manure and less odor is emitted than with anaerobic
systems. Aeration systems require significant hardware
(pumps, aerators), energy inputs (usually electricity)
and maintenance to keep the system operating
efficiently.
While a number of alternative management systems
for swine manure are available, including several research
projects that are converting manure into biological fuel,
most are more costly. They also require
greater inputs of management and levels of expertise.
Thus, traditional systems (lagoon or slurry storage with
land application) are usually most attractive to producers
unless other circumstances or incentives are
present.
Production and the Environment
Do swine operations treat manure like municipalities?
 Pigs
use much less water than humans do. A human generates about
60 times more wastewater than a pig through activities such
as flushing toilets, taking showers and running dishwashers
and washing machines. On average, 1,000 humans generate
about 90,000 gallons of wastewater per day whereas 1,000
pigs would generate about 1,500 gallons per day.
For humans, wastewater is treated so it can be released
directly to rivers, lakes or oceans because the
volume of water is usually too great for land application.
During this treatment, nutrients are |
released into
the air or collected in the sludge (settled
solids). The sludge is often applied to agricultural land.
Pig manure systems focus on storing smaller volumes of more
concentrated wastewater until conditions are
appropriate for land application of manure as a fertilizer.
 Unlike
municipalities, farmers are not allowed to let water from
their manure treatment systems enter rivers, streams or
other water bodies, even if the manure has been treated to
remove nutrients.
Do pork operations
affect water quality?
Nutrients from
agriculture are considered a problem in
nearly 50 percent of the impaired waters of the United
States. This represents 18 percent of assessed rivers,
streams, lakes and reservoirs. These nutrients are from all
forms of agriculture, not just from pork production. A
breakdown of the contribution of pork production versus
other agricultural enterprises has not been scientifically
researched. Some potential agricultural and residential
contributors include human waste, residential fertilizer,
wildlife, crop production and other types of animal
agriculture (fish, beef, dairy, poultry, horses, sheep,
goats and swine).
Plant growth in streams, lakes and agricultural fields
is limited by the availability of nutrients. Farmers add
nitrogen, phosphorus and potassium fertilizers to crops
because the nutrients necessary for plant growth are
deficient in most soils.
Fresh water streams and lakes are usually deficient in
phosphorus and sometimes in nitrogen. When phosphorus enters
a stream or lake, it acts like a fertilizer, stimulating
growth of aquatic organisms such as algae and fish.
The increased productivity can degrade water quality
through reduced water clarity, increased water treatment
costs for drinking water, disagreeable taste in drinking
water, reduced oxygen in the water, and in
extreme situations, promote the growth of toxic bacteria.
The process of surface water degradation by nutrients is
called eutrophication. |
