Protecting Food. Empowering Whistleblowers.

Food Integrity Campaign Blog

Introducing Waste-to-Biogas

FIC Staff | September 11, 2020


So far in this blog series we have explored the different measures that allow the public to vet new pipelinesas well as assessed the legal options for responding to pipeline projects and protecting those who blow the whistle on pipeline-related problems. 


As the landscape shifts around major oil and gas pipelines in the US, new conversations are emerging about the future of renewable energy production. One such possibility that is garnering increased attention is “biogas” – or, more specifically in this case, “waste-to-biogas” – projects that promise to turn animal waste from industrial farms into gas that can be injected into natural gas pipelines. In the wake of the cancellation of the Atlantic Coast Pipeline, a 600-mile natural gas pipeline that would have spanned West Virginia to North Carolina, the spotlight has shifted to two major southeastern utility companies as they partner with Smithfield Foods to roll out biogas from hog waste. But is biogas made from industrial animal waste really “renewable” energy, as proponents claim? 


Duke Energy in North Carolina and Dominion Energy based in Virginia have both stated in a press release following the cancellation of the Atlantic Coast Pipeline that they will redouble their efforts in building up “renewable” sources in their energy portfolio. Biogas from animal waste is a major component of their plan. Smithfield has also proudly announced their partnership with the two utilities, claiming that implementing waste-to-biogas projects on 90% of their contracted farms will allow the agribusiness giant to reduce their greenhouse gas emissions by 25% by 2025.  


On the surface, the prospect of industrial animal waste-to-biogas production may appear to be a win-win situation. The environmental damage wrought by industrial animal production every year has been well documented, and much of it stems from waste management problems. Proponents of waste-to-biogas systems claim that utilizing the waste to produce biogas will mitigate some of the environmental damage. But taking a closer look at actual waste-to-biogas operations, including the plans being rolled out by Smithfield in North Carolina, it is clear that this strategy will not offer a solution to industrial ag waste. In fact, it may actually make the situation worse.  


Without a doubt, industrial animal agriculture contributes heavily to climate change. According to a recent UN study, livestock production accounts for almost 14.5% of greenhouse gas emissions worldwide. Just in the US, livestock generate around 2 billion tons of solid waste each year. In the industrial model of raising animals, where cattle, hogs, and chickens are kept in close quarters in contained animal feeding operations (CAFOs), this waste is collected in massive piles or stored in liquid form in giant pits called lagoons. This method of condensing and storing waste increases the amount of methane generated from livestock, compared to pasture-based systems. US Energy Information Administration estimates that swine production results in 42% of total US agricultural livestock emissions, producing 25 million metric tons of carbon dioxide equivalent (MMTCO2e), and dairy cattle represents 49%, producing 28 MMTCO2e.  


In addition to methane, the lagoons emit other air pollutants like ammonia and hydrogen sulfide that cause disturbing odors for neighbors. The liquified waste is eventually sprayed onto fields in order to reduce the levels of lagoons. In some cases, this waste can be used as a fertilizer, but often the sheer volume of waste produced outstrips the need for the nutrients in the waste. Overapplication leads to nutrient runoff and water contamination problems. As the waste is sprayed on fields, the spray guns release particulate matter as well as strong odors and pollutants that can cause respiratory and other health problems for neighbors. This is what the industrial animal waste management system looks like before biogas is introduced.  


To capture methane and generate biogas, the Smithfield Renewables program plans to have farmers that contract with the company invest millions of their own money to cover their hog lagoons and install biogas digesters on each farm. Methane gas will be captured as it builds up under the lagoon cover, and will then be cleaned and turned into pressurized natural gas that can either become electricity to power the farm or return to the grid, or the gas can be piped off the farm to a central storage or processing facility, and later injected into natural gas pipelines. Smithfield’s plans will focus on the latter, with the company building miles of smaller pipeline infrastructure connecting farms to centralized processing and storage facilities, and utilizing regional natural gas pipelines.  


The main environmental benefit of this system is the capture and elimination of the methane gas that is produced as a result of industrial animal waste management. But the process of covering lagoons can pose additional environmental hazards of its own. In fact, covered lagoons can actually increase the content of ammonia in the liquid waste. Ammonia is a powerful air pollutant that causes strong odors and contributes to negative health impacts experienced by communities that neighbor industrial animal farms. In addition, digestion actually makes the nutrient nitrogen more soluble, meaning that when the same quantity of waste is sprayed on a field, the field will be saturated with the nutrient more quickly. This would contribute significantly to nutrient runoff and increased water pollution. So, while biogas production is effective at eliminating methane, it comes at the cost of increased environmental damage in water pollution and the intensification of other air pollutants.  


In a world where agribusiness interests have long denied their role in (and even the existence of) climate change, Smithfield’s plans may sound promising. But waste-to-biogas will not actually change manure management in industrial animal ag. Rather it will entrench the use of technologies and systems, like lagoons and sprayfields, with proven environmental drawbacks. And while a covered lagoon can capture methane, other pollutants are actually intensified in the process.  


Similarly, for the oil and gas industry, biogas may serve to further entrench fossil fuel infrastructure and systems rather than aid in moving away from these unsustainable operations. Critics of waste-to-biogas are concerned that these projects could lead to the justification and expansion of pipelines. Chevron has already launched an ad campaign promoting their efforts to partner with massive industrial dairy operations in California to create waste-to-biogas systems.  


The assertion that waste-to-biogas offers a new source of “renewable” energy is, therefore, questionable. A more accurate description may be to say that waste-to-biogas “recycles” animal waste, with the primary benefit being the reduction of methane emissions. But these plans come with considerable downsides, including justifying our dependency on fossil fuel infrastructure and industrial agriculture, both heavily polluting industries. For those who think recycling is an ideal solution, it may be worth noting that recycling is an inefficient process through which there is always resultant waste – a perfect metaphor. 


In the next blog in this series we will explore in-depth the potential impact of waste-to-biogas projects in North Carolina.