Solid Waste and
Emergency Response
(5306)
' contains at least 50 percent recycled fiber.
-------
DISCLAIMER
The mention of commercial products or composting vendor
systems in this report does not indicate endorsement or approval of
use by the U.S. Environmental Protection Agency.
-------
MARKETS FOR COMPOST
Project Manager:
Richard M. Kashmanian, Ph.D.
OFFICE OF POLICY, PLANNING AND EVALUATION
OFFICE OF SOLID WASTE AND EMERGENCY RESPONSE
U.S. ENVIRONMENTAL PROTECTION AGENCY
November 1993
-------
ACKNOWLEDGEMENT S
This report was prepared under U.S. Environmental Protection
Agency Contract Nos. 68-01-7310 and 68-C8-0036, at the direction of
Richard Kashmanian, EPA Work Assignment Manager. It was prepared
in conjunction with CalRecovery, Inc. and Franklin Associates, Ltd.
The study benefitted from comments by EPA's Hope Pillsbury, Truett
DeGeare, Robert Bellinger, and Terry Grogan, from the Office of
Solid Waste and Emergency Response.
EPA would also like to acknowledge the assistance of the
following reviewers, who commented on previous drafts of this
document and provided suggestions for improvements. These
individuals include:
Pegi Ballister-Howells
Patrick Kennedy
Geoffrey Kuter
John McCabe
Percival Miller
Nancy Vandenberg
N.C. Vasuki
Scat Engineering
Alternate Disposal Systems,
Inc.; and
American Soil, Inc.
International Process Systems,
Inc.
Michigan Department of Natural
Resources
New York Legislative
Commission on Solid Waste
Management
Markets for Recycled Products
Delaware Solid Waste Authority
-------
FOREWORD
The status of composting as a method of managing leaves, grass
clippings, brush, and other municipal organic materials is changing
rapidly. New programs continue to be implemented.
This compost market study was conducted primarily during the
Fall of 1989. At that time, there were 651 yard trimmings
composting facilities i.n the U.S. There were over 1,400 and 2,200
of these facilities in 1990 and 1991, respectively, and nearly
3,000 at the end of 1992. Growth also took place in municipal
solid waste composting, with the number of operational programs
increasing from 7 in 1989 to 18 in 1991 and 21 in 1992.
Furthermore, the number of States that have established landfill
disposal bans for some or all components of their yard trimmings
jumped from 10 in 1989 to 17 in 1991, 22 in 1992, and 23 by mid-
1993. The States added to the list are Arkansas, Georgia, Indiana,
Maryland, Massachusetts, Maine, Michigan, Missouri, Nebraska, New
Hampshire, South Carolina, South Dakota, and West Virginia. Tables
A and B summarize the status of composting programs as of 1991 are
provided as part of this foreword.
Although the basic principles of compostinq remain unchanged,
the types of technologies employed and, 'more importantly to this
report, the market development tools utilized have evolved sig-
nificantly. Again, the reader is reminded that the research for
this report was primarily conducted in 1989. Although some of the
facts may not be current, particularly with regard to the
individual program descriptions, the concepts presented are still
accurate.
-------
TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY
INTRODUCTION ES- 1
EXISTING COMPOST PROGRAMS AND MARKETS ES- 2
Yard Trimmings Composting ES- 2
Municipal Solid Waste Composting ES- 6
CHARACTERISTICS AND BENEFITS OF COMPOST ES- 6
CHARACTERISTICS AND BENEFITS OF COMPETING/
COMPLEMENTARY PRODUCTS ES-10
COMPOST USES AND MARKETS ES-10
Agriculture ES-12
Landscape Industry ES-12
Nursery Industry ES-12
Public Agencies ES-12
Residential ES-13
FACTORS PERTINENT TO DEVELOPING COMPOST MARKETS ES-13
Compost Specifications ES-13
Compost Testing Requirements ES-13
Compost Distribution ES-13
Compost Policies ES-14
BARRIERS TO DEVELOPING COMPOST MARKETS ES-17
Economic Barriers ES-17
Noneconomic Barriers ES-17
STRATEGIES TO MITIGATE/OVERCOME BARRIERS TO
DEVELOPING COMPOST MARKETS ES-17
Overcoming Economic Barriers ES-17
Overcoming Noneconomic Barriers ES-18
Chapter 1 - INTRODUCTION
STUDY OBJECTIVE 1- 1
ROLE OF COMPOSTING IN MUNICIPAL SOLID WASTE MANAGEMENT 1- 2
Composting Yard Trimmings 1- 2
Composting Other Municipal Organic Materials 1- 3
NEED FOR DEVELOPING COMPOST MARKETS 1- 5
SCOPE OF REPORT 1- 6
REFERENCES 1- 9
Chapter 2 - CHARACTERISTICS AND BENEFITS OF COMPOST
AND COMPETING/COMPLEMENTARY PRODUCTS
CHARACTERISTICS AND BENEFITS OF COMPOST 2- 1
Physical/Chemical Characteristics 2- 3
Carbon/Nitrogen Ratio 2-3
Nutrients 2- 3
pH 2- 5
Heavy Metals 2-5
Herbicides, Pesticides, and Other Potential
Toxics 2- 7
-------
Pathogens 2- 7
Soluble Salts 2- 7
CHARACTERISTICS AND BENEFITS OF COMPETING/
COMPLEMENTARY PRODUCTS 2- 8
Soils 2-12
Bark Mulch and Wood Chips 2-14
Potting Soils 2-18
Livestock Manure and Manure Compost 2-18
Peat 2-21
Livestock Bedding and Litter 2-25
Dairy Cattle Bedding 2-25
Poultry Litter 2-30
Others 2-31
Perlite 2-31
Vermiculite 2-31
Vermicompost 2-33
REFERENCES 2-34
Chapter 3 - COMPOST USES AND MARKETS
COMPOST USES 3_ l
COMPOST MARKETS 3_ 2
Agriculture 3-3
Landscape Industry 3-4
Nursery Industry 3-4
Public Agencies 3-5
Residential 3_ 5
REFERENCES 3_ 7
Chapter 4 - FACTORS PERTINENT TO DEVELOPING
COMPOST MARKETS
INTRODUCTION 4_ ]_
COMPOST SPECIFICATIONS 4_ l
Organic Matter Content 4-4
Water-holding Capacity 4-4
Bulk Density 4-4
Size Distribution 4_ 4
Nutrient Content 4-8
Level of Non-toxic Substances 4-8
Level of Potentially Toxic Substances 4-8
Concentration of Weed Seeds 4-20
Seed Germination and Root Elongation 4-20
Soluble Salts 4-20
Ratio of Available Carbon/Nitrogen 4-20
PH 4-20
Color 4_20
Odor 4_21
Specifications for Bark Products 4-21
Examples of Compost Standards 4-21
COMPOST TESTING REQUIREMENTS 4_23
COMPOST DISTRIBUTION 4_23
11
-------
Motor Carrier 4-27
Bagged Compost 4-27
Bulk Compost 4-27
Railroad 4-27
Shipping 4-30
Containerized Cargo 4-30
Bulk Cargo 4-30
COMPOST POLICIES 4-31
Environment and Public Health and Safety 4-31
Facility Control 4-31
Compost Quality 4-32
Composting Program Implementation 4-33
Distribution and Use of the Compost Product 4-34
REFERENCES 4-38
Chapter 5 - ECONOMIC AND NONECONOMIC BARRIERS
TO DEVELOPING COMPOST MARKETS
ECONOMIC BARRIERS 5- 1
Failure to Identify Potential Markets 5~ !
Cost Pressures from Competing Products 5~ !
Post-processing Costs 5~ 2
Transportation Costs 5~ 2
Impacts of Competing Product Capital Investment 5~ 2
NONECONOMIC BARRIERS 5- 2
Compost Quality Assurance 5~ 2
Horticulture 5~ 3
Field-grown Crops 5~ 3
Land Reclamation/Landfill Cover 5- 3
Compost User Attitudes 5- 4
Locations of Markets with Respect to Compost
Operations 5~ 4
Access to Transportation Routes 5~ 5
Comparative Availability of Compost 5~ 6
Procurement Policies for Compost 5~ 7
Restrictions on Compost Use 5~ 7
Legal Constraints 5~ 8
REFERENCES 5-10
Chapter 6 - STRATEGIES TO MITIGATE/OVERCOME BARRIERS
TO DEVELOPING COMPOST MARKETS
OVERCOMING ECONOMIC BARRIERS 6- 1
Identifying Potential Compost Markets 6- 1
Overcoming Cost Pressures from Competing Products 6-2
Recovering Post-processing Costs 6- 2
Mitigating Transportation Costs 6- 3
Overcoming Impacts of Competing Product Capital
Investment 6-4
OVERCOMING NONECONOMIC BARRIERS 6- 5
Providing Compost Quality Assurance 6- 5
Improving Compost User Attitudes 6-5
Identifying Locations of Compost Producers and Users 6- 7
Gaining Access to Transportation Routes 6- 7
i i i
-------
Increasing Comparative Availability of Compost g- 7
Establishing Procurement Policies for Compost g- 8
Complying with Restrictions on Compost Use 6- 8
Recognizing Legal Constraints g_ 9
REFERENCES 6-10
Appendix A - EXAMPLES OF EXISTING PROGRAMS AND MARKETS
INTRODUCTION A_ -]_
Yard Trimmings Composting A- 1
Municipal Solid Waste Composting A- 2
Composting Other Organic Materials A- 5
EXAMPLES OF COMPOSTING PROGRAMS BY REGION A_ 5
Central A- 5
Boulder, Colorado A- 5
Lincoln, Nebraska A- 5
Omaha, Nebraska A- 6
Industrial A- 6
Wilmington, Delaware A- 6
Montgomery County, Maryland A- 7
Traverse City, Michigan A- 7
Essex County, New Jersey A- 8
Franklin Township, New Jersey A- 8
Parlin, New Jersey A- 9
Wrightstown, New Jersey A- 9
Cleveland, Ohio A-ll
Toledo, Ohio A-ll
Allegheny County, Pennsylvania A-12
Midlands A-12
Chicago, Illinois A-12
Urbana and Champaign, Illinois A-13
Will and Lake Counties, Illinois A-13
Afton, Minnesota A-13
Carver County, Minnesota A-14
Fillmore County, Minnesota A-15
Hennepin County, Minnesota A-15
Swift County, Minnesota A-16
Monroe, Wisconsin A-16
Portage, Wisconsin A-16
Northeast A-17
Wellesley, Massachusetts A-17
Fort Fairfield, Maine A-17
Thomaston, Maine A-18
Brookhaven and Holtsville, New York A-18
Islip, New York A-18
Saratoga Springs, New York A-19
Scarsdale, New York A-19
Pacific A-20
Davis, California A-20
Palo Alto, California A-20
San Mateo, California A-21
Portland, Oregon A-21
iv
-------
King County, Washington A 22
Seattle, Washington A-22
South A~23
Gentry, Arkansas A 23
Ft. Lauderdale, Florida A~23
Perry, Florida A-23
Sumter County, Florida A-24
Mecklenburg County, North Carolina A-24
SUMMARY A~24
REFERENCES A"28
v
-------
LIST OF TABLES
Table Page
ES- 1 Characteristics of the Six Study Regions ES- 4
ES- 2 Status of MSW Composting/Co-Composting
Facilities in the U.S. (Fall 1989) ES- 7
ES- 3 Operational MSW Composting/Co-Composting
Facilities in the U.S. (Fall 1989) ES- 8
ES- 4 Competing/Complementary Products Identified ES-11
ES- 5 Municipal Solid Waste Management Policies
in the Six Study Regions ES-15
1- 1 State Bans on Landfilling Yard Trimmings (1989) 1- 4
2- 1 C/N Ratio of Various Municipal Organic Materials 2- 4
2-2 Competing/Complementary Products Identified 2-9
2-3 Competing/Complementary Products With Compost 2-10
2- 4 Average Prices for Topsoil and Fill Dirt (1989) 2-13
2- 5 Average Nutrient Composition of Wood 2-15
2- 6 Average Bulk Density and Particle Size of
Various Growth Media 2-16
2-7 Average Prices for Bark Mulch and
Wood Chips (1989) 2-17
2- 8 Average Prices for Various Soil Amendments (1989) 2-19
2- 9 Average Characteristics of Livestock Manures 2-22
2-10 Chemical Characteristics of Different Peat Types 2-24
2-11 Moisture Absorbing Capacities (MACs) of Several
Livestock Bedding and Litter Materials 2-26
2-12 Water Absorption Capacity of Livestock
Bedding Materials 2-29
2-13 Bedding Use Per Poultry Management Scheme 2-32
4- 1 Level of Importance of Compost Quality
Parameters for Various Uses 4-2
4-2 Water-holding Capacity of Various Soil Amendments 4-5
4-3 Bulk Densities and Moisture Contents of
Various Soil Amendments 4-6
4-4 Size Distribution of Yard Trimmings Compost 4- 7
4- 5 Examples of Nutrient Content Levels in Composts
and Selected Other Soil Amendments 4-9
4-6 Examples of Concentrations of Total Metals
in Composts 4-12
4-7 Examples of Concentrations of Herbicides,
Pesticides, PCBs, and PCP in Composts 4-14
4-8 Examples of Compost Standards for Various States 4-16
4-9 Categories and Nomenclature of Bark and Soil
Products 4-22
4-10 Council of European Communities' (CEC'S)
Proposed Physical and Chemical Parameters for
MSW Compost Applied to Agricultural Soils 4-24
4-11 Municipal Solid Waste Management Policies
in the Six Study Regions (July 1989) 4-35
vi
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A- 1 Status of MSW Composting/Co-Composting
Facilities in the U.S. (Fall 1989) A- 3
A- 2 Operational MSW Composting/Co-Composting
Facilities in the U.S. (Fall 1989) A- 4
A- 3 Test Results - Middlebush Compost, Inc.,
Franklin Township, New Jersey A-10
A- 4 Characteristics of the Six Study Regions
(July 1989) A-26
v i i
-------
LIST OF FIGURES
Figure Page
ES- 1 Regions of the United States as defined for the
study ES- 3
1- 1 Regions of the United States as defined for the
study 1- 7
2-1 pH scale showing the general range of finished,
stabilized compost 2- 6
4- 1 Intrastate motor carrier rates for bagged compost
(point of origin: Portland, Oregon) 4-28
4-2 Interstate motor carrier rates for bagged compost
(point of origin: Portland, Oregon) 4-29
Vlll
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EXECUTIVE SUMMARY
INTRODUCTION
Reducing the volume of municipal solid waste (MSW) that must
be disposed of is a priority for many communities around the
country. Generally, MSW generation is increasing while landfill
disposal capacity is decreasing and new landfills are becoming more
difficult and expensive to site. The U.S. Environmental Protection
Agency (EPA) established a national goal of reducing the MSW
requiring disposal by 25 percent through source reduction and
recycling ( including composting) as a means of reducing the
nation's dependence on landfills. Composting the organic portions
of the MSW stream is one management technique that is being
employed to help attain the EPA goal.
Composting is a biological process of stabilizing organic
matter under controlled conditions into a product that is rich_in
humus and provides organic matter and nutrients. The composting
process achieves both volume and weight reduction. Composting can
divert yard trimmings (including leaves, grass clippings, and
brush), 'food scraps (from residential, commercial, institutional,
and industrial sources) , and other easily decomposable organic
materials from disposal facilities and convert them into valuable
soil amendment products. Therefore, composting can conserve
considerable landfill space, save on MSW disposal costs, and
produce useful end products. However, as composting activity
expands, there also needs to be greater attention to stimulating
markets for compost in order to avoid possible oversupplies of
compost. This is particularly important as markets for compost
become more competitive with increased composting activity.
A key element in designing a market development strategy for
compost is to determine the quantity of the product which will be
available. However, there is currently a lack of accurate
information nationally from which to draw firm conclusions. Data
is sketchy for determining the percent contribution of leaves,
grass clippings, brush, etc. to the total amount of yard trimmings
generated, the current and projected composting levels and compost
supplies, the future quality of the compost product, etc.
The greatest potential uses for compost products in a given
locale depend on the identified local markets. Therefore, the
compost products offered should be designed to meet the quality
specifications and quantity demands of the intended markets. There
is, therefore, no single "best" compost product.
Likewise, there is no single "best" compost market. Markets
for compost must be identified and developed since the economics of
composting improve with demand for the finished product. If little
or no demand exists for the compost, the cost of storage increases
E S - 1
-------
and disposal costs may be incurred. Primary markets have been
municipal applications and use by local residents. if increased
amounts of compost are to be produced, additional markets must be
secured.
The objective of this study is to provide information to
expand markets for compost. The information will be useful to
producers, marketers, and users of compost, as well as to all
levels of government officials.
The study is based primarily on a review in 1989 of the
appropriate literature and information obtained from informal
discussions with compost marketing experts, compost users, and
potential compost users. The nationwide compost market study was
conducted on a regional basis, as shown in Figure ES-1. The
definition of the six regions defined was not based on size in
terms of land area. Rather, criteria such as MSW management
activities and characteristics, geographic region, and population
density were considered in determining the regions.
EXISTING COMPOST PROGRAMS AND MARKETS
Yard Trimmings composting
composting yard trimmings has been practiced for many years in
the U.S. However, this practice has attained a much greater
popularity recently. Although the quantities of yard trimmings
generated vary from region to region, their contribution to a
community's solid waste stream is significant. At the national
level, yard trimmings contribute approximately 20 percent annually
to the MSW stream. The relative ease with which yard trimmings can
be source separated and diverted from landfills has prompted
hundreds of yard trimmings composting programs to be implemented in
the United States. Many different approaches have been taken in
these composting programs, from low-technology to high-technology
composting.
Table ES-1 presents certain characteristics of the six study
regions. The data in the table show that there seems to be a rough
correlation between the tipping fee for landfill disposal and the
number of operational composting programs.
The results of the assessment of existing composting programs
and markets show that there is a considerable interest in
composting, driven primarily by landfill capacity pressures and the
consequent need to reduce the amount of materials disposed of. The
markets for the finished products vary from uses by public
entities, to wholesale and retail sale, to private individuals and
residents, to commercial markets. The majority of the existing
programs have found adequate markets for the volumes of compost
currently produced.
