Blue, green, and gray water categorize sources of water used in hog production. Blue water comes from surface and groundwater sources, green water is rainwater used by crops, and gray water is the water required to dilute polluted water. A water footprint measures the total water used and impacted in producing goods and services, including direct water used by hogs in a barn and indirect water used on farm operations. The Pig Production Environmental Calculator provides hog farmers data on their water footprint in gallons for total use, per pig per year, and per pound of pork, categorized by sources like feed, management, and facilities. This allows farmers to identify areas to reduce their water usage and environmental impact.

1. What is a
Water Footprint?
What is blue, green, and gray water?
Blue water, green water, and gray water categorize where our water comes from and its use. These classifications include water ex-
tracted from rivers, lakes, and groundwater; rainwater used directly by crops; and water needed to dilute polluted water into usable
condition, respectively. Each of these classifications can be found during the production of hogs.
A water footprint is a measure of the amount of water used to produce goods and services and the water impacted by the
system. It can cover a process, product, or even a whole company. Analysis of water footprints depend on the boundaries
of the system, recognizing the footprint for a barn is a component of the footprint for a county, which is a component of the
water footprint for a state. Every sector from agriculture to industry has a water footprint; the analysis of these footprints
varies depending on how specific the target of investigation is. There are direct and indirect uses of water. Footprints are
direct if they evaluate the amount of water a person or product uses in an immediate situation. Indirect footprints tally the
water usage of an entire process. The water consumed by hogs in a barn would be an illustration of a direct water
footprint, whereas the water it takes to run a hog operation is an indirect water footprint.
The Pig Production Environmental Calculator gives producers data in
gallons of water used. These gallons are divided into a total, per pig per
year, and per pound live pig produced per year. The full results page will
also divide water consumption between specific production components
such as feed, management, and general water usage. This section of re-
sults is also where producers are able to categorize their water into blue,
green, and gray.
NPB Pig Production Environmental Calculator
Tia Muller, Agricultural Engineering Student, South Dakota State University
Abigail Repenning, Agricultural Engineering Student, South Dakota State University
Ashley Schmit, Animal Science Student, University of Nebraska-Lincoln
Amy Millmier Schmidt, Livestock Bioenvironmental Engineer, University of Nebraska-Lincoln
Erin Cortus, Agricultural Engineer, South Dakota State University
Richard Stowell, Livestock Housing Engineer, University of Nebraska-Lincoln
The Pig Production Environmental Footprint Calculator
was developed with grant support (#2011-68002-30208)
from the USDA National Institute of Food and
Agriculture.
Barn Water – Blue Water Feed – Green Water Manure Digester – Gray Water
Example screen from the NPB Pork
Environmental Footprint Calculator
Water Usage for this farm
Farm: Gestation Barn and Lagoon
How can I use this information?
Producers benefit from having the data represented in gallons and
separated into categories because they then have the ability to pinpoint
specific areas of their operation where adjustments can be made. These
adjustments could include cutbacks to direct water usage or possibly using
alternative functions to lessen their footprint. Although the Pig Production
Environmental Calculator gives a good estimate of water footprint it cannot
produce exact results. This noted, hog producers around the United States
can still improve their operation efficiency while being environmentally
conscious by using results from the calculator.