Summer 2015: Full from Landfill

Before I begin, I want to review the basic waste management hierarchy. Everyone should strive on a personal level to follow these steps to effective waste management. There will be more on this later but I just wanted to remind you all to (in order of importance):
1. Reduce
2. Reuse/Recycle
3. Energy Recovery
4. Landfill (AKA final disposal)

The EPA's Solid Waste Management Waste Hierarchy.

Monday of this week, Memorial Day was very exciting, we had our first group project due and ate dinner at a TexMex place (we had some mediocre ribs but also a delicious burrito and an actual TON of french fries)! My group was tasked on presenting policy of end of life vehicles (ELV) and end of life tires (ELT). The goal was to consider the policy and regulations of the European Union to the United States... Exciting stuff! We determined in general that European Union has a more advanced policy to handle the ELV it produces, but the European Union's policy for ELT focuses on landfill reduction, which should only occur as a final resort. Additionally, we found that the United States, for our presentation and others, was often lacking in federal policy, but there were measures implemented on some state levels that could be spread throughout the country.

One of my favorite presentations was on organic waste, such as food waste. Fun fact: since the installation of the garbage disposal, the fraction organic waste has decreased. However, even since this decrease, organic waste is the easiest waste to biodegrade and in doing so produces methane. Methane can then be recovered and converted into energy. Municipalities around the world are recognizing this neat science and are trying to harness it. This also sparks the debate of whether or not organic waste should be landfilled, which poses a question for the waste management hierarchy. Should organic waste be recycled to biogas by putting it in a landfill, or should it be composted to create a recycled product? It is impossible to create a blanket solution to this problem because every circumstance is very different from the other. We learned more about this dilemma Tuesday that I will go into more detail.

Tuesday we visited the Ecoserdiana landfill before having my second meal of ribs and a burger., much more delicious Anyways, we were given a tour by two female engineers (WAHOO!) and were shown the landfill, monitoring equipment, and biogas fuel generation plant. We saw a lot so I am just going to highlight a few things. There were many landfills on this site, most of which accepted municipal solid waste (the waste generated by the average Joe) at some point, however the only current active landfill accepts designated waste. Designated waste is waste that is inert, such as nonhazardous construction and demolition waste or ashes from an incinerator plant. On every landfill was an extensive biogas and leachate collection system. Biogas is the methane mixture of gas emitted from the landfill and leachate is any liquid that runs off from the landfill, aka landfill juices. These are meant to collect both the leachate and biogas so they can either treated or transformed into energy. Additionally, we could see monitoring equipment such as groundwater wells and air quality monitoring. These measures make sure that the landfill is contained within it's lining. Finally, we saw the energy conversion plan where the discharged gas is burned, electricity is created, transformed, then sold onto the energy grid. The equipment used to generate this power was comparable to the powerplant last semester's Air Quality class visited on Northeastern's campus.

I think an interesting question this experience posed was whether municipal solid waste, trash from the average person, should be added for fuel production or composted for reuse. According to the EPA's hierarchy pyramid, the composting is the better solution. The trend is for the organic matter to be processed separately to be reused, however this cuts into the landfills ability to create methane, the energy source. Knowing this engineering agrees with Ecoserdiana 's consideration to add a anaerobic digestor (speedy composting technology) to their site to maintain biogas production. This is a problem that cites will continually face as they try to find environmentally friendly solutions without ignoring the cost and applicable policies.