E S - 2
-------
PAC
M
CO
Figure ES-1. Regions of the United States as defined for the study.
-------
Number of States
Population in 1987
(millions)
Population density
(population/square mile)
Average landfill tipping
fee ($/ton) 1 /
Number of yard trimmings
composting programs
n Number of operational
M MSW composting programs
I
j*. List of States
Table ES-1
CHARACTERISTICS OF THE SIX STUDY REGIONS
Central
14
39
26
9
7
0
AZ
CO
ID
KS
MT
NE
NV
NM
ND
OK
SD
TX
UT
WY
Industrial
8
52
235
28
354
1
DE
IN
MD
MI
NJ
OH
PA
WV
Midlands
5
29
91
20
135
4
IL
IA
MN
MO
WI
Northeast
7
31
278
58
134
0
CT
ME
MA
NH
NY
RI
VT
Pacific
3
35
110
29
15
1
CA
OR
WA
South
11
56
110
14
5
1
AL
AR
FL
GA
KY
LA
MS
NC
SC
TN
VA
(continued)
-------
Table ES-1 (cont.)
1 / Average of tipping fees reported in Pettit, C.L. "Tip Fees Up More Than 30% in
Annual NSWMA Survey." w?gte Agg. pp. 101-106. March 1989.
Sources: Glenn, J. and D. Riggle. "Where Does the Waste Go? -- Part I." Biocycle.
30(4):34-39. April 1989.
Goldstein, N. "Solid Waste Composting in the U.S." BioCycle. 30 (11):32-37.
November 1989.
-------
Municipal Solid Waste Composting
Following a decline in interest in MSW composting in the U.S.
during the 1960s, it is currently receiving a substantial amount of
attention for reasons similar to the growth in yard trimmings
composting. This type of composting is typically more capital
intensive than yard trimmings Composting, and is capable of
composting these materials with food scraps, and non-recycled
paper.
Composting source separated MSW refers to the processing of
only organic materials suitable for composting which have been
segregated at the point of generation. Mixed MSW composting
involves the processing of the entire MSW stream without separation
at the point of generation, but rather separation at the composting
facility with varying degrees of effectiveness. The type of
collection system selected should consider and carefully balance
costs and equipment needs for collection as well as processing,
quality, marketability, and value of the recovered products (i.e.,
compost and recyclable), total diversion rates from disposal
facilities, the public perception toward composting and recycling,
etc.
Table ES-2 outlines the status of MSW composting by region.
The seven full-scale MSW composting facilities in operation in the
U.S. as of Fall 1989 are listed in Table ES-3. Capacities of the
facilities range from about ten to a few hundred tons per day.
Very little detailed information is available on the quantity or
quality of the finished compost. Their output of compost has not
been sufficient to permit a long-term definition of the market for
their respective products.
CHARACTERISTICS AND BENEFITS OF COMPOST
Compost is a valuable soil amendment. Some of the
improvements in soil properties that can result from using compost
are:
improved soil porosity;
- improved water retention;
- improved soil infiltration;
improved resistance to erosion;
enhanced storage and release of nutrients;
decreased soil crusting;
improved soil tilth; and
plant disease suppression.
Due mainly to its organic matter and humus content, compost
helps to reduce erosion and improve plant growth, which can
substantially reduce nutrient transport in runoff to surface
waters. Therefore, the addition of compost to soil not only
E S - 6
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Table ES-2
STATUS OF MSW COMPOSTING/CO-COMPOSTING
FACILITIES IN THE U.S. (FALL 1989)
Region Consideration Planning I/ Operational Total
Central 0 404
Industrial 3 418
Midlands 10 16 4 30
Northeast 7 8 0 15
Pacific 2 316
South 4. 6. 1 11
Totals 26 41 7 74
1 / Includes planning, design, permitting, and construction
stages, as well as pilot-scale or research facilities.
Source: Goldstein, N. "Solid Waste Composting in the U.S."
BioCvcle. 30(11) :32-37. November 1989.
E S - 7
-------
Table ES-3
OPERATIONAL MSW COMPOsTING/CO-COMPOSTING
FACILITIES IN THE U.S. (FALL 1989)
Location
Delaware
Wilmington
Florida
Sumter County
Minnesota
Fillmore County
Lake of the Woods
County
St. Cloud
Washington
Skamania County
Wisconsin
Portage
Type of System
In-vessel
Windrow
Windrow
Windrow
In-vessel/drum
Windrow
In-vessel/drum
Material Added
to MSW
Biosolids
None
None
None
Biosolids
None
Biosolids
Source: Goldstein, N. and B. Spencer. "Solid Waste composting
Facilities ." BioCycle. 31(1) :36-39. January 1990.
E S -
-------
reduces erosion and recycles nutrients, but also can provide
important water quality benefits.
Compost usually does not contain nutrients in amounts
necessary to be a one-for-one substitute for inorganic fertilizer
due to its generally low content of the macronutrients: nitrogen,
phosphorus, and potassium (NPK) . However, it has the advantage of
releasing nutrients slowly to plants so that the nutrients may be
used over a period of years; therefore, annual applications of
compost can build up nutrient reserves. Precautions should be
taken so that build-up of excessive levels of nutrients or unwanted
substances does not also occur. Compost also can be a good source
of micronutrients which plants likewise need, but in smaller
amounts compared to macronutrients.
Some composts exhibit plant disease suppression traits by
reducing the incidence of certain plant diseases which can plague
the nursery industry, for example. This can lead to the reduced
use of fungicides for fighting plant diseases.
Feedstocks for composting may exhibit high carbon-to-nitrogen
ratios, but these will generally be lowered to a suitable range
during the composting process. The composting process is
relatively insensitive to the pH of feedstocks, and stable, cured
compost tends to have a pH around neutral.
Tests performed on yard trimmings compost indicate heavy
metals are not normally a concern. Depending on the quality of the
feedstocks and the degree of materials separation performed, mixed
MSW compost may contain heavy metals above levels acceptable under
current regulations.
Herbicides, pesticides, and other potential toxics are
generally not a concern with yard trimmings compost. Tests
performed have tended to find these to be within acceptable levels.
Toxic organics diminish over time during the composting process.
Pesticides that may be present in grass clippings also undergo a
dilution effect when grass clippings are mixed with leaves and
other organic materials.
A properly maintained composting process should eliminate
dangers of pathogens. Temperatures maintained at 55 degrees
Celsius for three days ensure adequate pathogen destruction for in-
vessel and aerated static pile composting methods. Using the
windrow composting method, temperatures must attain at least 55
degrees Celsius over at least 15 days, with a minimum of five
turnings during the high temperature period to ensure adequate
pathogen destruction. Periodic turning and mixing is important to
assure all materials are subjected to such temperatures to achieve
pathogen destruction throughout the compost.
E S - 9
-------
Soluble salts should be tested for in composts, since high
salinity can adversely affect plants and crops, especially
seedlings. Tests performed have generally found total soluble salt
concentrations to be at safe levels, which would not be harmful to
plants.
CHARACTERISTICS AND BENEFITS OF COMPETING/COMPLEMENTARY PRODUCTS
The competing/complementary products that have been identified
are listed in Table ES-4. They have a long history of use in
agriculture, horticulture, construct ion, landscaping, and
residential gardening. Some of the uses of these products include:
- soil amendment;
soil aeration;
moisture retention;
soil stabilization;
erosion control and repair;
growing medium;
decorative cover; and
land reclamation.
The prices of competing/complementary products vary depending upon
location, availability, and season.
The nutrient content of the competing products is generally
low, but these products may be fortified with additions of
nitrogen, phosphorus, and potassium prior to retail sale. Other
physical and chemical characteristics of competing/complementary
products are acceptable for the uses for which the products are
intended. These products have a reputation and proven track record
which enhances their desirability.
COMPOST USES AND MARKETS
Five primary market segments with significant potential uses
for compost were identified. They are:
agriculture;
landscape industry;
nursery industry;
public agencies; and
residents.
Uses of different types of compost (e.g., yard trimmings or
MSW) in each market are affected by each market's needs as to
quality, composition, and appearance, as well as by applicable
regulations.
ES - 10
-------
Table ES-4
COMPETING/COMPLEMENTARY PRODUCTS IDENTIFIED
Soils
Topsoil
Pulverized topsoil
Screened topsoil
Fill dirt
River-bottom silt
Wood Products
Bark mulch
Wood chips
Other Products
Potting soils
Custom soil mixes
Livestock manure and manure compost
Peat
Livestock bedding and litter
Perlite
Vermiculite
ES - 11
-------
Agriculture
The agriculture industry is the largest potential market for
compost although it is the most difficult to penetrate. Studies
have shown that the sustained application of compost to soil has
many beneficial effects. Some of the problems 'that need to be
overcome to develop the market are availability of compost,
consistency in composition and nutrient content, ensuring low
levels of potentially toxic substances, the effectiveness of bulk
application, distribution methods, effect on yields, cost, and
acceptance by farmers.
Landscape Industry
The landscape industry, which includes residential
landscapers, uses large amounts of soil amendments. Soil with poor
physical properties can be significantly improved by the correct
use of compost. Areas of new planting could benefit from the use
of compost to improve the quality of existing soil rather than
replacing the soil with topsoil at a potentially higher cost.
However, landscapers have expressed concern that compost from yard
trimmings may contain harmful amounts of viable seeds, herbicides,
and pesticides. Making results of laboratory tests demonstrating
the safety of yard trimmings compost available to landscapers
should alleviate these concerns. Other factors important to the
utility of compost in the landscaping industry include
availability, distribution channels, and "cost .
Nursery Industry
The potential for using compost in the nursery industry is
greatly dependent on the economy and the housing industry. Home
sales have a direct effect on the demand for nursery products.
Quality, availability, distribution channels, and cost 'are also
important to the utility of compost in the nursery industry.
Public Agencies
Public agencies have the potential to use large quantities of
both high-quality and low-quality composts. High-quality compost
can be used in areas where humans and/or animals may come in
contact with the compost. Lower-quality, relatively stable
composts may be suitable for land reclamation, fill material, and
landfill cover. Other uses by public agencies include:
landscaping and redevelopment;
weed abatement on public lands;
land upgrade; and
roadway maintenance and median strip landscaping.
ES - 12
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Residential
The residential segment represents a substantial market for
soil amendments. The amount of compost that the residential
segment will use in the future is largely dependent on the ability
to consistently produce a quality product, regulations,
distribution channels and form, availability, public education,
cost , as well as population growth, the economy, and the housing
industry.
FACTORS PERTINENT TO DEVELOPING COMPOST MARKETS
Compost Specifications
Quality, which is very important for developing markets for
compost, can be defined by a set of specifications. However,
specifications have not been uniformly developed for composts and
other soil amendments. Specifications for soil amendments could
include a number of parameters from the following list, some of
which overlap:
organic matter content;
water-holding capacity;
bulk density;
size distribution (i.e., particle size);
nutrient content;
level of contaminants;
concentration of potentially toxic compounds;
concentration of weed seeds;
seed germination and root elongation;
soluble salts;
ratio of available carbon/nitrogen;
pH ;
color; and
odor.
Compost Testing Requirements
Although procedures for testing the above parameters exist, a
standard procedure for testing composts has not been established
across the U.S. Some public and private producers of compost
conduct their own tests and guarantee levels of nutrients and other
constituents. Positive test results can enhance the marketability
of compost products, although testing adds to costs.
Compost Distribution
The method and cost of transporting compost from the compost
processing facility to the distribution center or user can play a
critical role in the cost-effectiveness of the composting facility.
Compost can be expensive to transport over long distances relative
ES - 13
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to its economic value. Bulk transportation, in some cases, may be
feasible by rail (trips of several hundred miles) or ship (when
there is access to navigable waterways) . However, local
distribution will usually be the most desirable, with bulk or
bagged compost carried primarily by truck.
Compost Policies
Policies regarding compost use can be implemented on the
Federal, State, or local level and can be in the form of guidelines
or regulations. Most compost use policies have only recently been
developed or are still in the developmental stages. Policies and
regulations can affect:
- environment;
public health and safety;
program implementation; and
distribution, cost, and use of the product.
Examples of environmental and public health and safety
policies are those that regulate the siting and operation of
composting facilities and those that affect compost quality. Yard
trimmings compost is regulated less stringently than composts from
mixed MSW or biosolids (also referred to as municipal sewage
sludge) because the compost typically contains a much lower level
of contaminants and poses less potential to harm the environment
and public health. Efforts to regulate compost quality have
focused on the process and the finished product. These efforts
include controlling the feedstock to avoid contamination,
maintenance of high temperature levels to ensure pathogen and weed
seed destruction, and developing compost quality standards.
Labeling standards can also be developed so that users are aware of
the product content and quality.
Policies encouraging the implementation of composting programs
have resulted in greater quantities of compost produced and
marketed. Programs have been both voluntary and mandatory. Table
ES-5 summarizes policies in the study regions which affect compost
program implementation.
Policies that affect the distribution and use of the product
are probably the least developed. Policies that give purchasing
preference to compost could do much to encourage use of the
product. Also, policies that give compost a lower-transportation
rate, and policies regarding bid specifications for materials
needed by governmental agencies, would have a beneficial effect on
compost market development.
ES - 14
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Table ES-5
MUNICIPAL SOLID WASTE MANAGEMENT POLICIES IN THE SIX STUDY REGIONS
(July 1989)
M
cn
in
Number of States
Number with MSWM I. /plans
currently in place
Number planning to have MSWM
MSWM I/ plans in place within
two years
Number of MSWM I/ plans
providing mandatory guidelines
Number of MSWM I/ plans
providing voluntary guidelines
Number which gave composting
higher priority than
combustion
Number which ban landfilling
of yard trimmings
tral Industrial
14
1
2
0
3
3
0
8
7
1
1
7
6
3
Midlands
5
5
0
1
4
4
4
Northeast
7
7
0
4
3
3
1
Pacific
3
2
1
0
3
3
0
South
11
4
4
1
7
6
2
(continued)
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w
en
Table ES-5 (cont.)
List Of States AZ DE IL CT CA AL
CO IN IA ME OR AR
ID MD MN MA WA FL
KS MI MO NH GA
MT NJ WI NY KY
NE OH RI LA
Nv PA VT MS
NM WV NC
ND SC
OK TN
SD VA
TX
UT
WY
i / MSWM = municipal solid waste management.
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BARRIERS TO DEVELOPING COMPOST MARKETS
Economic and noneconomic barriers to developing and/or
expanding compost markets have been identified. At least some of
these barriers may be faced in establishing a composting program.
Economic Barriers
Economic barriers that can hinder developing and/or expanding
compost markets are:
failure to identify potential markets;
cost pressures from competing products;
post-processing costs;
transportation costs; and
impacts of competing product capital investment.
Noneconomic Barriers
Noneconomic barriers that can adversely affect developing
and/or expanding compost markets have also been identified. These
noneconomic barriers are:
compost quality assurance;
user attitudes;
location of markets with respect to compost
operations;
access to transportation routes;
comparative availability of compost;
product procurement policies;
restrictions on compost use; and
legal constraints.
Economic and noneconomic barriers must be avoided or overcome
to enhance the marketability of compost products.
STRATEGIES TO MITIGATE/OVERCOME BARRIERS TO
DEVELOPING COMPOST MARKETS
Overcoming Economic Barriers
Diversification of compost products can increase their overall
market opportunities. Identifying the potential compost markets is
important to determine their desired quantity and quality of
compost. This allows post-processing and other production factors
(e.g., quantities of different grades of compost) to be adjusted to
meet the markets' needs.
Compost must be shown to be of equal or greater benefit and
value to compete successfully with other products. Compost can be
offered free or at a reduced price to attract users and markets
ES - 17
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though this may lower its perceived value. Compost can also be
promoted as an ingredient or source of input material to
manufacturers and suppliers of competing or complementary products.
Post-processing costs can be recovered if the post-processing
sufficiently increases the value of the compost, and, in doing so,
satisfies a market demand. Therefore, this potential barrier is
avoidable by recognizing when and to what extent post-processing is
necessary.
The barrier of transportation costs can be mitigated by one,
or a combination of several, measures, including:
modifying transportation rate structures to be more in
favor of the compost product;
obtaining lower backhaul rates where available or taking
advantage of backhaul routes;
increasing the value of compost (e.g., by screening
and/or bagging) so that it is better able to economically
bear the cost of transportation;
locating the composting facility at, or close to, the
primary users' location(s); and
finding and developing markets in the immediate local
area in which the compost is produced.
Overcoming the impacts of competing product capital investment
can be difficult. One method is through the use of financial
incentives, such as consumption tax credits, sales and property tax
exemptions, grants, and low interest loans. Also, lower bulk-rate
prices may be offered to potentially large users of compost.
Overcoming Noneconomic Barriers
Measures that would mitigate or overcome noneconomic barriers
include:
formulating an acceptable set of standards and
specifications;
providing product guarantees;
enhancing the product's recognition factor;
providing information on the benefits and uses of
compost;
working with university agricultural and cooperative
extension services and soil and water conservation
districts to develop and expand compost markets;
providing the public with technical assistance;
meeting with professional groups to influence product
acceptance;
establishing distribution centers at strategic locations;
satisfying user demands for compost; and
modifying or removing conflicting or restrictive legal
and regulatory constraints.
ES - 18
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Also , developing and maintaining favorable user attitudes
(especially as concerns mixed MSW compost), and replacing biased
procurement policies with unbiased or favorable ones would help to
overcome these barriers. A telephone hotline for information on
compost availability would also be beneficial.
Each of these strategies acts upon one or more of the
identified noneconomic barriers. Quality assurance (by testing, if
need be) and compost or labeling specifications appear to be two of
the more favorable strategies that would be beneficial to aid in
mitigating many noneconomic barriers. Likewise, they may also
contribute to overcoming at least some of the economic barriers.
However, different markets require different quality material.
