February 23, 2010 | General

Climate Change Connections: Another Perfect Storm

BioCycle Advancing Composting, Organics Recycling and Renewable EnergyBioCycle February 2010, Vol. 51, No. 2, p. 35
Sally Brown
The garbage barge in the early 1990s was the eye of a perfect storm: A clear visual image that generated plenty of headlines, all pointing to the fact that the waste management industry was a failure. A rallying cry that got composting operations started across the country.
The barge was floating at a time when new rules were about to change the face of the landfill industry. Many old landfills would have to close and new ones were required to include sanitary clay lined cells, daily covers and at a certain size, gas collection systems. All things that were expected to make landfilling a very expensive proposition. Municipalities and the public reacted to the very visible image of the barge by financing and outreach (municipalities) and participating in (the public) recycling programs. From the time of the barge until 1996, recycling rates more than doubled. Yard trimmings diversion became common. People participated because they knew they were helping the environment. And composting operations blossomed.
That was then, this is now. For most of the country, recycling rates have stayed flat since about 1996. Yard trimmings disposal bans are in danger of being overturned in Florida, Missouri, Georgia and Michigan. There are a few islands, places like San Francisco and Seattle, where food waste and soiled paper can now be combined with yard trimmings and the material either gets digested and then composted or directly composted. However, these places are few and far between. Instead, it is more common to find yard trimmings bans with lax enforcement.
Now we are faced with the potential for another storm. This time melting ice caps rather than barges are the focal point. The question is, how can the organics management industry (and here I mean composters and anaerobic digestion facilities) position itself to capture the eye of the public and the pocketbooks of the municipalities.
This time the stakes are higher and the game is tougher. Waste management companies are much savvier than they used to be. I would imagine that infamous barge was the first time many of the players in the landfill industry had to deal with any alternative to business as usual. Landfills and traditional waste disposal had been an integral part of our culture since World War II. The days of saving aluminum foil and Victory Gardens had been long forgotten.
Since then, the waste management industry has become more service oriented and much more aggressive about labeling themselves as a “green alternative.” If you pay attention to ads, you probably are aware that landfills are a source of green energy from methane generation. For the carbon that doesn’t degrade, landfills transform into a carbon sink. In National Geographic, the Waste Management ad also told me that landfills provide valuable wildlife habitat.


So how do you fight a powerful publicity machine? There are several approaches: Science and facts; Common sense; and Public outreach.
Claim #1-Green Energy: Now, my “Landfill Math” column in December laid waste to the claims about green energy from landfills. There is a bit of common sense in there as well. Forming methane requires particular temperatures, appropriate moisture content, the right microbial fauna and near neutral pH. If energy production is really your goal, then you put your feedstocks in a controlled digestion facility. Think about it: A banana peel is going to give you much more methane much faster in a controlled digestion facility than in a several hundred acre landfill where it is surrounded by things like old newspapers and sheetrock. Retention times in digesters are in the order of 30 days rather than 30 years. Gas production in digesters is likely two times that of landfills. Plus there is the added bonus that all of the gas produced is collected. Digesters are common in Europe, and at wastewater treatment plants across the U.S. We know how to do this.
If it is energy that people really want, controlled digestion – either wet or dry – is the way to go. It is also a great way for composting facilities to go. Cedar Grove, a composter in the Northwest, is putting in a dry digestion facility where cocollected food scraps, yard trimmings and soiled paper will be digested prior to composting. Recology, a waste management company based in San Francisco, is using a digester at a local wastewater treatment plant to digest commercial food scraps prior to composting, with power sold back to the grid.
Claim #2-Carbon Sink: Science and facts also work on the carbon sink argument. Carbon storage in landfills is likely a real phenomenon. There are questions over how long those newspapers and tree branches last but studies have shown minimal decomposition in landfill environments with residence times of over 20 years. The problem is that the carbon sunk in the landfill doesn’t do a whole lot.
In many circles there is a perception that organic matter in soils just “burns up.” This is not the case – organic matter in soils is a gift that keeps giving. As an article in last month’s BioCycle showed (see “Compost Boost To California Agriculture”), adding compost to soils not only increases soil carbon, it improves soil nutrient status and physical properties. More and more research is starting to say the same thing. Results from my graduate students are showing anywhere from 0.2 to over 2 tons of CO2 stored for each ton of compost applied. And studies have often seen yield improvements with composts in comparison to control and fertilized soils.
One easy way to demonstrate this to potential municipal partners and to the general public is by using compost to restore disturbed soils. Organic matter addition to disturbed soils greatly accelerates the restoration process. Not only do you get carbon accumulation in the soils, you get a beautiful landscape.
Claim #3-Wildlife Habitat: This does not require too much effort to refute. Yes, it is true that there is a wetland area where I walk my dog that is the site of a former landfill. It is used extensively by students for restoration projects and studies. However, with organics diversion from landfills and good recycling programs, you have the potential to reduce the quantity of materials going to landfills by well over 50 percent, significantly prolonging the capacity of the landfills we already have. And that means areas that are currently wildlife habitat can stay that way. By the way, grass is the only acceptable cover for most closed landfills as the managers fear trees might harm the cap. Grass is not the most effective wildlife habitat around. Some animals actually prefer trees and shrubs.
So now that we’ve shown the emperor is at best scantily clad, what about compost?
By combining anaerobic digestion with composting, the green energy credit is there. Without the AD, composting can provide a methane avoidance credit, i.e., a credit for the methane that isn’t emitted by landfills before those green energy systems are in place. It may not make you rich, but the credit provides confirmation that landfills are leaky systems that add to climate change.
Compost gives soils back their health. And we need those soils to clean and store our water and help us grow our food. And that may be the key to the public outreach component of this battle. People are looking for something they can do to fight climate change. Organics diversion is that something. They may not be able to afford to exchange the SUV for a hybrid. They certainly can’t afford to sell the house in the current market. But they can separate food scraps. They can plant a garden. If people realize the power of these tools to fight climate change, I think that the composting and anaerobic digestion industries have found the new version of the garbage barge.

Sally Brown, Research Associate Professor at the University of Washington, authors this monthly column on the connections of composting, organics recycling and renewable energy to climate change. Email Dr. Brown at slb@u.washington.edu.

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