Metro's plan to burn much of the Portland-area's garbage at the Covanta incinerator in Brooks appears headed for the trash heap.
After reviewing a 211-page Health Impact Assessment commissioned by Metro, the regional government's staff now recommends that the project be tabled.
"We came to the conclusion that we just weren't seeing the benefit from greenhouse gas emissions to justify the cost," said Ken Ray, a Metro spokesman who works on solid waste issues.
The elected Metro Council will consider the staff recommendation at an Aug. 8 work session.
Voting to burn the Metro area's garbage to convert it to electricity was always going to be tough politically for Metro councilors to swallow, given major opposition from local health and environmental advocates and Portland's Bureau of Planning and Sustainability.
Even Covanta, whose garbage incinerator would have been doubled in size to handle the new volume, seems to accept this deal is dead.
"Whenever your staff ... are suggesting you shouldn't go forward, you'd be hard-pressed as an elected official to go against the staff analysis," said Paul Gilman, senior vice president and chief sustainability officer for the New Jersey-based company.
If the Metro Council does decide to proceed, Ray said, the agency's staff recommended more research is needed on health and environmental impacts. That's likely to take two years and cost $500,000.
Doing its homework
Metro's contract to truck most of the Portland area's garbage to the Arlington landfill 140 miles east expires in 2019. As that date nears, the agency is exploring a variety of options to reduce the amount of trash sent to Arlington.
Metro commissioned HDR Engineering to prepare a Health Impact Assessment that compared the health and environmental merits of sending 200,000 tons of garbage each year to Covanta's waste-to-energy incinerator in Brooks versus burying it in a landfill.
The report found few health or environmental concerns from either option, though many critics remain skeptical. One of the biggest unanswered questions: the heath impacts of burning medical waste, plastics and other materials, releasing dioxins and other toxins into the air, plus ultrafine particulate matter that is so small that when inhaled it goes directly into humans' bloodstream.
But Metro's staff recommendation came down to a simple cost-benefit analysis.
"Landfills are always going to be the least expensive options," Ray said. But there was a presumption that garbage burning, which produces more renewable energy, would score much higher on environmental factors, particularly carbon emissions that contribute to climate change and global warming.
Rotting garbage in landfills emits a significant amount of methane, which is at least 25 times more potent as a greenhouse gas than carbon dioxide. Furthermore, trucking waste so far from Portland — the drive to Arlington is about a five-hour round trip — produces significant diesel exhaust and other carbon emissions.
Dueling computer models
The Metro-commissioned study used two different computer models to compare greenhouse gas emissions, and they produced startlingly different results.
The Waste Reduction Model, known as WARM, found that burying the garbage in a landfill would produce fewer carbon emissions. That's because landfills, comparable to forests, store significant amounts of carbon rather than emit it into the atmosphere as a greenhouse gas. Think of all the plastics — made from petroleum — buried in a landfill.
The alternative and newer Municipal Solid Waste Decision Support Tool, or DST model, found that converting waste to energy in a garbage incinerator had a lower carbon footprint.
Gilman said the DST model is clearly superior, but he thinks HDR Engineering sowed confusion by citing both methods. Covanta sent a four-page letter to Metro that explains its case, Gilman said.
"That really lays out to a great degree the failings of the analysis that was done by the staff, in particular the use of one model," Gilman said.
In the letter, he wrote: "It became apparent that HDR's analysis was based on very low predictions for the methane generated in a landfill, well below published and peer-reviewed ranges."
Covanta's actual carbon emissions from its various garbage incinerators have turned out to be close to what the DST model predicted, Gilman said.
He suggested members of a Metro advisory committee focus on just the DST methodology.
DEQ begs to differ
Metro is consulting with the Oregon Department of Environmental Quality, which has historically used the WARM model, said David Alloway, a DEQ senior policy analyst.
Development of both models was funded by the U.S. Environmental Protection Agency, he said, and there is "raging debate," with no scientific consensus, about which one is best.
Alloway said he found it curious that Covanta cited two studies in its letter to back up its assertion that energy-to-waste technology "has consistently been recognized as preferable to landfilling" on environmental merits.
One of those studies was conducted about a project in Boulder, Colorado, by the Joint Institute for Strategic Analysis, operated by the U.S. Department of Energy's National Renewable Energy Laboratory, and the University of Colorado-Boulder.
"In this report," Covanta wrote, waste-to-energy "leads to a higher reduction in (greenhouse gas) emissions compared to landfill-to-energy disposal per kilowatt hour production."
Alloway said that study "demonstrated exactly the opposite" of what Covanta hoped to portray, because it found carbon emissions would be 40 percent lower by landfilling Boulder's trash instead of burning it. The sentence is technically correct only because waste-to-energy projects produce more energy than landfilling, he said. But producing energy is not Metro's main goal, Alloway noted.
Covanta's letter also cited published studies by CalRecycle, DEQ's counterpart in California, that found incineration at three California garbage burners provided lower net methane emissions than landfills. However, CalRecycle acknowledged it wasn't fully factoring in the carbon storage benefits from landfills, so that analysis was "incomplete" at best, Alloway said.
Weak cost-benefit results
Covanta's letter, citing results of the DST modeling, said garbage burning would reduce greenhouse gas emissions compared to landfilling by .345 metric tons of carbon dioxide or its equivalents for every ton of garbage burned.
Metro's staff concluded that — even using the DST numbers most favorable to Covanta's case — burning garbage didn't pencil out well. Landfilling costs about $25 per ton, Ray said, and burning garbage in Brooks was estimated to cost $60 to $80 per ton.
If Metro pays $60 per ton, the low end of that range, to send garbage to Brooks, Alloway calculated, it would be paying $35 per ton more to reduce carbon emissions by .345 ton. That translates to spending $101.45 to eliminate 1 ton of greenhouse gas, he said.
That's not an "outrageous" price, Alloway said. Even still, he remarked, "It's a pretty expensive way to reduce greenhouse gas emissions."
State analysts, in a 2014 study, found there are far cheaper ways to get more dramatic results in lowering carbon emissions.
"There's a pretty significant cost premium to send garbage to Brooks instead of sending it to the landfill," noted Angus Duncan, chairman of the Oregon Global Warming Commission. The state commission has recommended that Oregon seek the most cost-effective and least-disruptive ways first.
Right now, Duncan said, the commission is focused on helping Oregon utilities shift away from coal and natural gas to zero-emission solar and wind power, and to reduce emissions from transportation.
Europe and the East Coast, where garbage burners are more common, have a shortage of land to site landfills and have much higher electricity prices than Oregon, Ray said. Here, he said, "There are not the urgent drivers that drive you to waste-to-energy."
Gilman said the expansion of the Brooks incinerator isn't dead, because Marion County is exploring sending more of its garbage to Brooks, and there's a trend among municipalities of voting to divert garbage from landfills.
But for the foreseeable future, it doesn't appear Portland-area trash is headed to the garbage burner.
Landfill vs. burning garbage
Here's what two dueling computer models calculated as the net greenhouse gas emissions of landfilling 200,000 tons of Portland-area garbage per year versus burning it to produce energy, measured by metric tons of carbon dioxide emissions or the equivalent:
Waste Reduction Model (WARM):
Landfill: minus 15,874 tons (a reduction in emissions due to carbon storage in the landfill)
Garbage burning: 21,320 tons
Municipal Solid Waste Decision Support Tool (MSW-DST):
Landfill: 68,281 tons
Garbage burning: 906 tons
Source: HDR Engineering's Health Impact Assessment