Consistency and uniformity of a lower grade product may meet the
demand of some markets, while a higher quality, higher grade of
compost is required by other markets. This stresses the importance
of developing quality compost products that meet the needs of
specific markets.
ES - 19
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Chapter 1
INTRODUCTION
Municipal solid waste (MSW) generation in the United States is
increasing. An estimated 196 million tons of MSW were generated in
1990 and generation is expected to increase to over 220 million
tons per year by the year 2000 (1). At the same time, landfill
disposal capacity is decreasing and new landfills are becoming more
difficult to site. Approximately one-third of the MSW landfills in
1989 are expected to be closed by 1993 (2). Also , as overall
landfill capacity decreases, disposal fees are rising (3) . As a
result, officials at all levels of government are looking to source
reduction and recycling (including composting) to help alleviate
their MSW disposal problems.
Composting yard trimmings (including leaves, grass clippings,
and brush) and other organic materials from the MSW stream is one
management technique with considerable promise for many areas of
the country. However, as composting activity expands, greater
attention is needed to develop and expand markets for finished
compost in order to make composting a more effective MSW management
tool and avoid possible oversupplies of compost. This is
particularly important as markets for compost become more
competitive with increased composting activity.
STUDY OBJECTIVE
The objective of this study is to provide information to help
stimulate markets for compost, including yard trimmings compost and
MSW compost. This involves identifying and evaluating existing and
potential markets for compost and, also, the products that compete
with, or complement, compost in those markets. In addition, the
economic and noneconomic barriers to developing and/or expanding
compost markets must be recognized and strategies developed to
mitigate or overcome those barriers. Thus, the markets and compost
products that will allow the greatest potential for increased uses
of compost can be more effectively pursued.
The information contained in this report will be useful to
producers, marketers, and users of compost, as well as to
municipal, State, and Federal solid waste management officials.
Persons considering development of new markets for compost (perhaps
through increased production of compost or upgrading its product
quality) or analyzing the feasibility of a new composting facility
should also find this information helpful.
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ROLE OF COMPOSTING IN MUNICIPAL SOLID WASTE MANAGEMENT
Reducing the volume of MSW that must be combusted or buried
has become a priority for many communities around the country. The
Us. Environmental Protection Agency (EPA) has established a
national goal of reducing the MSW disposed of by 25 percent through
source reduction and recycling (including composting) (2).
Composting is a process which can divert organic materials, such as
yard trimmings and food scraps, from MSW disposal facilities and
convert them into useful products. Therefore, composting can
conserve landfill space, save on MSW disposal costs, and produce a
valuable soil amendment product.
Composting is a biological process of stabilizing organic
matter under controlled conditions into a product that is rich in
humus and provides organic matter and nutrients, as well as carbon
dioxide, water, and heat as by-products. The composting process
achieves both volume and weight reduction. The composting process
can range from low technology, where the material is piled or put
into windrows and left to break down with infrequent turning, to
high technology, which involves frequent turning with specialized
machinery and/or more controlled aeration and moisture levels using
a variety of specialized equipment.
Composting Yard Trimmings
Yard trimmings, which include grass clippings, leaves, brush,
and tree prunings, are estimated to comprise 19 percent of the
annual MSW discarded nationally. This amounts to about 31 million
tons of yard trimmings discarded per year nationwide (1). However,
according to numerous MSW characterization studies, individual
locales have demonstrated a wide range in the amount of yard
trimmings generated (as a percentage of their MSW) .
Yard trimmings exhibit a great deal of seasonal and regional
variations due to climatic and other influences, such as
topography, population density, vegetation, and soil types. Grass
clippings are generated in greatest volume from late spring to
early fall. Leaves are generated in relatively shorter periods
during the fall. However, areas of the country with a year-round
growing season often generate large amounts of yard trimmings
throughout the year. Seasonal peaks of yard trimmings can place
hardships on traditional collection and disposal methods.
Landfilling and combustion (through incineration or waste-to-
energy facilities) are not ideally suited to the management of yard
trimmings. Landfilling of yard trimmings occupies rapidly
dwindling disposal space and can be inefficient. Also, as yard
trimmings decompose in a landfill they contribute to release of
methane gas (a potential problem if uncollected for energy
generation), and acidic leachate, as well as uneven settling (4) .
Yard trimmings are generally undesirable for combustion due to
1 - 2
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their high moisture content which may inhibit complete combustion
and result in very little net usable energy for power or steam
generation. Burning yard trimmings may also contribute greater
nitrogen oxide and carbon dioxide emissions. The seasonal nature
of yard trimmings generation poses problems for the design of
combustors to ensure that they not be oversized or operate
inefficiently (4) . Composting can be an efficient method for
dealing with yard trimmings since it may be more cost-effective
than disposal, treats these materials as a resource, and produces
a humus product which can provide organic matter and nutrients to
the soil.
Landfill capacity pressures and the common practice of
household separation of yard trimmings have helped to prompt
hundreds of municipalities to implement yard trimmings composting
programs. It has been estimated there were at least 986 yard
trimmings composting facilities as of the end of 1989 operating in
the United States, an increase of over 50 percent in just one year
(5) . The trend is encouraged by legislative measures, some of
which ban disposal of yard trimmings in landfills. Ten States (and
the District of Columbia) had passed legislation as of the end of
1989 prohibiting the disposal of some or all yard trimmings in
landfills (see Table 1-1) . In addition, various States are
addressing composting in their MSW management plans or anticipating
legislative initiatives regarding composting (6) .
Composting Other Municipal Organic Materials
Other organic materials, such as food scraps and non-recycled
paper, also lend themselves to composting. For example, food
scraps generated by residential, commercial (e.g., restaurants) ,
institutional (e.g., school cafeterias), and industrial (e.g.,
factory lunchrooms) sources are estimated to be about 8 percent of
the nation's MSW stream, or more than 13 million tons annually (1).
Food scraps also vary by locale as to percentage of MSW, depending
on such factors as economics, lifestyle, season, etc.
Furthermore, food scraps are generally not separated from the
remainder of the MSW stream as yard trimmings tend to be.
Therefore, they are not as readily available for composting. If
not properly dealt with during the composting process, food scraps
may also attract vermin and insects, and create odor problems since
they tend to decompose rapidly.
MSW composting, though currently not very common in the U.S.,
is a method of managing the compostable organic portion of MSW.
Besides yard trimmings, other components of MSW, such as food
scraps and non-recycled paper, are also decomposable. Other
components of the MSW stream do not readily decompose, are
noncompostable, or are undesirable in the compost, and are usually
removed either before or after the composting process. if not,
presence of household hazardous waste, for example, could
1-3
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Table 1-1
STATE BANS ON LANDFILLING YARD
(as of 1989)
State
Connecticut 1 /
Florida
Illinois
Iowa
Minnesota
New Jersey
North Carolina
Ohio
Pennsylvania
Wisconsin
Date Effective
1/1/91
1/1/92 (from lined
landfills only)
7/1/90
1/1/91
1/1/90 (7-county
metro area)
1/1/92 (rest of State)
8/89
1/1/93
1/1/93
9/26/90
1/1/93
TRIMMINGS
Yard Trimmings Banned
Leaves only
Vegetative matter
including stumps
and branches
All landscaping
trimmings, grass,
leaves, and
trimmings
Not yet specified
Yard trimmings
including
clippings, boughs,
etc.
Leaves only
All yard trimmings
Leaves, grass,
brush, and other
wood bits
Leaves only
Leaves, grass, and
small woody bits
under 6 inches
I/ Leaves are included in the State's list of recyclable items
and therefore must be recycled.
Source: Glenn, J. "Regulating Yard Waste Composting." BioCYcle.
30(12) :38-41. December 1989.
1-4
-------
contribute toxic constituents to the finished compost product,
lowering its marketability.
MSW composting can generally process up to 30-60 percent of
the MSW stream with the remainder being recovered for recycling,
composting a segregated component, combustion, or landfilling (7) .
The method is typically capital intensive, requiring construction
of a physical plant and the dedicated use of heavy equipment.
Composting source separated MSW refers to the processing of
only organic materials suitable for composting which have been
segregated at the point of generation. Mixed MSW composting
involves the processing of the entire MSW stream without separation
at the point of generation, but rather separation at the composting
facility with varying degrees of effectiveness. The type of
collection selected should consider and carefully balance costs and
equipment needs for collection as well as processing, quality,
marketability, and value of the recovered products (i.e. , compost
and recyclable) , total diversion rates from disposal facilities,
the public perception toward composting and recycling, etc. (8).
Livestock manure from farms and animal feedlots (including
poultry operations) can be composted with yard trimmings or other
organic materials. Due to its relatively high nutrient levels,
livestock manure can be a desirable additive to the composting
mixture, or composted separately with a bulking agent. Livestock
manure is typically generated at farms and animal feedlots and not
included in the MSW stream. However, livestock manure generated by
feedlots and other concentrations of livestock can be a source of
surface or ground water pollution. Therefore, livestock manure
collected for composting from feedlots may lead to water quality
benefits.
Biosolids (also referred to as municipal sewage sludge) , which
can also be composted, is not covered in this report because it has
been extensively covered in other reports.
NEED FOR DEVELOPING COMPOST MARKETS
Markets for compost must be identified and developed since, if
no demand for the compost exists, the cost for storing the compost
increases and disposal costs may be incurred. Therefore, it is
essential that a market be found for the anticipated supply of
compost products. Whether the compost is sold or given away, it is
important to identify and secure end users to have a successful
composting program.
Also important in developing a market development strategy for
compost is determining its present and future supply . However,
1 - 5
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this study has not attempted to estimate existing and future
compost supplies for the nation due to the following:
lack of accurate (or reliable) estimates for the
composition of the yard trimmings (i.e. , the percent
contribution of leaves, grass clippings, brush, etc.);
which yard trimmings and remaining municipal organics
will be composted (or mulched) ;
existing and projected composting levels; and
the quality of the compost.
It is estimated that approximately 12 percent of the nation's yard
trimmings (i.e., 4.2 million tons) were composted in 1988 (1). To
estimate the amount of compost produced from this feedstock, there
is roughly an average 50-percent weight reduction by composting
yard trimmings (4) (9) . However, it is expected that in at least
some cases, mulch was produced rather than compost.
Diversification of compost products can increase overall
market opportunities. Compost has been successfully marketed in
bulk or bag. Therefore, there is no single "best" method to market
a compost product.
Primary markets for yard trimmings compost have thus far been
municipalities and local residents. Markets beyond these users
have been more difficult to develop and maintain. However, yard
trimmings compost has also been marketed to soil amendment dealers,
landscapers, nurseries, farmers, greenhouses, land developers, and
others. Markets for MSW compost are still being established
because the product is relatively new in the United States. Market
development obstacles include competitive pricing of other related
products, a lack of uniform user specifications, inconsistent or
lack of regulations, maintenance of consistent quality,
contaminants in the finished product, and transportation distance
and costs.
SCOPE OF REPORT
This study is based primarily on a review of the appropriate
related literature and information obtained from informal
discussions with compost marketing experts and compost users, as
well as others potentially involved in using compost (e.g.,
horticulture, agriculture, land reclamation, and other
applications) .
This nationwide compost market study was conducted on a
regional basis. As shown in Figure 1-1, the following six regions
were defined: Central, Industrial, Midlands, Northeast, Pacific,
and South. As demonstrated by Figure 1-1, the definition was not
based on size in terms of land area. Rather, criteria such as MSW
management activities and characteristics, geographic region, and
1-6
-------
PACFIG
ii>
V. - .'.-.
r—-i\x» ,'•" !«v 1 t'1 u!n\ i!
m
OE
MO
Figure 1-1- Regions of the United States as defined for the study.
-------
population density were given consideration in determining the
regional definitions.
Characteristics and benefits of compost and competing/
complementary products are discussed in Chapter 2. Chapter 3
identifies potential uses and markets for compost. in Chapter 4,
factors pertinent to developing and/or expanding compost markets
are presented, including specifications and testing requirements.
Economic and noneconomic barriers to increased development and/or
expansion of compost markets are identified in Chapter 5. Chapter
6 presents strategies to mitigate or overcome these barriers. An
overview of existing composting programs and their compost markets
is contained in Appendix A. This study should provide useful
information and direction which can lead to expanded markets for
compost and increased composting activity.
1 -
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Chapter 1
REFERENCES
U.S. Environmental Protection Agency. Characterization of
Municipal Solid Waste in the United States: 1992 Update.
Executive Summary. EPA/530-R-92-019. July 1992.
United States Environmental Protection Agency. The Solid
Waste Dilemma: An Agenda for Action. Municipal Solid Waste
Task Force. Office of Solid Waste. September 1988.
Pettit, C.L. "Tip Fees Up More Than 30% in Annual NSWMA
Survey." Waste Age. 20(3) :101-106. March 1989.
Taylor, A.C. and R.M. Kashmanian. Yard Waste Composting: A
Study of Eight Programs. United States Environmental
Protection Agency. Office of Policy, Planning and Evaluation;
Office of Solid Waste and Emergency Response. EPA/530-SW-89-
038.
Glenn, J. "The State of Garbage in America: Part 1."
BioCycle. 31(3) :48-53. March 1990.
Glenn, J. "Regulating Yard Waste Composting." BioCycle.
30(12) :38-41. December 1989.
United States Environmental Protection Agency. The Solid
Waste Dilemma: An Agenda for Action, Background Document.
Municipal Solid Waste Task Force. Office of Solid Waste.
September 1988.
M.M. Dillon and Cal Recovery Systems, Inc. Composting; A
Literature Study. Prepared for Ontario Ministry of the
Environment. 1989.
Smith, W.H. "Organic Waste Management in Florida." BioCycle.
31(4) :52-55. April 1990.
i - 9
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Chapter 2
CHARACTERISTICS AND BENEFITS OF COMPOST AND
COMPETING/COMPLEMENTARY PRODUCTS
This chapter examines the characteristics and benefits of yard
trimmings compost and MSW compost, as well as the characteristics
and benefits of competing/complementary products. Appendix A
includes information for developing markets for primarily yard
trimmings compost. Together, this information is important to
producers and users of compost since their product must be a
suitable replacement for other products or create a new demand, to
gain acceptance and successfully compete.
CHARACTERISTICS AND BENEFITS OF COMPOST
Compost is a valuable soil amendment. For example,
improvements in physical properties of soil that can result from
using compost include:
improved soil porosity;
improved water retention;
improved soil infiltration;
improved resistance to erosion;
enhanced storage and slow release of nutrients;
decreased soil crusting;
improved soil tilth; and
plant disease suppression (1) -(7) .
The greatest improvements in the physical properties of soil
occur at the extremes of soil texture; that is, with light or sandy
soils at one extreme and heavy or clay soils at the other. The
addition of compost to sandy or light soils, due to the organic
matter in the compost, increases their ability to retain water and
lessens the effects of drought and heavy rain. Added organic
matter loosens clay soils, increases their permeability to air and
water, and improves their water retention (3) (4) .
Due mainly to its organic matter and humus content, compost
also helps to reduce erosion and improve plant growth. This can
substantially reduce nutrient transport in surface runoff to water
systems, since sediment is a major transport vehicle for phosphorus
and nitrogen (8) . Thus , the addition of compost to soil not only
reduces erosion and recycles nutrients, but also provides important
water quality and economic benefits.
Research and experience have also shown that some composts
will inhibit soil-borne pathogens, reducing the incidence of plant
diseases in nurseries, gardens, and specialized commercial
cultivation of plants. Bark composts and certain other composts
2 - 1
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display the ability to suppress certain soil-borne plant diseases,
although the mechanism by which this works is not fully understood
at present. Not all composts exhibit this disease suppression
trait. Nevertheless, the use of these composts by the
horticultural industry has all but ended certain plant diseases
that used to sweep through the nursery industry routinely. A
related benefit is the reduced use of fungicides that had been used
to fight plant diseases (1) (2) (5)- (7) .
It should be recognized that characteristics and, therefore,
benefits of compost depend on several factors. These factors
include the materials used as feedstocks, the effectiveness of
source- and facility-separation techniques, the level of
contamination by foreign material (e.g., noncompostables) , chemical
residues, or heavy metals that may be present, the chosen
composting technology, and the level of expertise and quality
control measures applied during the composting process.
The soil benefits of adding mulch derived from yard trimmings
should also be considered. These benefits include:
increased moisture retention in the soil;
reduced evaporation;
reduced soil spattering from rainfall;
reduced soil compaction;
reduced soil erosion;
suppressed weed growth;
reduced use of pesticides; and
moderated soil temperature.
Feedstocks for MSW composting will likely be different than
those for yard trimmings composting. Essentially, the entire
organic portion of the MSW stream is a potential feedstock to mixed
MSW composting, depending the effectiveness of facility separation.
This includes non-recycled paper, and food scraps, as well as yard
trimmings. Also, it becomes more likely that other materials, such
as pieces of metal, glass, and plastics, may be mixed in with the
feedstocks during mixed MSW composting. Not only is quality
control more difficult, but end uses may also be more limited.
However, a number of separation systems are offered to overcome
these problems. These processes vary by degree of materials
separation before, during, and after the composting process and the
resulting compost product quality varies accordingly.
The uses of mixed MSW compost may be more limited than yard
trimmings compost due to potentially higher heavy metal content,
the presence of glass, metal, and plastic objects, and possible
negative public perceptions. However, MSW and mixed MSW composting
have the capability of composting a larger portion of the municipal
stream than yard trimmings composting alone. Frequent testing of
mixed MSW compost is needed to determine its heavy metal content,
2 - 2
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other potential toxics, presence of pathogens and, thereby,
identify acceptable uses of the end product.
Physical and chemical characteristics, including carbon-to-
nitrogen ratio, nutrient value, pH, heavy metals, presence of
potentially toxic substances, and soluble salts, are described
below.
Physical/Chemical Characteristics. Mature compost is a
relatively stable humus product. Uncured, or unstable, compost is
still volatile and can compete with plants for nitrogen in the
soil. This can be avoided by using mature, stabilized compost, so
that this reaction does not occur after application.
Stable, mature compost would be expected to exhibit
characteristics as discussed below.
