EPA/530-SW-90-073B
November 1993
United States
Environmental Protection
Agency
Solid Waste and Emergency Response (5306)
Summary of Mark<
for Compost
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Summary of Markets
for Compost
The Role of Markets in Recycling
Recycling, along with waste
prevention, combustion, and
disposal in landfills, is a key
component of an integrated
municipal solid waste man-
agement strategy. (The word recycling as
used throughout this booklet encom-
passes composting as a form of recy-
cling.) Recycling may consist of several
steps, including collection, separation,
processing, remanufacture, and market-
ing. A material is not considered "recy-
cled" until all of these steps are com-
pleted and the "recycling loop" is closed.
Since materials must be converted
into products and used by consumers to
close the recycling loop, understanding
the markets for recyclable materials and
for goods manufactured from recyclable
materials is key to continued and
expanded recycling. Markets for recy-
clable materials, like all markets, are
influenced by the laws of supply and
demand. As more and more commu-
nities across the nation implement recy-
cling programs and more recyclable
materials enter the marketplace, both
supply and demand are affected.
The U.S. Environmental Protection
Agency (EPA) is supporting market
development by promoting the govern-
ment purchase of goods containing recy-
cled materials; providing assistance to
local governments; and researching,
developing, and evaluating policy
options.
This booklet summarizes EPA's
Markets for Compost. It describe^pfactors
affecting the current supply and demand
for compost, and provides information
on future market trends. It also explains
how to obtain a copy of the full report.
Supply of Compostable Materials
Composting is a biological process
of stabilizing organic matter under con-
trolled conditions into a product that is
rich in humus and provides organic mat-
ter and nutrients to the soil. Composting
converts yard trimmings, food scraps,
and/or nonrecyclable paper into useful
products, thereby diverting them from
disposal in landfills or combustion
facilities.
Yard trimmings include grass clip-
pings, leaves, brush, and tree prunings.
While the amount of yard trimmings
generated nationwide fluctuates by
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Materials generated in MSW by weight 1990
Ions
d6
Com ostables (yard trimmings, Food scraps, and paper) made up more than 60 percent
of the i/ISW stream in 1990
region and by season, an estimated 31
million terns were discarded in 1990,
accounting for approximately 19 percent
of the municipal solid waste (MSW)
stream. More than 2,200 composting
facilities for yard trimmings were operat-
ing in the United States at the end of
1991, and nearly 3,000 at the end of 1992.
This truck is picking up leaves tor
transport to yard trimmings
compost facility
Food scraps and other organic mate-
rials also may be composted. More than
13 million tons of food scraps were gen-
erated in 1990, accounting for 8 percent
of the MSW stream. Food scraps are not
generally separated from discards (as
yard trimmings tend to be), and there-
fore are not as readily available for com-
posting.
The entire compostable portion of
the MSW stream (yard trimmings, food
scraps, and nonrecyclable paper) can be
managed through MSW composting.
MSW composting generally can process
up to 60 percent of the MSW stream (a
much larger portion than composting of
yard trimmings alone). The remainder
either is recycled or is sent to combustion
or landfill facilities.
As of the end of 1991, eighteen MSW
composting facilities were operating in
the nation, and twenty-one were oper-
ating at the end of 1992. These facilities
process anywhere between less than five
tons of MSW per day up to a few hun-
dred tons of MSW per day.
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There are two main approaches to
MSW composting: 1) compostable mate-
rials may be segregated from discards at
the point of generation and then pro-
cessed; or 2) the entire MSW stream may
be processed without separation at the
point of generation, but rather at the
composting facility with varying degrees
of effectiveness. That is, noncompostable
materials are usually removed either
before or after the composting process.
The two approaches will vary in terms
of cost, equipment needed for collection
and processing, marketability of the
compost, and value both of the compost
produced and any recyclables that may
be recovered.
Factors Affecting Supply
Compost supply is influenced by
several factors. Landfill and combustor
capacity pressures and high disposal fees
have helped stimulate many composting
programs. Several states have banned
yard trimmings from disposal in landfills
because these materials would occupy
valuable landfill space. In addition, as
yard trimmings and other organic
Composting often involves the construction of elongated piles called windrows
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Some municipalities collect yard trimmings at the curb in paper bags like the ones
shown here Paper bags can withstand rain and snow, and decompose, along with the
yard trimmings, during the composting process
materials decompose in landfills, they
contribute to the release of methane gas
and acidic leachate and uneven settling.
Combustion is generally not a desirable
method to manage yard trimmings due
to their high moisture content, which
inhibits complete burning and results in
very little net usable energy for power or
steam generation. When burned, yard
trimmings also emit nitrogen oxide and
carbon dioxide gases.
Failure to identify and understand
potential markets for compost can result
in either over- or under-producing com-
post. If this happens, suppliers may end
up creating stockpiles of compost or may
not be able to satisfy demand. To help
ensure the availability of compost, sup-
pliers can identify markets before com-
posting operations begin and adjust
compost production accordingly.
Future Trends in Supply
The supply of compost produced
from yard trimmings is expected to
increase in the future. The long-term
supply of MSW compost is uncertain
because existing facilities have not been
operating long enough to make accurate
forecasts. Until more MSW composting
facilities come into operation, MSW
compost availability will continue to
be limited.
