Page 355 - Solid Waste Analysis and Minimization a Systems Approach

ADDITIONAL INFORMATION 333

from the audit indicated that the farm generated approximately 31 tons of solid
waste per year at a cost of $1700. The majority of the waste was manures and crop
residue, of which about 25 percent was recycled in the form of composting.
As a result of the audit, the farm was able to increase its recycling level for crop
residue and manure to 100 percent using a combination of improved composting meth-
ods and anaerobic digestion to produce fertilizer, which was sold to the neighboring
farms. In addition, the farm was able to reduce its solid waste disposal costs by 30 per-
cent to $1200 and generate an additional $1000 per year from the sale of fertilizer
resulting in a net annual economic benefit of $1500. The cost of the anaerobic diges-
tion equipment was $600, which was offset by the cost savings.
In addition, the farm implemented computer software to maintain the financial
records and monitor income and expense statements on a quarterly basis. The farm also
summaries each year and uses those results to track the farm’s performance from year
to year. The farm has also set stronger financial performance goals including a return
on equity and return on capital in the range of 10 to 20 percent each year depending on
uncontrollable factors (price of milk, weather, etc).

22.8 Exemplary Performers

and Future Research

Oak Ridge National Laboratory (ORNL) is a multiprogram science and technology
national laboratory managed for the United States Department of Energy and is located
in Oak Ridge, Tennessee, near Knoxville. Scientists and engineers at ORNL conduct
basic and applied research and development to create scientific knowledge and techno-
logical solutions that build the nation’s expertise in key areas of science; increase the
availability of clean, abundant energy; restore and protect the environment; and con-
tribute to national security.
An ORNL study found that farmers could grow 188 million dry tons of switch grass
on 42 million acres of cropland in the United States at a price of less than $50 per dry
ton delivered. This level of production would increase total U.S. net farm income by
nearly $6 billion. ORNL also estimates that about 150 million dry tons of corn stover
and wheat straw are available annually in the United States at the same price, which
could increase farm income by another $2 billion. This assumes about 40 percent of
the total residue is collected and the rest is left to maintain soil quality.

22.9 Additional Information

1 “Biosolids Recycling: Beneficial Technology for a Better Environment,”
Environmental Protection Agency, June 1994 (EPA 832-R-94-009).
2 “AgSTAR Digest,” Environmental Protection Agency, February 2003 (EPA 430-
F-02-028).