To the University of Wyoming:
The members of the Committee approve the thesis of Dylan Freeman presented on 5/9/2019.
Drew Bennett, Ph.D., Chairperson
Temple Stoellinger, Esq., MA, Co-Chairperson
Hannah C. Cunningham-Hollinger, Ph.D., Outside Member
Sam Kalen, Esq.
APPROVED:
Melinda Benson, Department, Division, or Program Chair, Haub School of Environment and Natural Resources.
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Freeman, Dylan C., MA, Haub School of Environment and Natural Resources, May 2019.
Ammonia emissions are a growing concern worldwide as a result of their environmental impact through increased nitrogen deposits. A notable contributor to ammonia emissions are livestock operations. Understanding the science and good production practices associated with the livestock industry are key in developing the best approach to addressing emissions concerns. Three key areas to on focus on at the operational level are nutrition, genetics, and waste management. Good production practices can be implemented to assist in mitigating emissions in each of these categories. Given the concerns over ammonia emissions, there are many options for regulatory mechanisms to address such concerns. Several federal environmental statutes have the potential to address ammonia emissions, including the Resource Conservation and Recovery Act (RCRA), the Comprehensive Environmental Response, Compensation, and Liability ACT (CERCLA), and the Clean Air Act (CAA). This thesis presents an analysis of both the benefits and drawbacks of utilizing existing statutes. Alternatively, it presents an incentive-based program that can be developed to address ammonia emissions in a manner that achieves beneficial outcomes for the livestock industry and the environment.
AMMONIA EMISSIONS, THE NEXT GREAT ENVIRONMENTAL THREAT…WHAT’S ON THE REGULATORY HORIZON
By Dylan Freeman
A Plan B thesis submitted to the Huab School of Environment and Natural Resources and the University of Wyoming
in partial fulfillment of the requirements for the degree of
MASTER OF ARTS in
ENVIRONMENT AND NATURAL RESOURCES
Laramie, Wyoming May 2019
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ACKNOWLEDGEMENTS
I would Like to thank Dr. Drew Bennett and Temple Stoellinger, who served as co-chairs on my graduate committee. I deeply appreciate their guidance and useful recommendations through the duration of my project. I would also like to thank Dr. Hannah Cunningham-Hollinger and Sam Kalen, who also served as members of my committee. They provided an abundance of wisdom and assistance during the construction of my project. I would also like to thank my family; my parents Bryce and Pam Freeman, as well as my sisters Lindsey & Kinsey Freeman. They have supported me through my entire educational journey.
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TABLE OF CONTENTS
acKnowledgements ... ii
table of contents ... iii
LIST OF TABLE/FIGURES ... iv
CHAPTER I: INTRODUCTION ... 5
CHAPTER II: A SCIENTIFIC APPROACH TO LIVESTOCK PRODUCTION ... 10
a) Livestock Nitrogen Cycle ... 10
b) Nutrition ... 13
c) Genetics ... 19
d) Waste Management ... 22
CHAPTER III: EXISTING ENVIRONMENTAL LAWS ... 28
a) Resource Conservation and Recovery Act (RCRA) ... 28
b) Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) ... 32
c) The Clean Air Act (CAA) ... 36
CHAPTER IV: A NEW REGULATORY FRAMEWORK ON THE HORIZON ... 39
iv LIST OF TABLE/FIGURES Figure 1 ... 11 Figure 2 ... 12 Figure 3 ... 14 Figure 4 ... 24
CHAPTER I: INTRODUCTION
Regulatory uncertainty is one of the biggest concerns facing livestock producers in America and environmental regulations represent one source of uncertainty. Here, the focus will be on the regulatory uncertainty surrounding ammonia emissions from livestock operations, specifically those associated with confined cattle feed yards. Developing an incentive-based program that helps address environmental concerns, while helping producers become more efficient, may be an effective way to address the challenge.
Environmental concerns have continued to be at the forefront of policy development for the agriculture industry. Specifically, several categories of emissions from the livestock sector have driven policy development. Of notable concern in the Rocky Mountain region are ammonia emissions and their correlation with nitrogen deposits, particularly those in higher elevations. These concerns are prevalent countrywide as well. For example, over the last several years, as a result of nitrogen deposits in Rocky Mountain National Park (RMNP) and subsequent impacts to ecological systems in the park, concerns over emissions have arisen from the front range of Colorado. The National Park Service and Colorado State University conducted studies in RMNP in order to better understand nitrogen deposition trends within the park as a result of atmospheric nitrogen from multiple sources (Blett & Morris, n.d.). One study identified livestock waste as a leading contributor to available nitrogen in the atmosphere, which is subsequently deposited in higher elevations such as RMNP (Id). The impacts from nitrogen deposits in the park vary across the ecosystem, with effects on various plant species and living organisms that rely on waterbodies and watershed in the park. For example, according to Blett & Kristi (4), “Old-growth Engelmann spruce forests in the east side of the Continental Divide show significantly altered chemistry attributable to nitrogen deposition, compared to similar spruce forests on the westside.” Resulting
effects of nitrogen deposits often have a positive impact on some species but are detrimental to others. “Experiments... show that increasing nitrogen changes the specific assemblages of plants that live on the tundra. Grasses and sedges outcompete flowering plants, a change that could diminish alpine flowers of the Park and reduce habitat for some animals” (id). Nitrogen deposits in the Rocky Mountain National park are undoubtedly impacting the ecosystems within the park.
Of the nitrogen deposited in Rocky Mountain National Park, 75% is deposited in wet form and 25% in dry form (Blett, 2004). An underlying question is why nitrogen deposition levels are increasing in the park? Nitrogen deposition levels in the Rocky Mountains have increased post- industrial revolution. “Total annual (wet and dry) nitrogen deposition monitored in the Park over the most recent five-year period averages around 3.9kg/ha/yr. Pre-industrial or ‘natural’ levels of nitrogen deposition are estimated to be about 0.2 kg/ha/yr. or approximately 20 times lower than current deposition (id).” This study indicates the trend of Nitrogen levels in the Rocky Mountains continuing to rise. As a result of changes within these ecosystems, conservationists and environmentalists seek to combat such adverse impacts.
There are numerous contributors to nitrogen deposits within the park; however, this paper will be more narrowly focused. Studies have identified numerous contributors located in the Front Range of Colorado. Such contributors either emit a nitrogen oxide (NOx) directly into the atmosphere or ammonia resulting from volatilization. Sources that contribute to ammonia loss to the atmosphere include vehicles, industrial emissions, and agricultural sources (nitrogen fertilizers & animal waste). “The largest Colorado source of ammonia emissions is confined animal feeding operations (id).” This paper will focus on ammonia emissions from livestock operations, how those losses affect the nitrogen cycle and how the issue may be addressed.
Before discussing the science and law portions of this paper, a discussion of the relevant stakeholders engaged in the issue is appropriate. On a broad scale, there are several categories of stakeholders interested in regulating ammonia emissions, specifically regulations pertaining to livestock production.