Carbon/Nitrogen Ratio. Mature, stabilized compost should
have an available carbon to nitrogen (C/N) ratio of about 15-20:1
(weight/weight ratio) . Compost having an excessively high C/N
ratio can lead to nitrogen deprivation for plants as discussed
above (9) . Achieving a compost with a C/N ratio near 15-20:1 can
be achieved with the right combination of feedstocks and time.
Table 2-1 shows the C/N ratios of various possible yard trimmings
feedstocks.
Carbon/nitrogen ratios above 30:1 for feedstocks mean a slower
composting process initially because microbial growth is limited by
the amount of nitrogen available. As carbon is metabolized and
released as carbon dioxide, the C/N ratio improves and the
composting process speeds up. The ideal C/N ratio for composting
is approximately 25-30:1. This is seldom achieved initially with
leaves unless they can be mixed with a nitrogen source (e.g., with
grass clippings) to produce the ideal C/N ratio (9) (10) .
Nutrients. Yard trimmings compost is low in
macronutrients (nitrogen, phosphorus, and potassium -- NPK) and
therefore is not a one-for-one substitute for inorganic fertilizer.
Generally, the percentage of each of the elements N, P, and K is
less than one or two percent dry weight (10) .
One of the most comprehensive testing programs for yard
trimmings compost is performed by the Metropolitan Service District
(Metro) in Portland, Oregon. An analysis on yard trimmings compost
produced in Portland found total NPK to vary between 1.39 and 1.78
percent dry weight (11). A similar analysis on mixed MSW compost
found the nitrogen, phosphorus, and potassium contents were 1.08,
0.35, and 0.76 percent dry weight, respectively (11).
Although its NPK is generally low, compost, because of its
organic nutrient content, has the advantage of releasing nutrients
slowly to the plants so that the nutrients may be used over a
2 - 3
-------
Table 2-1
C/N RATIO OF VARIOUS MUNICIPAL ORGANIC MATERIALS
Material C/N Ratio
Grass clippings 12-20:1 1/2./2./4./
Food scraps 15:1 4 /
Fruit scraps 35:1 2 / 3. / 4_ /
Leaves 40-80:1 2 L 1 1± I
Bark 100-130:1 4/
PaPer 150-200:1 3. / i /
Sawdust 200-510:1 1/2./1/4./
Wood 700-725:1 3/i/
Wood chips 800:1 2. /
Sources: 1
Golueke,
Wastes.
1977.
C.G. Biological Reclamation of Solid
Rodale Press. Emmaus, Pennslyvania.
II
II
i/
May, J.H. and T.W. Simpson. The Virginia Yardwaste
Management Manual. Virginia Polytechnic Institute
and State University. Prepared for the Virginia
Department of Waste Management. 1990.
Poincelot, R.P.
of Composting.
The Biochemistry and Methodology
. _ - The Connecticut Agricultural
Experiment Station, New Haven. Bulletin 754
September 1975.
Richard, T.L.; N.M. Dickson; andS.J.
Yard Waste Management : A Planning nu
Rowland.
for
York State. Co-Sponsored by New York State Energy
Research and Development Authority, Cornell
University Cooperative Extension, an(j New York
State Department of Environmental Conservation.
June 1990.
2 - 4
-------
period of years. Annual applications can build up reserves of
nutrients, possibly providing a greater fertilizing effect than the
NPK measurement would indicate (10) (12) . However, precautions
should be taken to prevent the nutrients or unwanted substances
from being accumulated to undesirable or unacceptable levels.
Compost is often a good source of micronutrients (trace
elements such as iron, manganese copper, zinc, boron, molybdenum,
chlorine, and cobalt) which plants also need, but in smaller
amounts compared to macronutrients. Except for iron, and in some
cases manganese, trace elements are found sparingly in most soils,
and their availability to plants is often very low.
Portland's quarterly testing program of yard trimmings compost
also indicates calcium in the range of 0.25-0.47 percent and
magnesium in the range of 0.06-0.09 percent. Traces of copper,
manganese, iron, and boron are also indicated (13) .
pH. The acidity or alkalinity of a substance is
represented by a number on a logarithmic scale from 0 to 14, which
is called pH (see Figure 2-1) . Numbers below 7 are increasingly
acidic, 7 is neutral, and numbers above 7 are increasingly
alkaline.
The composting process is relatively insensitive to the pH of
its feedstocks (9) . Finished compost generally ends up with a pH
around neutral, usually between 6 and 8, according to tests
performed on finished, stable compost (9) (11)- (14). Therefore,
properly cured compost is suitable for most plants, although
certain acid-loving plants may need a lower pH (which can be
attained by the addition of a supplement, such as sulfur) .
Heavy Metals. Several areas of the United States have
tested yard trimmings compost for heavy metal content. In two
years of sampling for lead, average high concentrations ranged
between 92 and 128 milligrams per kilogram in Minnesota. The
highest recorded sample was 380 milligrams per kilogram in the
heart of St. Paul. This was attributed to vehicle exhaust along
roadways from leaded gasoline. These concentrations were within
limits considered safe by the State (15) . In analysis conducted
by Cornell University, heavy metal concentrations found in leaf
compost were significantly lower than State standards for Class I
compost (see Table 4-8) (16) . Research performed at a leaf
composting site in Newton, Massachusetts found lead levels that
ranged between 130 and 190 milligrams per kilogram (17) . Tests
conducted in Portland, Oregon found relatively low concentrations
of heavy metals (11) (13). These results are presented in Chapter
4, Table 4-6, along with the test results for mixed MSW compost
from Minnesota and mixed MSW and biosolids compost from Delaware.
These data suggest that heavy metal concentrations are normally not
a concern in yard trimmings compost due to their low levels of
concentration. However, they are a greater concern in mixed MSW
2-5
-------
INCREASING
ACIDITY
NEUTRAL
INCREASING
ALKALINITY
T
CO
I
23456789 10 11 12
M
General range of properly cured compost
Figure 2-1. pH scale showing the general range of
finished, stabilized compost
-------
compost due to higher concentrations in the feedstock of some heavy
metals such as lead, mercury, and cadmium.
Herbicides. Pesticides, and Other Potential Toxics. Some
of the most extensive testing of yard trimmings compost for
potential toxic contamination has probably occurred in Portland,
Oregon. Nineteen compounds are tested for, including commonly used
pesticides and herbicides. Four compounds were found at extremely
low levels and were determined to be of no concern as they would
not be toxic to seed germination or plant growth (11) (13).
A study by Cornell University on leaf compost reported
pesticide residue analysis results that indicated presence of
captan, chlordane, lindane, and 2,4-D. Of these, all except
chlordane were found in concentrations well below the United States
Department of Agriculture (USDA) food tolerance level. The study
states the USDA food tolerance level provides a conservative
indicator of compost safety and, since the chlordane-related
compounds are low relative to background levels in suburban soils
and are tightly bound to the compost itself, these residues should
not constrain the use of compost (16). Also, the presence of toxic
organics is diminished over time due to their breakdown during the
composting process.
Toxic substances, such as household hazardous wastes, should
be removed from MSW prior to composting (e.g., through source
separation, household hazardous waste collection, and up-front
separation at the composting facility) to minimize contamination of
the compost product.
Pathogens. A properly maintained composting process
should eliminate the concern for pathogens. Temperatures in excess
of 55 degrees Celsius are needed over at least three days to ensure
adequate pathogen destruction using in-vessel or aerated static
pile composting methods. Using the windrow composting method,
temperatures must attain 55 degrees Celsius or greater over at
least 15 days during the composting period. There must be a
minimum of five turnings of the windrow during the high temperature
period (18). These procedures should assure complete pathogen
destruction throughout the windrow.
Portland, Oregon has tested for human and animal pathogens in
yard trimmings compost. Pathogens were either not detected or
found in low concentrations. The only pathogens found were those
normally found in soils. The pathogens were at acceptable levels,
and concluded to be due to reintroduction into the compost after
composting (11)(13).
Soluble Salts. Total soluble salts (also expressed as
electrical conductivity level) is a measure of water soluble salts
(or salinity) present in soil or compost to which plant roots will
be exposed. An exceedingly high salinity (above 8-10 millimhos per
2 - 7
-------
centimeter) may adversely affect the growth of plants and crops,
especially that of seedlings. The electrical conductivity level of
compost intended for application to plants or crops should not
exceed two millimhos per centimeter. Compost with a greater
conductivity level may be diluted with a low-salinity medium to
lower the overall conductivity to a safe level. Tests in Portland
on yard trimmings compost have found total soluble salt
concentrations to be at safe levels (0.17-1.9 millimhos per
centimeter) (13). Tests performed by Cornell University on yard
trimmings compost have also found levels far below what would cause
harm to plants (16) . A test performed on mixed MSW compost also
found an acceptable conductivity level (1.95 millimhos per
centimeter) (19)- (21) .
CHARACTERISTICS AND BENEFITS OF COMPETING/COMPLEMENTARY PRODUCTS
Potential markets for compost produced from the above organic
materials are primarily those which competing/complementary
products already satisfy. Therefore, successful market development
and distribution of compost depends upon the ability to
consistently provide a similar or superior product at a reasonable
price, when compared to existing products.
An informal survey of vendors was conducted for this study to
determine the types, demand, quality, and cost of yard trimming and
MSW compost, and their competing" (and complementary) products.
Information that could not be obtained by this method was collected
from available literature. A listing of the competing/
complementary products identified is included in Table 2-2. Table
2-3 provides information on the bases by which compost competes
with, or complements, these products. These products have a long
history of use in agriculture, construction, horticulture,
landscaping, and residential gardening. Some of the uses for the
materials include the following: soil amendment, soil aeration,
moisture retention, soil stabilization, erosion control and repair,
growing medium, decorative cover, and land reclamation.
The products are sold in bulk or in bag either by weight or
volume. Bulk materials generally are sold in quantities greater
than 2 cubic yards. Bagged products typically range from one to
four cubic feet in size. Sources of these materials range from the
immediate vicinity of the market to national distributors, as well
as importation from Canada. AS such, the price of each of these
products varies depending upon location, availability, and season.
The uses and characteristics of the competing/complementary
products mentioned above are discussed in the following
subsections. With the exception of the nutrient content levels,
manufacturers rarely report or display the characteristics (i.e.,
particle size, pH , elemental analysis) of their product, especially
when sold in bulk form. Thus, characteristics presented in this
2 - 8
-------
Table 2-2
COMPETING/COMPLEMENTARY PRODUCTS IDENTIFIED
soils
-Topsoil
-Pulverized topsoil
-Screened topsoil
-Fill dirt
-River-bottoms!It
Wood Products
-Bark mulch
-Wood chips
Other Products
-Potting soils
-Custom soil mixes
-Livestock manure and manure compost
-Peat
-Livestock bedding and litter
-Perlite
-Vermiculite
2 - 9
-------
to
I
M
O
Table 2-3
COMPETING/COMPLEMENTARY PRODUCTS WITH COMPOST
Material
Top Soil
Fill Dirt
Bark Mulch and
Wood Chips
Potting Soils
Manures
Peat
Livestock Bedding
and Litter
Degree of Competition 1 /
Compete Complement
xx
XX
XX
X
XX
X
X
X
X
XX
X
X
Basis of
Competition
Organic matter
Porosity
Moisture retention
Moisture retention
Weed control
Erosion prevention
Moisture retention
Porosity
Organic matter
Porosity
Organic matter
Moisture retention
Porosity
Moisture retention
Use as
Complement
Mixed with topsoil
for specific
applications
Compost placed on
top of fill dirt
Mixed for special
needs
May be mixed with
manure
Mixed with peat and
other amendments in
potting soil blend
Mixed with other
bedding materials
(continued)
-------
Table 2-3 (cont.)
Perlite — x -- Mixed with perlite
and other amendments
as potting soil
blend
Vermiculite — X — Mixed with
vermiculite and
other amendments as
potting soil blend
1 / X indicates one particular use
XX indicates multiple uses.
to
I
-------
report are based on average compositions. The characteristics, of
course, vary depending upon the region and source of materials.
Soils
The types and characteristics of soils sold nationwide depend
upon the predominant local soil type and its expected use. In
general, three types of soils have been identified: topsoil, fill
dirt, and river silt. Topsoil may be pulverized and/or screened
depending upon the range of particle size, uniformity, and degree
of purity from contamination required by the buyer.
Information regarding nutrient content, particle size, and
soil types was either unknown or not provided by compost vendors
contacted during the study. Several vendors indicated that this
information may not be necessary since large users of soils
visually inspect the product before sale.
Soils are sold in all areas. Soils are typically required by
the construction industry and landscapers to increase the elevation
of an" area, to minimize erosion, as a growth medium, or as fill
material. Screened topsoil is more readily available in the
Industrial and Northeast regions of the country. Individual
vendors can experience fluctuations in availability depending upon
their source of supply. Some vendors located within metropolitan
areas obtain soils for resale from excavation companies. When
regional excavation activity is low, vendors may not be able to
meet the demand for soils.
Based upon qualitative information supplied by vendors, demand
for soils depends upon two critical factors: time of year, and
economic development activity. Demand for soils is greatest during
spring and autumn, which tend to be the most active construction
and landscaping seasons. Seasonal demand becomes more pronounced
as one moves north and east across the United States. Economic
development activity, as measured by construction and commercial
improvement activity, was mentioned by all vendors as another
primary barometer of soil sales. Vendors in Georgia and Louisiana
stated that the demand for soil was low.
The prices of soils, by region, are presented in Table 2-4.
Prices vary depending upon the distance from the site where the
soils are extracted, the amount of physical processing desired by
the purchaser, and the quantity of soils purchased. Prices
indicated in Table 2-4 generally reflect local delivery of bulk
quantities (6 to 20 cubic yards) of soil.
It is unlikely that compost will replace soils in every
possible application. Compost can be used to prepare specialized
soil mixtures and thus displace only a fraction of the soil
typically used. Compost may be able to replace up to 20 percent
(by weight) of the soil.
2 - 12
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Table 2-4
AVERAGE PRICES FOR TOPSOIL AND FILL DIRT (1989)
Region
Northeast
Product
Price I/ Delivery 2/
Boston, MA
Hartford, CT
Industrial
Pittsburgh, PA
South
Atlanta, GA
Birmingham, AL
Little Rock, AR
New Orleans, U
Richmond, VA
Midlands
Chicago, IL
Cleveland, OH
St. Paul, MN
Central
Boise, ID
Kansas City, MO
Phoenix, AZ
Pacific
San Diego, CA
Santa Cruz, CA
Screened topsoil
Screened topsoil
Topsoil
Topsoil
Screened topsoil
Shredded & screened
topsoil
Screened topsoil
Fill dirt
Topsoil
Topsoil
Fill dirt
Topsoil
Topsoil
Topsoil
Topsoil
Screened topsoil
Topsoil
Topsoil
Pulverized topsoil
Topsoil
Topsoil
Topsoil
Pulverized topsoil
Fill dirt
Screened topsoil
River silt
Screened topsoil
Amended topsoil
Topsoil blend
w/compost
Fill dirt
$17.00
$15.00
$ 9.50
$10.00
$12.50
$15.00
$12.00
$10.00
$12.00
$17.50
$ 3.99 3j_
$ 2.50
$ 3.00
$17.00
$ 2.00 3j_
$12.00
$ 4.00
$18.00
$19.00
$ 9.50
$ 9.50
$ 2.99 3j_
$ 5.00
$ 8.90
$12.00
$ 9.95 I/.
$13.50 4j_
$13.95 4j_
$11.50
$14.00
$27.95
$11.00
1 / All prices are per cubic yard unless otherwise
2 / D= local delivery (generally
P = picked up
3 / Price is for
4/ Price is for
at site.
40 -pound bag.
one ton of material.
less than
D
P
P
P
P
P
P
P
P
P
P
P
D
P
D
P
D
D
D
D
P
D
D
D
P
P
P
P
P
P
P
indicated.
10 miles;
2 - 13
-------
Bark Mulch and Wood Chips
Competing wood products include bark mulch, sawdust, and wood
chips. Wood products are used extensively by landscapers and
homeowners to conserve moisture and for decorative purposes. In
addition, wood chips and bark mulch are used in stabilizing steep
slopes and for rejuvenating soils severely disturbed by mining or
construction activities. Wood chips and bark mulch reduce erosion
from raindrop splash and protect new seedlings. Lastly, using wood
chips as a garden mulch is reported to suppress plant diseases,
reducing the damage from nematodes (1) .
The average composition of hardwood and softwood sawdust is
provided in Table 2-5. As shown in the table, the nutrient value
of wood is relatively low. These materials should not be tilled
into the soil since significant amounts of nitrogen would be needed
to supplement that used by microorganisms during decomposition and
this may tie up otherwise available nitrogen. Most barks tend to
be acidic with a pH between 4 and 5, although the pH increases
during the aging process. The cation exchange capacity (CEC) of
bark also increases during decomposition. The CEC is the total
amount of exchangeable cations that a soil (or soil amendment) can
sorb and is measured in milliequivalents per 100 grams of soil.
Among the exchangeable cations are some of the required plant
nutrients. In addition, the soil can also sorb nonessential
cations and in essence retain heavy metals. Sawdust, which is
generally recommended to be composted and aged prior to its use in
potting soils, has adequate CEC for sorption of cations. The
average bulk density and particle size of various growth media are
presented in Table 2-6.
Sources of bark mulch include cedar, cypress, and pine. Bark
mulch can be marketed in various sizes to accommodate the
preference of the consumer. Depending on the type and quantity,
retail prices for bagged bark mulch can range from $1.70 to $5.00
per cubic foot. Bulk prices for bark mulch and wood chips can
range from $12 to $30 per cubic yard (see Table 2-7) .
Based upon comments received during this study, the use of
wood chips by office park developers and residents is now in vogue
and has become an important retail market in regions where soil
sales have suffered due to an economic downturn. Wood chips are
used as a protective mulch cover for the existing soil.
A percentage of the compost made from yard trimmings will
compete directly with mulches and wood chips. The exact amounts
will depend upon the type and degree of processing. Coarse size
reduction will result in the production of a material suitable for
either use as mulch and wood chips or a composting feedstock.
