Concentrated Animal Feeding Operations: EPA Needs More Information and a Clearly Defined Strategy to Protect Air and Water Quality from Pollutants of Concern
Published: 2008-09-04T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: Concentrated Animal Feeding Operations (CAFO) are large livestock and poultry operations that raise animals in a confined situation. CAFOs can improve the efficiency of animal production but large amounts of manure produce can, if not properly managed, degrade air and water quality. The Environmental Protection Agency (EPA) is responsible for regulating CAFOs and requires CAFOs that discharge certain pollutants to obtain a permit. This report discusses the (1) trends in CAFOs over the past 30 years, (2) amounts of waste they generate, (3) findings of key research on CAFOs' health and environmental impacts, (4) EPA's progress in developing CAFO air emissions protocols, and (5) effect of recent court decisions on EPA's regulation of CAFO water pollutants. GAO analyzed U.S. Department of Agriculture's (USDA) data from 1982 through 2002, for large farms as a proxy for CAFOs; reviewed studies, EPA documents, laws, and regulations; and obtained the views of federal and state officials.
section_title: What GAO Found
paragraphs: Because no federal agency collects consistent, reliable data on CAFOs, GAO could not determine the trends in these operations over the past 30 years. However, using USDA data for large farms that raise animals as a proxy for CAFOs, it appears that the number of these operations increased by about 230 percent, going from about 3,600 in 1982 to almost 12,000 in 2002. Also, during this 20-year period the number of animals per farm had increased, although it varied by animal type. Moreover, GAO found that EPA does not have comprehensive, accurate information on the number of permitted CAFOs nationwide. As a result, EPA does not have the information it needs to effectively regulate these CAFOs. EPA is currently working with the states to establish a new national data system. The amount of manure generated by large farms that raise animals depends on the type and number of animals raised, but large operations can produce more than 1.6 million tons of manure a year. Some large farms that raise animals can generate more raw waste than the populations of some U.S. cities produce annually. In addition, according to some agricultural experts, the clustering of large operations in certain geographic areas may result in large amounts of manure that cannot be effectively used as fertilizer on adjacent cropland and could increase the potential of pollutants reaching nearby waters and degrading water quality. Since 2002, at least 68 government-sponsored or peer-reviewed studies have been completed that examined air and water quality issues associated with animal feeding operations and 15 have directly linked air and water pollutants from animal waste to specific health or environmental impacts. EPA has not yet assessed the extent to which these pollutants may be impairing human health and the environment because it lacks key data on the amount of pollutants that are being emitted from animal feeding operations. As a first step in developing air emissions protocols for animal feeding operations, in 2007, a 2-year nationwide air emissions monitoring study, largely funded by industry, was initiated. However, as currently structured, the study may not provide the scientific and statistically valid data it was intended to provide and that EPA needs to develop air emissions protocols. Furthermore, EPA has not established a strategy or timetable for developing a more sophisticated process-based model that considers the interaction and implications of all emission sources at an animal feeding operation. Two recent federal court decisions have affected EPA's ability to regulate water pollutants discharged by CAFOs. The 2005 Waterkeeper case required EPA to abandon the approach that it had proposed in 2003 for regulating CAFO water discharges. Similarly, the 2006 Rapanos case has complicated EPA's enforcement of CAFO discharges because EPA believes that it must now gather significantly more evidence to establish which waters are subject to the Clean Water Act's permitting requirements.

section_title: Letter
paragraphs: Over the last 40 years, diversified, independent, family-owned-and- operated farms that produce a variety of crops and a few animals are  becoming a smaller share of the agricultural sector and are being replaced  by fewer, much larger farms. For animal production, this change has  meant a movement to significantly larger operations that can raise, for  example, as many as 2 million chickens or 800,000 hogs at one facility at  one time.
These large-scale livestock and poultry operations are generally referred  to as animal feeding operations. An animal feeding operation is one that  (1) raises animals in a confined situation for a total of 45 days or more  during a 12-month period and (2) brings feed to the animals rather than  having the animals graze or seek feed in pastures and fields or on  rangeland. Concentrated animal feeding operations (CAFO) are a subset of  animal feeding operations and usually operate on a much larger scale.  Generally, a CAFO is an animal feeding operation that raises enough  animals to meet or exceed certain minimum thresholds, depending upon  the type of livestock being raised. For example, as defined in Clean Water  Act regulations, an animal feeding operation would be considered a CAFO  if it raised 1,000 or more beef cattle, 2,500 hogs weighing more than 55  pounds, or 125,000 broiler chickens. In addition, an animal feeding  operation of any size can be designated a CAFO if it meets certain  conditions, such as being a significant contributor of pollutants to  federally regulated waters.
While CAFOs may have improved the efficiency of the animal production  industry, they have also raised environmental and health concerns  because of the large amounts of manure they produce. Generally, to  minimize potential environmental problems, these operations retain the  manure that they produce in storage facilities onsite and periodically  dispose of it by spreading it on nearby or adjacent cropland as fertilizer. If  the manure is properly contained and managed, it can benefit crop  production; if improperly contained and managed, it can degrade air and  water quality, thereby potentially impairing human health and damaging  the environment. Specifically, these operations can potentially degrade air  quality because large amounts of manure may emit unsafe quantities of  ammonia, hydrogen sulfide, and particulate matter, and they can  potentially degrade water quality because pollutants in manure such as  nitrogen, phosphorus, bacteria, and organic matter could enter nearby  water bodies.
Several federal laws provide the Environmental Protection Agency (EPA)  with the authority to regulate water and air pollutants from CAFOs. The  Clean Water Act specifically addresses CAFOs by requiring EPA to  consider CAFOs like any other industry if they discharge pollutants into  federally regulated waters. As a result, CAFOs that have such discharges  must obtain a permit that establishes design standards and management  practices for retaining and disposing of manure in such a way as to limit  the amounts and types of pollutants from manure that are released into  federally regulated waters. EPA, or the states that have been authorized by  EPA to administer the Clean Water Act, are responsible for issuing these  permits. In contrast, three other acts provide EPA with certain authorities  related to air emissions from these operations, although they do not  specifically cite CAFOs as regulated entities. Under the Clean Air Act, any  animal feeding operation, regardless of size, that exceeds established air  emission thresholds for certain pollutants can be regulated. For example,  pollutants such as particulate matter that are emitted by animal feeding  operations are regulated under the Clean Air Act and other pollutants such  as hydrogen sulfide or ammonia may be regulated under the act in certain  circumstances. Similarly, the Comprehensive Environmental Response,  Compensation, and Liability Act of 1980 (CERCLA) and the Emergency  Planning and Community Right-to-Know Act of 1986 (EPCRA) do not  specifically mention CAFOs, but they do require owners or operators of  these facilities to report to federal or state and local authorities when a  “reportable quantity” of certain hazardous substances, such as hydrogen  sulfide or ammonia, is released into the environment. Together,  CERCLA’s and EPCRA’s reporting requirements provide government  authorities, emergency management agencies, and citizens the ability to  know about the source and magnitude of hazardous releases into the  environment.
In light of the growing concerns regarding the potential human health and  environmental impacts of CAFOs, you asked us to determine the (1) trends  in CAFOs over the past 30 years; (2) amount of waste they generate; (3)  findings of recent key academic, industry, and government research on the  impacts of CAFOs on human health and the environment, and the extent  to which EPA has assessed the nature and severity of such impacts; (4)  progress that EPA and the states have made in regulating and controlling  the emissions of, and in developing protocols to measure, air pollutants  from CAFOs that could affect air quality; and (5) extent to which recent  court decisions have affected EPA and the states’ ability to regulate CAFO  discharges that impair water quality.
In conducting our work, we reviewed laws and regulations and federal and  state agencies’ documents; met with officials from EPA and the U.S.  Department of Agriculture (USDA), industry, citizen and environmental  groups, and academia. We also spoke with state officials and visited  CAFOs in eight states. These states were Arkansas, California, Colorado,  Iowa, Maryland, Minnesota, North Carolina, and Texas. We chose these  states because they were geographically dispersed and contained  numerous CAFOs representing various animal types. In addition, to  determine trends in CAFOs over the past 30 years, from 1974 through 2002,  we obtained the most recent data available from USDA on large farms that  raise animals to use as a proxy for CAFO data. However, because of  limitations in USDA’s data for 1974 through 1982, we could not determine  from these data which farms prior to 1982 would meet EPA’s minimum  size thresholds for CAFOs. Consequently, our analysis of trends in CAFOs  focuses on the 20-year period between 1982 and 2002. We also obtained  and reviewed the data that EPA compiled over the last 5 years from each  of its regions on the number of CAFOs that were issued a permit. To  identify the amount of waste CAFOs generate, we estimated the amounts  of manure generated by various size farms that raise animals. To provide a  perspective of the amount of waste that large farms that raise animals can  generate, we selected certain cities based on their population and  estimated the amount of sanitary waste generated by the human  population and compared these amounts with the amount of waste  generated by three different sizes of large farms. To report on key  research on the impacts of CAFOs on human health and the environment,  we reviewed EPA’s 2003 Rule regulating discharges from CAFOs under the  Clean Water Act and the National Academy of Sciences study on air  emissions from animal feeding operations. We also conducted library and  Internet searches to identify key studies completed since 2002 on air and  water pollutants from waste generated by animal feeding operations. We  compared the findings from these studies with EPA assessments to date  and interviewed EPA officials regarding these assessments. To assess the  progress that EPA and the states have made in regulating and controlling  the air emissions of, and in developing protocols to measure, air pollutants  from CAFOs, we reviewed relevant documents and interviewed EPA  officials, as well as officials responsible for an ongoing national air  emissions monitoring study. In addition, we contacted state officials in all  50 states to determine which states had developed air emission regulations  applicable to CAFOs. Finally, to determine the extent to which recent  court decisions have affected EPA and the states’ ability to regulate CAFO  discharges that impair water quality, we reviewed the results of recent  federal and state court decisions. We also interviewed EPA and state  officials on how the court decisions have affected their ability to regulate  CAFOs. A more detailed description of our scope and methodology is  presented in appendix I.
We conducted this performance audit between July 2007 and August 2008,  in accordance with generally accepted government auditing standards.  These standards require that we plan and perform the audit to obtain  sufficient, appropriate evidence to provide a reasonable basis for our  findings and conclusions based on our audit objectives. We believe that  the evidence obtained provides a reasonable basis for our findings and  conclusions based on our audit objectives.
subsections: section_title: Background
paragraphs: The livestock and poultry industry is vital to our nation’s economy,  supplying meat, milk, eggs, and other animal products; however, the past  several decades have seen substantial changes in America’s animal  production industries. As a result of domestic and export market forces,  technological changes, and industry adaptations, food animal production  that was integrated with crop production has given way to fewer, larger  farms that raise animals in confined situations. These large-scale animal  production facilities are generally referred to as animal feeding operations.  CAFOs are a subset of animal feeding operations and generally operate on  a larger scale. While CAFOs may have improved the efficiency of the  animal production industry, their increased size and the large amounts of  manure they generate have resulted in concerns about the management of  animal waste and the potential impacts this waste can have on  environmental quality and public health.
Animal manure can be, and frequently is, used beneficially on farms to  fertilize crops and to restore nutrients to soil. However, if improperly  managed, manure and wastewater from animal feeding operations can  adversely impact water quality through surface runoff and erosion, direct  discharges to surface water, spills and other dry-weather discharges, and  leaching into the soil and groundwater. Excess nutrients in water can  result in or contribute to low levels of oxygen in the water and toxic algae  blooms, which can be harmful to aquatic life. Improperly managed manure  can also result in emissions to the air of particles and gases, such as  ammonia, hydrogen sulfide, and volatile organic compounds, which may  also result in a number of potentially harmful environmental and human  health effects.
Most agricultural activities are considered to be nonpoint sources of  pollution because the pollution that occurs from these activities is in  conjunction with soil erosion caused by water and surface runoff of  rainfall or snowmelt from diffuse areas such as farms and rangeland.  However, section 502(14) of the Clean Water Act specifically defines point  sources of pollution to include CAFOs, which means that under the act,  CAFOs that discharge into federally regulated waters are required to  obtain a federal permit called a National Pollutant Discharge Elimination  System (NPDES) permit. These permits generally allow a point source to  discharge specified pollutants into federally regulated waters under  specific limits and conditions.  These permits are issued by EPA or a state  agency authorized by EPA to implement the NPDES program for that  state. Currently, 45 states are authorized to administer the NPDES permit  program, and their programs must be at least as stringent as the federal  program. In 1976, in accordance with the Clean Water Act’s designation of  CAFOs as point sources, EPA defined which poultry and livestock  facilities constituted a CAFO and established permitting regulations for  CAFOs. According to EPA regulations issued in 1976, to be considered a  CAFO a facility must first be considered an animal feeding operation.  Animal feeding operations are agricultural operations where the following  conditions are met:    animals are fed or maintained in a confined situation for a total of 45 days  or more in any 12-month period, and     crops, vegetation, forage growth, or post harvest residues are not  sustained during normal growing seasons over any portion of the lot.
If an animal feeding operation met EPA’s criteria and either met or  exceeded minimum size thresholds based on the type of animals being  raised, EPA considered the operation to be a CAFO. For example, an  animal feeding operation would be considered a CAFO if it raised 1,000 or  more beef cattle, 2,500 pigs weighing more than 55 pounds, or 125,000  chickens. In addition, EPA could designate an animal feeding operation of  any size as a CAFO under certain circumstances. For example, if an animal  feeding operation was a significant contributor of pollutants to federally  regulated water, EPA could designate the operation as a CAFO. Appendix  II lists the full text of EPA’s current CAFO definition, including the size  thresholds established for small, medium, and large CAFOs.
Under EPA’s 1976 CAFO regulations, certain animal feeding operations did not  require permits. These included (1) those animal feeding operations that only  discharged during a 25-year, 24-hour storm event—which is the amount of  rainfall during a 24-hour period that occurs on average once every 25 years or  more and (2) chicken operations that use dry manure-handling systems— systems that do not use water to handle their waste. In addition, EPA generally  did not regulate animal waste that was applied to cropland or pastureland.
In January 2003, we reported that although EPA believed that many animal  feeding operations degrade water quality, it had placed little emphasis on its  permit program and that exemptions in its regulations allowed as many as 60  percent of the largest operations to avoid obtaining permits. In its response  to our 2003 report, EPA acknowledged that the CAFO program was hampered  by outdated regulations and incomplete attention by EPA and the states. EPA  pointed out that it had revised its permitting regulations for CAFOs to  eliminate the exemptions that allowed most animal feeding operations to  avoid regulation. The revisions, issued in February 2003 and known as the  2003 CAFO rule, resulted, in part, from the settlement of a 1989 lawsuit by the  Natural Resources Defense Council and Public Citizen, in which these groups  alleged that EPA had failed to comply with the Clean Water Act. EPA’s 2003  CAFO rule included the following key provisions:    Duty to apply. All CAFOs were required to apply for an NPDES permit  unless the permitting authority determined that the CAFO had no potential  to discharge to federally regulated waters.
Expanded CAFO definitions to include all poultry operations and stand- alone operations raising immature animals. The previous rule had  applied only to poultry operations that used a liquid manure-handling  system. The 2003 rule expanded the CAFO definition to all types of poultry  operations, and EPA officials estimated that this revision could result in  almost 2,200 additional poultry operations requiring a permit.