Conservationists and environmentalists are particularly relevant to this topic because they are the principal driving force behind movements for change. For instance, groups such as Environmental Integrity Project and Waterkeepers Alliance are groups that have taken a position on this topic. These groups focus primarily on the ecological changes continuously occurring throughout the Rocky Mountain Region. These stakeholders are concerned with effects on plant species, but also those animal species whose habitat may be affected as a result of such environmental changes. This stakeholder group is also concerned with the role the other stakeholders play in addressing the issue, for example, through governmental regulation limiting the permissible emissions levels from livestock operations. Environmentalists and conservationists also drive change on an operation level, pushing producers to adopt environmentally friendlier practices. This stakeholder group also has a persuasive connection with consumers and how they choose to exercise their purchasing power. Undoubtedly, this stakeholder group plays a substantial role in shaping the regulatory scheme.
The livestock production industry, regardless of the sector, also has a significant stake in the outcome of this issue. Ultimately, the industry is responsible for the implementation of tools and strategies that will address emissions levels of ammonia on an operation level. Operators may also be responsible for complying with potential regulatory schemes and may be liable for non- compliance. Monetarily, there will be substantial pressure put on livestock producers as a result of implementation of technologies and practices, but as we will discuss further in the paper there is upside potential from financial investments in ammonia emissions mitigation strategies. As
production efficiencies change, at all production levels, the profit margins of each operation will change as well. Differences associated with the types of production systems will affect the emissions levels on each specific operation.
State and federal governmental bodies both play a role in managing this issue. Several existing federal statutes have the potential to address ammonia emissions. Particularly, the Clean Air Act, if amended, would have the ability to address ammonia emissions with enforcement falling under the jurisdiction of the Environmental Protection Agency (EPA) (USDA; Agricultural Air Quality Task Force, 2014). Other acts require reporting, but do not give authority to regulate livestock ammonia emissions; these include the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), and the Resource Conservation and Recovery Act (RCRA). If EPA were to regulate ammonia emissions, it would require livestock producers to interact with all other stakeholders. State governments may potentially be implicated in this regulatory framework as well. For example, some states already have existing statutes in place requiring reporting, and to some extent regulation of ammonia emissions, which requires compliance by emitters. Depending on the development of a regulatory framework, states may play a role in the regulation process.
Although consumers are not directly involved in the application of production practices and may not be directly involved in the development of regulations, they still have a significant impact on the maturity of the issue. The role consumers play is through their purchasing power, which effects market prices. Considering the increased cost associated with various mitigation practices, those costs will need to be passed on to the consumer. The objective here is to evaluate an incentive-based program in the form of a federal grant program, and its ability to effectively assist in mitigating ammonia emissions
The remaining portions of the paper will explore various aspects of the issue, starting with the science. Understanding the nitrogen cycle on livestock operations and the various factors that affect the nitrogen cycle is the key to determining the best approach to regulating emissions. Following the scientific discussion in Chapter II, Chapter III is an in-depth analysis of the current federal environmental regulations. Finally, Chapter IV will be an exploration of a new proposed incentive-based program, in which producers benefit and ammonia emissions reductions are achieved.
CHAPTER II: A SCIENTIFIC APPROACH TO LIVESTOCK PRODUCTION
There are many factors to take into consideration from a scientific standpoint for ammonia emissions that originate from livestock operations. Science plays an important role in understanding the most effective ways to manage emissions. Understanding the nitrogen cycle of livestock operations is a logical starting point of the scientific analysis.
a) Livestock Nitrogen Cycle
Nitrogen (N) is one of the elements forming the chemical compound ammonia. “Ammonia is a colorless gas with a pungent odor that is noticeable at concentrations above 50 [parts per million (ppm)] (Phillips, 1995).” Ammonia is a concern for two reasons; first, in confined feeding operations it can cause extreme nuisance from its odor, secondly, it can cause environmental impacts as a result of atmospheric transfer. The discussion here will focus specifically around the latter concern. According to the EPA, livestock waste management and the production of fertilizer account for most of the ammonia emitted from the livestock industry (Phillips, 1995). The agriculture industry is estimated to contribute 60-85% of total ammoniaemissions in the United States (USDA Air Quality Task Force, 2014). In order to address the concern of excess ammonia being lost to the atmosphere, livestock operations need to be considered.
Regardless of the species, N plays a key role in livestock production. Nitrogen forms the backbone of the amino acids, which serve as the building blocks of protein (USDA Agricultural Air Quality Task Force, 2014). Dietary nitrogen supports growth and efficiency for all livestock in the production system. Amino acids are provided to livestock primarily through plant sources of crude protein (CP) such as corn, soybeans, wheat, barley, forages, and byproducts such as distillers grains. Any N that is not absorbed through the digestive process of livestock is excreted
through the feces and urine. In a lactating cow, up to 70% of N from ingested feeds can be excreted, primarily in the urine (Id). Both manure and urine contain chemical compounds that lead to ammonia emissions with urea being the primary form of N in urine. When urea is excreted into the environment, urease, an enzyme found in, rumen as microbial enzyme, feces, and soil, enzymatically hydrolyzes urea to NH4+ and ultimately to ammonia (Id). Although manure is
excreted with a higher composition of nitrogen, urine is more easily converted to ammonia and volatilized. When excess dietary nitrogen is excreted in manure ammonialosses are only 10-30% of total N input, although this is dependent on the feed type and use of low-emission techniques (Oenema, 2006). However, the rates at which different species produce ammonia varies, as shown in Figure 1, which is primarily a result of differences in the digestive tract between the species.
Figure 1. Depicts ammonia emissions from animal housing, manure storage and land application (Outreach, 2005).
Excess ammonia that is excreted by the animal, is susceptible to volatilization as a result of several environmental factors. Ammonia volatilization, nitrification, denitrification, leaching, and runoff emit inorganic N, with volatilization leading to the greatest N loss (Phillips, 1995). Volatilization of ammonia depends on several categories of factors including manure type and characteristics, environmental factors, including weather conditions, manure application and timing for use as fertilizer, and soil characteristics and conditions, although, these vary depending on location and the production practices utilized.
Temperature is one environmental factor that contributes substantially to the process, and volatilization is likely to increase in warmer temperatures. A 5°C drop in temperature leads to a
15% drop in total N volatilization as ammonia (Agri facts & Atia, 2008). When cleaning pens, transporting, treating, or land application of manure, ambient temperatures should be considered. Wind speeds also affect ammoniavolatilization with higher wind speed leading to more air exchange between the manure and atmosphere (Agri facts & Atia, 2008). Finally, precipitation levels affect the amount of ammonia that is volatilized from manure, and usually have a positive effect on emission reduction. Volatilization after manure spreading is reduced with precipitation due to the decrease in evaporation and increased soil infiltration. Thus, higher relative humidity also decreases ammonia emissions (Id). Each of these factors are implicated on each level of a production system, which can be seen in Figure 2.