2 - 14
-------
Table 2-5
AVERAGE NUTRIENT COMPOSITION OF WOOD
Woody Plant Group
Hardwoods
Softwoods
Nitrogen
(Percent
wet
weight)
0.20
0.10
Phosphorus
(Percent
wet
weight)
0.03
0.03
Potassium
(Percent
wet
weight)
0.15
0.10
Source: Follet, R.H.; L.S. Murphy; and R.L. Donahue. Fertilizers
and Soil Amendments. Prentice-Hall, Inc. England
Cliffs, New Jersey. 1981.
2 - 15
-------
Table 2-6
AVERAGE BULK DENSITY AND PARTICLE SIZE OF VARIOUS GROWTH MEDIA
Bulk Density
Material (Dry g/ml) Particle Size
Pine Bark 0.12 2to5mm
0.21 0.5 to 1 mm
0.30 < 0.5 mm
0.25 to 0.27 Mixed
Peat Moss
Fine 0.03 <10 mm; 90% <6 mm
Medium 0.10 <38 mm; 80% <6 mm
Coarse 0.14 19 to 38 mm
Perlite 0.21 2to5mm
Vermiculite 0.11 1 to 2 mm
Source: Handrick, K. and N. Black. Growing Media for Ornamental
Plants and Turf. New South Wales University Press.
Kensington, NSW, Australia.
2-16
-------
Table 2-7
AVERAGE PRICES FOR BARK MULCH AND WOOD CHIPS (1989)
Region Product Price 1 / Delivery 2. /
Northeast
Boston, MA Bark mulch $20.00 D
Wood chips $30.00 D
Industrial
Pittsburgh, PA Bark mulch $14.00 P
South
Atlanta, GA Bark mulch $12.00 P
Birmingham, AL Bark mulch $20.00 P
$ 3.99 3. / P
New Orleans, LA Bark mulch $20.00 D
Richmond, VA Bark mulch $16.00 D
Midlands
St. Paul, MN Bark mulch $ 4.99 i / P
Cedar chips $ 4.95 i / P
Central
Dallas, TX Bark mulch $25.00 P
Pacific
Portland, OR Bark mulch $13.00 D
Wood chips $12.00 D
!/ All prices given are per cubic yard unless otherwise
indicated.
2. / D= local delivery (generally less than 10 miles) ;
P = picked up at site.
I/ Price stated is for one cubic foot.
i/ Price stated is for three cubic feet.
2 - 17
-------
Potting Soils
Because of difficulties experienced in obtaining natural soils
that meet detailed specifications, the horticulture industry began
seeking alternative mixtures for potting soils 40 years ago (22) .
The first feedstocks developed were based on mixtures of peat and
sand. Today, a variety of materials are used, including soils,
peat, clay, compost, perlite, sand, sawdust, vermiculite, and
vermicompost (which is made by worms) . Compost may not be able to
compete directly with potting soils. However, compost can become
an ingredient in some potting soils, e.g., used as an ingredient
comparable to peat in potting soils.
A variety of potting soils are commercially available using
different mixtures of these materials. As such, the price for
potting soils depends upon the composition of the mixture, grade of
materials used, location, and manufacturer. The current retail and
bulk prices for a variety of potting soils and soil mixtures are
provided in Table 2-8.
Livestock Manure and Manure Compost
Manures produced by confined domestic livestock (including
poultry) were estimated at 990 million tons (dry weight) per year
in the mid- to late-1970s (23) . It was estimated that approximate
ely 47 million tons (dry weight) of the manure were available for
cropland application: Quantities and types of livestock manures
used for application on croplands in the U.S. were estimated to be
as follows: dairy cattle, 17 million tons; beef cattle, 13 million
tons; swine, 11 million tons; broilers, 4 million tons; and laying
hens, 3 million tons (24) .
There may be some competition between compost and manures.
The competition depends upon the compost feedstock and the type of
manure. Increased use of manures for agricultural purposes is
presently hampered because large feedlots generally may not be
located in the vicinity of croplands. Compared to chemical
fertilizers, any cost advantage for livestock manure is eliminated
if long distance transport is required. Furthermore, most large
feedlots are located in arid and semi-arid regions of the U.S.,
where insufficient croplands or pasturelands are available for the
appropriate application of manure (e.g., excess loadings of
nitrogen can affect ground or surface water) . if the level of
nitrogen added to the soil is excessive, surface and/or ground
water may be negatively affected if runoff and/or leaching problems
ensue.
Because of its nutrient value and organic matter content,
livestock manures enhance plant growth and crop production.
Manures may be applied wet or dry. Direct application of wet or
dry manures should be done carefully in order to prevent negative
2 - 18
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Region
Northeast
Boston, MA
Hartford, CT
Industrial
Newark, NJ
Pittsburgh, PA
South
Atlanta, GA
Birmingham, AL
Midlands
Chicago, IL
St. Paul, MN
Central
Phoenix, AZ
Table 2-8
AVERAGE PRICES FOR VARIOUS SOIL AMENDMENTS (1989)
Product Price Unit
Peat
Potting soil 2. /
Soil mix 3. /
Mushroom manure compost
Manure compost
Potting soil
Manure compost
Peat moss
Peat humus
Potting soil
Manure compost 4. /
Manure compost 5. /
Peat moss
Potting soil
Soil mix £ /
Soil mix 1 I
$12.00
$20.00
$18.00
$20.00
$10.00
$30.00
$ 3.99
$
99
1
$ 9.95
$ 1.69
$ 2.59
1.99
$ 3.99
$ 5.49
$ 2.99
$
$14.95
$15.95
6 cu ft bale
1 cu yd
1 cu yd
1 cu yd
1 cu yd
1 cu yd
40 Ib bag
40 Ib bag
4 cu yd bale
40 Ib bag
40 Ib bag
45 Ib bag
45 Ib bag
1 cu ft
40 Ib bag
1 cu yd
1 cu yd
Delivery 1. /
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
(continued)
-------
Table 2-8 (cont.)
Pacific
San Diego, CA Manure compost $12.75 1 CU yd P
Screened manure compost $14.00 1 CU yd P
Santa Cruz, CA Proprietary mix $27.50 1 CU yd D
Mushroom compost $12.95 1 CU yd D
Potting soil $ 2.00 1-1/2 Cu ft D
Planting mix $ 2.00 1-1/2 Cu ft D
I/ D = local delivery (generally less than 10 miles) ; P = picked up at site.
2 / Mixture includes soil, peat, and leaf compost.
I/ Mixture includes soil and leaf compost.
4_/ Steer manure.
M 5/ Sheep manure.
I £/ Mixture includes soil, leaf mulch, and sand.
M I / Mixture includes soil, river silt, and manure.
o
-------
impacts on water quality. Studies comparing equivalent nitrogen,
phosphorus, and potassium applications from livestock manures and
chemical fertilizers have demonstrated more favorable results with
manure in terms of yields (23), as well as reduced nitrate leaching
(25) (26). It is explained that the addition of manure to the soil
increases its concentration of organic matter, increases its
infiltration rate, and decreases its bulk density.
The composition of livestock manures varies according to its
origin. In addition, the diet, type, and age of the animal, and
storage conditions will affect the composition of the manures. The
characteristics of manures from six types of livestock animals are
presented in Table 2-9. As shown in the table, the density of the
manures is approximately 63 pounds per cubic foot. Total solids
range from 8.6 percent for swine to 25 percent for sheep. Values
for volatile solids, biochemical oxygen demand (BODS), and chemical
oxygen demand (COD)are also presented. Total kjeldahl nitrogen (a
method to determine the concentration of nitrogen) varies from 2.9
percent for horse manure to 7.5 percent for swine manure.
Phosphorus ranges from 0.49 to 2.5 percent, as a percent of total
solids; potassium ranges from 1.8 to 4.9 percent. Approximately 70
percent of the nitrogen in uncomposted manure is water soluble.
This is important for-water quality reasons since the nitrogen may
be more leachable to ground water and could negatively affect the
water quality.
The livestock manure sold at retail stores, or used by
landscapers and horticulturists, is usually composted, relatively
dry, and free of odors. Prices reported for composted manure range
from $1.99 to $3.69 for a 45-pound bag. These composted manures
have nitrogen, phosphorus, and potassium contents of 0.5 percent
(wet weight) each. Average prices for livestock manure composts
are included in Table 2-8.
Compost, particularly that produced from yard trimmings, can
compete with composted or uncomposted livestock manures. The
displacement can be on a one-to-one ratio or in some instances only
a portion of the manures in order to take advantage of the
beneficial properties of both materials.
Peat
Peat is used extensively by horticulturists, greenhouse
operators, and to a lesser degree by landscapers and homeowners.
In 1988, 1.468 million tons of peat were sold and used in the U.S.
(including .59 million tons imported). The average sales price was
$18.14 per ton in bulk and $24.68 per ton in package or bale (27)
One of the most important features of peat is its capacity to
absorb and retain water, and at the same time maintain adequate
quantities of oxygen. It is valued as a substrate for the rooting
2 - 21
-------
Table 2-9
AVERAGE CHARACTERISTICS OF LIVESTOCK MANURES
NJ
NJ
Characteristics
Density (Ib/cu ft)
Total solids
(% of raw manure)
Volatile solids
(% of total solids)
BOD 5.
(% oftotal solids)
COD
(%of total solids)
Kjeldahl nitrogen
(total)
Phosphorus as P
(% of total solids)
Potassium as K
(% of total solids)
NA = no data available
Source: Acrricultural
Dairy
62.7
10.8-12.7
82.5
16.6
68.1
3.4-3.9
6.7-3.9
2.6
Encrineers
Beef
63.0
11.6-12.8
85.0
23.0
95.0
3.5-4.9
1.6
3.6
Yearbook 1981.
Swine
63.0
8.6-9.2
75.0-80.0
30.0-33.0
90.0-95.0
7.5
2.5
4.9
Sheep
NA
25.0
85.0
9.0
118.0
4.5
0.66
3.2
Poultry
65.5
25.2
70.0
27.0
90.0
5.4-6.8
1.5-2.1
2.1-2.3
Hors
NA
20.5
80.0
NA
NA
2.9
0.49
1.8
-------
of slippings because it is free of weeds, diseases, and pests, and
it is readily penetrated by plant roots (22) .
Peat is found in swampy areas in cool climatic zones. It is
produced by incomplete decomposition of plant matter by
microorganisms under wet, anaerobic conditions (22) .
Peat is divided into the following main categories (23) :
Peat moss--mainly sphagnum and hypnum mosses. The fibers
aereadily identifiable because they have not been
noticeably decomposed. This is the most acid, the most
expensive, and the most desirable of the peat mosses.
Reed-sedge peat--a mixture of residues from reeds, sedge
grasses, and cattails.
Humus peat--produced from the advanced decomposition of
hypnum moss and reed-sedge peat.
Muck soil--highly decomposed peat of any source, usually
mixed with mineral soil, often sold as "topsoil."
The physical and chemical properties of peat depend on the
species, degree of decomposition, and proportion of mineral matter.
As shown in Table 2-6, the average bulk density of peat is 0.1 gram
per milliliter. Peat is divided into three main grades: fine
(with particle size less than 38 millimeters and 90 percent less
than 6 millimeters) , medium (with particle size less than 38
millimeters and 80 percent less than 6 millimeters), and coarse
(with particle size greater than 38 millimeters). As stated
earlier, one of the most important physical properties of peat is
its ability to absorb water. Commercially available peat can
absorb 15 to 20 times its weight in water.
Table 2-10 presents the chemical characteristics of four
different types of peat. As shown, peat has a low pH (3.8 to 4.6)
and an ash content no greater than 8 percent. Concentrations of
nitrogen, phosphorus, potassium, and calcium are also presented in
the table. An ultimate analysis of peat indicates the following
characteristics: carbon, 56.8 percent; hydrogen, 5.6 percent;
sulfur, 0.3 percent; and oxygen, 34.6 percent (28) .
Peat is usually distributed in bales or bags. The sizes of
the bags range from 1 to 4 cubic feet (compressed) . Commercially
available peat is often pH balanced (5.0 to 6.0) and is guaranteed
to be 98 percent root-free. Sphagnum peat moss is reported to have
a retail cost between $2 and $5 per cubic foot, depending on the
grade (see Table 2-8).
2-23
-------
Table 2-10
CHEMICAL CHARACTERISTICS OF DIFFERENT PEAT TYPES
(Percentages on oven dry basis)
Peat Type
Sphagnum
Sphagnum"
Eriophorum
(cotton-grass )
Trichophorum
(deer-grass)
Sedge-grass
Ash N
1-2 0
1
1-3 1
1
1-4 1
2
2-8 1
2
.8-
.2
.0-
.6
.5-
.0
.5-
.5
P
0
0
0
0
0
0
0
0
.01-
.04
.01-
.05
.01-
.05
.04-
.07
K
Ca
trace-
0
0
0
0
0
0
0
.03
.01-
.03
.01-
.05
.02-
.07
0
0
0
0
0
0
0
0
.07-
.21
.14-
.25
.14-
.21
.14-
.36
pH
3
4
3
4
4
4
4
4
.8
.2
.9
.6
.0
.5
.2
.6
Source: Robinson, D.W. and J.G. Lamb. Peat in Horticulture.
Academic Press. New York. 1975.
2 - 24
-------
A high quality compost made from yard trimmings, for example,
or some of its components, can be very competitive with peat, based
on moisture retention and porosity.
Livestock Bedding and Litter
The increasing demand for animal products and by-products,
along with the marginal nature of certain types of agricultural
operations, and diminishing availability of land for siting
livestock operations, have resulted in a growing dependence upon
high density animal housing facilities in which the animals are
closely confined. This dependence is especially widespread in
poultry and dairy cattle operations. The confinement and high
density trends have engendered a heavy demand for bedding and
litter materials -- a demand that is increasingly difficult to
meet. The industries and activities that generated the residues
and other materials conventionally used as bedding have experienced
a sharp decline. Dwindling Supply , competition for these
materials, and transportation requirements combine to render the
monetary cost of these materials prohibitively high in many cases.
Accordingly, there is a search for new materials worthy of serious
consideration for use as livestock bedding (e.g., recovered
newspapers and phone books) .
A suitable bedding material is one that is easy to handle and
has a high moisture holding capacity. It must either be devoid of
pathogens and toxic inorganic and organic substances or have them
at or below acceptable concentrations. It must be reasonably
available and priced. Additionally, the moisture content of the
material should not be so high as to cause it to adhere to the
animal or so low as to make the material a source of dust. The
moisture holding capacities of several potential bedding materials
are listed in Table 2-11. Other materials that can supplement the
list in the table are various composts, whether derived from
livestock manure, yard trimmings (see Table 4-2 for its water-
holding capacity), or almost any other organic material (obvious
exceptions are hazardous wastes) .
At present, two uses of compost in animal husbandry are as
poultry litter and as dairy cattle bedding. Although use as
bedding in commercial horse stables (renting and/or boarding
horses) could be a third use, findings made in an unpublished
survey reveal that the strong concern on the part of the stable
operators over the possibility of the exposure of the horses to
disease transmission and/or toxic contaminants is a major obstacle
to the realization of that potential (29) .
Dairy Cattle Bedding. In addition to having been a feature of
long standing in dairy cattle husbandry, bedding has become a
necessity in free stall dairy housing facilities to keep the
animals clean and comfortable. Bedding absorbs urine and renders
manure easier to handle. As stated above, the absorption function
2 - 25
-------
Table 2-11
MOISTURE ABSORBING CAPACITIES (MACs) OF SEVERAL LIVESTOCK BEDDING AND LITTER MATERIALS
Material
Peat Moss
Oat Straw, Baled,
and Chopped
Mill Sawdust,
Stored Uncovered
Hay, Baled
Recycled Manure,
Wood Shavings
Bedding
Light Coarse
Sawdust, Stored
Under Cover
Wood Shavings,
Kiln-Dried
Peanut Hulls,
Unground
Heavy Fine
Sawdust, Stored
Under Cover
Saturated
Moisture Content
(% dry basis)
1,195.0
537.4
532.1
410.9
394.6
338.4
299.6
291.3
282.2
MAC units/
unit total
solids
11.9
5.4
5.3
4.1
3.9
3.4
3.0
2.9
Typical As-Stored
Moisture Content
(% dry basis)
13.6
309.8
8.7
12.4
38.5
4.7
10.4
38.5
MAC
10.4
4.5
0.5
3.7
3.4
1.8
2.5
1.
(continued)
-------
Table 2-11 (cont.)
Source: Sobel, A.T.; B.C. Ludington; and Kim-Van Yow . "Altering Dairy Manure
Characteristics for Solid Handling by the Addition of Bedding." Paper No. NA77-410
presented at 1977 Annual Meeting, North Atlantic Region, American Society of
Agricultural Engineers. University of New Brunswick, Canada. July 31 August 3,
1977.
NJ
I
-------
makes water absorption capacity a key factor in evaluating
candidate bedding materials. Table 2-12 lists the absorption
capacities of a more extensive collection of potential bedding
materials than listed in Table 2-11.
The reasons given above regarding the search for sources of
bedding material are particularly applicable to the dairy cattle
industry. Hence, it is not surprising that compost has become a
leading candidate. Use of compost as bedding material was
seriously explored as early as 1971 in a study on the role of
composting in a comprehensive study of management and utilization
of manure from high-density cow housing facilities (30) (31). An
interesting feature of this study was the gradual replacement of
the original bedding material with composted manure, such that
eventually composted manure became the sole bedding material. The
forced air (static pile) composting method was used. it was
determined essential that the manure bedding be removed from the
stalls as soon as its moisture content reached 70 percent. In
addition, 70 percent is the highest moisture level at which the
forced aeration system could be successfully used.
In recent years, hydraulic manure management (i.e., periodic
flushing and transport) has become commonplace in dairy housing
sanitation. Solids separated from the resulting manure slurries
can be composted and the liquids either are ponded or subjected to
treatment. Separation generally is done mechanically, i.e., by
means of screens (32) . composting usually is by one of three
methods, namely, forced aeration ("static pile") , turned windrow,
or "natural aeration" (33) (34). ("Natural aeration" involves
stacking the material in windrows and allowing air to diffuse
without assistance into the piles.)