More stringent design standard for new facilities in the swine, poultry,  and veal categories. Under the previous rule, facilities were to be  designed, constructed, and operated to contain runoff from a 25-year, 24- hour rainfall event; this continues to be the rule for existing facilities. For  new facilities, the 2003 rule established a no-discharge standard that can  be met if the facilities are designed, constructed, and operated to contain  the runoff from a 100-year, 24-hour storm event.
Best management practices. Operations would be required to implement  best management practices for applying manure to cropland and for  animal production areas. The rule required, among other things, specified  setbacks from streams, vegetated buffers, depth markers in lagoons, and  other impoundments for production areas to prevent or reduce pollution  from the operation.
Nutrient management plans. CAFO operations would be required to  develop a plan for managing the nutrient content of animal manure as well  as the wastewater resulting from CAFO operations, such as water used to  flush manure from barns.
Compliance schedule. The 2003 rule required newly defined CAFOs to  apply for permits by April 2006 and existing CAFOs to develop and  implement nutrient management plans by December 31, 2006.
According to EPA officials, the 2003 rule was expected to ultimately lead  to better water quality because the revised regulations would extend  coverage to more animal feeding operations that could potentially  discharge and contaminate water bodies and subject these operations to  periodic inspections.
Three laws provide EPA with certain authorities related to air emissions  from animal feeding operations: the Clean Air Act, the Comprehensive  Environmental Response, Compensation, and Liability Act of 1980  (CERCLA), and the Emergency Planning and Community Right-to-Know  Act of 1986 (EPCRA). Although these laws provide EPA with authority  related to air emissions from various sources, they do not expressly  identify animal feeding operations as a regulated entity. Specifically:    The Clean Air Act authorizes EPA to regulate stationary and mobile  sources of air pollution and emphasizes controlling sources that emit more  than threshold quantities of regulated pollutants. Livestock producers and  other agricultural sources whose emissions meet or exceed specific  statutory or regulatory thresholds are therefore subject to Clean Air Act  requirements. Although EPA has authorized states and local governments  to carry out certain portions of the act, EPA retains concurrent  enforcement authority.
Taken together, CERCLA and EPCRA require owners or operators of a facility  to report to federal or state authorities the release of hazardous substances  that meet or exceed their reportable quantities so as to alert federal, state, and  local agencies, as well as the public, to the release of these substances.   Section 103 of CERCLA requires that the person in charge of a facility notify  the National Response Center of any non-permitted release of “hazardous  substances” in a reportable quantity as soon as he or she has knowledge of  that release. Section 304 of EPCRA requires that the owner or operator of a  facility at which a hazardous chemical is produced, used, or stored give  immediate notice of a release of any “extremely hazardous substance” to the  community emergency coordinator. Among the reportable substances that  could be released by livestock facilities are hydrogen sulfide and ammonia.  The reportable quantity for each of these hazardous substances is 100 pounds  in a 24-hour period. Under these acts, EPA can assess civil penalties for  failure to report releases of hazardous substances or extremely hazardous  substances that equal or exceed their reportable quantities—up to $32,500 per  day or $32,500 per violation for first time offenders.
EPA is also working with USDA to address the impacts of animal feeding  operations on air and water quality and public health. In 1998, EPA  entered into a memorandum of understanding with USDA that calls for the  agencies to coordinate on air quality issues relating to agriculture and  share information. In addition, in 1999, the two agencies issued a unified  national strategy aimed at having the owners and operators of animal  feeding operations take actions to minimize water pollution from  confinement facilities and land application of manure and in 2001 adopted  an agreement to develop a process for working together constructively. To  help minimize water pollution from animal feeding operations and meet  EPA’s regulatory requirements, USDA, through its Natural Resources  Conservation Service, provides financial and technical assistance to CAFO  operators in developing and implementing nutrient management plans.
section_title: The Number of Large Farms Raising Animals Has Increased, but Specific Data on CAFOs Are Not Available
paragraphs: Because no federal agency collects accurate and consistent data on the  number, size, and location of CAFOs nationwide, it is difficult to  determine precise trends in CAFOs over the last 30 years. According to  USDA officials, the data USDA collects for large farms raising animals can  be used as a proxy for estimating trends in CAFOs nationwide. Using these  data, we determined that between 1982 and 2002, the number of large  farms raising animals has increased sharply, from about 3,600 to almost  12,000. Moreover, EPA has compiled some data from its regions on the  number of CAFOs that have been issued permits; however, these data are  inconsistent and inaccurate. As a result, EPA does not have a systematic  way of identifying and inspecting all of the CAFOs nationwide that have  been issued permits.
subsections: section_title: Since 1982 the Number of Large Farms Raising Animals Has Increased as Has the Average Number of Animals on Farms
paragraphs: We found that the number of large farms raising animals for all animal types  increased by 234 percent between 1982 and 2002. Table 1 shows the changes  in the number of large farms by animal type for 1982 through 2002.
As table 1 shows, large broiler and hog farms experienced the largest  increase, with large farms raising broilers increasing by 1,187 percent and  large farms raising hogs increasing by 508 percent. Large farms raising  layers and large farms raising beef cattle remained relatively stable over  these 20 years, while layer farms were the only farms that experienced an  overall decrease in number over the period, declining by 2 percent. In  contrast, while the number of large farms raising animals has increased,  the number of all farm raising animals has decreased. Appendix III  presents trends in the number of all farms raising animals, from 1982 to  2002.
Just as the number of large farms for almost all animal types increased  between 1982 and 2002, so did the size of these farms as illustrated by the  median number of animals raised on each farm. Table 2 shows the trends  in the median number of animals raised on large farms for all animal types  from 1982 through 2002.
The layer and hog sectors had the largest increases in the median number  of animals raised per farm, both growing by 37 percent between 1982 and  2002. Specifically, for layers, large farms increased the number of birds  they raised from 131,530 in 1982 to 180,000 in 2002 and for hogs, large  farms increased the number of animals they raised from 3,350 in 1982 to  4,588 in 2002. In contrast, large farms that raised either broilers or turkeys  only increased slightly in size with an overall increase of 3 and 1 percent,  respectively, from 1982 to 2002.
The increases in the number of large farms for almost all animal types, as well  as the increases in the median number of animals raised on these farms, are  also reflected in the percentage of animals raised on large farms as compared  with animals raised on all farms. Specifically, the number of animals raised on  large farms increased from over 257 million in 1982 to over 890 million in  2002—an increase of 246 percent. In contrast, the number of animals raised  on all farms increased from over 1,145 million in 1982 to 2,072 million in  2002—an increase of 81 percent. This is particularly noteworthy because the  number of animals raised on large farms only accounted for 22 percent of  animals raised on all farms in 1982; yet, the number of animals raised on large  farms accounted for 43 percent of animals raised on all farms in 2002. Table 3  shows the trends in the number of animals raised on large farms and the  number of animals raised on all farms from 1982 to 2002.
As table 3 shows, most of the beef cattle, hogs, and layers raised in the  United States in 2002 were raised on large farms. Specifically, 77 percent  of beef cattle and 72 percent of both hogs and layers were raised on large  farms.
section_title: EPA Does Not Have a Systematic Means of Identifying Permitted CAFOs Because It Lacks Accurate Data
paragraphs: EPA does not have its own data collection process to determine the  number, size, and location of CAFOs that have been issued permits  nationwide. Since 2003, the agency has compiled quarterly estimates from  its regions on the number of permits that have been issued to CAFOs.   These data are developed by EPA’s regional offices or originates with the  state permitting authority. However, we determined that these data are  inconsistent and inaccurate and do not provide EPA with the reliable data  that it needs to identify and inspect permitted CAFOs nationwide. For  example, according to EPA some uncertainty in the data exists because  some states may be using general permits to cover more than one  operation. In addition, EPA has not established adequate internal controls  to ensure that the data are correctly reported. For example, officials from  17 states told us that data reported by EPA for their states were  inaccurate. In one case, when we asked a state official for the number of  CAFOs in his state, the official realized that the CAFO numbers reported  by EPA’s regional office were incorrect because of a clerical error, which  resulted in some CAFO statistics for the state being doubled. After the  state official discovered this error the state’s data were corrected and  resubmitted to EPA. Without a systematic and coordinated process for  collecting and maintaining accurate and complete information on the  number, size, and location of permitted CAFOs nationwide, EPA does not  have the information it needs to effectively regulate these operations.
In commenting on a draft of this report, EPA stated that the information  from permit files is available to EPA upon request; however, the  information is currently not readily compiled in a national database.  EPA  is currently working with the states to develop and implement a new  national data system to collect and record operation-specific information.   As part of this effort, the agency plans to develop national requirements  for data that should be collected and entered into the database by the  states.  According to EPA, it may require the states to provide data that  identifies operations that have been issued or applied for a CAFO permit  as well as operations that should have applied for a permit based on an  inspection or enforcement action.
section_title: Large Farms That Raise Animals Can Produce Thousands of Tons of Manure Each Year, and Regional Clustering of Farms Can Exacerbate Manure Management Problems
paragraphs: The amount of manure a large farm that raises animals can generate  primarily depends on the types and numbers of animals raised on that  farm, and the amount of manure produced can range from over 2,800 tons  to more than 1.6 million tons a year. To further put this in perspective, the  amount of manure produced by large farms that raise animals can exceed  the amount of waste produced by some large U.S. cities. In addition,  multiple large farms that raise animals may be located in a relatively small  area, such as two or more adjacent counties, which raises additional  concerns about the potential impacts of the manure produced, stored, and  disposed of by these farms.
Table 4 shows the estimated number of animals and the typical amounts of  manure produced each year, by type of animal, for three different sizes of  large farms: (1) large farms that meet EPA’s thresholds for each animal  type, (2) large farms that raise the median number of animals according to  our analysis of USDA farm census data, and (3) large farms that fell into  the 75th percentile based on our analysis. As table 4 shows, a dairy farm  that meets the minimum threshold of 700 dairy cows could produce almost  17,800 tons of manure a year; a median-sized dairy farm with 1,200 dairy  cows could produce about 30,500 tons of manure a year; and a larger dairy  farm with 1,900 dairy cows could produce almost 48,300 tons of manure a  year.
Additionally, individual large farms that raise animals can generate as  much waste as certain U.S. cities. For example, a dairy farm meeting  EPA’s large CAFO threshold of 700 dairy cows can create about 17,800  tons of manure annually, which is more than the about 16,000 tons of  sanitary waste per year generated by the almost 24,000 residents of Lake  Tahoe, California. Likewise, a median-sized beef cattle operation with  3,423 head of beef cattle can produce more than 40,000 tons of manure  annually, which is more than the almost 38,900 tons of sanitary waste per  year generated by the nearly 57,000 residents of Galveston, Texas.  Similarly, some larger farms can produce more waste than some large U.S.  cities. For example, a large farm with 800,000 hogs could produce over 1.6  million tons of manure per year, which is one and a half times more than  the annual sanitary waste produced by the city of Philadelphia,  Pennsylvania—about 1 million tons—with a population of almost 1.5  million. Moreover, a beef cattle farm with 140,000 head of cattle could  produce over 1.6 million tons of manure annually, more than the almost  1.4 million tons of sanitary waste generated by the more than 2 million  residents of Houston, Texas.
Although manure is considered a valuable commodity, especially in states  with large amounts of farmland, like Iowa, where it is used as fertilizer for  field crops, in some parts of the country, large farms that raise animals are  clustered in a few contiguous counties. This collocation of large farms that  raise animals has resulted in a separation of animal production from crop  production because many of these operations purchase feed rather than  grow it on adjacent cropland. As a result, there is much less cropland on  which the manure can be applied as fertilizer. This clustering of large  farms that raise animals has occurred because of structural changes in the  farming sector. According to agricultural experts and USDA officials, the  overall decrease in the number of farms and increase in the average  number of animals raised on a farm may have occurred because these  operations wanted to achieve economies of size. To achieve these  economies, operators often need significant amounts of capital, which  they obtain through production contracts with large processing  companies.
A USDA report identified this concern as early as 2000 when it found that  between 1982 and 1997 as livestock production became more spatially  concentrated that when manure was applied to cropland, crops were not  fully using the nutrients in manure and this could result in ground and  surface water pollution from the excess nutrients. According to the  report, the number of counties where farms produced more manure  nutrients, primarily nitrogen and phosphorus, than could be applied to the  land without accumulating nutrients in the soil increased. Specifically, the  numbers of counties with excess manure nitrogen increased by 103  percent, from 36 counties in 1982 to 73 counties in 1997. Similarly, the  number of counties with excess manure phosphorous increased by 57  percent, from 102 counties in 1982 to 160 counties in 1997. As a result, the  potential for runoff and leaching of these nutrients from the soil was high,  and water quality could be impaired, according to USDA. Agricultural  experts and government officials who we spoke to during our review  echoed the findings of USDA’s report and provided several examples of  more recent clustering trends that have resulted in degraded water quality,  including the following:    As a result of adopting the poultry industry’s approach of developing close  ties between producers and processors, North Carolina experienced a  rapid growth in the number of hog CAFOs, primarily in five contiguous  counties. Based on our analysis of 2002 USDA data, we estimated that the  hog population of the five North Carolina counties was more than 7.5  million hogs in 2002 and that hog operations in these counties produced as  much as 15.5 million tons of manure that year. Figure 1 shows the  geographic concentration of hog farms in North Carolina in 2002.
According to North Carolina agricultural experts, excessive manure  production has contributed to the contamination of some of the surface  and well water in these counties and the surrounding areas. According to  these experts, this contamination may have occurred because the hog  farms are attempting to dispose of excess manure but have little available  cropland that can effectively use it. According to state officials, partly out  of concern for the potential contamination of waterways and surface  water from manure, in 1997, North Carolina placed a moratorium on new  swine farms and open manure lagoons, which was subsequently continued  through 2007.  While the moratorium included exceptions that could allow  a new swine farm to begin operations in this area, according to state  officials, the requirements for these exceptions are so stringent that they  effectively have prevented the construction of new swine operations or  the expansion of existing operations.
Similarly, a California water official told us that the geographic clustering  of large farms that raise animals is causing concern in his state as well.  Our analysis of USDA data shows that in 2002 two counties in the San  Joaquin Valley in California had 535,443 dairy cows that produced about  13.6 million tons of manure that year. According to the official, because of  the limited flow of water through the Valley, once pollutants reach the  water, they do not dissipate, resulting in a long-term accumulation of these  pollutants.
Regional clustering is also occurring in Arkansas. Two counties in  northwest Arkansas, located on the Arkansas-Oklahoma border, raised  14,264,828 broiler chickens that produced over 471,000 tons of manure  that year. According to EPA Region 6 officials, the Arkansas-Oklahoma  border is an area of concern due to the number of poultry operations  (primarily broilers, but also turkeys and layers) within this area.  Furthermore, region 6 officials identified numerous water bodies in  northwest Arkansas and northeast Oklahoma that have been impaired by  manure from animal feeding operations and identified these locations as  “areas of general ground water concern.”
