions in Metro Vancouver. There are direct emissions from rotting trash (mostly methane and carbon dioxide, along with trace amounts of CFCs and other greenhouse gasses), and the gasses released from vehicles that move the stuff around. Proponents for WTE say that the savings in CO2 from the trucks going up to Cache Creek Landfill, combined with the virtual elimination of methane wastes by burning the trash, by far offset the CO2 output of the WTE plant. Opponents say: give us the math. Seems to me it is easier to look at the GHG streams separately.

As far as methane and CO2 from the trash material, pretty much 100% of the carbon that goes into the system is instantly converted to CO2 (assuming the system is operating optimally). For material that goes into a landfill, things are more complicated. The complex chemistry inside landfill means that waxes and oils tend to be preserved in an anoxygenic environment. Some methane is produced, but again if the landfill is operating properly, that should be a low amount, and it can be trapped and converted to CO2 (even allowing the production of power at that point). With the removal or organics from the general waste stream, the potential for methane is reduced even further. However, all of the wood, paper, and plastic that does not get converted to methane are effectively sequestrated for an indefinite period of time. Landfills are a form of carbon sequestration.

Transportation is the other part of this, and there is no doubt the current landfill at Cache Creek has a huge carbon footprint, mostly because we choose to use fleet of 28 diesel trucks to move a half million tonnes of our trash per year over 350km of public roads Cache Creek. However, the math on this is going to change by 2014, when WasteTech plans to convert the trapped methane to Liquid Natural Gas, and use that LNG to fuel their trucks. This will close the loop on much of the GHG stream, with the vast majority of the non-sequestered carbon going to replace fossil-fuel powered trucks. The GHG argument in favour of WTE is going away as technology gets ahead of it.

WTE proponents may make further arguments that by producing power from the trash (which is a mix of fossil and non-fossil carbon) they reduce the need to burn gas to make the energy. This is a fallacious argument, as anyone who needs energy can make the decision to take it from fossil fuel sources or more sustainable sources, and if the WTE is not producing the power, one could just as easily get that power from hydroelectric, biomass, geothermal, solar/wind or wherever. The discussion isn’t WTE vs. fossil fuel, it is WTE vs. any other potential source.

The NIMBY argument against WTE plants is also one I don’t Waste too much Energy on (get it? second pun this post; maybe I can go for the hat trick). As much as I don’t want hundreds of trucks a day and a noisy, smelly industrial plant in my backyard, I really don’t want them in anyone’s backyard. In fact, if I was setting up a waste management policy for the region, I would move towards making it illegal for domestic waste to cross municipal boundaries. If we make Vancouver responsible for its trash, and New Westminster responsible for its own,. If New West had to manage it’s own landfill on valuable space that it would otherwise be able to generate tax revenue from, that would be a strong incentive to reduce the waste we produce. The City would do that by making it very expensive to dispose of trash, and would provide strong incentives for recycling of all materials.

Which brings me to the reason I do not support WTE: it is lucrative. Metro Vancouver could continue to pump money into a landfill, and continue to charge increasing tipping fees to cover those costs, and people leaving large piles on the curb to be removed every week will have to pay higher fees. Alternately, they can build incinerators and eventually get paid to dump your trash into them (through energy sales), and the people dumping large piles of trash on the curb pay less for their removal. Or, more realistically, Metro Vancouver will charge the same amount or more, and sell off the profitable business of operating the WTE to a corporation, so we taxpayers are stuck with the tipping fees, and the corporation nets the profits. Regardless, the WTE becomes a money-generating machine, and that effectively removes all of the incentive to stop producing trash.

In the end, it comes down to this inescapable point: Importing tonnes of one-time-use hydrocarbon plastics, then burning them to make electricity is not a sustainable way to manage the hydrocarbon resource, and it is not a sustainable way to produce power. You may argue neither is landfilling, but WTE facilities actually provide real financial incentives to a non-sustainable practice in a way landfills never will. WTE is sold under the sustainability banner, but is exactly the opposite, as it acts to replace investment in energy production that is actually sustainable, and makes our society more dependant on the import of cheap, disposable plastic products that burn.

6 comments on “What’s the problem with burning trash?

  1. Whats the problem with land fills ?

    Landfill produce Methane gas, which has a “green house” effect 25 times that of Co2 per ton. 40-50 percent of the gas emanating from land fills is methane. There is plenty of anaerobic activity in a landfill. I don’t buy into the notion that “waxes and oils tend to be preserved” can provide some evidence to support that statement ? I doubt it.

    The Cache Creek landfill is already 50 hectares and has received approval for further expansion.
    A engineered system to capture all the methane released over such an area does not exist, nor will it ever exist.

    Furthermore, the nature of rain causes leeching of volatile organic chemicals (VOC’s) into the surrounding ecosystem. It’s no surprise they are below BCMoE standards, as we have no other options of what to do with our trash at this time.

    I think it’s important to point out that incineration utilizes ALL the methane, and the slag is relatively inert of VOC’s having been combusted. The end result is Co2, which is at least 25 X less a GHG then Methane.

    It makes FAR more sense to capture that energy locally then shipping it to cash creek for some imaginary methane collection system that doesn’t exist.

  2. Yep, Landfills produce methane. They also produce CO2, H2S, CO, VOCs, H20(v), and a variety of other gasses, but for most existing landfills the gas is about 50% methane. There are also heavier carbon compounds produced, of varying viscosity and water solubility, including waxes and lignins, which remain in the landfill indefinitely. Depending on a number of factors, this can be more than 50% of the carbon that goes into the landfill. Click here for some evidence to support that statement.

    Systems to trap and extract the vast majority of the methane that comes out of landfills do indeed exist, and are increasingly relied upon, just as there are systems perfectly capable of trapping leachate. As I said in the original post, I am not going to argue over the relative effectiveness of engineered systems; the systems clearly exist and can work, the question is whether we want to spend the money and time to implement them (this includes equally trapping systems at landfills and air quality systems at incinerators). Instead of arguing about methane vs. CO2 vs. VOCs, let’s trace the actual carbon.

    I challenge your statement that slag out of the bottom the incinerator is “inert”. It is, in fact, rich in leachable metals, and presents as much problem in the landfill as it would have without the benefit of burning (arguably a higher risk due to the increased bioavalability of some metals that have been heated to high temperatures, but that is another topic altogether, and rather out of my area of expertise).

    Finally, all of this math about methane in landfills (and admittedly, the reference I cited above) assumes that landfills will continue to be loaded up with organic waste. However, with most organics being directed out of landfills and into organics recycling systems, with a higher proportion of wood and paper products being recycled (thanks in part to the upcoming EPR on printed paper), the remaining landfill materials will simply not be producing as much methane as they do now.

    Which raises the big unknown in the incinerator discussion: with the plastic, paper and organics removed from the waste stream, what is left to burn?

  3. “Which raises the big unknown in the incinerator discussion: with the plastic, paper and organics removed from the waste stream, what is left to burn?”

    This has always been my question… but I suspect the goal for incinerators is to burn plastics, paper, wood and organics… and what ever else they can get their hands on. Is this a bad thing? I don’t know but I suspect it does not discourage the creation of waste. It depends on what we’re trying to accomplish…

    As for GHG emissions from landfills vs incinerators: surely one needs to look at the ratio of GHGs produced vs material disposed. Not all of the landfill’s carbon-based materials will end up in the air and it would take many years. However I expect most of it would quickly become GHGs if the materials were incinerated.

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