The possibility of transmission of disease-causing organisms
between animals through the use of composted manure as bedding was
investigated by Clemson University in 1978 to determine survival
rates of pathogenic organisms and the temperature increases in the
composting piles (34). The piles were sampled every four days.
Results indicated a sharp decrease in numbers of streptococci and
salmonella. The drop in pseudomonades and coliforms was less
steep, and the number of staphylococci remained fairly constant at
an infectious level (i.e., 10,000 staph/gram) after an initial
drop. In all cases, temperature played a significant part.
A major question is the effect of compost bedding on the
incidence of udder infections, especially mastitis. The authors
state that it is generally believed that bedding materials are
second to the milking machine in terms of exerting a major
influence on the type of bacteria infections that are found in the
udder. Past data justify the conclusion that the type of bedding
may affect the bacterial populations on the teat skin. The authors
found no significant difference in bacteria counts between teats
and milk of animals bedded on composted dairy manure and clean
2 - 28
-------
Table 2-12
WATER ABSORPTION CAPACITY OF LIVESTOCK BEDDING MATERIALS
Bedding Material
Barley straw
Cocoa shells
Corn stover (shredded)
Corncobs (crushed or ground)
Cottonseed hulls
Flax straw
Hay (mature, chopped)
Leaves (broadleaf)
(pine needles)
Oat hulls
Oat straw (long)
(chopped)
Peanut hulls
Peat moss
Rye straw
Source:
Pounds of
Water Per
Pound of
Bedding
2.10
2.70
2.50
a) 2.10
2.50
2.60
3.00
2.00
1.00
2.00
2.80
3.75
2.50
10.00
2.10
Dairv Cattle
Bedding Material
Sand
Sugar cane bagasse
Vermiculite
Wheat straw (long)
(chopped)
Wood
Dry fine bark
Tanning bark
Pine chips
Sawdust
Shavings
Needles
Hardwood chips
Shavings
Sawdust
Science. Interstate Prini
Pounds of
Water Per
Pound of
Bedding
.25
2.20
3.50
2.20
2.95
2.
4.
3.
2.
2.
1.
1,
1,
50
00
00
50
00
00
50
50
1.50
Publishers, Danville, Illinois. 1990.
-------
rubber mats. Thus, there appeared to be no direct relation between
bedding and udder infection. The critical factor is good
management. If cows are well cared for, if the milking process is
performed properly with effective sanitation practices and teats
dipping, and if free stalls are cleaned periodically, mastitis
infection would be minimal. In general, the type of bedding
appears to have no direct relationship to incidence of udder
infections, if good management practices are observed (34) .
Poultry Litter. The use of compost as a poultry litter can be
traced back to the 1950s (35) . At that time, the "deep litter" (or
"thick litter") approach in poultry husbandry was strongly
recommended by its users and was fairly widely used in the U.S. and
the Netherlands.
In the deep litter method, hens and chicks are left on a 12-to
20-inch thick layer of organic matter such as straw, corn cobs,
wood shavings, horse manure, peat bedding, or Compost. The birds
spend their entire life on this bedding. Provided that an
intensive bacterial flora generating heat develops in the layer,
and the layer is properly maintained, the bedding may be used for
3 to 4 years without renewal. If necessary, the bedding layer can
be turned (aerated) or fresh organic matter may be mixed with it.
Among the several advantages attributed to the use of this approach
are a healthier flock and somewhat greater gain in body weight.
Apparently, the birds develop an immunity against coccidiosis.
In the years that followed, the use of litter (not necessarily
the deep litter approach) has continued to be an important feature
in the production of broilers and turkeys. Sawdust and wood
shavings became the material most commonly used because it is clean
and, until recently, it was the cheapest in most situations.
However, the dwindling availability of bedding and litter materials
and search for other materials discussed above have brought about
a renewed interest in the use of compost for poultry litter.
In three experiments involving a total of 33,920 broilers, the
utility of composted municipal garbage (CMC) as broiler litter was
evaluated (36) . The compost was obtained from two sources, namely
aerobically digested CMC and windrow processed CMC. They were each
compared to a wood shavings control. Broilers reared on CMG
compost were respectively 31, 12, and 44 grams heavier than those
reared on the wood shavings control. Feed efficiency was also
improved. However, the type of litter treatments had little or no
effect upon other production or carcass characteristics. Judging
from the few published reports, select trace elements and pesticide
levels in CMG litter and tissue as compared with wood base litter
were generally within previously reported levels. Exceptions were
high mercury, lead, chromium, and nickel in CMG litter. Additional
research would be necessary for quantifying the significance of the
high levels.
2-30
-------
If the views of one study are taken as being typical, the
outlook for compost as litter material for turkey houses had become
much less hopeful by 1990 (37). Their objection is that birds
produced on litter were somewhat dirtier than those grown on
shavings. This dirtiness would add more production costs .
Moreover, recycled litter could not be expected to satisfy
completely the bedding requirement for a given operation, because
of a 15-20 percent loss in volume during the composting process.
This study concludes that more work must be done before compost can
be recommended for use as bedding material.
An idea of the dimensions of the bedding use for compost in
various poultry management schemes may be gained from the data in
Table 2-13.
Others
Among the other soil amendments available in the market are
vermiculite, perlite, and vermicompost. These materials are mainly
used as additives for potting mixes, although they are relatively
expensive. A brief description of each of these materials is
provided below.
Perlite. Perlite is a porous siliceous material produced by
the rapid heating of natural volcanic glass to 1,200 degrees
Celsius. It is completely inert, without any buffering capacity,
and no nutrients. Perlite is used primarily in potting mixes,
because it has a similar water-holding capacity to peat. As shown
in Table 2-6, the bulk density of perlite is relatively low.
Compost can be used with perlite and other amendments for special
potting soil blends. Perlite retails for approximately $7.20 for
a 4-cubic foot bag. In 1988, 49.3 thousand tons of perlite were
sold and used as horticultural aggregates (includes fertilizer
carriers) , at an average price of $30.65 per ton of all perlite
sold (27).
Vermiculite. Vermiculite is a flaky mineral with a plate-like
structure that occurs naturally. The raw mineral is crushed,
graded, and then rapidly heated to 1,000 degrees Celsius. Rapid
heating results in particle expansion (exfoliation) to several
times its original size. The density of the exfoliated vermiculite
is similar to peat (see Table 2-6) . Compared to perlite,
vermiculite has a greater capacity to hold water, but has a lower
air-filled porosity (i.e., the space between the particles) (38).
This is due to its plate-like structure. Vermiculite provides some
magnesium and potassium to plants. Compost can be used with
vermiculite and other amendments for special potting soil blends.
It is reported by those interviewed that vermiculite costs between
$5.75 and $6.75 for a 4-cubic foot bag, depending on the grade. In
1988, 71.4 thousand tons of exfoliated vermiculite were sold and
used in agricultural applications (i.e., for horticulture, soil
2 - 31
-------
Table 2-13
BEDDING USE PER POULTRY MANAGEMENT SCHEME
System Type
Broiler - System 1
Broiler - System 2
System Description
- 5.5 Flocks per Year
- Annual Cleanout
- 6.0 Flocks per Year
- 1/3 Cleanout Annually
- Complete Cleanout
Every 2 Years
Turkey - System 1 Hen
Tom
Turkey - System 2 Hen
Tom
Pounds of Shavings
Used Per Bird
Produced
0.6
0.26
- 5.2 Flocks per Year
- Brooder House
Cleaned After
Every Flock
- Growout House
Cleaned Annually
- 4 Flocks per Year
- Brooder House
Cleaned After
Every Flock
- Growout House
Cleaned Annually
- 5 Flocks Annually
- Brooder House
Cleaned After
Every Flock
- Growout House
Cleaned Annually
- 4 Flocks Annually
- Brooder House
Cleaned After
Every Flock
- Growout House
Cleaned Annually
Brooder House 2.33
Growout House 1.33
3.66
Brooder House 3.5
Growout House 2.5
6.0
Brooder House 5.33
Growout House 2.67
8.00
Brooder House
Growout House
8.00
13.00
Source: Safley, L.M., Jr. and T.A. Carter. "Use of Composted Litter
as Bedding Materials for Broilers and Turkeys." Chapter 6 in
Composting Poultry Litter - Economics and Marketing Potential
of a Renewable Resource. North Carolina Agricultural
Research Service, North Carolina State University, Raleigh,
North Carolina. 1990.
2 - 32
-------
conditioning, and as a fertilizer carrier) at an average price of
$221 per ton of all exfoliated vermiculite sold (27) .
Vermicompost. Vermicompost is produced from the castings of
earthworms that feed on organic materials. Historically, only
limited quantities of vermicompost have been available. Increased
quantities of the product are expected for the future. Analysis of
vermicompost produced from swine manure contained the following (on
a dry weight basis): 4 percent nitrogen, 3.9 percent phosphorus,
0.9 percent potassium, 6.3 percent calcium, 2.0 percent magnesium,
and 2.3 percent iron (38).
2 - 33
-------
Chapter 2
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14. U.S. Environmental Protection Agency, U.S. Food and Drug
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17. Fulford, B. and J. Quinney. Leaf Composting Projects in the
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18. 40 Code of Federal Regulations. Chapter 1 - Part 257,
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Working document presented to the American Composting Council.
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20. Zucconi, F. and M. de Bertoldi. "specifications for Solid
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21. Fitzpatrick, G.E. "Solid Waste Composts as Growing Media."
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23. Follet, R.H.; L.S. Murphy; and R.L.Donahue. Fertilizers and
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25. Maynard, A.A. "Agricultural composts as amendments reduce
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2-4. Fall 1989.
2 - 35
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26. Brinton, W.F., Jr. "Nitrogen Response of Maize to Fresh and
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27. U.S Department of the Interior. Minerals Yearbook. Volume I:
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28. Punwani, D.V. "Peat as an Energy Alternative: An Overview, tl
in symposium papers. Peat as an Alternative. December 1-3,
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owners. 1982.
30. Senn, C.L. A comprehensive study of management and
utilization of waste from high-density cow-housing facilities.
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32. Safley, L.H., Jr. & W.C. Fairbanks. "Separation and
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of the Second National Dairy Housing Conference. Published by
American Society of Agricultural Engineers. March 1983. pp.
77-91.
33. Emerton, B.L.; C.R. Mote; H.H. Dowlen; J.S. Allison; and W.L.
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34. Bishop, J.R.; J.J. Janzen; and A.B. Bodine. "Composted solids
from manure can be used in free stalls." Hoard's Dairyman,
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35. Teensma, B. "Refuse Compost in Poultry Husbandry."
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36. Malone, G.W.; G.W. Chaloupka; and R.J. Eckroade."Composted
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37. Safley, L.M., Jr. and T.A. Carter. "Use of Composted Litter as
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38. Handrick, K. and N. Black. Growing Media for Ornamental
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2-37
-------
Chapter 3
COMPOST USES AND MARKETS
Successful market development of compost includes three main
requirements: 1) producing a consistent quality and quantity of
compost; 2) identification of a use or uses for the product; 3)
identification of potential users (i.e., markets) ; and 4)
acquainting prospective users with the compost and its uses. This
chapter discusses the first two of these requirements, namely uses
and markets for the compost products.
COMPOST USES
The utility of compost as a soil amendment has long been
recognized. The greatest benefit of compost is its organic matter
content. Following its incorporation into the soil, compost can
improve the soil's texture, water retention, and aeration capacity.
Compost also contains nutrients that can be helpful in plant
production. The effects of compost use on the biological,
chemical, and physical properties of soil, as well as on crop
yields, are summarized below (1)-(10):
Compost enhances the biological properties of soil by:
enhancing the development of fauna and microflora;
rendering plants less vulnerable to attack by parasites;
and
promoting faster root development of plants.
Compost enhances the chemical properties of soil by:
increasing nutrient content;
turning mineral substances in soil into forms available
to plants;
regulating mineral input, particularly nitrogenous
compounds;
serving as buffer in making minerals available to
plants; and
providing a source of micronutrients.
Compost enhances the physical properties of soil by:
improving soil texture;
increasing water retention capacity;
improving soil infiltration;
improving resistance to wind and water erosion;
improving aeration capacity;
improving structural stability; and
stabilizing soil temperatures.
3-1
-------
Compost enhances crop yields by:
producing higher yields; and
inhibiting weed growth.
Although serving as a soil amendment is a principal use for
compost, it can also be used in other applications including: 1) as
a mulch to lessen evaporation and inhibit weed growth; 2) as a top
dressing to improve the appearance of soil and discourage weed
growth; 3) in hydromulching for use in erosion control and
reforestation projects; 4) as bedding for dairy cattle and poultry
litter; and 5) as a landfill cover.
Composts from different types of organic materials (e.g., yard
trimmings, other municipal organics, and livestock manures) have
different characteristics and, therefore, the uses for these
products can differ. Typically, segregated yard trimmings have a
more consistent composition than mixed MSW. Consequently, compost
from yard trimmings generally has a more consistent quality than
that from mixed MSW.
COMPOST MARKETS
Consistent product quality is generally considered to be the
most important of the factors affecting the marketability of
compost. Regardless of the type of composting operation, the
quality of the product is a function of the biological, chemical,
and physical characteristics of the product. Biologically; the
product should be sufficiently mature; have a high concentration of
organic matter; be free from pathogenic organisms; and should
contain no active weed and plant seeds. Examples of desirable
chemical characteristics are: available nutrients (NPK); minimal
levels of heavy metals, PCBs, PCP, and pesticides and herbicides;
and low salinity. Examples of pleasing physical characteristics
are uniform particle size; absence of visually identifiable
unwanted substances (e.g., glass shards, bits of plastic, pieces of
metal) ; a moisture content less than 50 percent; a dark color; and
a pleasant earthy odor.
In the absence of a complete nationwide survey, no attempt was
made to quantify the full market potential for compost since this
would depend on: type and amount of materials composted; type,
number, and size of compost users; existing and new compost
markets; compost quality; etc. Information on current levels of
uses for some of the competing/complementary products is provided
in Chapter 2. These figures are not available for all of these
products since they may be produced and marketed locally.
Because of the beneficial characteristics of compost, the
product can be used for many different applications-. 'These
include: agriculture, grounds maintenance (e.g., golf courses,
3 - 2
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cemeteries, and athletic fields) , highway construction and
maintenance, hydromulching, industrial and commercial property
landscaping, bare roots nurseries (i.e., only deal with a dormant
stock and sold without growing medium) , forest seedling nurseries
and reforestation, sod farming, land reclamation, landfill cover,
parks and recreational areas, and residential landscaping and
gardening.
These applications can be broadly grouped into the following
five primary market segments:
agriculture;
landscape industry;
nursery industry;
public agencies; and
residential.
Various local and national organizations and groups represent
these users, e.g., agricultural extension services, farm bureaus,
soil and water conservation districts, landscape architect and
contractor institutes, bark and soil supply associations, public
works officials, and garden clubs. These types of organizations
represent key target groups to involve to stimulate compost use by
their members.
Uses of different types of compost in each market segment are
constrained by that market's particular requirements for quality,
composition, and appearance, as well as by applicable regulations.
Agriculture
The agriculture industry is the largest potential market for
compost. Agriculture, however, remains the most difficult to
penetrate. In general, given their experience and widespread use
of chemical fertilizers, farmers would need to be convinced through
field demonstrations and tests of the benefits of using compost
(e.g., affects on costs , crop yields, soil structure, soil
fertility, soil erosion) as well as the quantities of compost to
apply, and the timing and method of application. However, in some
parts of the country there are agricultural communities whose
farming traditions differ and where large amounts of organic matter
are incorporated into the soil. Also, there is an increasing trend
to organic methods of farming which should increase the demand for
organic-based soil amendments, such as compost, for use in
agriculture. In addition, there is an increasing awareness that
soil fertility is dependent upon maintaining a sufficient amount of
organic matter in the soil. Compost is an excellent source of
organic matter for maintaining soil fertility and reducing erosion
(10) (11) .
Studies have shown that the sustained application of compost
has beneficial effects that include favorable soil pH, higher crop
3 - 3
-------
yields, increased organic matter, increased water retention,
increased cation exchange capacity (i.e., ability of the soil to
sorb nutrients, as well as heavy metals and other substances) ,
enhanced supply of plant nutrients, and improved tilth. Primary
and secondary plant nutrient levels were increased significantly
due to the long-term application of mixed MSW compost to field
plots in Johnson City, Tennessee (3). Some of the problems that
need to be overcome to develop the agriculture market for compost
are its availability, consistency in composition and nutrient
content, ensuring low levels of potentially toxic substances,
effectiveness of bulk application, effectiveness of distribution
methods, information on its contribution to crop yields and soil
fertility, cost, and acceptance by farmers.
Landscape Industry
The landscape industry, including landscape service companies,
uses large amounts of soil amendments: bark or barkdust,
particularly in the Pacific Northwest, is frequently used as a top
dressing; topsoil is used for new planting; and compost is used as
a soil amendment. Soil with poor physical properties can be
significantly improved by the correct use of compost. Research
conducted by the USDA and by Rutgers University has shown that the
use of compost combined with chemical fertilizers produces better
turfgrass than when using the fertilizers alone (10) .
Compost is not expected to completely displace bark as a top
dressing because of the decorative appearance of bark. Areas of
new planting could benefit from the use of compost to improve the
quality of existing soil rather than replacing the soil with
topsoil at a potentially higher cost. The results of previous
studies show that landscapers are aware of the benefits of compost
produced from organic materials (2) . However, landscapers have
expressed concern that compost from yard trimmings may contain
harmful amounts of viable seeds, herbicides, and pesticides.
Following proper composting procedures, making results of
laboratory tests demonstrating the safety of yard trimmings compost
available to landscapers should alleviate these concerns. Other
factors affecting the use of compost in the landscaper industry
include product availability, distribution channels, and cost.
The commercial landscape industry operates such that the
materials used should, at a minimum, meet the specifications of the
landscape architect or inspector.