While USDA officials acknowledge that regional clustering of large animal  feeding operations has occurred, they told us that they believe the nutrient  management plans that they have helped livestock and poultry producers  develop and implement have reduced the likelihood that pollutants from  manure are entering ground and surface water. They also believe that as a  result of new technologies such as calibrated manure spreaders, improved  animal feeds, and systems that convert manure into electricity, large  animal feeding operations are able to more effectively use the manure  being generated. However, USDA could not provide information on the  extent to which these techniques are being utilized or their effectiveness in  reducing water pollution from animal waste.
section_title: Studies Have Identified Impacts of Pollutants from Animal Waste, but EPA Has Not Assessed the Extent of Such Impacts
paragraphs: Since 2002, at least 68 government-sponsored or peer-reviewed studies  have been completed on air and water pollutants from animal feeding  operations. Of these 68 studies, 15 have directly linked pollutants from  animal waste generated by these operations to specific health or  environmental impacts, 7 have found no impacts, and 12 have made  indirect linkages between these pollutants and health and environmental  impacts. In addition, 34 of the studies have focused on measuring the  amount of certain pollutants emitted by animal feeding operations that are  known to cause human health or environmental impacts at certain  concentrations. Appendix IV presents information, including the sponsor,  the pollutants, and impacts, identified for each of the 68 studies we  reviewed. Although EPA is aware of the potential impacts of air and  water pollutants from animal feeding operations, it lacks data on the  number of animal feeding operations and the amount of discharges  actually occurring. Without such data, according to EPA officials, the  agency is unable to assess the extent to which these pollutants are  harming human health and the environment.
subsections: section_title: Some Recent Studies Directly Link Pollutants from Animal Waste to Health and Environmental Impacts
paragraphs: Of the 15 studies completed since 2002 that we reviewed that directly link  pollutants from animal waste to human health or environmental impacts, 8  focused on water pollutants and 7 on air pollutants. Academic experts and  industry and EPA officials told us that only a few studies directly link  CAFOs with health or environmental impacts because the same pollutants  that CAFOs discharge also often come from other sources including  smaller livestock operations; row crops using commercial fertilizers; and  wastes from humans, municipalities, or wildlife, making it difficult to  distinguish the actual source of pollution. Table 5 shows the eight  government-sponsored or peer-reviewed studies completed since 2002 that  found direct links between water pollutants from animal waste and  impacts on human health or the environment.
As table 5 shows, EPA sponsored four of the water quality studies that  identified reproductive alterations in aquatic species caused by hormones  in discharges from animal feeding operations. Two of these studies found  that hormones from these discharges caused a significant decline in the  fertility of female fish in nearby water bodies. Similarly, three other  studies found water bodies impaired by higher nitrogen and phosphorus  levels from manure runoff from animal feeding operations. For example,  the study by Juniata College found that the runoff resulted in nutrient  concentrations in the water that were too high to sustain fish populations.  Only one of the eight water pollutant studies linked pollutants from animal  feeding operations to human health effects. This study, conducted by  Health Canada, directly linked water discharges from a cattle farm to  bacteria found in nearby waters. These bacteria, which included  Campylobacter and E. coli, caused gastrointestinal illnesses in more than  2,300 residents and 7 deaths in a nearby community.
Table 6 shows the seven government-sponsored or peer-reviewed studies  completed since 2002 that we reviewed that directly link air pollutants  from animal feeding operations with human health effects.
As table 6 shows, six of these studies identified airway inflammation or  wheezing in people working at or living on an animal feeding operation.
For example, the studies conducted by the Department of Veterans Affairs  show that the dust of hog confinement facilities induces airway  inflammation in workers. The seventh study, completed by Duke  University in a laboratory setting, exposed healthy volunteers to air  emissions consistent with those that would occur downwind from animal  feeding operations. These volunteers reported headaches, eye irritation,  and nausea following this exposure. According to experts who we spoke  with, the effects of air emissions from animal feeding operations on  workers are well known, but the impacts of these emissions on nearby  communities are still uncertain, and more research is needed to identify  these impacts. Additionally, experts said it is difficult to determine which  specific contaminant or mixture of contaminants causes particular health  symptoms. For example, while hydrogen sulfide causes respiratory and  other health problems, other contaminants emitted from animal feeding  operations, such as ammonia, can also cause similar symptoms.
section_title: Some Studies Found No Links between Pollutants from Animal Feeding Operations and Harm to Human Health or the Environment
paragraphs: We found seven government-sponsored or peer-reviewed studies that have  been completed since 2002 that found no impact on human health or the  environment from pollutants released by animal feeding operations. These  seven studies are shown in table 7.
As table 7 shows, the results of a U.S. Geological Survey study did not  indicate that poultry animal feeding operations were causing an increase  of nutrient concentrations and fecal bacteria in groundwater. Similarly,  another study by Agriculture and Agri-Food Canada found that odorants,  including ammonia and dust emitted by animal feeding operations, never  exceeded the established irritation threshold. According to EPA and  academic experts we spoke with, the concentrations of air pollutants and  water pollutants emitted by animal feeding operations can vary, which  may account for the differences in the findings of these studies. These  variations may be the result of numerous factors, including the type of  animals being raised, feed being used, and manure management system  being employed, as well as the climate and time of day when the emissions  occur.
section_title: Some Recent Studies Indirectly Link Pollutants from Animal Feeding Operations with Human Health and Environmental Impacts
paragraphs: We also identified 12 government-sponsored or peer-reviewed studies  completed since 2002 that indirectly link pollutants from animal feeding  operations to human health or environmental impacts. While these studies  found that animal feeding operations were the likely cause of human  health or environmental impacts occurring in areas near the operations,  they could not conclusively link waste from animal feeding operations to  the impacts, often because other sources of pollutants could also be  contributing. For example, 5 of these 12 studies found an increased  incidence of asthma or respiratory problems in people living or attending  school near animal feeding operations, compared with a control group.  These studies hypothesized that the pollutants emitted from animal  feeding operations were likely the cause of the increased incidence of  asthma, but some of these studies acknowledged that pollutants from  other sources could also be contributing to the increased incidence. Table  8 lists the 12 studies that have been completed since 2002 that made  indirect links between emissions from animal feeding operations and  human health and environmental impacts.
section_title: Many Recent Studies Have Measured the Level of Pollutants Emitted by Animal Feeding Operations
paragraphs: Thirty-four government-sponsored or peer-reviewed studies completed  since 2002 have focused on measuring the amounts of water or air  pollutants emitted by animal feeding operations that are known to cause  harm to humans or the environment. Specifically:    Nineteen of the 34 studies focused on water pollutants. Four studies found  increased levels of phosphorus or nitrogen in surface water and  groundwater near animal feeding operations. According to EPA, excessive  amounts of these nutrients can deplete oxygen in water, which could  result in fish deaths, reduced aquatic diversity, and illness in infants. The  other 15 studies measured water pollutants such as pathogens, hormones,  and antibiotics.
Fifteen of the 34 studies focused on measuring air emissions from animal  feeding operations. Seven of the 15 studies found high levels of ammonia  surrounding animal feeding operations. EPA considers ammonia a  hazardous substance that may harm human health or the environment, and  that must be reported when emissions exceed its reportable quantity. The  other eight studies measured the levels of other air pollutants, such as  hydrogen sulfide, particulate matter, and carbon dioxide.
Appendix IV provides additional details about each of the 34 studies.
section_title: EPA Has Not Yet Assessed the Extent of the Human Health and Environmental Impacts of Pollutants from Animal Feeding Operations
paragraphs: While EPA recognizes the potential impacts that water and air pollutants  from animal feeding operations can have on human health and the  environment, it lacks the data necessary to assess how widespread these  impacts are and has limited plans to collect the data it needs.
Water quality. EPA has long recognized the impacts of pollution from  CAFOs on water quality. For example, almost a decade ago, in its 1998  study on feedlot point sources, EPA documented environmental impacts  that may be attributed to these operations. This report identified  pollutants from animal feeding operations and listed about 300 spills and  runoff events that were attributable to animal feeding operations from  1985 through 1997. More recently when developing the 2003 CAFO rule,  EPA documented the potential water quality impacts from CAFOs. It  reported that contaminants in manure will have an impact on water quality  if significant amounts reach surface water or groundwaters. Moreover, as  discussed above, numerous studies completed since 2002 have provided  additional information on the direct and indirect impacts of discharges  from animal feeding operations on human health and the environment, and  many more studies have been completed that have measured the amounts  of pollutants being discharged.
EPA officials we spoke with acknowledged that the potential human  health and environmental impacts of some CAFO water pollutants, such as  nitrogen, phosphorus, and pathogens, are well known. They told us that  the agency has recently focused its research efforts on obtaining more  information on emerging pollutants, such as hormones and antibiotics, and  on how the concentrations of nutrients and pathogens differ among the  various types of animal feeding operations. However, these officials also  stated that EPA does not have data on the number and location of CAFOs  nationwide and the amount of discharges from these operations. Without  this information and data on how pollutant concentrations vary by type of  operation, it is difficult to estimate the actual discharges occurring and to  assess the extent to which CAFOs may be contributing to water pollution.  According to agency officials, because of a lack of resources, the agency  currently has no plans for a national study to collect information on CAFO  water discharges. However, the agency has recently taken the following  three steps that may help gather additional data on CAFO pollutants that  affect water quality:    EPA has begun research to determine (1) how the concentration of  pathogens and nutrients vary in manure on the basis of certain  characteristics, such as animal type and animal feed, and (2) how manure  management techniques can reduce the amount of pathogens and  nutrients in runoff.
EPA has set a long-term research goal, as part of its Multi-Year Plan for  Endocrine Disruptors (FY2007-2013), to characterize the magnitude and  extent of the impact of hormones released by CAFOs and to determine the  impact of management strategies on the fate and effects of hormones. At  the time of our review, according to an EPA official, the agency had only  limited preliminary findings because it has just recently begun this work.
EPA and the U.S. Geological Survey have discussed a joint project to  identify (1) the location of CAFOs nationwide and (2) those watersheds  where many CAFOs might be located. According to EPA officials, this  project is still in the discussion phase.
Air quality. More recently, EPA has recognized concerns about the  possible health impacts from air emissions produced by animal feeding  operations. Prompted in part by public concern, EPA and USDA  commissioned a 2003 study by the National Academy of Sciences (NAS) to  evaluate the scientific information needed to support the regulation of air  emissions from animal feeding operations. The NAS report identified  several air pollutants from animal feeding operations and their potential  impacts. For example, the study identified ammonia and hydrogen sulfide  as two air pollutants emitted from animal feeding operations that can  impair human health. According to the study, ammonia can cause eye,  nose, and throat irritation at certain concentrations, and hydrogen sulfide  can cause respiratory distress. While such effects are known to occur, the  study noted that additional research is warranted to determine if air  emissions from animal feeding operations are occurring in high enough  concentrations to cause these effects. The NAS report also concluded that  in order to determine the human health and environmental effects of air  emissions from animal feeding operations, EPA and USDA would first  need to obtain accurate estimates of emissions and their concentrations  from animal feeding operations with varying characteristics, such as  animal type, animal feed, manure management techniques, and climate.
Since the NAS report was issued, EPA has conducted one hypothetical  assessment of the impacts of air emissions from animal feeding  operations. In 2004, EPA updated a preliminary analysis to estimate the  levels of emissions of ammonia and hydrogen sulfide that occur downwind  from a manure lagoon and that could pose a risk to human health. EPA  found that ammonia would not reach levels associated with respiratory  irritation if emitted at the reportable quantity of 100 pounds per day. On  the other hand, the agency found that hydrogen sulfide could cause  respiratory irritation and central nervous system effects about one mile  downwind if emitted at the reportable quantity of 100 pounds per day.  EPA officials who conducted this analysis told us that there have been no  documented cases of hydrogen sulfide emissions from animal feeding  operations exceeding the reportable quantity. However, other officials  noted that the agency does not know exactly what type of species and  what size of operations are likely to have emissions above the reportable  quantity, and, as noted in the NAS report, accurate measurements of the  air pollutants being emitted by animal feeding operations are currently not  known.
In 2007, a national air emissions monitoring study to collect data on air  emissions from animal feeding operations was undertaken as part of a  series of consent agreements EPA entered into with individual animal  feeding operations. This study, funded by industry and approved by EPA,  is intended to help the agency determine how to measure and quantify air  emissions from animal feeding operations. The data collected will in turn  be used to estimate air emissions from animal feeding operations with  varying characteristics, and, according to EPA officials, it is only the first  step in a long-term effort to accurately quantify air emissions from animal  feeding operations. According to agency officials, until EPA can determine  the actual level of emissions occurring, it will be unable to assess the  extent to which these emissions are affecting human health and the  environment. Progress in conducting the national air emissions monitoring  study is discussed in greater detail in the following section.
section_title: It Is Unclear If EPA’s Efforts to Develop Air Emissions Protocols for Animal Feeding Operations Will Be Effective and How EPA Intends to Regulate These Emissions in the Future
paragraphs: The National Air Emissions Monitoring Study—a 2-year effort to collect  data on air emissions from animal feeding operations—is intended to  provide a scientific basis for estimating air emissions from these  operations. The results of this study were intended to help EPA develop  protocols that will allow it to determine which operations do not comply  with applicable federal laws. As currently structured, however, the study  may not provide the quantity and quality of data needed for developing  appropriate methods for estimating emissions. Furthermore, it is uncertain  if and when EPA will develop a process-based model that considers the  interaction and implications of all sources of emissions at an animal  feeding operation. Also, other more recent decisions suggest that the  agency has not yet determined how it intends to regulate air emissions  from animal feeding operations. In the absence of federal guidance on how  to regulate air emissions from animal feeding operations, a few states have  developed their own regulations.
subsections: section_title: A National Air Emissions Monitoring Study Has Begun, but the Study May Not Provide the Data EPA Needs to Develop Air Emissions Protocols
paragraphs: According to EPA, although it has the authority to require animal feeding  operations to monitor their emissions and come into compliance with the  Clean Air Act on a case-by-case basis, this approach has proven to be time  and labor intensive. As an alternative to the case-by-case approach, in  January 2005, EPA offered animal feeding operations an opportunity to  sign a voluntary consent agreement and final order, known as the Air  Compliance Agreement. To participate in the agreement, animal feeding  operations were required to take the following actions:    Pay a civil penalty ranging from $200 to $1,000 per animal feeding  operation, depending on the number of animals at the operation and the  number of operations that each participant signed up.
Pay up to $2,500 per farm to help fund a nationwide emissions monitoring  study and make their facilities available as a monitoring site for emissions  testing.
Once emission protocols are published, apply for all applicable air permits  and comply with permit conditions, if deemed necessary.
Since announcing the Air Compliance Agreement, EPA has proposed exempting such  releases from the CERCLA and EPCRA reporting requirements. The exemption, proposed  in December 2007, has not been finalized.
Any farm more than 10 times larger than EPA’s established size thresholds for CAFOs  must, within 120 days of receiving an executed copy of the agreement, provide the National  Response Center with a written statement noting the facility’s location, estimating air  emissions of ammonia, and stating that it will notify the Center of reportable releases when  emission rates are determined by the monitoring study.
In return for meeting these requirements, EPA agreed not to sue  participating animal feeding operations for certain past violations or  violations occurring during the emissions monitoring study.
Almost 13,900 animal feeding operations were approved for participation  in the agreement, representing the egg, broiler chicken, dairy, and swine  industries. Some turkey operations volunteered but were not approved  because there were too few operations to fund a monitoring site, and the  beef cattle industry chose not to participate. EPA collected a total of $2.8  million in civil penalties from participating animal feeding operations and  deposited these funds into the U.S. Treasury. An additional $14.8 million  was collected by a nonprofit, industry-established organization to fund the  national air emissions monitoring study. Industry groups representing the  participating operations provided the funding for the study as was called  for under the agreement. Table 9 shows the level of participation by type  of operation and the amount of funding provided by different industry  groups for the national air emissions monitoring study.