Figure 2. Depicts the major nitrogen flows from an agricultural operation. (Rotz, n.d.). Once ammonia has volatilized into the atmosphere, it is transported to various areas as a result of different atmospheric conditions. Nitrogen can be deposited in these areas in either wet or dry form. Ammonia is a water-soluble compound which allows it to be captured by water particles in the atmosphere. Once the compound has been absorbed by water particles, they are then deposited in various areas as a result of either rain or snowfall. Dry deposition occurs through atmospheric transport to a variety of landscapes including aquatic and terrestrial (Hall, n.d.).
Although both of these forms of deposition are important to understand, wet deposition accounts for more total ammonia transferred from the atmosphere to the earth’s surface. Diving deeper, there are specific, on farm factors to be considered for ammonia excretion and emission.
b) Nutrition
Perhaps one of the most direct influences on ammonia excretion from livestock is the feedstuffs that compose livestock rations and subsequent digestive breakdown of those feeds. Livestock nutrition is one of the most important elements in the livestock production system and has a significant impact on livestock performance on multiple levels. Thus, dietary modifications may be a way to reduce ammonia emissions from livestock operations (Ndegwa, et al., 2008). A proper balanced diet can be positively correlated with more efficient livestock that produce less waste as a result. There are numerous advantages to efficiency associated with correctly balanced diets, such as the fact that more efficient animals require fewer days on feed and need less resources for growth and maintenance. Fecal and urinary excretion is decreased when more of the nutrients and energy consumed is converted to fat and muscle. This is a profitable practice for feeders because they have to spend less money on low input livestock. When ruminant livestock are fed diets with excessive dietary protein, unbalanced amino acid profiles, or without adequate energy, urinary and fecal N loss is increased which leads to increased ammonia emissions (Id). Therefore, various feeding strategies can be implemented to decrease ammonia excretion.
The basic process of the digestive system, particularly in ruminant animals, is very complex. Protein requirements of the ruminant animal depend on stage and goal of production. For instance, dairy cattle will have different CP requirements during different stages of lactation; also, dairy cattle will have different CP requirements than beef cattle. The degradable intake protein (DIP) is usually 10-13% of daily total digestible nutrients (TDN; Lalman and Richards, n.d.). Differences are also notable from beef versus dairy cattle (Id).
The basic digestive process is the same in both dairy and beef cattle. Dietary protein is consumed and can be categorized as rumenally-degradable protein (RDP) or ruminally undegradable protein (RUP). Once protein is degraded or synthesized into ammonia in the rumen , it either moves to the small intestine where it is then absorbed by the body, or, it passes through the wall of the rumen, is absorbed into the blood stream and transported to the liver. Nearly 50-85% of total protein that reaches the small intestine for absorption is microbial synthesize protein (Id). In rations where the RDP provided exceeds the ruminal microbial requirement for protein, ammonia accumulates and is absorbed, metabolized, and converted to urea in the liver and subsequently lost in the urine (Bach, Calsamiglia, & Stern, 2005). The undegradable protein passes to the small intestine, where it is absorbed and use by the animal directly, instead of through microbial protein. The process of CP moving through the digestive tract is illustrated in Figure 3.
Figure 3. Depicts protein digestion and absorption in ruminates (Lalman & Richards, n.d.). The livestock industry is continuously researching feed stuffs and developing new feed technologies that are more efficient sources of nutrition with a lower cost for producers. One such feed product is dried distillers grains (DG), which is a byproduct of ethanol production. Briefly, fermentation of starch, which composes about 2/3 of total of corn content, in the dry milling process leads to the production of ethanol (Klopfenstein, Erickson, & Bremer, 2008). The remaining nutrients are left in the stillage, providing a highly condensed feed product. The nutrient
profile of DG, compared to corn, results in a dramatic increase in protein, fat, fiber, and phosphorus concentrations (Id). The high amounts of protein in DDGS often exceed the nutritional requirements for livestock. Thus, the excess protein and correlated amino acids lead to increased ammonia either in manure or excreted as urea in urine. Feed trials have focused on improving feed efficiency of livestock and subsequently balancing and reducing impacts on the environment.
Innovative technologies have been developed to offset the issue associated with feeding excess protein, such as the issues described with feeding DG. Feeding concentrated tannin extract (CT) can reduce ammonia emissions through a reduction in excess urea in urine and more readily fixing excess nitrogen in manure. Condensed tannins are polymers that are widely found in plants, formed by the condensation of flavans. A study conducted by Lethbridge Research and Development Centre in Canada, focused on feeding CT in numerous dietary makeups and determining the effect on intake, growth performance, carcass traits, and ammonia emissions of feedlot cattle. The study was prompted by the need to feed highly efficient cattle that are also more environmentally friendly. There were two parts to the study. Overall, the experiment concluded that, while distillers grain (DG) is a high quality, economic feed alternative and is replacing 15-50% of traditional grain rations, the N and P levels are 3 times higher in DG compared to corn. This leads to excess protein and P compared to the nutrient requirements of the cattle, which ultimately leads to increased N excretion, predominately via urea in the urine which is readily converted to ammonia by the microbial enzyme urease (Koenig, Beauchemin, & McGinn, 2018).
The first experiment was a necessary step before proceeding to experiment two of the study. The first experiment concluded that increasing the concentration of CT extract in the diet does not impact dry matter intake (DMI) in beef steers. A follow up experiment was then designed to determine if there is an impact on growth performance and ammonia emissions as a result of feeding CT (Id). The second experiment of the study focused on the impacts of feeding CT on
growth performance and ammonia emissions. Results of the study showed that the effect of feeding CT at 2.4% and 2.5% of dry matter (DM) of high-protein diets did not negatively affect growth performance. However, when CT was increased to 3.5% of DM, DMI was reduced. This study illustrates the balance to be struck for reducing ammonia emissions without having a negative impact on growth and performance, and subsequently, the effects on the producer’s bottom line. Feeding CT at 2.5% of DM did not have any negative implications on growth rates and was successful in reducing ammonia emissions. When diets consisted of 40% DG, there was an 11% increase in emissions compared to the 20% DG diet (Id). Incorporated in a properly balanced diet utilizing distillers grains, CT can play an important role in reducing emissions, without having a negative effect on growth performance or intake. Feeding CT can also bind up more excess dietary nitrogen in manure, resulting in less excess nitrogen being filtered through the liver and excreted in the urine. Excess protein is bound up in the rumen by CT extract. Therefore, when the formed compound moves to the small intestine, absorption into the body does not occur. Since the excess nitrogen is not absorbed, it does not have the opportunity to be converted into urea by the liver and excreted in the urine. Tannins are an effective tool to be utilized in the development of diets, especially for fat cattle diets, because, as the study shows, there is no significant effect on growth when CT extract is incorporated in diets–at the correct rates– that utilize high levels of distillers grains.