Nursery Industry
Similar to the landscape industry, the potential for using
compost in the nursery industry is greatly dependent on the economy
and the housing industry. Home sales have a direct effect on the
demand for nursery products (2) . in addition, quality of the
compost product, as well as its availability, distribution
3 - 4
-------
channels, and cost, can have an impact on the utility of compost in
the nursery industry.
Use of compost in potting mixes helps to retain water, improve
soil texture, and provide nutrients. Relatively inexpensive
compost could be a favorable alternative to the more expensive,
oftentimes imported, peat currently used in many areas of the
country. To displace peat in any quantity, laboratory analyses and
field tests would need to be conducted to demonstrate the benefits,
safety, and reliability of compost for use in potting mixes.
Bare roots nurseries offer excellent potential for the use of
compost. Other potential markets in the nursery industry include
forest seedling nurseries, greenhouses, and Christmas tree farms.
Public Agencies
Public agencies have the potential to use both high-quality
and low-quality composts. High-quality compost can be used in
areas where humans and/or animals may come in contact with the
materials (e.g., parks and playing fields). A lower-quality,
relatively stable compost may be suitable for land reclamation,
fill material, and landfill cover.
A study conducted by the City of San Jose identified uses
where the demand for compost could be increased or created by the
City (12) . Among the uses are:
parks and redevelopment;
weed abatement on public lands;
land upgrade; and
roadway maintenance and median strip landscaping.
The use of compost in parks is mainly as a turf builder and
maintainer. Compost helps maintain proper turf conditions on lands
of high use such as recreation areas. Weed abatement can be
achieved by using coarse compost that has low water retention.
Vacant public lands can be upgraded with the addition of high-
quality compost. Upgraded land requires less water to irrigate,
has an increased resale value, and the quality of the soil is
increased. The land can then be used for community gardening or
leased to commercial nurseries. Compost may be used in landscaping
to control weeds and improve soil conditions, and also as a
landfill cover. An additional use can be in landspreading for
reclamation programs. Some of the beneficial effects of
landspreading include a more favorable soil pH and increased
organic matter and nutrient levels (3).
Residential
The residential segment represents a substantial market for
soil amendments. In order to market compost successfully to the
3 - 5
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residential sector, the public needs to be informed about the uses
and benefits of compost, especially with the growing interest in
organic gardening (13) . A marketing study conducted in Portland,
Oregon showed that people are concerned about the safety of using
compost (2). Some of the concerns most frequently mentioned were:
disease transmission;
contamination, chemicals, hazardous waste;
harmful to children or pets;
harmful to plants;
dislike of garbage in yard;
odors;
insects;
health concerns; and
appearance.
To the extent that these types of concerns or perceptions hamper
compost market development efforts, they should be addressed (see
Chapters 5 and 6).
Results of the Portland marketing survey showed that of those
individuals not currently using compost, more would be willing to
use compost made from yard trimmings (45 percent) than from mixed
MSW (38 percent) (2) . The amount of compost that the residential
segment indicated they would use would be largely dependent upon
public education and the ability of the facility to produce a
product that was of consistently high quality. Other factors that
can affect the quantities of soil amendments used are their use
regulations, distribution channels, distribution form (bulk or
bag), availability, cost, population growth, the economy, and the
vitality of the housing industry. Additionally, areas with a large
percentage of single-family homes generally have a greater demand
for soil amendments than areas of high-density housing. Public
awareness of the benefits and limitations of compost will affect
how much compost the residential sector will use.
3 - 6
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Chapter 3
REFERENCES
1. de Lauzanne, R. "Methodologies and Technologies in Compost
Production: The French Experience." Presented at the
International Symposium on Compost Production and Use. S.
Michele All'Adige (Trento), Italy. June 1989.
2. Cal Recovery Systems, Inc. Portland Area Compost Products
Market Study. Prepared for Portland Metropolitan Service
District. Portland, Oregon. 1988.
3. Mays, D.A. and P.M. Giordano. "Landspreading Municipal Waste
Compost." BioCvcle. 30(,3) :37-39. March 1989.
4. Kubota, H. and K. Nakasaki. "State of the Art of Compost
Systems: The Current Situation and Future Outlook in Japan."
Presented at the International Symposium on Compost Production
and Use. S. Michele All'Adige (Trento), Italy. June 1989.
5. Shimell, P. "Refuse Derived Compost Boosts Vineyard Yields. "
World Wastes. 26(11):8-9. November 1983.
6. Levasseur, J.P. "Household Refuse Recycling in France."
BioCycle. 29(6):32-33. July 1988.
7. Porter, C. "French Farmers Favor Cordon Bleu Compost."
Surveyor. pp. 14-16. September 1981.
8. L'Hermite, P. "State-of-the-Art of Compost Systems: Current
Situation in Europe and Future Outlook." Presented at the
International Symposium on Compost Production and Use. S.
Michele All'Adige (Trento), Italy. June 1989.
9. Robotti, A.; G. Ramonda; A. Nassisi; A. Rattotti; and A.
Barilli. "Optimization of Composting Process Utilizing Urban
and Agricultural Wastes." Compost: Production. Quality and
Use, pp. 666-675. M. de Bertoldi; M.P. Ferranti; P.
1'Hermite; and F. Zucconi, eds. Elsevier Applied Science.
1987.
10. M.M. Dillon and Cal Recovery Systems, Inc. Composting: A
Literature Study. Prepared for Ontario Ministry of the
Environment. 1989.
11. Cal Recovery Systems, Inc. Composting Technologies, costs .
Programs, and Markets. Prepared for U.S. Congress Office of
Technology Assessment. Washington, D.C. 1989.
12. Yard Waste Composting Implementation Plan. City of San Jose.
Office of Environmental Management. 1988.
3 - 7
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13. Derr, D.A.; M.C. Varner; and G.J. DiLalo. "Marketing
Potential of Organic Based Fertilizers." BioCycle, 25(3): 42-
45. April 1984.
3 -
-------
Chapter 4
FACTORS PERTINENT TO DEVELOPING COMPOST MARKETS
INTRODUCTION
This chapter examines factors that should be considered when
developing and/or expanding compost markets. Pertinent factors are
specifications for compost labeling, testing requirements,
distribution methods, and policies such as guidelines or
regulations, which affect developing and/or expanding compost
markets.
COMPOST SPECIFICATIONS
Composting research and experience gained in producing and
developing markets for compost show that consistent quality is very
important to its marketability. Compost quality can be defined by
a set of specifications. However, rigorous sets of specifications
have not been uniformly developed for composts and soil amendments,
in general. A few State agencies, the U.S. Government, and other
countries have developed or proposed regulations to control the use
of soil amendments for specific applications produced from
different composted organic materials.
Relevant experience and information found in the literature
demonstrate that specifications for soil amendments could include
a number of parameters from the following list, some of which are
overlapping:
organic matter content;
water-holding capacity;
bulk density;
size distribution (i.e., particle size) ;
nutrient content;
level of non-toxic substances;
level of potentially toxic contaminants;
concentration of weed seeds;
seed germination and root elongation;
soluble salts;
- ratio of available carbon/nitrogen;
pH ;
color; and
odor.
The level of importance of these parameters to the major compost
market users discussed in Chapter 3 is provided in Table 4-1.
4-1
-------
Table 4-1
LEVEL OF IMPORTANCE OF COMPOST QUALITY PARAMETERS FOR VARIOUS USES 1 /
Parameter Agriculture Landscaping Nursery Public Residential
Agencies 2. /
Organic Matter
Content 221 2 3
Water-Holding
Capacity 222 2 2
Moisture
Content
Bulk Density
Porosity
Particle Size
Nutrient Content
Non-toxic
Substances
Heavy Metals
Toxic Substances
Pathogens
Weed Seeds
Soluble Salts
Maturity
pH
Color
Odor
3
2
1
2
2
3
2
3
2
1
3
2
2
1
1
1
2
1
2
2
3
2
3
3
3
3
2
1
3
2
1
1
2
3
3
3
3
3
2
2
3
2
3
2
2
2
2
1
3
3
3
3
3
2
3
2
3
2
2
2
1
1
1
2
2
3
3
3
3
3
3
3
2
3
3
I I Ranking: i — less important; 2--important; 3--very important.
21 These may change depending upon end use, e.g., athletic field versus
landfill cover.
(continued)
4 - 2
-------
Table 4-1 (cont.)
Sources: Cal Recovery Systems, Inc. Feasibility Evaluation of Municipal
Solid Waste Composting for Santa Cruz County, CA. December 1983.
Cal Recovery Systems, Inc. Portland Area Compost Products Market
Study . Prepared for the Portland Metropolitan Service District.
Portland, Oregon. October 1988.
Cal Recovery Systems, Inc. in association with Wilsey & Ham Pacific,
Inc.; C. Henry; Thomas/Wright, Inc. compost Classification/Qualit
Standards for the State of Washington. September 1990.
de Lauzanne, R. "Methodologies and Technologies in Compost
Production: The French Experience." Presented at the International
Symposium on Compost Production and Use, S. Michele All'Adige.
Trento, Italy. June 1989.
Inbar, Y. and H. A. J. Hoitink. "Growth Media for Container-Grown
Plants." Ohio State University, Ohio. Undated.
Maine Department of Agriculture. Standards for Compost Products.
Food and Rural Resources. April 1990.
Warncke, D. D., and D. M. Krauskopf. "Greenhouse Growth Media:
Testing and Nutrition Guidelines." MSU Ag Facts, Extension Bulletin
E-1736. September 1983.
4 - 3
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Organic Matter Content
One of the keys to soil fertility is its organic matter
content. As a result, plant growth is improved. As discussed in
Chapter 2, adding organic matter to the soil also improves its
ability to retain moisture and withstand droughty conditions.
Water-holding Capacity
The structure and texture of a soil amendment play an
important role in the capacity of the soil to retain moisture. The
water-holding capacity of a soil is primarily a function of the
concentration of organic matter and clay content of the soil.
The water-holding capacity of compost and other _ soil
amendments is indicated by the data in Table 4-2. Increasing a
soil's water-holding capacity can promote plant growth and help it
withstand drought conditions.
Bulk Density
Bulk density of material is a measure of its weight per unit
volume, e.g., pounds per cubic yard. The bulk density of soil
amendments should not be specified without referring to the
moisture content at which the measurement was made. Listed in
Table 4-3 are the bulk densities of some soil amendments reported
in the literature. If soils are too dense, i.e., too compacted,
seedlings may not emerge and root growth will be impaired. Adding
organic matter will reduce the soil's bulk density and improve
plant growth.
Size Distribution
The size distribution of soil amendment particles has an
impact on the storage, packaging, distribution, and utility Of the
product. The size distribution of the individual particles that
constitute a particular type of soil defines the texture and,
therefore, affects the productivity of the soil. Texture
determines porosity, permeability, and other parameters that are
important for plant production.
The size distribution of the particles that make up a soil
amendment depends upon whether, and to what extent, the material is
subjected to size reduction, as well as the type or degree of
processing (including pre- and post-processing). This is
especially true with an amendment produced from yard trimmings,
MSW, or forest by-products. Size distribution is important to the
user -- some users demand smaller particle sizes than others. The
results of size distribution analyses conducted on yard trimmings
compost are presented in Table 4-4.
4 - 4
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Table 4-2
WATER-HOLDING CAPACITY OF VARIOUS SOIL AMENDMENTS
Amendment
Quartz sand
Clay loam soil
Yard trimmings compost
Yard trimmings compost
Peat moss
Water-holding Capacity
(percent dry weight)
28 \J_
44 \L
110 I/ 2/
115-138 I/
1,057
2/ Results of Portland's quarterly testing program.
Sources: I/ Portland Metropolitan Service District. A User's
Guide to Yard Debris Compost. Portland, Oregon.
June 1989.
3/ Sound Resource Management Group, Inc. Cedar Grove
Compost: User's Guide for Landscape Professionals.
Prepared for Seattle Solid Waste Utility. 1991.
4 - 5
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Table 4-3
BULK DENSITIES AND MOISTURE CONTENTS
OF VARIOUS SOIL AMENDMENTS
Bulk Density Moisture Content
Material (Ib/cu yd) (percent)
Redwood sawdust 200- 350 10-15
Wood chips 400- 600 15-20
MSW compost 500- 700 25-35
Yard trimmings compost 700- 800 30-50
Biosolids compost 900-1,100 25-35
4 - 6
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Table 4-4
SIZE DISTRIBUTION OF YARD TRIMMINGS COMPOST \J_
Screen Size: 1/3" 1/4" 1/5" 1/10" 1/25" 1/50"
Percent Passing: 95 85 78 60 34 20
I/ Results of Portland's quarterly testing program.
Source: Portland Metropolitan Service District. A User's Guide
to Yard Debris Compost. Portland, Oregon. June 1989.
4 - 7
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Nutrient Content
A top quality compost contains appropriate concentrations of
nutrients for a given use. The nutrients must be in a chemical
form so that they can be used by plants. Major plant nutrients are
nitrogen, phosphorus, and potassium (N, P, K) . Minor plant
nutrients (i.e., micronutrients) include copper, manganese, iron,
and boron. Examples of the concentrations of nutrients found in
compost and in some competing/complementary products are presented
in Table 4-5. Nutrient levels can be supplemented by blending
compost with higher nutrient sources (e.g., dried blood, bone meal,
and inorganic fertilizer) .
Level of Non-toxic Substances
The presence of some non-toxic substances may be considered
contaminants. These substances can be objectionable due to reasons
of public health and safety (e.g., glass shards) , environmental, or
aesthetics (e.g., bits of plastic). The level of these substances
considered acceptable will depend on applicable compost standards
and compost uses and users.
Level of Potentially Toxic Substances
Composted yard trimmings, municipal organics, mixed MSW, and
biosolids may contain substances that can be toxic to plants,
animals, and humans. Some of these substances are toxic in very
small concentrations. On the other hand, certain elements and
compounds not only are tolerated, but also are required by plants.
Examples of the concentrations of heavy metals and other
potentially toxic compounds found in composts from yard trimmings
and mixed MSW (including with biosolids) are presented in Tables 4-
6 and 4-7.
The data in Table 4-6 show that, with minor exceptions, the
yard trimmings compost tested had the lowest concentrations of
heavy metals. Although the information for mixed MSW compost is
the result of only one test, it shows that the material had
relatively higher concentrations of some metals. In particular,
mixed MSW compost had the highest concentrations of cadmium, lead,
magnesium, calcium, sodium, iron, and aluminum. The concentrations
of metals in compost made from mixed MSW and biosolids were, for
the most part, higher than the concentrations in yard trimmings
compost (see Table 4-8 for a list of various State standards on
heavy metal and PCB concentrations for compost uses).
Information on pesticides, herbicides, and other potentially
toxic compounds is shown in Table 4-7. The data show that the yard
trimmings compost contained some organophosphorus compounds and
chlorinated hydrocarbons. As compared to yard trimmings compost,
relatively high concentrations of PCBs were found in composts made
4 - 8
-------
Table 4-5
EXAMPLES OF NUTRIENT CONTENT LEVELS IN COMPOSTS AND SELECTED OTHER SOIL AMENDMENTS
(Percent dry weight )
Nutrient
Nitrogen
Nitrate
Ammonium
Phosphorus
Potassium
Sulfur
Calcium
Magnesium
Copper
Manganese
Iron
Boron
Zinc
Peat I/ Sawdust I/ Bark I/
0.004
Leaf
Compost
(Westchester
Vermiculite I/ County, NY) 2/
0.01
0.11
0.04
0.18
0.06
0.006
0.09
0.12
0.01
0.011
0.11
0.52
0.01
0.02
0.00
0.06
0.23
0.62
0.04
1.11
0.23
1.84
0.59
ND
0.0374
2.67
0.0015
0.0082
(continued)
-------
Table 4-5 (cent.
I
r-
O
Nutrient
Nitrogen
Nitrate
Ammonium
Phosphorus
Potassium
Sulfur
Calcium
Magnesium
Copper
Manganese
Iron
Boron
Zinc
Yard
Trimmings
Compost
(Portland,
Oregon) 1 /
0.0002-0.0008
0.0003-0.0052
Yard
Trimmings
Compost
(Twin Cities,
Minnesota) 4. /
0.57-2.14
0
0
0
0
0
0
0
0
0
.0085
.2062
.2504
.0566
.0002
.0066
.0100
.0000
.0016
-0
-0
-0
-0
-0
-0
-0
-0
-0
.0171
.3756
.4726
.0920
.0006
.0300
.0412
.0001
.0042
0
0
0
0
0
0.08
0.06
1.36
0.20
.0008
.0289
.1327
.0018
.0052
-0
-0
-4
-1
-0
-0
-0
-0
-0
.44
.88
.51
.16
.0018
.0583
.3848
.0082
.0167
Yard
Trimmings
Compost
(Seattle,
Washington) 5/
1.3-1.5
2.1
I/
0.35-0.50
0.53-0.72
0.74-1.15
0.15-0.19
0.0004-0.0006
0.0144-0.0158
0.0288-0.0310
0.0078-0.0094
Mixed
MSW
Compost
(Fillmore Co.,
Minnesota) 6. /
1.08
0.35
0.76
.49
7.60
0.58
0.02
0.03
1.32
.10
2.L Average of five samples.
I/ Results of Portland's quarterly testing program.
i/ Based on two sample sets taken at 11 sites in each of two years.
5/ Tested at 30-day intervals from initial curing through maturity
]_] Soluble nitrogen ranged between 0.3-0.8%.
-: Indicates tests were not conducted.
190 days)
(continued)
-------
Table 4-5 (cont.)
Sources: I/ Portland Metropolitan Service District. A User's Guide to Yard Debris
Compost. Portland, Oregon. June 1989.
2/ Richard, T. and M. Chadsey. Croton Point Compost Site: Environmental
Monitoring Program. Cornell University. Prepared for Westchester
County Solid Waste Division. November 1989.
3/ Portland Metropolitan Service District. Yard Debris Compost Handbook.
circa 1989.
4/ Schumacher, N.; M. DuBois; M. Martindale; C. Clapp; and J. Molina.
