MYTH: “Digesters completely eliminate odors from animal manure.”

 

REALITY: Digesters have had the most success controlling odors in highly controlled conditions. In the real world, there are many examples of digesters failing to control odors. 
 

• Going back to the creation of the very first digester on a CAFO in the 1960s, the largest farms needed a way to reduce odors because they were being constantly sued by their neighbors before right to farm laws were implemented in the 1970s-1980s (D’Onofrio 2023). Digesters allowed farmers to hide or lessen their odors and continue production. 

• However, there are many recorded instances in the real world, particularly when the digester is co-digesting waste (which is what Vanguard is proposing to put in Lind) where digesters made odors worse instead of improving or eliminating them.

  • Rhode Island-Biogas co-digester (manure, wastewater, and food waste) described by neighbors as “putrid” and resulted in dozens of residents lodging complaints within 6 months 

  • Colorado-Biogas co-digester (manure and food waste) described by neighbors as “scorched manure” and resulted in physical illness for residents 

  • Ohio- State shut down a digester after the facility could not address their odor and water pollution problems after “illegally accepting and storing excessive organic wastes at the farm.”

  • Wales, UK- Biogas co-digester creates “constant stench 365 days a year"

 

MYTH: “Digesters benefit small farmers.”

 

REALITY: The farms that use digesters are NOT small IN SIZE. They are typically concentrated animal feeding operations (CAFOs), also known as factory farms, because they need a very large amount of manure to make a profit. 
 

• According to the AgSTAR project development handbook, “Successful farm-based AD/biogas systems typically operate with at least 500 cows in dairy operations or at least 2,000 hogs in swine operations.  As economies of scale yield more favorable conditions (e.g., larger number of animals, larger amount of recovered manure, increased amount of salable products produced) the likelihood of successful application and profitability increases. For example, dairy farms having greater than 1,000 animals or hog farms having greater than 5,000 animals increases the likelihood of project success.”

  • AgSTAR partners directly with digester producers like Vanguard to expand digesters on US farms (link to image site).

 

REALITY: Most small farmers cannot afford digesters because they are so expensive. 
 

• Farmers need to cover start up costs up front as well as operating costs. 

  • Digester equipment estimates: $400,000- $5,000,000 (or more) depending on size and biogas production

  • Operating cost estimates: $25,000-$600,000 (or more) depending on size and biogas production

 

REALITY: The digester and biogas industry is largely being driven by government programs and subsidies on the state and federal levels. 
 

• Since digesters are unaffordable, farmers are funding digesters via direct government support or indirect government support from companies who are using digesters/ biogas to make money from government programs/ subsidies.

• THE FEDERAL GOVERNMENT:

• The Inflation Reduction Act (IRA) provided over $2 billion for USDA’s Rural Energy for America (REAP) program to promote rural or agriculture-related renewable energy

• CALIFORNIA:

• Companies are investing in digesters to “offset” their emissions in California markets through their offset program.

• Companies are investing in biogas production to financially benefit from the Low Carbon Fuel Standard program led by California by selling renewable natural gas (RNG) to fuel producers in California.

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MYTH: “By utilizing the trapped biogas as a renewable energy source, digesters displace the need for additional fossil fuels.”

 

REALITY: Biogas adds to, rather than takes the place of fossil fuels and further ‘locks-in’ CAFOs to our fuel system.  
 

• Lock-in: Technological lock-in describes a scenario where the idea that the more a society adopts a certain technology, the more unlikely users are to switch. 

• Digesters deepen lock-in in two respects: 1) they lock CAFOs deeper into our food system by 2) locking CAFOs into our fuel infrastructure. Biogas production requires the buildup of a new network of RNG pipelines and transport systems. Once enough capital investment has been levied to build these pipelines, it becomes more difficult to back away from biogas production. If the US becomes dependent on biogas for things like public transportation, this will ensure that CAFOs become a part of the energy industry. CAFO owners can reap serious money for RNG production in California’s markets which is why they are calling manure “brown gold.” We already see the integration between big oil and big ag all over the US:

  • Blackrock, a leading investor in oil and gas, purchased Vanguard Renewables which develops infrastructure for biogas plants across the US

  • Chevron partnered with California Bioenergy to build up biogas production in CA

  • Duke Energy has partnered with Smithfield to produce biogas in NC

  • BP purchased Aria Energy (previously Archaea Energy) to produce biogas in CA’s Central Valley

  • BP also created a joint venture with Clean Energy Fuels and Gevo NW Iowa RNG to enable them to buy RNG from CAFOs in Iowa

  • Shell has biogas projects in California, Kansas, Idaho, and Oregon

  • Shell has also purchased Nature Energy, the largest manure biogas company in Europe. 

    • Nature Energy has previously set up projects in Denmark. Nature Energy has a website where nearby residents sign up for “alerts” when their manure/food digester is going to be “stinky” – and odors can be noticed miles away. See more issues like this in the next section. 

    • Nature energy tried and failed to introduce biogas production to St. Croix County, WI but remains committed to setting up in Wisconsin and Minnesota

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• MYTH:“RNG will benefit our neighbors by lowering their electricity bills with cheap natural gas.
  
  REALITY: Renewable natural gas (RNG) is not the same as natural gas. 
   

  • The cost of purchase of green natural gas is 5 to 6X more than regular natural gas. When this more expensive gas enters the line, the cost to the end consumer must rise.

  • Cost of natural gas via pipeline in WI from the ground: $8 - $14 USD/mmBTU

  • Cost of Anaerobic digestion gas:  $20 - $50 USD/mmBTU
    
    MYTHBUSTING DIGESTATE (I.E. the stuff that comes out of the digester)
     

• MYTH: According to AgSTAR (2018), “Digesters, particularly heated digesters, can destroy more than 90 percent of disease-causing bacteria that might otherwise enter surface waters and pose a risk to human and animal health,” (5).
   

• REALITY: Researchers admit that the bulk of research was conducted in laboratories, which are highly controlled environments and only a small number of studies have been conducted on the pathogen content of digestate on CAFOs in the real world. 
   

  • Burch et al. (2018) addressed these limitations by testing the pathogen levels of digestate from 9 different facilities in southern and eastern Wisconsin over a period of 9 months. They found that after the digestion process, the microbial content of the digestate was lower, but levels of “inactivation” of those microbes varied substantially across different digesters during different seasons. After the completion of the digestion process, the researchers found that “nearly every microbe we could detect” could be identified in the liquid digestate, which is framed as a safe to use fertilizer on fields around people’s homes (342). 

  • On Irish farms, Nag et al. (2020) found that, “Cryptosporidiumparvum, Salmonella spp., norovirus, Streptococcuspyogenes, E. coli enteropathogenic (EPEC), Mycobacterium spp., Salmonellatyphi (followed by S. paratyphi), Clostridiumspp., Listeria monocytogenes and Campylobactercoli were found to be the most relevant (top 10) pathogens in relation to potential risk from spreading anaerobic digestate on agricultural land, specifically in Ireland.”

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