CT extract is not the only feed stuff that has been examined for its impact on ammonia emissions. A research study produced by Cambridge University evaluated a variety of woody forages that have the potential to mitigate ammonia formation. The plant secondary metabolites (PSM) which are found in several grassland plants, more so in legumes, can decrease both CH4
and ammonia emissions. The PSM content may be higher in woody plants like shrubs and trees than in other forages (Terranova, Kreuzer, Braun, & Schwarm, 2018). The study tested 18 plant
materials from 16 different plant species and utilized an incubation method for replicating rumen fermentation, which allowed the researchers to measure both NH4 and ammonia levels (Id).
Results from the study illustrate that ammonia levels can be reduced by up to 36% with the inclusion of these plants in the diet (Id). However, there are specific characteristics associated with each of the plants used in this experiment that may impact the feasibility of using them in livestock rations. One such effect is a seasonal difference in growth of the plants and their nutritional makeup. From a practical perspective this study illustrates that resources to mitigate ammonia emissions are widely available. Producers can find economically favorable feed sources to reduce ammonia formation in the rumen, without decreasing production.
As previously discussed, urea is a large concern as a result of its conversion to excess ammonia. Once excess ammonia in the body is transferred to the liver, it is then converted to urea and excreted through urine. There is some variation based on dietary make up, but on average 60 to 80% of nitrogen excreted by cattle is in their urine which contains up to 97% urea nitrogen and is converted to ammonia via microbial urease (Varel, Nienaber, & Freetly, 1999). There is a push for research to find ways to mitigate volatilization associated with high levels of urea excreted in the urine. Urease inhibitors have become an effective tool in lowering the susceptibility of urea to being converted into ammonia as a result of urease presence, both in the digestive tract and greater environment. This technology has been utilized in several ways; first, through feeding natural urease inhibitors, and second, through applying urease inhibitors to the ground surface. For the purposes of this subsection, only the first application will be discussed; the second will be discussed under the waste management subsection.
It is important to understand both the urea compound and the urease enzyme. From the previous discussions, urea is a byproduct of nitrogen filtration through the liver. Urea has also become a key component of livestock diets worldwide as it is a very inexpensive ingredient that
can provide non-protein nitrogen in ruminant diets, and is subsequently converted into microbial protein (Patra & Aschenbach, 2018). Further research has been conducted to determine the effect of urease activity in the rumen in correlation with added urea in the diet. The urease enzyme causes the breakdown of urea into ammonia, and therefore, if the urease enzyme is not controlled, or urea is over fed, ammonia toxicity may occur. Regardless of concerns of ammonia toxicity, the urease enzyme within the rumen can cause excess production of ammonia which, up to 10-20%, can be converted into microbial protein (Id). However, nearly 80 to 90% of ammonia produced in the rumen is transported to the liver, with most of that being excreted as urea in the urine. Urease activity in monogastric animals is also noteworthy; urease interaction occurs in the small intestine, cecum, and colon (Id). Although, comparatively, in monogastric animals, urease activity is generally lower than that of ruminates.
Concerns about over production of ammonia in the rumen as a result of urea’s rapid hydrolysis by the urease enzymes have led to technological advancements to reduce this process. Natural and synthetic forms of urease inhibitors, including acetohy-droxamic acid (AHA), phosphoric phenyl ester diamide (PPD), N-(n-butyl) thiophosphoric triamide (NBPT), boric acid, bismuth compounds and hydroquinone, have been derived and have become an effective tool in lowering urease reactivity to urea present in the diet (Id). However, some of these urease inhibitors pose a risk to human and animal health, precluding their use. The compounds have illustrated promising use as tools for reducing ruminal urease activity. For example, hydroquinone, depending on its concentration, can reduce urease activity up to 63% and AHA can reduce urease activity up 50% (Id). Urease inhibitors have been successfully proven to reduce urease activity in the rumen, but there may be implications if they are not utilized properly and have been shown to impact growth of different microbial species which can alter carbohydrate fermentation (Id). Although, this technology may have consequences other than urease inhibition, it is still worth considering it
utilization in diet formations. The use of urease inhibitors in cattle diets are economical enough to be used to address concerns of excess urea production and excretion.
There are many other nutritional technologies that have been developed that are targeted at making livestock more efficient and subsequently reduce emissions associated with waste. There are other feed technologies that have been developed to assist in improving efficiency, with potential secondary benefits of reducing emissions. Feeding technologies such as monensin which helps control coccidiosis, a protozoal infection, and also increases feed efficiency, is a technology widely utilized in the livestock production industry (Gehman, et al., 2008). The feed technologies described above are just a few developments that have resulted in both economic dividends for producers and have yielded benefits for the environment. The task now is to help producers understand the implementation of these technologies based on their production systems, potentially producing mutually beneficial outcomes for producers and the environment. The outlined nutritional technologies are certainly not an exhaustive list, and there are other areas of production that can be addressed in relation to ammonia emissions.
c) Genetics
Genetics are also an important tool that livestock producers can use to increase the efficiency of their animals, which as previously discussed has a positive effect on the reduction of emissions. In general, producers try to incorporate positive genetic traits when making decisions about their breeding programs in some form or fashion. Producers can utilize expected progeny differences (EPD) when making decisions such as selecting replacement females, or when investing in new herd sire genetics. EPDs such a Rib Eye Area (REA) and Marbling are good indicators of how offspring will perform in the feed yard and subsequently carcass quality; specifically, their ultimate quality and yields grades. Growth numbers can also be a good indicator of how efficient cattle are going to be, for example, a higher yearling weight figure may be
illustrative of an animal’s ability to outperform its contemporaries in terms of growth. In analyzing EPDs, feed efficiency traits should also be considered, as they are an applicable tool in determining the effectiveness of cattle in converting feed to muscle and finish. Feed efficiency traits are recently developed genetic tools for selection. These traits are a better representation of improving efficiency of beef cattle in a way that would have a positive effect on emissions levels. It is important to for producers to take into consideration feed efficiency traits during genetic selection because it is a good indicator of growth, without increasing frame size. Figures included in most modern EPDs for angus cattle include numbers for average daily feed intake (AFI), residual feed intake (RFI), and average daily gain (ADG); (Rolf et al., 2012). Such EPD figures are useful as a result of their direct correlation to feed efficiency in a cumulative way. Genetically speaking, EPD’s are great tools for producers to utilize in any production system, not only for the monetary benefits associated with them, but the environmental ones associated with ammonia emission reduction.
