Landfill Gases; Regulations and Emission Solutions

Landfill Methane Outreach Program

The Landfill Methane Outreach Program of the Environmental Protection Agency deals with landfill gas issues and concerns. Although it encompasses a complex set of rules and regulations, the main requirement is that landfills must recover and combust these gases instead of allowing them to seep into the soil and the air. With this, the EPA hopes to reduce emissions from landfills, as Methane is one of the worst gases for the atmosphere and global climate change. This began in 1996 with the EPA’s Standards of Performance for New Stationary Sources (NSPS) and later the National Emission Standards for Hazardous Air Pollutants (NESHAP), seeking to require landfills to collect these gases and combust them to reduce emissions. In addition to this regulation, NESHAP and NSPS, also require « gas collection systems [to] be well–designed and well-operated. » (EPA, Public Health, Safety, and the Environment). Through this, the EPA requires landfills to monitor surface methane emissions, ensuring that they are properly collecting the gas. 

Also, as part as the EPA’s criteria for municipal solid waste landfills, they state that, 

(b) Open burning of solid waste, except for the infrequent burning of agricultural wastes, silvicultural wastes, land clearing debris, diseased trees, or debris from emergency cleanup operations, is prohibited at all MSWLF units (EPA, Criteria for Municipal Solid Waste Landfills)

Delving more into this issue, methane is one of the most common gases found in landfills, amongst various others. Methane is especially troublesome because it is 25 times more effective at trapping heat than carbon dioxide, making it a worrisome gas for the atmosphere (EPA, Public Health, Safety, and the Environment). According to energyjustice.net/lfg, landfills are the second largest manmade contributor to methane emissions, therefore much attention have been placed on reducing or combusting these emissions to reduce their impact. 

But despite methane’s prevalence in landfill gas composition, it is not the only gas, and usually makes up only 40-60% (energy justice). Methane comes from decomposing organic materials, such as food scraps and yard waste. Other gases are often found at landfills such as carbon dioxide and smaller traces of water vapor, nitrogen, and oxygen, amongst others.

Methane is of particular concern because it is 25 times more effective at trapping heat in the atmosphere than carbon dioxide (EPA, Public Health, Safety, and the Environment).

So to target this issue, the EPA has required combustion of these gases. This is possible through several methods, all with benefits and drawbacks, but most importantly combusting instead of releasing these organic gases generally reduces landfill emissions. Options include methods such as;

-flare it (flame)

-boiler - makes heat rather than electricity 

-internal combustion engine - makes electricity (dirtiest) 

-gas turbine - makes electricity

-fuel cell - makes electricity (expensive, experimental, but potential for very clean conversion)

-convert the methane to methyl alcohol

-clean it up enough to pipe it to other industries or into the natural gas lines (would add contaminants to natural gas)

(list found at http://www.energyjustice.net/lfg)

Despite such positive efforts from the EPA to reduce gas emissions from landfills, there has been pushback from the Sierra Club, and surely not the only environmental organization. To begin, their publication title started with « PUBLIC BEWARE », so one can only assume that this organization is going to be a tad bit dramatic about the situation. They proceed to argue against the requirement to combust these gases, instead, they argue, that the focus should be placed on reducing these gases in the first place. They claim that landfill energy is very dirty by nature, despite it being an economical use of this energy otherwise wasted, the Sierra Club denounces the praise that landfill gas has received for being a « green energy ». Their solution?  To focus on organic recycling! by doing so less yard waste and food scraps will go to landfills, in turn directly reducing landfill gases, methane especially. Although I personally agree with their solution, it think it is a lot more difficult to implement compared to more policy based initiatives like the combustion of landfill gas requirement. For more information from the Sierra Club; (https://teamster.org/sites/teamster.org/files/6310GreenhouseGasReportrevisedlowres.pdf)

So how does this relate to my previous post?

Well, I focused on the Milwaukee Metropolitan Sewerage District (MMSD) and their use of landfill gas to power their operations at the Jones Island Water Reclamation site. Although it is neat that MMSD uses a resource to make energy that would be otherwise flared, it is interesting to see how they pride themselves on being « green » with this energy source, but as the Sierra Club begs to differ, is not all what it cracks up to be.  

Check out the links below for more info! 

http://www.ecfr.gov/cgi-bin/text-idx?SID=a6fe953e6112a11842fff12dbc6b4822&mc=true&node=pt40.25.258&rgn=div5#se40.25.258_124

http://www3.epa.gov/lmop/faq/public.html#07-c

http://www.energyjustice.net/lfg

https://teamster.org/sites/teamster.org/files/6310GreenhouseGasReportrevisedlowres.pdf