The purpose of the National Air Emissions Monitoring Study is to collect  data that will provide a scientific basis for measuring and estimating air  emissions from animal feeding operations and will help EPA to determine  operations’ compliance status. To provide a framework for the monitoring  study and develop a sampling plan that was representative of animal  feeding operations in the United States, in 2003 EPA convened a panel of  industry experts, university and government scientists, and other  stakeholders knowledgeable in the field. In 2004, the nonprofit  organization founded by the various livestock sectors selected an  independent science adviser to oversee the data collection at 20 of the  13,883 animal feeding operations that were selected to participate in the  study. Their selection was submitted to and approved by EPA. Data  collection began in May 2007. Once 2 years of data has been collected,  EPA will use these data to develop air emissions protocols. Figure 6 shows  EPA’s expected timeline for the development of air emissions protocols.
However, the National Air Emissions Monitoring Study may not provide  the data that EPA needs to develop comprehensive protocols for  quantifying air emissions from animal feeding operations for a variety of  reasons. First, the monitoring study does not include the 16 combinations  of animal types and geographic regional pairings recommended by EPA’s  expert panel. The panel recommended this approach so that the study  sample would be representative of the vast majority of participating  animal feeding operations, accounting for differences in climatic  conditions, manure-handling methods, and density of operations.  However, EPA approved only 12 of the 16 combinations recommended by  the expert panel, excluding southeastern broiler, eastern layer,  midwestern turkey, and southern dairy operations. Second, site selection  for the study has been a concern since the plan to select monitoring sites  for the monitoring study was announced in 2005. At that time, many  agricultural experts, environmental groups, and industry and state officials  disagreed with the site selection methodology. In commenting on EPA’s  Federal Register notice of the Animal Feeding Operation Consent  Agreement and Final Order, these experts and officials stated that the  study did not include a sufficient number of monitoring sites to establish a  statistically valid sample. Without such a sample, we believe that EPA will  not be able to accurately estimate emissions for all types of operations.  More recently, in June 2008, the state of Utah reached an agreement with  EPA to separately study animal feeding operations in the state because of  the state’s continuing concerns that the National Air Emissions Monitoring  Study will not collect information on emissions from operations in Rocky  Mountain states and therefore may not be meaningful for those operations  that raise animals in arid areas. Finally, agricultural experts have raised  concerns that the National Air Emissions Monitoring Study does not  include other sources that can contribute significantly to emissions from  animal feeding operations. For example, these experts have noted that the  monitoring study will not capture data on ammonia emissions from  feedlots and manure applied to fields. According to these experts, feedlots  and manure on fields, as well as other excluded sources, account for  approximately half of the total ammonia emissions from animal feeding  operations.
Furthermore, USDA’s Agricultural Air Quality Task Force has also recently  raised concerns about the quantity and quality of the data being collected  during the early phases of the study and how EPA will eventually use the  information. In particular, the task force expressed concern that the  technologies used to collect emissions data were not functioning reliably.  For example, according to data provided by EPA, almost one-third of the  preliminary data from one site were incomplete during a 2-month data  collection period. The task force was also concerned about EPA’s plans to  extrapolate the data across a variety of CAFO operating configurations. At  its May 2008 task force meeting, the members requested that the Secretary  of Agriculture ask EPA to review the first 6 months of the study’s data to  determine if the study needs to be revised in order to yield more useful  information.
EPA acknowledged that emissions data should be collected for every type  of animal feeding operation and practice, but EPA officials stated that  such an extensive study is impractical. According to EPA officials, the  industry identified those monitoring sites that they believed best  represented the type of operations and manure management practices that  are in their various animal sectors. EPA reviewed and approved these site  selections. According to EPA, it believes that the selected sites provide a  reasonable representation of the various animal sectors. EPA has also  indicated that it plans to use other relevant information to supplement the  study data and has identified some potential additional data sources. For  example, a study conducted at two broiler facilities in Kentucky has been  accepted as meeting the emissions study’s requirements. However,  according to agricultural experts, until EPA identifies all the supplemental  data that it plans to use, it is not clear if these data, together with the  emissions study data, will enable EPA to develop comprehensive air  emissions protocols.
Furthermore, EPA has also indicated that completing the National Air  Emissions Monitoring Study is only the first step in a multiyear effort to  develop a process-based model for predicting overall emissions for animal  feeding operations. A process-based model would capture emissions data  from all sources and use these data to assess the interaction of all sources  and the impact that different manure management techniques have on air  emissions for the entire operation. For example, technologies are available  to decrease emissions from manure lagoons by, among other things,  covering the lagoon to capture the ammonia. However, if an operation  spreads the lagoon liquid as fertilizer for crops, ammonia emissions could  increase on the field. According to NAS, a process-based model is needed  to provide scientifically sound estimates of air emissions from animal  feeding operations that can be used to develop management and  regulatory programs. Although EPA plans to develop a process-based  model after 2011, it has not yet established a timetable for completing this  model and, therefore, it is uncertain when EPA will have more  sophisticated approaches that will more accurately estimate emissions  from animal feeding operations.
section_title: Recent EPA Decisions Suggest That the Agency Has Not Yet Determined How It Plans to Regulate Air Emissions from Animal Feeding Operations
paragraphs: Two recent decisions by EPA suggest that the agency has not yet  determined how it intends to regulate air emissions from animal feeding  operations. EPA’s first decision in this context was made in December  2007. At that time EPA proposed to exempt releases to the air of  hazardous substances from manure at farms that meet or exceed the  reportable quantities from both CERCLA and EPCRA notification  requirements. According to EPA, this decision was in response to language  that was contained in congressional committee reports related to EPA’s  appropriations legislation for 2005 and 2006.  EPA was directed to  promptly and expeditiously provide clarification on the application of  these laws to poultry, livestock, and dairy operations. In addition, the  agency received a petition from the National Chicken Council, the  National Turkey Federation, and the U.S. Poultry and Egg Association  seeking an exemption from the CERLA and EPCRA reporting  requirements for ammonia emissions from poultry operations. The petition  argued that ammonia emissions from poultry operations pose little or no  risk to public health, and emergency response is inappropriate. In  proposing the rule, EPA noted that the agency would not respond to  releases from animal wastes under CERCLA or EPCRA nor would it  expect state and local governments to respond to such releases because  the source and nature of these releases are such that emergency response  is unnecessary, impractical, and unlikely. It also noted that it had received  26 comment letters from state and local response agencies supporting the  exemption for ammonia from poultry operations. However, during the  public comment period ending on March 27, 2008, a national association  representing state and local emergency responders with EPCRA  responsibilities questioned whether EPA had the authority to exempt  these operations until the agency had data from its monitoring study to  demonstrate actual levels of emissions from animal feeding operations.  This national association further commented that EPA should withdraw  the proposal because it denied responders and the public the information  necessary to protect themselves from dangerous releases. The timing of  this proposed exemption, before the National Air Emissions Monitoring  Study has been completed, we believe calls into question the basis for  EPA’s decision.
The second decision that EPA has recently made that calls into question  how the agency intends to regulate air emissions from animal feeding  operations involves the timing of key regulatory decisions. EPA has stated  that it will not make key regulatory decisions on how federal air  regulations apply to animal feeding operations until after 2011, when the  monitoring study is completed. According to EPA, the agency will issue  guidance defining the scope of the term “source” as it relates to animal  agriculture and farm activities. As a result, EPA has not decided if it will  aggregate the emissions occurring on an animal feeding operation as one  source or if the emissions from the barns, lagoons, feed storage, and fields  will each be considered as a separate source when determining if an  operation has exceeded air emissions’ reportable quantities. Depending on  the approach EPA takes, how emissions are calculated could differ  significantly. For example, according to preliminary data EPA has received  from an egg-laying operation in Indiana, individual chicken barns may  exceed the CERCLA reportable quantities for ammonia. Moreover, if  emissions from all of the barns on the operation are aggregated, they  might be more than 500 times the CERCLA reportable quantities. In  addition, EPA does not intend to issue guidance to address emissions, and  sources of emissions, that cannot reasonably pass through a stack,  chimney, or other functionally equivalent opening, i.e., fugitive emissions,  until after the conclusion of the monitoring study.
EPA has already been asked to clarify what it considers a source on an  animal feeding operation but has declined to do so. In a 2004 ruling on an  appeal of a civil suit against a swine operation, the U.S. Court of Appeals  for the 10th Circuit overturned a 2002 federal district court ruling that a  farm’s individual barns, lagoons, and land application areas could be  considered separate “sources” for purposes of CERCLA reporting  requirements. The Court of Appeals ruled that the whole farm site was  the proper entity to be assessed for purposes of CERCLA reporting. The  Court invited EPA to file a friend-of-the-court brief in order to clarify the  government’s position on this issue, but EPA declined to do so within the  court-specified time frame. Another court reached similar conclusions in  2003. Despite these court rulings, EPA has indicated that it will not  decide on what it considers a source until the National Air Emissions  Monitoring Study is completed.
section_title: Lacking Federal Guidance, Some States Have Begun to Regulate Air Emissions from Animal Feeding Operations
paragraphs: In the absence of federal guidance on how to regulate air emissions from  animal feeding operations, officials in 6 states, out of the 47 states that  responded to our survey, are regulating some emissions covered under the  Clean Air Act, CERCLA and EPCRA. As table 10 shows, state officials in  California, Idaho, Minnesota, Missouri, Nebraska, and North Dakota  reported that they have developed state air regulations for certain  pollutants that are emitted by CAFOs.
Specific examples of the types of regulations that the states have  developed include the following:    Minnesota has established state emissions thresholds for hydrogen sulfide  that apply to CAFOs. CAFO operators in the state must develop an air  emissions control plan and must implement it if the Minnesota Pollution  Control Agency detects elevated levels of hydrogen sulfide. According to  state officials, once an operator reduces emissions, the agency re-monitors  to ensure the emission levels remained below the state-established  threshold. Minnesota may take legal action against CAFO operators  violating this standard. For example, in June 2008, monitoring by the  Minnesota Pollution Control Agency at a dairy operation recorded  hydrogen sulfide levels above the state threshold and in cooperation with  the State Attorney General, the agency, using state authorities, filed a  lawsuit against the dairy’s operator.
In 2003, California passed a law that authorized the state and local air  districts to require animal feeding operations above a certain size to apply  for clean air permits and develop a plan to decrease air emissions. For  example, one air district in California—the San Joaquin Valley Air  Pollution Control District with large clusters of animal feeding  operations—developed a rule in 2006 to implement the law that required  large animal feeding operations to apply for a permit that includes a plan  for mitigating their emissions. According to air district officials, the district  has implemented specific regulations for dairy animal feeding operations  that require these operations to obtain five separate permits for  components of their operations, including barns and land application of  manure. The officials told us that these regulations were put in place, in  part because the area is designated as a severe nonattainment area under  the Clean Air Act and they are required to regulate a broader range of  emission sources. According to state officials we spoke with, as a result of  these more stringent state regulations, CAFOs in California may be  relocating to other states—such as Texas and Iowa.
section_title: Two Federal Court Decisions Have Affected EPA’s and Some States’ Ability to Regulate Water Pollutants Discharged by CAFOs
paragraphs: Two federal court decisions have affected EPA and some states’ abilities  to regulate CAFOs for water pollutants. The 2005 Waterkeeper Alliance  Inc. v. EPA decision forced EPA to revise its 2003 rule for permitting  CAFOs and abandon its approach of requiring all CAFO operators to  obtain a permit. Although this court decision affected EPA’s ability to  regulate CAFOs, states’ reaction to the Waterkeeper decision has varied:  some states such as Minnesota continue to require all CAFOs to obtain  permits while others such as Colorado have delayed developing new rules  until EPA issues its final revised rule. In addition, the Supreme Court’s  2006 decision—Rapanos v. United States—has made determination of  Clean Water Act jurisdiction over certain types of waters more complex.  According to EPA, this has required the agency to gather significantly  more evidence to establish Clean Water Act jurisdiction in some  enforcement cases.
subsections: section_title: The Waterkeeper Decision Has Impacted EPA’s Ability to Regulate CAFOs, but Has Not Had a Similar Impact on Some States
paragraphs: In its 2005 Waterkeeper decision, the U.S. Court of Appeals for the Second  Circuit set aside a key provision of EPA’s 2003 CAFO rule requiring every  CAFO to apply for a NPDES permit. Under the 2003 rule, large numbers of  previously unregulated CAFOs were required to apply for permits and  would have been subject to monitoring and reporting requirements  imposed by the permit as well as periodic inspections. According to EPA,  the 2003 rule would have expanded the number of CAFOs requiring  permits from an estimated 12,500 to an estimated 15,300, an increase of  about 22 percent. According to EPA officials, when fully implemented, this  requirement for all CAFOs with a potential to discharge to apply for  permits would have provided EPA with more comprehensive information  on the number and location of CAFOs and how they are operated and  managed, thus allowing EPA to more effectively locate and inspect CAFOs  nationwide.
However, in 2003, both environmental and agricultural groups challenged  EPA’s 2003 rule. In the Waterkeeper case, environmental groups argued,  among other things, that EPA’s 2003 rule did not adequately provide for (1)  public review and comment on a CAFO’s nutrient management plan and  (2) permitting authorities to review the CAFO’s nutrient management plan.  The court agreed with the environmental groups and instructed EPA to  revise the rule accordingly. The agricultural groups challenged the 2003  rule’s CAFO permitting requirement, arguing that the agency exceeded its  authority under the Clean Water Act by requiring CAFOs that were not  discharging pollutants into federally regulated waters to apply for permits  or demonstrate that they had no potential to discharge. The court also  agreed with the agricultural groups and set aside the permitting  requirements for CAFOs that did not actually discharge. Following the  court’s decision, many aspects of the 2003 rule remained in effect,  including EPA’s revised regulatory definition of CAFOs and the expansion  of the number of CAFOs needing permits by deleting a significant  exception.
In effect, the Waterkeeper decision returned EPA’s permitting program to  one in which CAFO operators are not required to apply for a NPDES  permit unless they discharge, or propose discharging, into federally  regulated waters. As a result, EPA must identify and prove that an  operation has discharged or is discharging pollutants in order to require  the operator to apply for a permit. To help identify unpermitted discharges  from CAFOs, EPA officials stated that they have to rely on other methods  that are not necessarily all-inclusive, such as citizens’ complaints, drive-by  observations, aerial flyovers, and state water quality assessments that  identify water bodies impaired by pollutants associated with CAFOs.  According to EPA officials, these methods have helped the agency identify  some CAFOs that may be discharging as well as targeting inspections to  such CAFOs.