Feed efficiency has been a predominant area of interest in livestock production research, even more so in recent years. Determining the genetic component of these traits is imperative in order to utilize those indicators successfully in breeding programs. Such traits include, feed conversion ratio (FCR), average daily gain (ADG), and residual feed intake (RFI). Feed conversion ratio, or the amount of feed required to achieve one pound of gain, is negatively correlated with ADG, suggesting that as growth increases the FCR is more favorable in that, less feed is required to achieve the desired gain (Arthur et al., 2001). Thus, selection for decreased FCR may lead to faster growing animals. This illustrates the importance of using these traits in selecting both replacement females and sire selection regardless of the species, for terminal targeted livestock. This is especially true for traits like feed efficiency, which is a polygenic trait. Thus, many genes are associated with the specific phenotype and those genes may also impact other traits. Thus,
single trait selection on a single trait may lead to negative results in other related traits. For example, when selecting on more efficient animals based on RFI, selection on that single trait can lead to negative impacts in terms of carcass characteristics (Arthur et al., 2001). A multi-trait selection approach is most appropriate and the use of genetic testing, EPD, and other genetic technologies can improve the accuracies of selecting on these traits of interest. There is little doubt that utilizing these genetic traits as a selection tool helps improve feed efficiency. Therefore, when a producer is making a decision about the production value of both males and females, they should balance data for growth traits such as birth weight, weaning weight, and yearling weight, while also considering various carcass traits and feed efficiency traits such as RFI. One trait cannot produce the desired result of more efficient cattle without the other; they are co-dependent. For instance, you might have great carcass traits genetically, but if it took those cattle twice as long to reach their end point, then those cattle still lack efficiency. Effects of these traits on the production systems as a whole should be considered, to balance both genotype and phenotype. The common reference to phenotype is phenotype = genotype x environment. Improvements can be made on each of these fronts to improve efficiency as well as reducing emissions levels.
Currently, novel genetic studies are being conducted to determine the efficiency of cattle, as well as the role genetics play in reducing emissions of various kinds. Typically, the livestock industry has focused on feed technologies to facilitate production efficiency in livestock. However, several studies are currently looking at genetically selecting animals to be both feed efficient, as well as more environmentally friendly. New Zealand is one of the leading countries in genetic research, targeting emissions from livestock. An article published in the New Zealand Herald in January 2019, discusses genetically breeding cattle with less environmentally harmful urine (The Vision is Clear, 2019). The goal of the study is to explore numerous options for controlling excess nitrogen being excreted through the urine without sacrificing production yields. One thing the
study hopes to find is a way to increase milk protein levels in cows, without increasing urinary nitrogen levels. Studies such as this one, although results are pending, show promise for continued research in the livestock industry regarding the use of genetics to select for more environmentally friendly livestock.
Cutting edge research is currently being conducted to develop important genetic tools. Studies are being conducted regarding genetics and their correlation to microbes present in the rumen (Mann, et al., 2018). Research evaluating the heritability of the microbiome as a whole is currently underway. This will allow producers to select specifically for cattle which are digestively predisposed to being more efficient, via activity of the rumen microbiome. These research projects are cutting edge and illustrate the scientific interest in increasing efficiency of livestock animals from several aspects including nutrition, host genetics, and even microbial genetics. The opportunity to utilize advanced selection technology to improve feed efficiency and subsequently environmental impact appear to be within reach as these research programs continue.
d) Waste Management
Waste management is one of the biggest factors in ammonia being emitted to the atmosphere. As discussed in previous sections, volatilization of ammonia can occur as a result of ammonia excreted in the manure, or as urea in urine. In confined cattle feeding operations, waste can sit on the surface of pens for extended periods of time before it is removed. Depending on weather, number of cattle in a pen, availability of labor, and several other factors, producers’ ability to clean pens is variable. As a result, the longer that waste sits in a pen without any intervention, the more likely volatilization of ammonia will occur, which has been estimated to account for 50% of feed N loss (Parker et al., 2005). To reiterate what was previously discussed, one of the biggest factors in ammonia volatilization in livestock operations is the microbial enzyme urease. Numerous research studies have been conducted to explore the application of urease inhibitors to
the surface of cattle feed-yard pens to reduce urease’s interaction with urea excreted in the urine (Koenig et al., 2018).
Livestock facilities vary widely, which makes it more difficult to uniformly treat emissions close to their source. For instance, fat cattle are raised outside, free from the ability to capture emissions that are a byproduct of waste. Livestock such as poultry and hogs are usually raised inside, which opens the door for such operations to utilize a wide range of waste management tools. Two such waste management tools are scrubbers and biotrickling filters which can be affixed to these enclosed facilities.
Scrubbers can be used to capture these emitted compounds by trapping them in acid form, resulting in the creation of an ammonium salt solution. Scrubbers are extremely effective at capturing ammonia and its odor and have been heavily implemented in the Netherlands. Scrubbers can capture approximately 95% of emitted ammonia (Id). This may be an extremely useful technology, but it is not the only tool available and depends on the infrastructure of the operation.
Biotrickling filters are another technology that can be utilized to capture ammonia emissions from hog and poultry operations. Biotrickling results in the capture and removal of ammonia via bacterial conversion which leads to biofilm formation on the recirculated water (Id). This process is an effective way to filter emissions before they reach the greater environment, but its use may be cost prohibitive for some operations.
These technologies work only for those operations where livestock are housed indoors. Under the current regulatory framework, there is no incentive for producers to take on the extra cost of implementing these tools in their operations. Cost comparisons of these two technologies should be considered and the benefits associated with each, when deciding to implement them in an operation.
The type of manure and its characteristics such as total nitrogen (TN), ammonium nitrogen, %DM and others can be attributed to an animal’s dietary compilation and affect volatilization during use of manure as a fertilizer on soils (Agri-Facts, 2008). The ammonia content of manure certainly varies from species to species, as depicted in Figure 4. Not only does nutrition play a vital role in the profitability of livestock, but it is also an important factor in various kinds of emissions and subsequent environmental impacts.
Manure type
Ammonia content
(kg/ton of semi-solid manure)
Poultry manure 4.2
Swine manure 2.4
Dairy manure 1.9
Beef manure 0.8
Figure 4. Depicts the ammonia content of manure from each respective species (Agri facts & Atia, 2008).
Both manure application, and soil characteristics and conditions, are more relevant when it comes to using manure as a fertilizer. However, application type plays a significant role in the management of waste. The largest losses occur when the manure is not incorporated into the soil. Particular characteristics that are important in soil makeup are moisture content, texture, cation exchange capacity, pH, and plant residue or cover (Id). The lack of incorporation into the soil is particularly important in confined feeding operations because livestock waste sits in the pens for longer periods of time. There are several technologies discussed above in several other sections that are applicable to waste management strategies.
Under the nutrition portion of this chapter, evidence was presented of the beneficial use of CT extract and its effects on mitigating ammonia emissions. When CT extract is incorporated at 2.5% in a high protein diet, statistically speaking, ammonia emissions are lowered without adverse effects on growth performance or carcass traits. As described above, CT extract prevents excess crude protein from being absorbed into the body and binds the excess dietary nitrogen in the manure. The reason this is more beneficial from a waste management standpoint is because there are less emissions associated with the manure from cattle fed CT extract, than the emissions associated with manure from cattle not fed CT extract (Koenig et al., 2018). The practical implication for utilizing this feed technology means that with waste remaining in pens for extended periods of time it is less susceptible to volatilization. As discussed above, there are concerns about volatilization resulting from transportation and application of manure to fields for fertilizer. Less volatilization occurs from manure applied to fields when CT extract is used because it ties up excess ammonia. Therefore, CT extract has multiple beneficial uses within the production systems; these uses may not have significant impact on the economics of cattle feeding but do assist in mitigating excess emissions of ammonia.
