5 October 2008

4 minute read

Concentrated animal feeding operations (CAFOs), large livestock and poultry operations that raise animals in a confined situations, congregate animals, feed, manure and urine, dead animals, and production operations on a small land area.

Feed is brought to the animals rather than the animals grazing or otherwise seeking feed in pastures, fields, or on rangeland.

In these operations animals are confined for at least 45 days in a 12-month period and there is no grass or vegetation for them to feed on during this time.

CAFOs may improve the efficiency of animal production, but the large amounts of manure they produce can, if improperly managed, degrade air and water quality. The US Environmental Protection Agency (EPA) regulates CAFOs and requires CAFOs that discharge certain pollutants to obtain a permit.

The EPA analyse the amount of waste CAFO's generate, findings of key research on CAFOs’ health and environmental impacts, progress made in developing CAFO air emissions protocols, and the effect of recent court decisions on EPA’s regulation of CAFO water pollutants.

A Growing Issue

Photo: EPA

To better understand the issue that they were dealing with the US Government Accountability Office (GAO) decided to analyse U.S. Department of Agriculture’s (USDA) data that had been collected from 1982 through to 2002. Sources they used included reviewed studies, EPA documents, laws, and regulations, and obtained the views of federal and state officials.

In the September 2008 report, GAO recommended that EPA complete its inventory of permitted CAFOs, reassess the air emissions monitoring study, and establish a strategy and timetable for developing a process-based model for measuring CAFO air emissions. EPA partially agreed with GAO’s recommendations.

The GAO found that the number of these large CAFOs farms has increased by almost 230 per cent in this time bracket. In 1982 these farms numbered approximately 3,600, but twenty years on the figure had jumped to 12,000.

The number of animals raised on large farms also increased during this period, but the rate of increase varied by animal type.

However the GAO said that its report was severely hampered by the lack of information available to it. A GAO testimony declared that "because no federal agency collects accurate and consistent data on the number, size, and location of CAFOs, GAO could not determine the exact trends for these operations."

The Problem with CAFOs

The amount of manure generated by large farms that raise animals depends on the type and number of animals raised, but according to GAO figures these operations can produce "from 2,800 tonnes to 1.6 million tonnes of manure each year. In fact it is true to say that some large farms that raise animals can generate more manure annually than the sanitary waste produced by some U.S. cities.

Despite this huge amount of manure can be used beneficially to fertilize crops, failures to properly manage manure and wastewater at CAFOs can negatively impact the environment and public health. Manure and wastewater have the potential to contribute pollutants, such as nitrogen and phosphorus, organic matter, sediments, pathogens, heavy metals, hormones and ammonia, to the environment.

The EPA say that the environmental impacts resulting from mismanagement of wastes include, among others, "excess nutrients in water (such as nitrogen and phosphorus), which can contribute to low levels of dissolved oxygen (fish kills), and decomposing organic matter that can contribute to toxic algal blooms."

They also say that contamination from runoff or lagoon leakage can degrade water resources, and can contribute to illness by exposing people to wastes and pathogens in their drinking water. Dust and odors can contribute to respiratory problems in workers and nearby residents.

The report says that since 2002, at least 68 government-sponsored or peer-reviewed studies have been completed that have 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.

A Void of Data

"EPA has not yet assessed the extent to which pollutants from animal feeding operations may be impairing human health and the environment because it lacks key data on the amount of pollutants being discharged by these operations", the report said.

"Considered a first step in developing air emission protocols for animal feeding operations, a 2-year nationwide air emission monitoring study, largely funded by the industry, was initiated in 2007. However, the study, as currently structured, may not provide the scientific and statistically valid data it was intended to provide and that EPA needs to develop these protocols. In addition, EPA has not yet 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 decision required EPA to abandon the approach that it had proposed for regulating CAFOs in 2003. Similarly, the Rapanos decision has complicated EPA’s enforcement of CAFO discharges because EPA believes that it must now gather more evidence to establish which waters are subject to the Clean Water Act’s permitting requirements.