In response to the Waterkeeper decision, EPA proposed a new rule in June  2006 requiring that (1) only CAFO operators that discharge, or propose to  discharge, apply for a permit; (2) permitting authorities review CAFO  nutrient management plans and incorporate the terms of these plans into  the permits; and (3) permitting authorities provide the public with an  opportunity to review and comment on the nutrient management plans.  According to EPA officials, the final rule is currently being reviewed by the  Office of Management and Budget before it is formally published in the  Federal Register. These officials said it is uncertain when the OMB review  will be completed and the final rule issued. Estimates vary on how this  rule, when implemented, will affect the number of CAFOs that will obtain  a permit. EPA estimates that 25 percent fewer CAFOs will need to apply  for a permit under the new rule than would have been required to apply  for a permit under the 2003 rule. In contrast, an association representing  state water program officials believes that many fewer CAFOs than EPA  estimates will voluntarily apply for a permit under the new 2006 rule, when  it is finalized.
The need to develop and implement a new rule that meets the Waterkeeper  requirements has also resulted in delays in implementing the provisions of  the 2003 rule that the Court upheld. Specifically, EPA has not yet  implemented, among other things the expanded CAFO definitions, which  cover operations such as dry-manure poultry operations. This is  particularly significant since, according to a USDA official with extensive  knowledge of the poultry industry and another agricultural expert that we  spoke to, at least 90 percent of poultry operations use a dry-manure  management system. An EPA Region 6 official told us that in Texas alone  this expanded definition would result in about 1,500 additional dry-manure  poultry operations being covered under the new CAFO definition.
Although the Waterkeeper decision has affected EPA’s ability to regulate  CAFOs’ water pollutant discharges, this decision has not had the same  impact on the ability of some of the states to regulate these operations.  According to officials in the 47 states responding to our survey, the impact  of the Waterkeeper decision on their ability to regulate water pollution  from CAFOs has been mixed. As table 11 shows, the impacts of the  Waterkeeper decision ranged from having little impact on state regulation  of CAFOs to impairing state CAFO programs.
Officials from several of the states that told us that the Waterkeeper  decision had little impact on their regulation of CAFOs, saying that this  was primarily because their states had implemented CAFO regulations  that were more stringent than those required under the Clean Water Act.  For example, Minnesota officials stated that the Waterkeeper decision had  no impact on their state’s regulations because the state used its own  authority to adopt regulations more stringent than EPA’s regulations.  Moreover, according to Minnesota officials, even after the Waterkeeper  decision, the state has continued to require all CAFOs to obtain permits  from the state environmental agency. Similarly, Kansas officials stated that  the Waterkeeper decision had only minimal effects because the state has  regulated CAFOs since the 1960s.
However, 34 states indicated that the Waterkeeper decision directly  affected their state programs. Officials from 15 states told us that the  number of CAFOs that had obtained permits since the Waterkeeper  decision had decreased although none provided us with numbers on what  this decrease had been. Similarly, officials in 10 states told us that the  Waterkeeper decision had impaired their state’s ability to regulate CAFOs  because it discredited the program, created confusion or uncertainty, or  made it difficult for them to determine which operations needed a permit.  For example, according to the state official responsible for Indiana’s  CAFO permitting program, although the state has had a CAFO permitting  program since 1971, it adopted EPA’s 2003 CAFO Rule because the rule  was more protective. However, when the Waterkeeper decision set aside  portions of the 2003 rule, this official told us that the decision, in effect,  discredited the state’s regulatory program. In addition, officials from nine  states who are responsible for their state’s permitting program told us that  their programs remain in limbo while they wait for EPA to issue its final  revised rule. These state officials, including officials in Colorado, said that  they will update their state rules once EPA’s final rule is issued.
Finally, state water pollution control officials have expressed some  concerns that EPA’s new 2006 rule will place a greater administrative  burden on states than the 2003 rule would have. In an August 2006 letter to  EPA, the Association of State and Interstate Water Pollution Control  Administrators noted that the “reactive” enforcement that EPA will now  follow will require permitting authorities to significantly increase their  enforcement efforts to achieve the level of environmental benefit that  would have been provided by the 2003 rule. These officials believe that  requiring EPA and the states to identify CAFOs that actually discharge  pollutants into federally regulated water bodies will consume more  resources than requiring all CAFOs to apply for a permit.
section_title: The Rapanos Decision Has Affected EPA’s Overall Ability to Regulate Pollutants Entering Federally Regulated Waters
paragraphs: The Supreme Court’s 2006 Rapanos decision has also affected EPA’s  enforcement of the Clean Water Act because the agency believes that it  must gather significantly more evidence to establish which waters are  subject to the act’s permitting requirements. At issue in the Rapanos  decision was whether the Clean Water Act’s wetlands permitting program  applied to four specific wetlands that were adjacent to non-navigable  tributaries of traditional navigable waters. The Court rejected the  standards applied by the lower courts in determining whether wetlands at  issue fell under the act’s jurisdiction and, therefore, could be subject to  permitting requirements. Although a majority of the justices rejected the  standards applied by the lower courts, a majority could not agree on how  to determine which waters would fall under the act’s jurisdiction, and thus  how far EPA could reach to regulate discharges of pollutants under the  act.
Although the Rapanos case arose in the context of a different permit  program, the scope of EPA’s pollutant discharge permit program  originates in the same Clean Water Act definition that was discussed in the  decision. According to EPA enforcement officials, the agency may now be  less likely to seek enforcement against a CAFO that it believes is  discharging pollutants into a water body because it may be more difficult  to prove that the water body is federally regulated. According to EPA  officials, as a result of the Rapanos decision, the agency must now spend  more resources developing an enforcement case because the agency must  gather proof that the CAFO not only has illegally discharged pollutants,  but that those discharges ultimately entered a federally regulated water  body. These officials told us that the farther a CAFO is from a regulated  water body, the more evidence they will need to prove that the discharges  entered that water body. To ensure “nationwide consistency, reliability,  and predictability in their administration of the statute,” EPA has issued  national guidance to clarify the agency’s responsibilities in light of the  Supreme Court’s decision. However, in a March 4, 2008, memorandum,  EPA’s Assistant Administrator for Enforcement and Compliance  Assurance stated that the Rapanos decision and EPA’s guidance has  resulted in significant adverse impacts to the clean water enforcement  program. According to the memorandum, the Rapanos decision and  guidance negatively affected approximately 500 enforcement cases,  including as many as 187 cases involving NPDES permits. In May 2007,  Members of Congress, in both the House and Senate, introduced a bill  entitled the Clean Water Restoration Act of 2007 to clearly define the  scope of the Clean Water Act. As of August 2008, neither bill had been  reported out of committee.
section_title: Conclusions
paragraphs: For more than 30 years, EPA has regulated CAFOs under the Clean Water  Act and during this time it has amassed a significant body of knowledge  about the pollutants discharged by animal feeding operations and the  potential impacts of these pollutants on human health and the  environment. Despite its long-term regulation of CAFOs, EPA still lacks  comprehensive and reliable data on the number, location, and size of the  operations that have been issued permits and the amounts of discharges  they release. As a result, EPA has neither the information it needs to  assess the extent to which CAFOs may be contributing to water pollution,  nor the information it needs to ensure compliance with the Clean Water  Act. More recently, EPA has also begun to address concerns about air  pollutants that are emitted by animal feeding operations. The Nationwide  Air Emissions Monitoring Study, along with EPA’s plans to develop air  emissions estimating protocols, are important steps in providing much  needed information on the amount of air pollutants emitted from animal  feeding operations. However, questions about the sufficiency of the sites  selected for the air emissions study and the quantity and quality of the data  being collected could undermine EPA’s efforts to develop air emissions  protocols by 2011 as planned. Finally, while the study and resulting  protocols are important first steps, a process-based model that more  accurately predicts the total air emissions from an animal feeding  operation is still needed. While EPA has indicated it intends to develop  such a model, it has not yet established a strategy and timeline for this  activity.
section_title: Recommendations for Executive Action
paragraphs: In order to more effectively monitor and regulate CAFOs, we recommend  that the Administrator of the Environmental Protection Agency should  complete the agency’s effort to develop a national inventory of permitted  CAFOs and incorporate appropriate internal controls to ensure the quality  of the data.
In order to more effectively determine the extent of air emissions from  animal feeding operations, the Administrator of the Environmental  Protection Agency should  reassess the current data collection efforts, including its internal controls,  to ensure that the National Air Emissions Monitoring Study will provide  the scientific and statistically valid data that EPA needs for developing its  air emissions protocols;   provide stakeholders with information on the additional data that it plans  to use to supplement the National Air Emissions Monitoring Study; and    establish a strategy and timetable for developing a process-based model  that will provide more sophisticated air emissions estimating  methodologies for animal feeding operations.
section_title: Agency Comments and Our Evaluation
paragraphs: We provided a draft of this report for review and comment to the EPA and  the Secretary of USDA.  We received written comments from EPA.  USDA  did not provide written comments, but did provide technical comments  and clarifications, which we incorporated, as appropriate.
EPA partially concurred with our conclusions and recommendations.  In  its written comments, EPA acknowledged that currently no national  inventory of permitted CAFOs exists.  The agency stated that it is currently  working with its regions and the states to develop and implement a new  national data system to collect and record facility-specific information on  permitted CAFOs. We have revised our recommendation to reflect the  actions that EPA has underway.  In response to our recommendations that  EPA reassess the current data collection effort, EPA stated that the agency  has developed a quality assurance plan for the study and is continuously  evaluating the National Air Emissions Monitoring Study.  We are aware  that EPA has developed a quality assurance plan for the data collected  during the study.  However, our recommendation also reflects other  concerns with the study.  For example, the monitoring sites selected may  not represent a statistically valid sample or animal feeding operations that  account for the differences in climatic conditions, manure-handling  methods, and density of operations; and the study does not address other  sources that can contribute significantly to emissions from animal feeding  operations. EPA did not address these issues in its comments.  Therefore,  we continue to believe that EPA should reassess the ongoing effort to  ensure that the study, as currently structured, will provide the data that  EPA needs.
In response to our recommendation that the agency identify the  information that it plans to use to supplement the National Air Emissions  Monitoring Study, EPA stated that it cannot yet identify the data that it will  use to augment the data collected during the monitoring study.  However,  the agency indicated that it has begun discussions with USDA to identify  ongoing research that is focused on agricultural air emissions and gaps  that may still exist, but did not provide any additional information on  when it plans to identify the supplemental data that it plans to use to  augment the monitoring study.  Until it does so, neither EPA nor  stakeholders can be assured that these data, in combination with the  emissions study data, will enable EPA to develop the planned protocols.   The agency also agreed with our recommendation to establish a strategy  and timetable for developing a process-based model and said that it has  begun to evaluate what is needed to develop such a model.  However, the  agency did not provide any information on when it expects to complete  plans for developing a process-based model.  EPA also provided technical  comments, which we have incorporated, as appropriate. EPA’s written  comments are provided in appendix V.
As agreed with your offices, unless you publicly announce the contents of  this report earlier, we plan no further distribution until 30 days from the  report date. At that time, we will send copies to interested congressional  committees, the Administrator of the Environmental Protection Agency,  the Secretary of the United States Department of Agriculture and other  interested parties. We also will make copies available to others upon  request. In addition, the report will be available at no charge on GAO’s  Web site at http://www.gao.gov.
If you or your staff have any questions regarding this report, please  contact me at (202) 512-3841 or mittala@gao.gov. Contact points for our  Office of Congressional Relations and Public Affairs may be found on the  last page of this report. Key contributors to this report are listed in  appendix VI.
section_title: Appendix I: Objectives, Scope, and Methodology
paragraphs: For this report we were asked to determine the (1) trends in concentrated  animal feeding operations (CAFOs) over the past 30 years; (2) amount of  waste they generate; (3) findings of recent key academic, industry, and  government research of the potential impacts of CAFOs on human health  and the environment, and the extent to which the Environmental  Protection Agency (EPA) has assessed the nature and severity of these  identified impacts; (4) progress that EPA and states have made in  regulating and controlling the air emissions of, and in developing protocols  to measure, air pollutants from CAFOs that could affect air quality; and (5)  extent to which recent court decisions have affected EPA and the states’  ability to regulate CAFO discharges that impair water quality.
In conducting our work, we reviewed laws and regulations and federal and  state agencies’ documents. We met with officials from EPA, the U.S.  Department of Agriculture (USDA), the National Pork Producers Council,  the National Pork Board, the National Cattlemen’s Beef Association, the  Environmental Integrity Project (a nonpartisan, nonprofit environmental  advocacy group), the Sierra Club, California Association of Irritated  Residents, Waterkeeper Alliance, Iowa Citizens for Community  Improvement, Environmental Defense, National Association of Clean Air  Agencies, Association of State and Interstate Water Pollution Control  Administrators, as well as state officials. The National Chicken Council did  not respond to our requests for information. Additionally, we visited  CAFOs in eight states: Arkansas, California, Colorado, Iowa, Maryland,  Minnesota, North Carolina, and Texas. We chose these states because they  were geographically dispersed and contained numerous CAFOs  representing multiple types of animals.
For our analysis of trends in CAFOs over the past 30 years, we used  USDA’s Census of Agriculture data. We assessed the reliability of these  data by reviewing USDA’s documentation on the development,  administration, and data quality program for the Census of Agriculture. We  also electronically tested the data used in this study to determine if there  were any missing data or anomalies in the dataset. Furthermore, we  compared the results of our nationwide results for each year by animal  sector to USDA’s published reports. On the basis of these assessments, we  determined the data to be sufficiently reliable for the purposes for which it  was used in this report. In addition, respecting USDA’s requirement to  protect the privacy of individual farmers responding to the Census of  Agriculture surveys, we conducted these analyses at USDA and worked  with USDA to review our results and verify that no single operation could  be identified from our analysis.
From USDA’s Census of Agriculture data, we analyzed the most recent  data available for large farms raising animals from 1974 through 2002. We  used these data on large farms as a proxy for CAFOs because no federal  agency collects consistent data on these types of operations. USDA has  periodically collected data on farms nationwide using the Census of  Agriculture survey. Prior to 1982, these surveys were conducted every four  years; whereas since 1982, the agency has administered the survey every  five years (the most recent survey results, conducted in 2007, will not be  available until February 2009). In analyzing Census data prior to 1982, we  found that the categories reported by USDA were not consistent with  EPA’s minimum size threshold for large CAFOs: 2,500 hogs, 700 dairy or  milk cows, 55,000 turkeys, 1,000 beef cattle, 82,000 layers, and 125,000  broilers. For instance, the largest farm categories USDA reported for  broilers prior to 1982 was farms with sales of 100,000 and more. Since  sales data must be converted to an inventory number, we had to make  adjustments for production cycles to determine the number of animals on  a farm per day. Broiler farms complete six production cycles per year  therefore, when we divided the USDA provided number of 100,000 in  broiler sales by 6 to account for the total number of possible production  cycles, the USDA reported broiler sales represent a farm with an inventory  of about 17,000 broilers. Farms of this size are much smaller than the  125,000 broiler CAFO threshold defined by EPA. Similarly, categories for  farms raising other types of animals, in the pre-1982 USDA data, were also  different than the EPA CAFO definitions for these types of operations. As  a result, we used the time frame of 1982 through 2002 because USDA could  provide us with detailed electronic data that allowed us to apply EPA’s  CAFO thresholds to determine the trends in the overall number of large  farms that raised animals and could be potentially considered a CAFO. For  broilers and layers/pullets, we used EPA’s CAFO minimum size threshold  for dry-litter manure handling systems because these systems represent  the majority of poultry operations. These thresholds are larger than for  those poultry operations that have liquid manure handling systems.