In the nutritional portion of this chapter, urease inhibitors were also introduced, which is a technology utilized to reduce the enzymatic process of breaking down urea to ammonia. The urease enzyme is endogenous in manure and soil, resulting in more susceptibility of urea conversion to ammonia and subsequent volatilization. Urease inhibitors have become an effective tool in limiting urease’s interaction with urea excreted in confined feed yard settings. This technology is an effective tool to employ in feed yards because it can be applied directly to the surface of waste sitting in pens, in turn reducing ammonia emissions without requiring intensive routine cleaning of pens. There are both synthetic as well as natural based urease inhibitors, which can be applied to the surface of pens on a regular basis. A study that was published in the Advanced Research
Journal focused on the use of naturally sourced urease inhibitors such as C. sinensis (black tea), which affected enzymatic activity when applied to soil (Modolo, de Souza, Horta, Araujo, & de Fátima, 2015). The study illustrates the effectiveness of natural compounds derived from plants as urease inhibitors when applied to the surface of pens. As a result of applying urease inhibiting compounds, the carbon/nitrogen ratio of the soil is altered (Parker et al., 2005). One study looked at the frequency and amount of N-(n-butyl)thiophosphoric triamide (NBPT) applied to the surface and showed a reduction in the level of ammonia emissions (Id). The study illustrates the effectiveness of the technology when utilized in eight-day increments. “When applied every eight days, and without simulated rainfall, NH3 emissions were reduced by 49.4% and 66.0% at NBPT
rate of 1 and 2 kg/ha, respectively… Simulated rainfall reduced the NH3 emission rates from 1%
to 25% as compared to the non-rainfall treatments, although the differences were not statistically different (id).” However, the study noted that as urea continued to build up in the pen with little of it hydrolyzing, more NBPT was required to continue reduction in ammonia emissions levels (id). Given these results, NBPT applied to the surface of feedlot pens can assist in reduction of ammonia emissions when applied in combination with an effective pen cleaning system.
As this technology progresses there may be associated economic benefits. The primary benefit is a result of increased value of the manure for fertilizer (Id). Inhibiting the enzymatic process associated with urease allows the manure to retain more nitrogen, increasing the nutrient content of the manure, and making livestock waste more marketable as a fertilizer source. NBPT is not economical when applied at a rate of 1 kg/ha, at 8-day increments, yet associated air quality and environmental benefits may improve viability of this option (Id). The discussion in the remaining chapters may determine the viability of this technology as a potential tool to reduce ammonia emissions.
The above subsections of this chapter are potentially viable tools that can be used by livestock operations to reduce ammonia emissions resulting from high performance diets. It is important to note, however, that the technologies that I have discussed are not an exhaustive list of potential resources available to make operations more environmentally friendly. With the development of regulations and programs targeting ammonia emissions from livestock operations, research and development of technologies will continue.
CHAPTER III: EXISTING ENVIRONMENTAL LAWS
The 1970s were pivotal years for developing federal environmental regulations, and many of these regulations are very prominent today in regulating environmental impacts. Under this chapter three federal environmental laws will be placed under a microscope; understanding the ins and outs of the acts, as well as a pros and cons analysis of utilizing these laws to regulate ammonia emissions on livestock operations. There are three statutes in specific that aim to address concerns of private emissions and address their environmental impacts; the Resource Conservation and Recovery Act (RCRA), Comprehensive Environmental Response, Compensation and Recovery Act (CERCLA), and the Clean Air Act (CAA). As these laws stand now, ammonia emissions are not regulated.
a) Resource Conservation and Recovery Act (RCRA)
RCRA was passed by Congress on October 21, 1976, in order to address concerns associated with disposal and management of solid and disposable waste. Triggering language under provisions of RCRA allows private individuals to determine whether or not their activities fall within the jurisdiction of RCRA. First, it must be determined whether or not a substance qualifies as a solid waste under the definition of ‘solid waste’ which is provided in the Environmental Protection Agency’s (EPA) regulations:
Solid waste means any garbage, refuse, sludge from a waste treatment plant, water supply treatment plant, or air pollution control facility and other discarded material, including solid, liquid, semisolid, or contained gaseous material resulting from industrial, commercial mining, and agricultural operations, and from community activities, but does not include solid or dissolved materials in domestic sewage, or solid or dissolved material
irrigation return flows or industrial discharges which are point sources subject to permits under section 402 of the Federal Water Pollution Control Act, as amended, or source, special nuclear, or byproduct material as defined by the Atomic Energy Act of 1954, as amended (40 C.F.R. §267.2, Resource Conservation and Recovery Act, 1980).
Livestock waste would typically meet the definition of solid waste under the above definition; however, the code does provide several exceptions to regulation. Under 40 C.F.R. §257.1, the EPA has provided exemptions for sources of solid waste, “(c) these criteria apply to solid waste disposal facilities and practices with the following exceptions: (1) the criteria do not apply to agricultural wastes, including manure and crop residues, returned to the soil as fertilizers or soil conditioners… (Id).” Since livestock waste is considered an exempt practice, EPA does not currently have jurisdiction to regulate such wastes under RCRA. If a change in position was to be implemented in the existing regulations, waste from livestock operations could be regulated under the act. The purpose of this subsection is to look at the potential benefits and challenges of regulating livestock operations under RCRA.
RCRA typically regulates those solid wastes which fall into the definition set out above under §267.2, unless one of the exemptions under subsection C of §267.1 applies. RCRA also establishes a program for regulating hazardous wastes. “ A solid waste, or combination of solid wastes, which because of its quantity, concentration, or physical, chemical, or infectious characteristics may: (i) cause, or significantly contribute to, an increase in mortality or an increase in serious irreversible, or incapacitating reversible, illness; or (ii) pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, or disposed of, or otherwise managed (42 USCS §6903, Resource Conservation and Recovery Act, 1980).” In determining whether or not a substance classifies as hazardous under RCRA, two standards can be applied. First, a substance can be classified as hazardous if the EPA has listed
such a substance as hazardous through regulation. Second, characteristics of the substance can determine its eligibility as a hazardous substance. Such characteristics include ignitability, reactivity, corrosiveness or toxicity (40 C.F.R. §261, Resource Conservation and Recovery Act, 1980). The ‘hazardous waste’ definition is also not applicable here. Although, the act was created with the intent to address concerns regarding pollution under these two categories. With livestock waste having various uses, for instance, fertilizer, it is typically not considered the same kind of solid waste as those that are regulated under the act. Therefore, before altering regulations to include livestock waste it should be determined whether or not RCRA is the right statute to administer regulations under.
