IATP Hog Report - Institute for Agriculture and Trade Policy

Section 3
III. Building
Sewerless Cities
Sub-sections:
Hog Factory Impacts on
Surface and Groundwater
What's Wrong With
Liquefied Manure?
Hog Factory Impacts on
Groundwater
Hog Factory Impacts on
Surface Water
Problems With
Abandoned Lagoons
Some Choices We Face
Some Strategies and
Action Alternatives for
Alleviating the Water
Quality Impacts of
Animal Production
References
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Building Sewerless Cities
Hog Factory Impacts on Surface and Groundwater
At one time, crop and livestock production were complementary
enterprises on farms. The number of animals on any one farm was
proportional to the number of acres that grew crops for the animals' food.
The soil, in turn, benefited from the crop nutrients and organic matter
contained in their manure. The number of animals was also consistent with
the availability of farm labor. As a consequence, "most of the nutrients
originating from the soils of a given area were returned to that same area." 1
Animals' living quarters were bedded with hay or straw and, when soiled,
the bedding was removed to a manure heap where it composted, killing
most of the pathogens that may have been present in the manure. Under
such conditions, environmental problems arising from animal production
activities, while they sometimes occurred, were minimal and relatively
easily solved by improving management or taking other, low-cost,
remedial measures. 2
Environmental problems were exacerbated when specialization separated
livestock production from the land and the availability of cheap mineral
fertilizers made it possible to produce crops without manure nutrients. 3
Today, most farm animals are concentrated in large holdings on small
acreages and are raised under intensive conditions resembling
manufacturing processes. Animal feeds generally come from areas far
away from the industrialized livestock farm. Manures from these "animal
factories" often are handled as wastes or surpluses to be disposed of rather
than as valuable soil amendments. Viewed in this way, they are often
applied to the land in quantities far exceeding the nutrient needs of crops.
Manure from animal factories contains little or no bedding material. It is
liquefied when massive quantities of water are used to flush the buildings
where the animals are housed. The use of unpriced, ground or surface
water to flush the barns saves on the number of employees (and, hence,
labor costs) that otherwise would be required for handling manure. The
resulting "slurry" may be stored temporarily in cement pits under the
slatted floors of the barns, or in outdoor structures, and emptied once or
twice a year by being spread or sprayed onto land.
Handling manure as a liquid or slurry, storing it untreated in open, earthen
or clay-lined basins or lagoons, and spraying it onto the land are the
cheapest methods of manure handling and disposal. Consequently, they
are the methods preferred by the vast majority of animal factory operators.
http://www.iatp.org/hogreport/sec3.html (1 of 23)2/27/2006 3:50:08 AM