Because USDA does not report the average number of animals on a farm,  we used USDA Census of Agriculture inventory, sales, and inventory plus  sales data for this purpose. The choice of using inventory only, sales only,  or inventory and sales data for a particular animal type depended on the  wording of Census survey questions during the years we analyzed. When  only sales data or inventory plus sales data were used, we adjusted these  data using the appropriate USDA formulas to determine the average  number of animals on a farm. When both inventory and sales were used  for an animal type, we applied an approved USDA approach to determine  the average number of animals on a farm. As a result, we made the  following adjustments for each animal type:    For beef cattle, USDA only collected sales data for 1982 through 1997. As a  result, for beef cattle, we used sales of cattle on feed (2002 survey) or sales  of fattened cattle (1982 through 1997 surveys) adjusted for the number of  production cycles. This increased the likelihood that we were including  cattle raised on CAFOs instead of operations that allow the cattle to graze  on pastureland.
For dairy cows, we used the inventory of animals as of December 31 for  each Census year since these animals are maintained to produce milk and  not specifically for slaughter. For dairy cows, we included the categories:  lactating and nonlactating cows.
For hogs, the Census of Agriculture reported both inventory and sales data  for hogs and pigs. These data were not reported by either the weight or  age, so we used the total for all hogs and pigs of all ages. We used both the  inventory and sales data for hogs and adjusted for the number of  production or finish cycles. Hogs may be sold more than once because of  the practice of selling feeder pigs at about 10-12 weeks of age to producers  to be grown to typical slaughter size. For example, in 1997, about 25  percent of all hog and pig sales reported on the Census of Agriculture were  feeder pigs. We adjusted the hog data to factor out these multiple sales.
For layers, we used survey responses of inventory as of December 31 for  layers 20 weeks old and older plus pullets for laying flock replacement.
For broilers, we used inventory and sales data from the categories:  broilers, fryers, capons, roaster and other chickens raised for meat.
For turkeys, both inventory and sales data were used and included both  hens and tom turkeys.
We also reviewed EPA’s data on the number of CAFOs that had been  issued permits—these data are either collected by EPA’s regional offices  or from the states—for the period 2003 to 2008. We assessed the accuracy  and reliability of these data by interviewing officials in 47 states and we  asked them to verify the information that EPA had for the numbers of  CAFOs permitted in their state. Based on the information we obtained  from the state officials, we determined that EPA’s data for permitted  CAFOs was not reliable and could not be used to identify trends in  permitted CAFOs over the 5-year period.
To identify the amount of manure, including urine, a large CAFO is  estimated to generate for each animal type, we used EPA’s thresholds for  the minimum number of animals that constitute a CAFO. To illustrate the  size of a “typical” large farm for each animal type, we used the median for  a large-sized farm. We used the median instead of the mean because we  believe it provides a more representative measure for a typical large farm.  We also present information on farms at the 75th percentile of all large  farms for a particular animal type to represent larger farms.
To estimate the amount of manure produced by each type of animal, we  used engineering standards for manure production cited by the American  Society of Agricultural and Biological Engineers (ASABE). These  standards report the total amount of manure over the production cycle for  hogs, beef cattle, turkeys, and broilers. In order to estimate the average  pounds of manure per day, we divided the total manure produced over the  production cycle by the number of days in the production cycle. Further,  we converted the pounds of manure into tons of manure per farm per year.  We adjusted the manure calculations for the following animal types:    For layers, the standards provided the average daily pounds of manure  produced by layers. We multiplied the average pounds of manure per day  times the average number of animals times 365 days to get manure  produced per year.
For broilers, we determined the average daily pound of manure from the  information provided in the standards. We multiplied the average pound of  manure per day times the average number of animals times 365 days to get  manure per year.
For dairy cows, the standards provided the average daily pounds of  manure produced by dairy cows. We multiplied the average pounds of  manure per day times the average number of animals times 365 days to get  manure per year. However, we adjusted the data to take into account the  typical percentage of cows that are either lactating or dry (nonlactating)  and applied the different amounts of manure produced by each type of  dairy cow.
For turkeys, we adjusted the turkey statistics based on the ratio of hens to  tom turkeys raised on farms and applied different amounts of manure due  to the different sizes of the animals.
For hogs, the manure standards report manure produced by hogs covering  a specific stage of production: feeder-pig-to-finish pigs—beginning with a  pig weighing on average about 27 pounds and resulting in a hog weighing  154 pounds. Estimates for other hog operation types such as nursery,  farrow to feeder, and farrow to finish would therefore differ. Census of  Agriculture data for 2002 indicate that about a third of all hogs sold were  from the grow-to-finish (called finish only on the survey) operation type.  The ASABE manure standards for this type of operation use 154 pounds as  the finish weight. However, USDA reports that typical hog finish  (slaughter) weights at the time of the 2002 Census were about 260 pounds.  For hogs only, we adjusted the ASABE manure estimates by 1.7 to account  for the larger finish weights reported by USDA. We believe this is a  conservative adjustment because manure produced by hogs weighing 154  to 260 pounds will be the maximum amount per day that ASABE used to  calculate the average pounds produced for the hogs growing from about  27 pounds to 154 pounds.
For beef cattle, we used the manure standard for “beef-finishing cattle.”
This standard is for cattle fattened from about 740 pounds to about 1,200  pounds at marketing. Beef cattle (listed as cattle on feed) data from the  Census are for cattle sold for slaughter and thus similar in weight to those  for the standard. The reported manure results for beef cattle are for  operations of this type only.
In addition, the number of days on feed for hogs, turkeys, and broilers  used for the ASABE manure standards does not take into account time  between herds or flocks entering and leaving an operation; therefore, we  adjusted the manure generated to account for the time between cycles.
We recognize that all amounts of manure reported are estimates because  amounts of manure per animal type vary by feeding programs, feeds used,  climatic conditions, production techniques, and animal genetics, among  other things. As feeds, animal genetics, and production techniques change  in the future, these estimates might change—and may have changed since  2002—but USDA did not provide specific information on what changes  have occurred and how those changes may have impacted the manure  production on farms. We did not estimate the ability of the farm or  surrounding farms to assimilate the manure if applied to pastures and crop  land nor did we take into account various technologies to process and/or  convert manure. Reported estimates of manure are for amounts produced.  We did not determine whether these amounts were discharged into the air  or streams and wetlands. Manure harvested from CAFOs for application to  land might be less than that excreted by animals because of shrinkage due  to evaporation.
To provide a perspective of the amount of wastes generated by these large  farms, we compared them with the amount of human sanitary waste  generated in various cities. We selected certain cities on the basis of their  population, as reported by the U.S. Census Bureau’s Population Estimates  for 2002, and calculated the amount of sanitary waste generated by the  human population of those cities by applying estimates for human sanitary  waste production. Human sanitary waste includes feces and urine but does  not include wastes such as water from showers, washing dishes and  clothes, and flushing toilets. We found two sources of information for  average daily human sanitary waste.  Because these sources provided  different estimates (2.68 and 4.76 pounds per person per day), we averaged  the two amounts to use in our calculations of human sanitary waste  produced for cities (3.72 pounds per person per day). All amounts of  human sanitary waste reported are estimates because amounts will vary  based on differences in age, dietary habits, activity levels, and climatic  conditions, among other things. Human sanitary waste is a small portion of  human discharge into sewage systems. Our reported estimates of human  sanitary waste for a city are illustrative only and are not intended to be  estimates of actual human sanitary waste entering a particular city’s waste  treatment system. These estimates are for a population the size of selected  cities assuming that the residents do not commute outside the city  boundaries and that nonresidents do not enter the city for work or other  reasons.
To identify the findings of recent key academic, industry, and government  research on the potential impacts of CAFOs on human health and the  environment, and the extent to which EPA has assessed the nature and  severity of such impacts, we reviewed EPA’s 2003 CAFO rule (for water  impact studies) and the findings and supporting documents of the National  Academy of Sciences study on air emissions from animal feeding  operations (for air impact studies). In addition, we    conducted library, online journal and Internet searches to identify recent  studies;    consulted with EPA, USDA, state agencies, industry groups, environmental  groups, and academia to help identify additional studies; and identified studies through citations in previously identified studies.
We only included in our review studies that (1) were peer-reviewed or  produced by a federal agency, (2) were new and original research  completed since 2002, (3) had a clearly defined methodology, and (4)  identified pollutants found in animal waste and/or their impacts. Through  this effort, we found over 200 studies and identified 68 studies that  examined air and water quality issues associated with animal waste and  met our criteria. We also classified these studies according to whether  they  found a direct link between pollutants from animal waste and impacts on  human health or the environment;   did not find any impacts on human health or the environment from  pollutants from animal waste; found an indirect link between animal waste and human health or  environmental impacts; or   measured pollutants from animal waste otherwise known to cause human  health or environmental impacts.
The classification for each study involved two reviewers. If the reviewers  disagreed on the classification, they turned to a third reviewer for  resolution. Finally, we compared the findings from these studies with EPA  assessments to date and interviewed EPA officials regarding these  assessments.
To determine the progress that EPA and states have made in regulating  and controlling the air emissions of, and in developing protocols to  measure, air pollutants from CAFOs, we reviewed relevant documents,  interviewed officials responsible for the ongoing air monitoring study and  visited several National Air Emissions Monitoring Study sites in North  Carolina. Additionally, we interviewed industry and environmental groups,  the umbrella association for state and local clean air agencies, and citizen  groups about how EPA air emissions protocols affect them. Finally, we  contacted state CAFO officials in all 50 states to determine which states  had developed air emission regulations applicable to CAFOs. Officials in  47 states responded.  These 47 states account for an estimated 99 percent  of large animal feeding operations that could be defined as CAFOs under  EPA’s 2003 rule.
Finally, to determine the extent to which recent court decisions have  affected EPA and the states’ ability to regulate CAFO discharges that  impair water quality, we examined recent federal decisions, including the  Waterkeeper Alliance Inc. v. EPA (Waterkeeper), and the Supreme Court’s  2006 decision in Rapanos v. United States. We interviewed EPA officials  about how these court decisions have affected their regulations. To better  understand the bases for the lawsuits and what has occurred since the  court decisions, we contacted plaintiffs and defendants involved in  Waterkeeper and other court cases, including industry and environmental  groups. To identify the impact of these cases on states regulations, we  contacted state CAFO officials in all 50 states to determine how the  Waterkeeper decision affected their regulations. We asked the states if the  Waterkeeper decision had affected their state’s CAFO program. Using the  responses we received from 47 states, we conducted content analyses and  classified them into six categories, including if the decision (1) had little  impact on the state program, (2) caused the state to wait for EPA guidance  (3) impaired the state program, (4) proactively changed legislation, (5)  reduced the number of CAFOs with permits, or (6) other. Some officials  identified more than one impact. The responses in the “other” category  included such responses as “not applicable,” “because the state does not  have delegated authority,” and “we have spent a large amount of time  studying the ruling and commenting on EPA proposed rules that were  developed to satisfy the ruling.”
We conducted this performance audit between July 2007 and August 2008,  in accordance with generally accepted government auditing standards.  Those standards require that we plan and perform the audit to obtain  sufficient, appropriate evidence to provide a reasonable basis for our  findings and conclusions based on our audit objectives. We believe that  the evidence obtained provides a reasonable basis for our findings and  conclusions based on our audit objectives.
section_title: Appendix II: EPA’s Definition of Concentrated Animal Feeding Operations
paragraphs: EPA’s National Pollutant Discharge Elimination System (NPDES) permit  program regulates the discharge of pollutants from point sources to waters  of the United States. The Clean Water Act defines point sources to include  CAFOs. To be considered a CAFO, a facility must first be defined as an  animal feeding operation, which is a lot or facility (other than an aquatic  animal production facility) where the following conditions are met:    Animals have been, are, or will be stabled or confined and fed or  maintained for a total of 45 days or more in any 12-month period.
Crops, vegetation, forage growth, or post-harvest residues are not  sustained in the normal growing season over any portion of the lot or  facility.
Generally CAFOs must meet the above definition of an animal feeding  operation and stable or confine a certain minimum number of animals at  the operation. EPA classifies CAFOs as large, medium, or small, based on  size. Table 12 shows the number of animals at a farm that meet EPA’s  definition of a large, medium, and small CAFO.
In addition to size, EPA uses the following criteria to determine if a CAFO  operator needs to apply for a NPDES permit.
A large CAFO confines at least the number of animals described in table  12.
A medium CAFO falls within the size range in table 12 and either:    discharged pollutants into federally regulated waters through a  manmade ditch, flushing system, or similar manmade device;     discharged pollutants directly into federally regulated waters that  originate outside of and pass over, across, or through the facility or  otherwise come into contact with animals confined in the operation; or  is designated as a CAFO by the permitting authority as a significant  contributor of pollutants.
A small CAFO confines the number of animals described in table 12 and  has been designated as a CAFO by the permitting authority as a significant  contributor of pollutants.
section_title: Appendix III: Nationwide Trends in the Number of All Animal Farms and the Number of Animals Raised on Large Farms, 1982-2002
paragraphs: This appendix provides our analysis of USDA’s data for trends on the  number of all animal farms and the number of animals raised on large  farms per day for all animal types for the period from 1982 through 2002.
section_title: Appendix IV: Government-Sponsored or Peer- Reviewed Studies Completed Since 2002 on the Impacts of Pollutants from Animal Waste
paragraphs: Pollutant(s)
Ankley, Gerald T., Kathleen M. Jensen,  Elizabeth A. Makynen, Michael D. Kahl,  Joseph J. Korte, Michael W. Hornung, Tala R.  Henry, Jeffrey S. Denny, Richard L. Leino,  Vickie S. Wilson, et al. “Effects of the  Androgenic Growth Promoter 17β-trenbolone  on Fecundity and Reproductive Endocrinology  of the Fathead Minnow.” Environmental  Toxicology and Chemistry. Vol. 22, no. 6  (2003):1,350–1,360.
Fertility of fish was  significantly reduced by  hormones and female fish  developed male sex  characteristics.
Clark, Clifford G., Lawrence Price, Rafiq  Ahmed, David L. Woodward, Pasquale L.  Melito, Frank G. Rodgers, Frances Jamieson,  Bruce Ciebin, Aimin Li, and Andrea Ellis.  “Characterization of Waterborne Outbreak– Associated Campylobacter jejuni, Walkerton,  Ontario.” Emerging Infectious Diseases. Vol. 9,  no. 10 (2003):1,232-1,241.
Cattle manure from a nearby  farm entered the  groundwater system and  caused gastrointestinal  illness and death in  residents.
Diesel, Elizabeth A., Melissa L. Wilson, Ryan  Mathur, Evan Teeters, David Lehmann, and  Caitlan Ziatos. “Nutrient Loading Patterns on  an Agriculturally Impacted Stream System in  Huntingdon County Pennsylvania Over Three  Summers.” Northeastern Geology &  Environmental Sciences. Vol. 29, no. 1  (2007):25-33.
Excess nutrients from CAFO  manure contributed  significantly to impaired  water quality and resulted in  the inability to sustain fish  populations.
Hill, Dagne D., William E. Owens, and Paul B.  Tchounwou. “Impact of Animal Application on  Runoff Water Quality in Field Experimental  Plots.” International Journal of Environmental  Research and Public Health. Vol. 2, no. 2  (2005):314–321.
Nutrients from manure  spread on fields contributed  to water pollution.