RCRA has been in place for more than forty years, which provides the benefit of having established law to regulate under. Using RCRA to regulate livestock waste eliminates some of the leg work associated with developing a new regulatory scheme. Efficiency is the biggest benefit for utilizing RCRA to regulate livestock waste. For instance, EPA has already developed and enforced regulations targeting solid waste. Along these lines follows case law that has been well settled for solid and hazardous waste issues. The EPA typically has jurisdiction to administer numerous environmental statutes, including RCRA. Therefore, the system that has been developed to monitor solid waste concerns is already under the control of an agency that has expertise for implementing programs addressing environmental concerns. The practical implications of RCRA being well established, is that protection of the environment can be more readily achieved because the system has been changed an altered over the years as a result of new regulations as well as case law. This goes hand in hand with the development of consequences to be suffered by solid waste producers who do not comply with regulations. The above described beneficial attributes associated with regulating livestock waste under RCRA, may not be as significant as the potential drawbacks of such a regulatory framework.
As great as efficiency is with RCRA, there are negative implications of providing EPA with jurisdiction to regulate livestock producers as a result of ammonia emissions associated with their operations. As described above, regulations have been developed by the EPA to carry out RCRA, along with extensive case law on the matter. Although, these are great things in the name of efficiency, they prove to be more rigid for livestock waste. The difficulty is that regulations and cases were decided without consideration of the implication it might have on livestock waste producers. Livestock waste was not intended to be regulated under RCRA, therefore, EPA has had no reason or jurisdiction to take such solid waste into consideration when developing regulations. It might be considered unequitable to later include livestock waste under RCRA’s jurisdiction, when such waste generators did not have the ability to participate in the regulatory process. Such a concern relates directly to participatory democracy, the foundation of democracy in the United States.
The EPA typically has jurisdiction to administer many federal environmental statues, which may qualify the agency as the best suited to manage such environmental concerns. EPA has been designated as the agency most appropriate to implement RCRA, but RCRA and the EPA may not be the best choice for addressing ammonia emissions from livestock operations. EPA no doubt has the expertise to implement and carry out regulations under RCRA. However, RCRA and the EPA may not be the best approach for this concern. The agriculture industry is very unique and no matter what area of the law is involved, laws typically apply differently to the industry. Just as an example, typical implied warranties that attach to regular goods sold are often not applicable to agricultural goods sold. This is just one example of how the law is different for the agriculture industry. The primary purpose for such distinctions is the type of business and commodities involved in the industry. Changes are slow to implement as a result of a wide variety of factors associated with livestock and crop production. As a result, there are stark contrasts in the
characteristics of the agriculture industry compared with industries that are currently regulated under RCRA. This is one of the biggest drawbacks in utilizing RCRA to regulate ammonia emissions from livestock operations; EPA may not be the best agency to regulate such emissions, rather the United States Department of Agriculture (USDA) may be better equipped to carry out such regulations. USDA has no authority currently to regulate ammonia emissions in relation to their effects on the environment, nor does the EPA, as a result of a statutory exemption. This exemption implies that RCRA is not a suitable statute to regulate ammonia emissions from livestock operations. There are both notable benefits and challenges associated with using RCRA to address such concerns, leaving the floor open for a better regulatory proposition.
b) Comprehensive Environmental Response, Compensation and Liability Act (CERCLA)
RCRA and CERCLA are two environmental statutes that go hand in hand, and often are both implicated when such environmental concerns arise. CERCLA’s primary purpose is to address concerns from release of hazardous wastes, and therefore provide a means of compensation, awarded based on the finding of liability of potentially responsible parties (PRPs). Under CERCLA the preliminary question is whether a release of a hazardous substance from a facility has occurred. 42 USCS §9601, defines release as follows:
The term "release" means any spilling, leaking, pumping, pouring, emitting, emptying, discharging, injecting, escaping, leaching, dumping, or disposing into the environment (including the abandonment or discarding of barrels, containers, and other closed receptacles containing any hazardous substance or pollutant or contaminant) … (Comprehensive Environmental Response, Compensation and Liability Act, 1980).
The definitional provision does include several exceptions to the general definition stated above. If there has not been a release of a hazardous substance from a facility or an exception applies, CERCLA does not apply. CERCLA permits recovery of cleanup costs from those parties that are potentially responsible. 42 USCS §9607, establishes four categories of potentially responsible parties; current owners and operators, previous owners and operators, arrangers, and transporters (Comprehensive Environmental Response, Compensation and Liability Act, 1980). Under §101 and §102, CERCLA both defines and provides additional authority to the EPA to make regulations regarding future hazardous substances.
CERCLA places liability for cleanup costs on PRPs for four types of costs; governmental response costs, PRPs response costs, natural resource damages, and health assessment and monitoring (id). U.S. v. Alcan Aluminum Corp, is the seminal case on the matter of determining liability under Section 107 of the act (U.S. v. Alcan Aluminum Corp., 1992). “Liability is imposed where the plaintiff establishes the following four elements: (i) the defendant falls within one of the four categories of ‘responsible parties’; (ii) the hazardous substances are disposed at a ‘facility’; (iii) there is a ‘release’ or threatened release of hazardous substances from the facility into the environment; (iv) the release causes the incurrence of ‘response costs (id).’” Under CERCLA ammonia is considered to be a hazardous waste in the air emissions category. Previously, EPA developed regulations exempting livestock operations from liability under CERCLA. However, the United States District Court for the District of Columbia in Waterkeeper Alliance v. EPA, overturned the EPA’s regulation (Waterkeeper Alliance v. EPA, 2017). “Because the EPA’s action here can’t be justified either as a reasonable interpretation of any statutory ambiguity or implementation of a de minimis exception, we grant Waterkeeper’s petition and vacate the Final Rule (Id).” As a result of this case livestock producers were required to report ammonia emissions which exceed reportable quantities. Following the opinion issued by the court in Waterkeeper
Alliance, on March 23, 2018 Congress passed the Fair Agricultural Reporting Method Act (FARM Act). The Omnibus Bill amended Section 103(e) of CERCLA, exempting air emission reporting from farm operations (U.S. Environmental Protection Agency, n.d.). The act also amended reporting requirements under the Emergency Planning and Community Right-to-Know Act (EPCRA) (Id). This case illustrates the freshness of this environmental issue, and the need to address concerns through regulations or another mechanism.
Considering the passage of this amendment by Congress, it is important to note that this does not relieve livestock operators from potential liability. Potential liability is still a looming consequence for livestock operations both under CERCLA and other areas of the law, for instance, tort liability. Livestock operators may still be found liable for a tort judgement of nuisance. However, such liabilities are outside the purview of this paper and the legal analysis herein.