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Demand for Compost
Compost is a valuable soil amend-
ment that improves many soil proper-
ties, such as porosity, structural and
thermal stability, water retention, resis-
tance to wind and water erosion, and
tillage. Compost also decreases soil
crusting, regulates storage and release of
nutrients, enhances the development of
beneficial microorganisms, builds up
plant resistance to parasites and disease,
and promotes faster root development.
Plants and crops treated properly with
compost may produce higher yields and
have less weed growth.
Because of these beneficial character-
istics, five major market segments for
compost have been identified:
• Agriculture (for food and nonfood
crops and sod farms).
- Landscapers (for industrial and
commercial properties; golf
courses, cemeteries, and athletic
fields; landfill covers; and dam-
aged soils).
temperature, and moisture levels.
id monitored to ensure proper oxygen.
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• Nurseries (for plant and forest
seedling crops and reforestation
projects).
Public agencies (for highway
median strips, parks, recreational
areas, and other public property).
• Residents (for home landscaping
and gardening).
The different market segments
require different grades of compost. For
example, high-grade compost is needed
for horticulture while lower grade com-
post may be suitable for landfill cover.
Factors Affecting Demand
Product quality and consistency gen-
erally are considered to be the most
important factors affecting the demand
for compost. High-quality, mature com-
post has a dark color, uniform particle
size, and a pleasant earthy odor. It
should not contain visually identifiable
contaminants (such as bits of glass,
metal, and plastic). In addition, the com-
post should contain minimal levels of
chemical residues, heavy metals (such as
cadmium, lead, and mercury), herbi-
cides, pesticides, and other potential tox-
ics. The compost also should have a high
concentration of organic matter, contain
nutrients, be free from pathogenic organ-
isms, and contain no viable weed seeds.
While product quality is very impor-
tant to the marketability of compost,
uniform specifications have not been
developed for compost. This lack of
standards fosters skepticism in some
potential compost users. Agricultural
users are among the most hesitant to use
MSW compost, which they fear contains
unsafe levels of heavy metals and other
contaminants that can damage crops.
Heavy metals, herbicides, pesticides, and
other potential toxics, however, are gen-
erally not a concern with composted
yard trimmings.
Specifications could be established
for various parameters, including
organic matter content, size distribution
(particle size), nutrient content, poten-
tially toxic compound concentrations,
nontoxic contaminant levels, weed
seed concentrations, seed germination
and elongation, soluble salts, ratio of
Mature compost has a dark color and uniform particle size
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available carbon-to-nitrogen, and pH.
Standard laboratory procedures have
not been established for testing compost.
This lack of standards also may steer
some potential users away from compost.
Another factor that affects demand is
the availability of compost compared to
its competing and complementary prod-
ucts in the marketplace. In some cases,
compost availability may currently be
inadequate, but there are many available
competing and complementary products
on the market, including fill dirt, top-
soils, riverbottom silt, potting soils, cus-
tom soil mixes, bark mulch and wood
chips, manure, peat moss, mushroom
compost, perlite, and vermiculite. Many
of these products have a long history of
consistency, availability, reliability,
acceptance, and use in agriculture, horti-
culture, public and private landscaping
projects, and residential gardening.
Distance also is a factor affecting
demand. Proximity to composting facili-
ties promotes product acceptance and
recognition. Thus, a potential user is
more likely to know of a product that is
produced nearby, rather than one pro-
duced many miles away. In addition, if
the composting facility is located a long
distance from compost markets (e.g.,
more than 50 miles away), the compost
may have to be transported by rail or
ship. Shipping costs, however, might
exceed the value of compost, which may
already be low. Various strategies can be
employed to mitigate high transporta-
tion costs, including developing local
markets for compost and backhauling
compost in cleaned, otherwise empty
departing trucks (especially in the case of
dropping off yard trimmings and haul-
ing back compost), establishing a net-
work of distribution centers that each
maintain an adequate inventory, and
locating composting facilities near the
primary compost users' sites.
use cor
amendment in their gardens
Future Trends in Demand
The agriculture industry is the
largest potential market for compost,
although it is also the most difficult to
penetrate. To increase the use of compost
by this industry, the compost must be
available at the appropriate time of year,
consistent in composition and nutrient
content, contain low levels of potentially
toxic substances, be offered at a low cost,
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and be accepted by farmers. Landscapers
use large amounts of soil amendments
and are therefore a potentially large user
of compost. However, landscapers have
expressed concern that compost may
contain harmful amounts of viable seeds,
herbicides, and pesticides. Making avail-
able to landscapers results of laboratory
tests demonstrating the safety of com-
post made from yard trimmings should
ease these concerns. The potential for the
nursery industry to use compost in the
future greatly depends on the economy
and housing industry. If home sales rise,
the demand for nursery products is
likely to increase as well. Public agencies
also have the potential to use large
amounts of both high-quality and low-
quality compost in landscaping, land
maintenance, land reclamation, and
other projects. In addition, the residential
segment represents a substantial market
for soil amendments. The amount of
compost this segment will use depends
on the ability of suppliers to consistently
produce a quality product at a reason-
able cost.
Market Report Availability
A copy of the full report, Markets for Compost, is available from the
federal government's National Technical Information Service (NTIS),
5285 Port Royal Road, Springfield, VA 22161, (703) 487-4650.
*U.8. GOVERNMENT PRIMTING OFFICE: 1993 - 516-108 - 1302/80617
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Office of Solid Waste
U.S. Environmental Protection Agency
401 M Street, SW. (5306)
Washington, DC 20460
Official Business
Penalty for Private Use $300
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