Jensen, Kathleen M., Elizabeth A. Makynen,  Michael D. Kahl, and Gerald T. Ankley.  “Effects of the Feedlot Contaminant 17α- Trenbolone on Reproductive Endocrinology of  the Fathead Minnow.” Environmental Science  & Technology. Vol. 40, no. 9 (2006): 3,112- 3,117.
Fertility of fish was  significantly reduced by  hormones and female fish  developed male sex  characteristics.
Pollutant(s)
Orlando, Edward F., Alan S. Kolok, Gerry A.  Binzcik, Jennifer L. Gates, Megan K. Horton,  Christy S. Lambright, L. Earl Gray, Jr., Ana M.  Soto, and Louis J. Guillette, Jr. “Endocrine- Disrupting Effects of Cattle Feedlot Effluent on  an Aquatic Sentinel Species, the Fathead  Minnow.” Environmental Health Perspectives.  Vol. 112, no. 3 (2004):353–358.
University of Florida; St.  Mary’s College of  Maryland, University of  Nebraska, EPA, Tufts  University.
Male fish were  demasculinized and there  was defeminization of  female fish.
Weldon, Mark B. and Keri C. Hornbuckle.  “Concentrated Animal Feeding Operations,  Row Crops, and Their Relationship to Nitrate  in Eastern Iowa Rivers.” Environmental  Science & Technology. Vol. 40, no. 10 (2006):  3,168-3,173.
High concentrations of  nutrients in waters are a  result of CAFO manure and  degrade water quality.
Mathisen, T., S. G. Von Essen, T. A. Wyatt,  and D. J. Romberger. “Hog Barn Dust Extract  Augments Lymphocyte Adhesion to Human  Airway Epithelial Cells.” Journal of Applied  Physiology. Vol. 96, no. 5 (2004):1,738–1,744.
Dust from hog confinement  facilities induces airway  inflammation.
Romberger, D. J., V. Bodlak, S. G. Von Essen,  T. Mathisen, and T. A. Wyatt. “Hog Barn Dust  Extract Stimulates IL-8 And IL-6 Release in  Human Bronchial Epithelial Cells Via PKC  Activation.” Journal of Applied Physiology. Vol.  93, no. 1 (2002):289–296.
Dust from hog confinement  facilities induces airway  inflammation.
Schiffman, Susan S., Clare Studwell,  Lawrence R. Landerman, Katherine Berman,  and John S. Sundy. “Symptomatic Effects of  Exposure to Diluted Air Sampled from a Swine  Confinement Atmosphere on Healthy Human  Subjects.” Environmental Health Perspectives.  Vol. 113, no. 5 (2005):567-576.
Short-term exposure to  emissions expected  downwind from a swine  confinement facility can  induce headaches, eye  irritation, and nausea.
Sigurdarson, Sigurdur T., Patrick T.  O’Shaughnessy, Janet A. Watt, and Joel N.  Kline. “Experimental Human Exposure Inhaled  Grain Dust and Ammonia: Towards a Model of  Concentrated Animal Feeding Operations.”  American Journal of Industrial Medicine.Vol.  46, issue 5 (2004):345:348.
Exposure to endotoxin-rich  dust from CAFOs causes  airflow obstruction in  subjects with mild asthma.
Sundblad, B-M., B-M. Larsson, L. Palmberg,  and K. Larsson. “Exhaled Nitric Oxide and  Bronchial Responsiveness in Healthy Subjects  Exposed to Organic Dust.” European  Respiratory Journal. Vol. 20, no. 2 (2002):  426–431.
Airway inflammation is  induced by exposure to a  farming environment.
Pollutant(s)
Wickens, K., et. Al. “Farm Residence and  Exposures and the Risk of Allergic Diseases in  New Zealand Children.” Allergy. Vol. 57, no. 12  (2002): 1,171-1,179.
University of Otago (New  Zealand)
Utrecht University (The  Netherlands)
There was a greater  prevalence of allergic  disease for children on  farms.
Wilson, Vickie S., Christy Lambright, Joe  Ostby, and L.E. Gray, Jr. “In Vitro and in Vivo  Effects of 17β-Trenbolone: A Feedlot Effluent  Contaminant.” Toxicological Sciences. Vol. 70,  no. 2 (2002): 202-211.
Hormones found in feedlot  effluent caused reproductive  malformations in laboratory  rats and human cells.
Wyatt, Todd A., Rebecca E. Slager, Jane  DeVasure, Brent W. Auvermann, Michael L.  Mulhern, Susanna Von Essen, Tracy  Mathisen, Anthony A. Floreani, and Debra J.  Romberger. “Feedlot Dust Stimulation of  Interleukin-6 And 8 Requires Protein Kinase C- Epsilon Human Bronchial Epithelial Cells.”  American Journal of Physiology-Lung Cellular  and Molecular Physiology. Vol. 293, no. 5  (2007):1,163-1,170.
Dust extract from cattle  feedlots stimulates airway  inflammation at  concentrations found  downwind from the  operation.
Hill, Dagne D., William E. Owens, and Paul B.  Tchounwou. “Prevalence of Escherichia coli  O157:H7 Bacterial Infections Associated With  the Use of Animal Wastes in Louisiana for the  Period 1996-2004.” International Journal of  Environmental Research and Public Health.  Vol. 3, no. 1 (2006): 107-113.
Escherichia  coli (not  measured)
Although some of the  parishes surveyed had large  amounts of animal waste  generated each year,  statistics did not show a  correlations with Escherichia  coli 0157:H7 bacterial  infections.
Hill, Dagne D., William E. Owens, and Paul B.  Tchounwou. “Prevalence of Selected Bacterial  Infections Associated with the Use of Animal  Waste in Louisiana.” International Journal of  Environmental Research and Public Health.  Vol. 2, no. 1 (2005): 84–93.
Escherichia  coli (not  measured)
Although the four parishes  surveyed had large amounts  of animal waste generated,  statistics does not show a  correlation between this and  bacterial infections.
Krapac, I.G., W.S. Dey, W.R. Roy, C.A. Smyth,  E. Storment, S.L. Sargent, and J.D. Steele.  “Impacts of Swine Manure Pits on  Groundwater Quality.” Environmental Pollution.  Vol. 120, issue 2 (2002): 475-492.
Groundwater near swine  CAFOs has not been  significantly impacted.
Mugel, Douglas N. “Ground-Water Quality and  Effects of Poultry Confined Animal Feeding  Operations on Shallow Ground Water, Upper  Shoal Creek Basin, Southwest Missouri,  2000.” U.S. Geological Survey Water- Resources Investigations Report 02-4125  (2002).
The results do not indicate  that poultry CAFOs are  affecting the shallow ground  water with respect to  nutrients and fecal bacteria.
Pollutant(s)
Braun-Fahrlander, Charlotte, Josef Riedler,  Udo Herz, Waltraud Eder, Marco Waster,  Leticia Grize, Soyoun Maisch, David Carr,  Florian Gerlach, Albrecht Bufe. “Environmental  Exposure to Endotoxin and its Relation to  Asthma in School-Age Children.” The New  England Journal of Medicine. Vol. 347, no. 12  (2002): 869-877.
Institute of Social and  Preventive Medicine  (Switzerland), Children’s  Hospital (Austria),  Philipps University  (Germany), Ruhr  University (Germany),  University Children’s  Hospital (Switzerland),  University of Munich  (Germany)
Decreased risk of hay fever,  asthma, and wheeze in  children exposed to high  levels of endotoxin in dust.
Elliott, L., K. Yeatts, and D. Loomis.  “Ecological Associations Between Asthma  Prevalence And Potential Exposure to  Farming.” European Respiratory Journal. Vol.  24, no. 6 (2004): 938–941.
Findings are consistent with  the hypothesis that certain  farm exposures are  protective against childhood  asthma.
McGinn, S. M., H. H. Janzen, and T. Coates.  “Atmospheric Pollutants and Trace Gases:  Atmospheric Ammonia, Volatile Fatty Acids,  and Other Odorants near Beef Feedlots.”  Journal of Environmental Quality. Vol. 32, no.  4 (2003):1,173–1,182.
Odorants from feedlots were  effectively dispersed.  Emitted ammonia was  deposited to the soil  downwind.
Studies showing an indirect link between pollutants and impacts  Valcour, James E., Pascal Michel, Scott A.  McEwen, and Jeffrey B. Wilson. “Associations  between Indicators of Livestock Farming  Intensity and Incidence of Human Shiga Toxin- Producing Escherichia coli Infection.”  Emerging Infectious Diseases. Vol. 8, no. 3  (2002): 252-257.
Escherichia  coli (not  measured)
The strongest associations  with human Escherichia coli  infection were the ratio of  beef cattle to human  population and the  application of manure to the  surface of agricultural land  by a solid spreader and by a  liquid spreader.
Wing, Steve, Stephanie Freedman, and  Lawrence Band. “The Potential Impact of  Flooding on Confined Animal Feeding  Operations in Eastern North Carolina.”  Environmental Health Perspectives. Vol. 110,  no. 4 (2002): 387–391.
Flood events have a  significant potential to  degrade environmental  health because of dispersion  of wastes from industrial  animal operations in areas  with vulnerable populations.
Avery, Rachel C., Steve Wing, Stephen W.  Marshall, and Susan S. Schiffman. “Odor from  Industrial Hog Farming Operations and  Mucosal Immune Function in Neighbors.”  Archives of Environmental Health. Vol. 59, no.  2 (2004): 101-108.
This study suggests that  malodor from industrial  swine operations can affect  the secretory immune  system, although the  reduced levels reported are  still within normal range.
Pollutant(s)
Bullers, Susan. “Environmental Stressors,  Perceived Control, and Health: The Case of  Residents Near Large-Scale Hog Farms in  Eastern North Carolina.” Human Ecology. Vol.  33, no. 1 (2005): 1-16.
Residents living near large- scale hog farms in eastern  North Carolina report  symptoms related to  respiratory and sinus  problems and nausea.
Chénard, Liliane, Ambikaipakan Senthilselvan,  Vaneeta K. Grover, Shelley P. Kirychuk,  Joshua A. Lawson, Thomas S. Hurst, and  James A. Dosman. “Lung Function and Farm  Size Predict Healthy Worker Effect in Swine  Farmers.” Chest. Vol. 131, no. 1 (2007): 245- 254.
Some swine workers are  less affected by swine air  and continue in the  profession. Other workers  are more affected.
Chrischilles, Elizabeth, Richard Ahrens,  Angela Kuehl, Kevin Kelly, Peter Thorne, Leon  Burmeister, and James Merchant. “Asthma  Prevalence and Morbidity Among Rural Iowa  Schoolchildren.” Journal of Allergy and   Clinical Immunology. Vol. 113, no. 1 (2004):  66-71.
Among children who  wheeze, farm and nonfarm  children were equally likely  to have been given a  diagnosis of asthma and had  comparable morbidity.
Dosman, J.A., J.A. Lawson, S.P. Kirychuk, Y.  Cormier, J. Biem, and N. Koehncke.  “Occupational Asthma in Newly Employed  Workers in Intensive Swine Confinement  Facilities.” European Respiratory Journal. Vol.  24, no. 6 (2004): 698–702.
Institute of Agricultural  Rural and Environmental  Health, University of  Saskatchewan (Canada),  Laval University  (Canada)
Newly employed workers in  intensive swine confinement  facilities reported  development of  acute onset  of wheezing and cough  suggestive of asthma.
Merchant, James A., Allison L. Naleway, Erik  R. Svendsen, Kevin M. Kelly, Leon F.  Burmeister, Ann M. Stromquist, Craig D.  Taylor, Peter S. Thorne, Stephen J. Reynolds,  Wayne T. Sanderson, and Elizabeth A.  Chrischilles. “Asthma and Farm Exposures in a  Cohort of Rural lowa Children.” Environmental  Health Perspectives. Vol. 113, No. 3 (2005):  350-356.
There was a high prevalence  of asthma health outcome  among farm children living  on farms that raise swine  and raise swine and add  antibiotics.
Mirabelli, Maria C., Steve Wing, Stephen W.  Marshall, and Timothy C. Wilcosky. “Asthma  Symptoms Among Adolescents Who Attend  Public Schools That Are Located Near  Confined Swine Feeding Operations.”  Pediatrics. Vol. 118, no. 1 (2006): 66-75.
Estimated exposure to  airborne pollution from  confined swine feeding  operations is associated with  adolescents’ wheezing  symptoms.
Palmberg, Lena, Britt-Marie Larsson, Per  Malmberg, and Kjell Larsson. “Airway  Responses of Healthy Farmers and   Nonfarmers to Exposure in a Swine  Confinement Building.” Scandinavian Journal  of Work, Environment, and Health. Vol. 28, no.  4 (2002): 256-263.
National Institute of  Environmental Medicine  (Sweden), National  Institute for Working Life  (Sweden)
Altered lung function and  bronchial responsiveness  was found in nonfarming  subjects. Only minor  alterations were found in the  farmers.
Pollutant(s)
Radon, Katja, Anja Schulze, Vera Ehrenstein,  Rob T. van Strien, Georg Praml, and Dennis  Nowak. “Environmental Exposure to Confined  Animal Feeding Operations and Respiratory  Health of Neighboring Residents.”  Epidemiology. Vol. 18, no. 3 (2007): 300-308.
Respiratory disease was  found among resident living  near confined animal feeding  operations.
Sigurdarson, Sigurdur T. and Joel N. Kline.  “School Proximity to Concentrated Animal  Feeding Operations and Prevalence of Asthma  in Students.” Chest. Vol. 129, no. 6  (2006):1,486–1,491.
Children in the study school,  located one-half mile from a  CAFO, had a significantly  increased prevalence of  physician-diagnosed  asthma.
Anderson, M.E. and M.D. Sobsey. “Detection  And Occurrence of Antimicrobially Resistant E.  Coli In Groundwater on or Near Swine Farms  In Eastern North Carolina.” Water Science &  Technology. Vol. 54, no. 3 (2006): 211-218.
Antibiotic-resistant E. coli  strains are present in  groundwaters of swine  farms.
Batt, Angela L., Daniel D. Snow, and Diana S.  Aga. “Occurrence of Sulfonamide  Antimicrobials in Private Water Wells in  Washington Country, Idaho, USA.”  Chemosphere. Vol. 64, issue 11 (2006): 1,963- 1,971.
All six sampled wells were  contaminated by veterinary  antimicrobials and had  elevated concentrations of  nitrate and ammonium.  Three wells had nitrate  levels exceeding EPA  thresholds.
Campagnolo, Enzo R., Kammy R. Johnson,  Adam Karpati, Carol S. Rubin, Dana W.  Kolpin, Michael T. Meyer, J. Emilio Esteban,  Russell W. Currier, Kathleen Smith, Kendall M.  Thu, and Michael McGeehin. “Antimicrobial  Residues in Animal Waste and Water  Resources Proximal to Large-Scale Swine and  Poultry Feeding Operations.” The Science of  the Total Environment. Vol. 299, no. 1 (2002):  89-95.
CDC, U.S. Geological  Survey, Iowa Department  of Public Health, Ohio  Department of Health,  University of Iowa  antimicrobial compounds  were detected in surface and  groundwater samples  collected proximal to the  swine and poultry farms.
