ABSTRACT
Nutrients such as nitrogen (N) and phosphorus (P),
which are primarily of concern because of their ability
to cause eutrophication in surface waters. In the case of
N, additional concerns exist about direct contamination of
groundwater by oxidized species (i.e., nitrate), and about
air pollution due to ammonia emissions, 2) Organic mat-
ter, which can cause depletion of oxygen in receiving
waters, and which is a primary driver of odor production,
3) Pathogenic organisms that can contaminate surface and
ground waters, and 4) Hormones and antibiotics. The
environmental significance of this last category is the
subject of ongoing research at the current time, and
design guidelines to address this last category of pollu-
tants have not been developed. Currently, the primary
concerns of the animal waste treatment designer are
nutrients, organic matter, and pathogens. The relative
importance of these potential pollutants depends on the
local environment into which the manure will be intro-
duced. It should not be surprising that waste production
figures (e.g., mass of N excreted per unit mass of live
animal weight per time) vary temporally and spatially.
While gross generalizations about manure production are
possible, the designer should use caution when using such
values because animal type and genetics, animal health,
feeds, weather conditions, and other factors will influence
the actual amounts and quantity of animal waste
produced.