Just as discussed above under the RCRA analysis, there are certainly notable advantages to regulating ammonia emissions under CERCLA. Many of the potential advantages associated with utilizing CERCLA follow the same logic as was discussed under RCRA. There is a big convenience factor with implanting ammonia emissions regulations under CERCLA. The EPA has already developed regulations to address similar environmental pollutants, along with well settled case law. CERCLA has been effective at addressing hazardous waste concerns across the country for years, and was originally prompted by the superfund site known as Love Canal (Environmental Protection Agency, n.d.). Instances such as Love Canal reveal the big advantages of CERCLA, that being the ability of the government to recover cleanup costs from the parties that are liable for the release of the hazardous waste from their facilities. From that standpoint CERCLA’s advantages are two-fold; first, it allows the government to timely and effectively cleanup hazardous waste releases, and second, it permits compensation for such efforts. Under this process, the concern that the contamination is not going to be cleaned up properly is eliminated, with the
cost being pushed onto those PRPs. There is ample case law that illustrates the ability of parties in cleaning up hazardous waste releases and to be compensated for such efforts, whether it be the government conducting the cleanup or the PRPs recouping costs from fellow PRPs.
Although there is an advantage to CERCLA’s broad ability to provide compensation based on a PRPs liability for the release of a hazardous substance, there are certainly some negative characteristics as well. One such characteristic is the types of hazardous wastes that have shaped CERCLA regulations over the years. Similarly, as discussed above under the RCRA analysis, there are challenges with regulating ammonia from livestock waste, when such releases have not contributed to the formation of regulations throughout the life of the act. Therefore, there are advantages to developing a separate regulation for ammonia emissions from livestock operations; such a program would more specifically address the problem.
When we considered CERCLA in relation to the current problems in Rocky Mountain National Park, the resulting nitrogen deposits in the area are from a much broader scope of facilities. Traditionally under CERCLA, liability in a specific contamination is placed on those PRPs which may have been responsible for the release associated with their facility. Allocating liability for ammonia emissions under CERCLA is not as feasible because of the inability to specifically trace nitrogen particles back to their source. Therefore, determining who the PRPs are is virtually impossible. Cleanup cost may also differ because the goal with nitrogen deposits in the region is not to remove the nitrogen from the park, but rather reduce emissions in order to limit the amount of excess nitrogen deposited. Considering these two challenges, it may be more appropriate to use a different regulatory framework other than CERCLA to address ammonia emissions concerns from livestock operations.
c) The Clean Air Act (CAA)
The CAA was established by Congress in 1963, with major revisions occurring in 1970, 1977 and 1990. Dense and visible smog through cities both in the United State and cities around the world prompted the passage of the Act. The CAA was amended as a result of evolving environmental concerns needing to be addressed, such as acid rain and damage to the ozone layer (Envrionmental Protection Agency, n.d.-a). The CAA is one of the most comprehensive and complex statutes ever passed by the United States Congress. The act requires the EPA to develop ambient air quality standards for criteria pollutants established by regulation (Id). Congress requires EPA, per the act, to develop these criteria pollutants based on the most recent scientific information, and to review each pollutant every five years (Clean Air Act, 1963). The six criteria air pollutants that the EPA has identified and set ambient air quality standards for are ground-level ozone pollutants, particulate matter, carbon monoxide, lead, sulfur dioxide, and nitrogen dioxide (Envrionmental Protection Agency, n.d.-b). This paper focuses on pollution levels of ammonia, which does not fall under the categories listed. As discussed under previous sections ammonia is volatilized and released into the atmosphere where it is transformed and deposited as nitrogen. However, when ammonia is released into the atmosphere it is in a gaseous form, but is not a nitrogen oxide, therefore, not falling under one of the criteria pollutant categories.
However, there are other ways that the EPA could choose to regulate ammonia emissions under the CAA. For instance, the EPA currently regulates sources of pollution such as utilities, chemical plants, and other stationary sources (Mceowen, 2017). The EPA could designate ammonia as a pollutant rather than a criteria pollutant; for example, it could designate livestock operations as a stationary source of a pollutant. However, the EPA has yet to use this means of regulation under the CAA.
As a result of ammonia being a concern once it has been volatilized, but still not being a nitrogen oxide compound, it is not currently regulated under any current criteria pollutant. Therefore, the EPA could designate ammonia as a criteria pollutant and set ambient air quality standards. The EPA could also just simply designate ammonia as a general pollutant. As was illustrated under CERCLA this pollutant has been a subject of concern relatively recently and may be addressed by the EPA in the near future, potentially under the CAA.
Just as above, for each of the previously discussed statutes there are potential benefits and drawbacks associated with adapting the regulatory scheme of the CAA to include ammonia emissions. The question is whether or not the potential benefits outweigh the potential drawbacks, and vice versa for addressing ammonia emissions?
Without a doubt the CAA has been instrumental in addressing major air quality concerns all around the country. The act has successfully taken on and assisted in mitigating concerns such as acid rain resulting from the burning of high sulfur coal, or toxic smog which trapped toxic pollutant in the air causing severe human health concerns (Dwyer, 2017). The long-term success is illustrative of the CAA usefulness in addressing air pollution concerns. The CAA was effective in promoting development of ambient air quality standards targeting sulfur dioxide, subsequently virtually eliminating the threat of acid rain in the United States. When such standards are set, geographical areas are permitted to have certain levels of pollution in the air, and if those standards are exceeded, polluters may be liable under the CAA. As a result of sulfur dioxide emissions exceeding ambient air quality standards, a push for cleaner sources of coal developed. As a result of effective regulations developed by the EPA, the CAA succeeded in addressing a significant air quality concern. This was achieved through changes in sourcing of coal. Although the act was successful in reducing sulfur dioxide emissions, it may not be as easily applied to ammonia emissions coming from the livestock industry. When the EPA sets an ambient air quality standard
it is very rigid when applied to polluters, and therefore, it is more effective in addressing certain air emissions over others. EPA develops attainment areas in which pollution is the most concerning. Based on the ambient air quality standards those areas are monitored by the EPA. Both attainment areas and ambient air quality standards designated for ammonia poses some challenges as a result of the rigidity of the standards in relation to the adaptability of a particular polluter.
The adaptability of the livestock industry in relation to standards of the CAA is difficult to achieve for numerous reasons. Looking back to the scientific discussion under section b, it is evident that technological advancements continue to be made in the livestock industry. However, technology and tools available to livestock producers do not effect change overnight, and rather take time to implement as a result of a wide variety of factors. As was already discussed, ammonia emissions from livestock operations are affected by nutritional composition of diets for livestock, genetics as they pertain to efficiency of animals, waste management techniques, and especially differences in weather patterns. As a result of the differences associated with each of these categories of factors, it makes it difficult for emitters to meet these arbitrary standards. Without question, the CAA is achieving results for the current list of criteria pollutants and those parties that are responsible for emitting those pollutants. However, it may not be the most effective or flexible regulatory scheme. It may achieve a reduction in ammonia emissions from livestock operations; however, developing such standards may be detrimental to the industry. Under the next section, ideas will be presented to strike a balance between addressing ammonia emissions concerns, while maintaining the viability and longevity of the livestock industry.