Durhan, Elizabeth J., Christy S. Lambright,  Elizabeth A. Makynen, James Lazorchak,  Phillip C. Hartig, Vickie S. Wilson, L. Earl Gray,  and Gerald T. Ankley. “Identification of  Metabolites of Trenbolone Acetate in  Androgenic Runoff from a Beef Feedlot.”  Environmental Health Perspectives. Vol. 114,  supp. 1 (2006):65–68.
Whole-water samples from  the discharge contained  detectible concentrations of  hormones.
Pollutant(s)
Gessel, Peter D., Neil C. Hansen, Sagar M.  Goyal, Lee J. Johnston, and Judy Webb.  “Persistence Of Zoonotic Pathogens in Surface  Soil Treated With Different Rates of Liquid Pig  Manure.” Applied Soil Ecology. Vol. 25, issue  23 (2004): 237-243.
Manure application rate was  correlated positively with the  persistence of fecal  indicators but did not relate  to survival of indicators with  short survival times.
Haggard, Brian E. , Paul B. DeLaune, Douglas  R. Smith, and Philip A. Moore, Jr. “Nutrient and  B17-Estradiol Loss in Runoff Water From  Poultry Litters.” Journal of the American Water  Resources Association. Vol. 41, no. 2  (2005):245-256.
In general, poultry litter  applications increased  nutrient and hormone  concentrations in runoff  water.
Hutchins, Stephen R., Mark V. White, Felisa  M. Hudson, and Dennis D. Fine. “Analysis of  Lagoon Samples from Different Concentrated  Animal Feeding Operations for Estrogens and  Estrogen Conjugates.” Environmental Science  & Technology. Vol. 41, no. 3 (2007): 738-744.
Estrogen conjugates  contribute significantly to the  overall estrogen load, even  in different types of CAFO  lagoons.
Koike, S., I.G. Krapac, H.D. Oliver, A.C.  Yannarell, J.C. Chee-Sanford, R.I. Aminov,  and R.I. Makie. “Monitoring and Source  Tracking of Tetracycline Resistance Genes in  Lagoons and Groundwater Adjacent to Swine  Production Facilities over a 3-Year Period.”  Applied and Environmental Microbiology. Vol.  73, no. 15 (2007): 4,813-4,823.
University of Illinois,  USDA, Illinois State  Geological Survey,  Rowett Research  Institute (UK)
Antibiotic resistance genes  in groundwater are affected  by swine manure and also  part of the indigenous gene  pool.
Miller, David H. and Gerald T. Ankley.  “Modeling Impacts On Populations: Fathead  Minnow (Pimephales Promelas) Exposure to  the Endocrine Disruptor 17ß-Trenbolone as a  Case Study.” Ecotoxicology and Environmental  Safety. Vol. 59, issue 1 (2004): 1-9.
Model shows that if fathead  minnow is exposed to  continuous concentrations of  hormone, there will be a risk  of extinction.
Nelson, Nathan O., John E. Parsons, and  Robert L. Mikkelsen. “Field-Scale Evaluation of  Phosphorus Leaching in Acid Sandy Soils  Receiving Swine Waste.” Journal of  Environmental Quality. Vol. 34, no. 6 (2005):  2,024-2,035.
The results show that  substantial quantities of  phosphorus can be leached  through soils with low  phosphorus sorption  capacities.
Peak, Nicholas, Knapp, Charles W, Richard K.  Yang, Margery M. Hanfelt, Marilyn S. Smith,  Diana S. Aga, and David W. Graham.  “Abundance of Six Tetracycline Resistance  Genes in Wastewater Lagoons at Cattle  Feedlots With Different Antibiotic Use  Strategies.” Environmental Microbiology. Vol.  9, no. 1 (2007): 143-151.
CAFOs using larger  amounts of antibiotics had  significantly higher detected  resistance gene levels.
Pollutant(s)
Sapkota, Amy R., Frank C. Curriero, Kristen E.  Gibson, and Kellogg J. Schwab. “Antibiotic- Resistant Enterococci and Fecal Indicators in  Surface Water and Groundwater Impacted by  a Concentrated Swine Feeding Operation.”  Environmental Health Perspectives. Vol. 115,  no. 7 (2007):1,040–1,045.
Detected elevated levels of  fecal indicators and  antibiotic-resistant bacteria  in water sources down  gradient from a swine  facility.
Soto, Ana M., Janine M. Calabro, Nancy V.  Prechtl, Alice Y. Yau, Edward F. Orlando,  Andreas Daxenberger, Alan S. Kolok, Louis J.  Guillette, Jr., Bruno le Bizec, Iris G. Lange, and  Carlos Sonnenschein. “Androgenic and  Estrogenic Activity in Water Bodies Receiving  Cattle Feedlot Effluent in Eastern Nebraska,  USA.” Environmental Health Perspectives. Vol.  112, no. 3 (2004):346–352.
Feedlot effluents contain  sufficient levels of  hormonally active agents to  warrant further investigation  of possible effects on  aquatic ecosystem health.
Thorsten, Christiana, Rudolf J. Schneider,  Harald A. Farber, Dirk Skutlarek, Michael T.  Meyer, and Heiner E. Goldbach.  “Determination of Antibiotic Residues in  Manure, Soil, and Surface Waters.” Acta  hydrochimica et hydrobiologica. Vol. 31, no. 1  (2003):36–44.
In each of the surface waters  tested antibiotics could be  detected.
Thurston-Enriquez, Jeanette A., John E. Gilley,  and Bahman Eghball. “Microbial Quality of  Runoff Following Land Application of Cattle  Manure And Swine Slurry.” Journal of Water  and Health. vol. 3, no. 2 (2005): 157-171.
Large microbial loads could  be released via heavy  precipitation events and  could have a significant  impact on water bodies.
Toetz, Dale. “Nitrate in Ground and Surface  Waters in the Vicinity of a Concentrated  Animal Feeding Operation.” Archives of  Hydrobiology. Vol. 166, no. 1 (2006): 67-77.
Drinking water was  contaminated with CAFOs  as the suspected source.
U.S. Department of Interior. U.S. Geological  Survey. In cooperation with U.S.  Environmental Protection Agency, National  Exposure Research Laboratory. Geochemistry  and Characteristics of Nitrogen Transport at a  Confined Animal Feeding Operations in a  Coastal Plain Agricultural Watershed, and  Implications for Nutrient Loading in the Neuse  River Basin, North Carolina, 1999-2002.  Scientific Investigations Report 2004-5283,  Reston, Va.: (2004).
Large amounts of nitrogen  moving in the estuary as a  result of extreme events may  potentially cause algal  growths.
Pollutant(s)
United State Geological Survey in cooperation  with Virginia Department of Health. Water- Quality Data from Ground- and Surface-Water  Sites near Concentrated Animal Feeding  Operations (CAFOs) and non-CAFOs in the  Shenandoah Valley and Eastern Shore of  Virginia, January-February, 2004. Reston, Va  (2005).
United States Geological Survey. Fractionation  and Characterization of Organic Matter in  Wastewater from a Swine Waste-Retention  Basin. Scientific Investigations Report 2004- 5217 (2004).
The bulk of the organic  matter consists of microbial  cellular constituents and  their degradation products.
Chapin, Amy, Ana Rule, Kristen Gibson,  Timothy Buckley, and Kellogg Schwab.  “Airborne Multidrug-Resistant Bacteria Isolated  from a Concentrated Swine Feeding  Operation.” Environmental Health  Perspectives. Vol. 113, no. 2 (2005):137-142.
Multidrug-resistant bacterial  pathogens were detected in  the air of a swine CAFO.
Donham, Kelley. J., Joung Ae Lee, Kendall  Thu, and Stephen J. Reynolds. “Assessment  of Air Quality at Neighbor Residences in the  Vicinity Of Swine Production Facilities.”  Journal of Agromedicine. Vol. 11, no. 3-4  (2006): 15-24.
Average concentration of  hydrogen sulfide exceeded  EPA recommended  community standards in all  three areas assessed.
Gibbs, Shawn G., Christopher F. Green,  Patrick M. Tarwater, Linda C. Mota, Kristina D.  Mena, and Pasquale V. Scarpino. “Isolation of  Antibiotic-Resistant Bacteria from the Air  Plume Downwind of a Swine Confined or  Concentrated Animal Feeding Operation.”  Environmental Health Perspectives. Vol. 114,  no. 7 (2006):1,032–1,037.
Bacterial concentrations with  multiple antibiotic  resistances or multidrug  resistance were recovered  inside and outside to 150 m  downwind of a facility, even  after antibiotic use was  discontinued.
Harper, Lowry A., Ron R. Sharpe, Tim B.  Parkin, Alex De Visscher, Oswald van  Cleemput, and F. Michael Byers. “Nitrogen  Cycling through Swine Production Systems:  Ammonia, Dinitrogen, and Nitrous Oxide  Emissions.” Journal of Environmental Quality.  Vol. 33, no. 4 (2004): 1,189-1,201.
USDA, Ghent University  (Belgium)
In contrast with previous and  current estimates of  ammonia emissions from  CAFOs, this study found  smaller ammonia emissions  from animal housing,  lagoons, and fields.
Hamscher, Gerd, Heike Theresia Pawelzick,  Silke Sczesny, Heinz Nau, and Jörg Hartung.  “Antibiotics in Dust Originating from a Pig- Fattening Farm: A New Source of Health  Hazard for Farmers?” Environmental Health  Perspectives. Vol. 111, no. 13 (2003):1,590– 1,594.
Five different antibiotics  were detected in dust  samples swine feeding  operation.
Pollutant(s)
Hoff, Steven J., Dwaine S. Bundy, Minda A.  Nelson, Brian C. Zelle, Larry D. Jacobson,  Albert J. Heber, Jinqin Ni, Yuanhui Zhang,  Jacek A. Koziel, and David B. Beasley.  “Emissions of Ammonia, Hydrogen Sulfide,  and Odor before, during, and after Slurry  Removal from a Deep-Pit Swine Finisher.”  Journal of the Air & Waste Management  Association. Vol. 56, no. 5 (2006): 581-590.
Emissions of ammonia,  hydrogen sulfide, and odor  had large increases during  slurry removal. A slurry  removal even will result in  acute exposure for animals  and workers.
O’Connor, Rod, Mark O’Connor, Kurt Irgolic,  Justin Sabrsula, Hakan Gurleyuk, Robert  Brunette, Crystal Howard, Jennifer Garcia,  John Brien, June Brien, and Jessica Brien.  “Transformations, Air Transport, and Human  Impact of Arsenic from Poultry Litter.”  Environmental Forensics. Vol. 6, no. 1 (2005):  83-89.
Levels of arsenic found in  homes. This could represent  a significant health risk.
Radon, Katja, Brigitta Danuser, Martin Iversen,  Eduard Monso, Christoph Weber, Jorg  Hartung, Kelley J. Donham, Urban Palmgren,  and Dennis Nowak. “Air Contaminants in  Different European Farming Environments.”  Annals of Agriculture and Environmental  Medicine. Vol. 9, no. 1 (2002): 41-48.
Ludwig-Maximilians- University (Germany),  Swiss Federal Institute of  Technology, Aarhus  University Hospital  (Denmark), Hospital  Germans Trial I Pujol  (Spain), School of  Veterinary Medicine  (Germany), University of  Iowa, Pegasus Labor  GmbH (Germany)
The exposure level found in  this study might put the  farmers at risk from  respiratory diseases.
Razote, E.B., R.G. Maghirang, B.Z. Predicala,  J.P. Murphy, B.W. Auvermann, J.P. Harner III,  and W.L. Hargrove. “Laboratory Evaluation of  the Dust-Emission Potential of Cattle Feedlot  Surfaces.” Transactions of the ASABE. Vol.  49, no. 4 (2006): 1,117-1,124.
Robarge, Wayne P., John T. Walker, Ronald  B. McCulloch, and George Murray.  “Atmospheric Concentrations of Ammonia and  Ammonium at an Agricultural Site in the  Southeast United States.” Atmospheric  Environment. Vol. 36, no. 10 (2002): 1,661- 1,674.
Elevated ambient ammonia  concentrations near an  agricultural site.
United State Environmental Protection Agency.  National Emission Inventory – Ammonia  Emissions from Animal Husbandry Operations,  Draft Report. Washington, D.C. (2004).
Pollutant(s)
Walker, J.T., W.P. Robarge, Y. Wu, and T.P.  Meyers. “Measurement of Bi-Directional  Ammonia Fluxes Over Soybean Using  Themodified Bowen-Ratio Technique.”  Agricultural and Forest Meteorology. Vol. 138,  no. 1-4 (2006): 54-68.
In general, the net  deposition flux was lower  than expected.
Walker, John T., Wayne P. Robarge, Arun  Shendrikar, and Hoke Kimball. “Inorganic  Pm2.5 at a U.S. Agricultural Site.”  Environmental Pollution. Vol. 139, no. 2  (2006): 258-271.
Model results show that  reductions in atmospheric  ammonia will have minimal  effect on organic PM2.5  during summer and a  moderate effect during  winter.
Walker, J.T., Dave R. Whitall, Wayne P.  Robarge, and Hans W. Pearl. “Ambient  Ammonia and Ammonium Aerosol Across a  Region of Variable Ammonia Emission  Density.” Atmospheric Environment. Vol. 38,  no. 9 (2004): 1,235-1,246.
Agricultural ammonia  emissions influence local  ambient concentrations of  ammonia and PM2.5.
Wilson, Sacoby M. and Marc L. Serre.  “Examination of Atmospheric Ammonia Levels  Near Hog Cafos, Homes, and Schools In  Eastern North Carolina.” Atmospheric  Environment. Vol. 41, issue 23 (2007): 4,977– 4,987.
Distance to one or more  CAFOs is the key variable in  controlling atmospheric  ammonia at the community  level in Eastern N.C.
Muller-Suur, C., P.H. Larsson, K. Larsson, J.  Grunewald. “Lymphocyte Activation After  Exposure to Swine Dust: A Role Of Humoral  Mediators and Phagocytic Cells.” European  Respiratory Journal. Vol. 19, issue 1 (2002):  104-107.
About immune system  response.
Charavaryamath, Chandrashekhar,  Kyathanahalli S Janardhan, Hugh G  Townsend, Philip Willson, and Baljit Singh.  “Multiple Exposures to Swine Barn Air Induce  Lung Inflammation and Airway Hyper- Responsiveness.” Respiratory Research. Vol.  6, no. 1 (2005):50-66.
Does not address human  impacts.
Eduard, Wijnand, Ernst Omenaas, Per Sigvald  Bakke, Jeroen Douwes, and Dick Heederik.  “Atopic and Non-atopic Asthma in a Farming  and a General Population.” American Journal  of Industrial Medicine. Vol. 46, issue 4 (2004):  396-399.
National Institute of  Ocupational Health  (Norway), University of  Bergen (Norway),  University of Wellington  (New Zealand)
Protective effect of the farm  environment on asthma.
section_title: Appendix V: Comments from the Environmental Protection Agency
section_title: Appendix VI: GAO Contact and Staff Acknowledgments
subsections: section_title: GAO Contact
section_title: Staff Acknowledgments
paragraphs: In addition to the individual named above, Sherry L. McDonald, Assistant  Director; Kevin Bray; Yecenia C. Camarillo; Wendy Dye; Paul Hobart;  Cathy Hurley; Holly L. Sasso; James W. Turkett; and Greg Wilmoth made  key contributions to this report. Also contributing to this report were  Elizabeth Beardsley, Ben N. Shouse, and Carol Herrnstadt Shulman.