"Composition of Yard Waste Composts Produced at Twin Cities Metropolitan
Area Centralized Composting Sites." Soil Series #124. Department of
Soil Science, University of Minnesota, St. Paul, Minnesota. 1987.
5/ Sound Resource Management Group, Inc. Cedar Grove Compost: User's Guide
for Landscape Professionals. Prepared for Seattle Solid Waste Utility.
1991.
6/ Cal Recovery Systems, Inc. Portland Area Compost Products Market Study.
Prepared for the Portland Metropolitan Service District. Portland,
Oregon. 1988.
-------
Table 4-6
EXAMPLES OF CONCENTRATIONS OF TOTAL METALS IN COMPOSTS
(Parts per million)
M
Compound
Cyanide
Mercury
Arsenic
Cadmium
Chromium
Nickel
Lead
Magnesium
Calcium
Sodium
Iron
Aluminum
Manganese
Copper
Zinc
Leaf
Compost
(Westchester
Co., NY) 1 /
0.08
ND
10.46
10.08
31.70
5,900
18,400
2,300
26,700
33,800
373.76
19.14
81.60
Yard Trimmings
Compost
(Portland,
Oregon) 2/ 3/
A
0.15
0.05
4.80
0.80
24.20
21
72.90
2,500
10,500
200
13,500
7,800
396
25
160
B
0.08
0.08
5.20
0.80
21.60
22.70
71.50
2,600
10,300
200
15,000
7,000
3,390
42
160
Yard Trimmings
Compost
(Twin Cities,
Minnesota) 4. /
0.2-
2.5-
3.5-
10-
2,000-
13,600-
61-
1,327-
1,179-
289-
8-
52-
0.6
14.1
14.1
128
11,600
45,100
563
3,848
3,198
583
18
167
Mixed MSW
Compost
(Fillmore, Co.,
Minnesota) 3_ /
0.49
3.70
1.10
4.80
56
32.80
913
5,800
76,000
4,700
13,200
5,400
340
190
1,010
Mixed MSW
and Biosolids
Compost
(Delaware) 5. /
2.5
4.1
7.4
3.2
240.0
296.0
508.0
3,200
17,000
2,142
11,900
490
300
1,039
I/ Average of 5 samples.
2 / One sample; A and B represent composts from two separate composting facilities.
4/ Based on two sample sets taken at 11 sites in each of two years.
5. / Average of 32 samples.
NO.- Not detected.
-: Indicate tests were not conducted.
(continued)
-------
Table 4-6 (cont.)
Sources: !/. Richard, T. and M. Chadsey. "Croton Point Compost Site, Environmental
Monitoring Program." Cornell University. Prepared for Westchester County
Solid Waste Division, Department of Public Works. White Plains, New York.
November 1989.
3/ Cal Recovery Systems, Inc. Portland Area Compost Products Market Study.
Prepared for the Portland Metropolitan Service District. Portland, Oregon.
1988.
!/. Schumacher, N. ; M. DuBois; M. Martingale; C. Clapp; and J. Molina.
"Composition of Yard Waste Composts Produced at Twin Cities Metropolitan Area
Centralized composting Sites." Soil Series #124. Department of Soil
Science, University of Minnesota, St. Paul, Minnesota. 1987.
*• 5 / Delaware Solid Waste Authority. "The Delaware Reclamation Plant." 1988.
i Fairfield Service Company. "Fairgrow Easy Reference Chart." 1989.
-------
Table 4-7
EXAMPLES OF CONCENTRATIONS OF HERBICIDES,
PCBs, AND PCP IN COMPOSTS
(Parts per million)
PESTICIDES,
HERBICIDE/
PESTICIDE
Chlordane
p'p'DDE
p'p'DDT
O'p'DDT
Toxaphene
Aldrin
Dieldrin
Dursban
Endrin
Lindane
Malathion
Parathion
Diazinon
Trifluralin
Casoron
Dalapon
Dicamba
MCPD
MCPA
Dichloprop
2, 4-D
Silvex
2,4,5-T
2,4-DB
Dinoseb
Captan
PCBs
PCP
Leaf
Compost
(Westchester Co.,
New York) I/
0.0932
0.1810
0.0025
0.0052
Yard Trimmings
compost
(Portland,
Oregon) 21 31
A B
0.324
0.014
0.019
0.004
0.300
ND
ND
ND
Present
Present
<0.50
0.5-12.9
<0.5
0.5-7.1
<0.5
<0.5
<0.5
<0.5
<0.5
0.152
0.005
0.008
ND
0.300
0.007
0.019
0.039
ND
ND
ND
ND
ND
Present
Present
<0.50
<0.50
<0.50
<0.5-2.4
<0.5-1.2
<0.5
<0.5
<0.5
<0.5
<0.5-1.0 <0.5-1.0
Mixed MSW
compost
(Fillmore Co.,
Minnesota) 1 /
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Mixed MSW
and Biosolids
Compost
(Delaware) i /
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.210
ND
0.120
2.53
0.016
1.0-6.0
ND = not detected/below detection limit.
Hyphens indicate tests were not conducted.
PCBs = Polychlorinated biphenyls
PCP = Pentachlorophenol
I/
II
i/
Average of 12 samples.
One sample; A and B represent composts from two separate facilities
Average of 32 samples.
(continued)
4-14
-------
Table 4-7 (cont.)
Sources: I/ Richard, T. and M. Chadsey. "Croton Point Compost Site,
Environmental Monitoring Program." Cornell University.
Prepared for Westchester County Solid Waste Division,
Department of Public Works. White Plains, New York. November
1989.
3/ Cal Recovery Systems, Inc. Portland Area Compost Products
Market Study. Prepared for the Portland Metropolitan Service
District. Portland, Oregon. 1988.
4 / Delaware Solid Waste Authority. "The Delaware Reclamation
Plant." 1988.
Fairfield Service Company. "Fairgrow Easy Reference Chart."
1989.
4 - 15
-------
Table 4-8
EXAMPLES OF COMPOST STANDARDS FOR VARIOUS STATES
(Parts per Million)
State:
Feedstock:
Use: 1 /
Mercury
Cadmium
Nickel
Lead
Chromium
Copper
Zinc
PCS
Part, size (mm)
Foreign Material
Maturity
Florida
YT/LM
U 2/
<15
<50
<500
<450
<900
< 25
<2%
Mature or
Semi -mature
Florida
MSW
u
15
<50
<500
<450
<900
< 1 0
< 21
Mature
Florida
MSW
L2
<30
<100
<1,000
<900
<1,800
< 15
< 41
Mature or
Semi -mature
Florida
MSW
L2 1 /
100
500
1,500
3,000
10,000
< 25
< 10%
Mature or
Semi -mature
Florida
YT/LM/MSW
L4
100
500
1,500
3,000
10,000
< 25
< 10%
Fresh
Florida
MSW
L5
>100
>50
>1,500
>3,000
>10,000
(continued)
-------
State:
Feedstock:
Use : i /
Mercury
Cadmium
Nickel
Lead
Chromium
Copper
Zinc
PCB
Minne
MSW
U
5
10
100
500
1,000
500
1,000
1
Table 4-8 (cont.)
New Hampshire New Hampshire New Hampshire
YT MSW MSW
U 2/
Part, size (mm) < 10 ; < 16; < 25
Foreign Material 1.0%; 2.0%; 4.0%
Maturity Mature Mature
LI, L2 L3, L4 i / L4 5/
10
10
200
500
1,000
1,000
2,500
1
10
10
200
500
1,000
1,000
2,500
1
i/
(continued)
U
-------
State:
Feedstock:
Use: l /
Mercury
Cadmium
Nickel
Lead
Chromium
Copper
Zinc
PCB
New York
Msw
LI, L2, L3, L4
i/
10
10
200
250
1,000
1,000
2,500
1
New York
MSW
LI
10
25
200
1,000
1,000
1,000
2,500
10
Part, size (mm) <. 10
i Foreign Material
M Maturity !
oo
Table 4-8 (cont.)
North Carolina
MSW
U
10
10
200
250
1,000
800
1,000
2
North Carolina
MSW
L2
15
25
500
1,000
2,000
1,200
2,500
10
North Carolina
MSW
LI, L4
15
25
500
1,000
2,000
1,200
2,500
10
< 25
(if >10 and <. 25,
then Use = L4 )
11
25.(
Mature or
Semi-mature
(continued)
< 25.f
Mature or
Semi-mature
< 25.f
Mature,
Semi-mature,
or Fresh
-------
Table 4-8 (cont. )
l/ Use: U = Unrestricted distribution
L= Limited distribution:
1) Non-food chain crops
2) Commercial, agricultural, institutional, or governmental agencies
3) Public distribution
4) Land reclamation or landfill uses
5) Disposed 9f unless demonstrated that use does not endanger the public or the environment.
21 Not subjected to testing; yard trimmings compost is assumed to meet limits for contaminants.
I/ Cannot be used where contact with the general public is likely.
4/ Cannot be applied to crops grown for direct human consumption.
s/ This "off-spec" compost can be used as a landfill cover if the only difference between this compost and the
higher grade is that the particle size is > 10 mm.
However if any of the contaminant levels is exceeded, then the compost must be disposed of, even if the
particle size <. 10 mm.
6/ Must be produced from a composting process with a minimum active composting and curing period of 90 days.
?/ Must be produced from a composting process with a minimum active composting and curing period of 50 days.
YT = Yard Trimmings
*" LM = Livestock Manure
i MSW = Municipal Solid Waste
-= Not included in the standards
vo
-------
from mixed MSW and from mixed MSW with biosolids. Small
concentrations of PGP were found in composts made from yard
trimmings and mixed MSW.
Concentration of Weed Seeds
Prospective users of compost, particularly of yard trimmings
compost, invariably are concerned about the presence of weed
seeds. Even though, theoretically, weed seeds should be killed by
the heat generated during the composting process, composts should
be tested periodically for viable weed seeds, and the results
reported.
Seed Germination and Root Elongation
Seed germination and root elongation are used as indications
of the stability of the soil amendment. Generally, seeds of
timothy or water cress are used in this test.
Soluble Salts
Excessive levels of soluble salts can deteriorate the soil and
be harmful to many types of plants, especially if the salts
accumulate in the soil. On the other hand, the leaching of
excessive amounts of salt may be a concern to local ground water
supplies.
Ratio of Available Carbon/Nitrogen
As discussed in Chapter 2, the ratio of available carbon-to-
nitrogen of 15-20:1 generally indicates a stabilized compost,
although the significance of this ratio is dependent on the
material (s) composted and the C/N ratio prior to composting.
pH
In a composting operation, it is not necessary to adjust the
pH level of the composting material. Generally, the pH level drops
at the beginning of the composting process, at times to as low as
4.5 to 5.0. After a few days, the pH begins to rise, and
eventually reaches levels of 8.0 to 9.0. Unless the material being
composted is unusual, the pH of the finished compost will be in the
range of 6.0 to 8.0-9.0.
Color
The composting of practically every type of organic material
results in a darker color as the process advances. The organic
component of MSW, for example, changes from grayish green to black.
Similarly, wood chips, sawdust, and yard trimmings are darkened due
to the adsorption of the heavily pigmented humic acids. In some
4 - 20
-------
cases, producers of soil amendments add a compound specifically
designed to darken the finished product.
A deep, dark material is typically associated with stability,
maturity, and a high concentration of-organic matter.
Odor
Odor is a crude but effective means of monitoring the status
of the composting process. In a well-run operation, the
characteristic odor of the material being composted generally
disappears after a few days. The sequence of odors generated by
composting yard trimmings and MSW can often begin with foul odors,
which are followed by a period of aromatic smells, and ends with
earthy odors. Sometimes the earthy odors are preceded by the odor
of ammonia. The persistent presence of a strong earthy odor is a
good (but not absolute) indication that the composting process is
completed, and that the compost is mature.
Specifications for Bark Products
The National Bark and Soil Producers Association (NBSPA) was
established in 1971. The NBSPA is a non-profit organization that
was established to represent professional processors and packagers
of bark mulch and soil products. One of the primary objectives of
the NBSPA is to assist the industry and its customers in defining
quality products. As such, the organization developed categories
and product nomenclature for bark and soil. The categories and
nomenclature are presented in Table 4-9. As indicated by the
table, the specifications are limited to the definition of size
distribution and concentration of cambium and wood. In addition,
the Association has developed its own logo. Permission to use the
logo on packaged products is granted only to those processors who
comply with the specifications listed in the table.
Shredding woody materials can produce various grades (e.g.,
fine and coarse) of mulch. The composting process can be used to
prepare woody and vegetative materials into a better mulch product,
and in less time, than it would take to produce a humus product
(i.e., a mature compost). With the high temperatures achieved in
composting, weed seeds and plant diseases can be inactivated or
killed. In addition, the decomposition will darken the color of
the mulch produced, and more closely resemble commercially
available grades of mulch (1).
Examples of Compost Standards
To protect public health and reduce potentially harmful
environmental impacts, some States and Federal agencies, as well as
other countries, have established regulations and guidelines
controlling the use of composts. Examples of the regulations and
guidelines are given in Table 4-8 for five States in the U.S.
4 - 21
-------
Table 4-9
CATEGORIES AND NOMENCLATURE OF BARK AND SOIL PRODUCTS
Decorative Bark Products:
A.
c.
D.
A.
B.
C.
Southern Pine Bark Nuggets:
Southern Pine Mini -Nuggets :
West Coast Large Bark:
West Coast Medium Bark:
West Coast Pathway Bark:
Bark Mulch Products:
Southern Pine Mulch:
West Coast Bark Mulch:
Hardwood Bark Mulch:
Cypress Mulch A:
Cypress Mulch:
Consisting of Products
mechanically screened for
uniform size and containing
cambium or wood content equal
to 15 percent of less of total
product weight.
Particle size ranging from 1.25
inches to 3.50 inches in
diameter.
Particle size ranging from one-
half inch to 1.5 inches in
diameter.
Particle size ranging from 1.75
inches to 3 inches in diameter.
Particle size ranging from one-
half inch to 2 inches in
diameter.
Particle size ranging from one-
fourth inch to one-half inch in
diameter.
Consisting of products
mechanically screened or
shredded with cambium or wood
content limited in accordance
to the terms set forth, below:
Particle size less than 1.5
inches in length.
Particle size less than one
inch in length.
Particle size less than 3
inches in length with cambium
and wood content equal to 15
percent or less of total
product weight.
Particle size less than 3
inches in length with wood
fiber content equal to 15
percent or less of total
product weight.
Particle size less than 3
inches in length.
Source: National Bark and Soil Producers Association.
Nomenclature for Bark Products." 1989.
"Uniform
4 - 22
-------
The Council of European Communities! compost regulations are listed
in Table 4-10.
COMPOST TESTING REQUIREMENTS
Developing compost markets, particularly those produced from
yard trimmings, MSW, and biosolids, is also affected by the type of
product testing program established. The type, frequency, and
results of the tests can afford a certain degree of comfort to the
user. On the other hand, numerous and excessively frequent tests
can be financially prohibitive.
Although procedures for testing the parameters listed above
exist, a standard procedure for testing composts has not been
established across the U.S. Some government agencies that
encourage composting, such as the Metropolitan Service District in
Portland, Oregon, have established and are financing a testing
program. Tests are conducted on a quarterly basis. Some private
organic material processors and producers of compost conduct their
own tests and guarantee levels of nutrients and other constituents.
The tests that are most commonly conducted are those developed
for determining the concentration of plant nutrients and
potentially toxic compounds to plants, humans, and animals. Some
entities also are testing for maturity by using growth germination
tests and root length. Tests are also conducted for the presence
of viable weed seeds. The methods followed for conducting the
tests are those that have been developed over the years in the
wastewater treatment, soil, and agricultural industries.
In most cases, the tests are carried out by independent
laboratories typically paid for by the compost producer.
COMPOST DISTRIBUTION
The method and cost of transporting the compost from the
composting facility to the distribution center or to the user can
play a critical role in the cost-effectiveness of the composting
facility. Consequently, it is important to understand the various
factors that influence transportation. Some of the terms commonly
used in the transportation industry and that will be used in this
section include:
Consignor: the party that has something to ship;
Carrier: the hauler (trucking company, railroad,
barging company, etc.) ;
Consignee: the individual to whom the material or
goods are shipped;
TL : truck load;
4 - 23
-------
Table 4-10
COUNCIL OF EUROPEAN COMMUNITIES (CEC'S)
PROPOSED PHYSICAL AND CHEMICAL PARAMETERS FORtfSW COMPOST
APPLIED TO AGRICULTURAL SOILS
Recommended Mandatory
Element (mg/kg dry wt. ) (mg/kg dry wt.)
Mercury 5 5
Cadmium 5 5
Nickel 50 100
Chromium 150 200
Copper 300 500
Lead 750 1,000
Zinc 1,000 1,500
1987 Values Target Values
Minimum Organic Matter
(% drywt.) 1 / 30 40
Maximum Particle Size (mm) 1/24 24
Minimum Detention (days) 1 / Variable Variable
Maximum Moisture Content (%) 1/40 40
Maximum Inerts
(% of drywt.) 1 /
Glass 4 2
Plastic 1.6 0.8
Minimum
Minimum Mineral Content Admissible
(% of dry wt.) Levels
Nitrogen 0.6
Phosphorus 0.5
Potassium 0.3
Calcium Oxide 2.0
Calcium Carbonate 3.0
Magnesium Oxide 0.3
Carbon/Nitrogen Ratio <22 2. /
Conductivity <2 g salt/liter (NaCl)
pH 5.5-8.0
Allowable Uses 3 /
(continued)
4-24
-------
Table 4-10 (cont.)
Note: This is a partial summary. Refer to regulations for
additional or complete requirements.
I I Data reported represent 1987 values for medium grade compost;
other grades include very fine, fine, and coarse.
I I Applicable when starting materials have C/N ratio of 35-40 or
slightly above.
3.7 Allowable uses depend on the stage of stabilization, ranging
from fresh organic matter (e.g., unsuitable for agricultural
use, but possible substrate for composting, preparation of
mushroom compost, etc.) to cured compost (e.g., safe for
agricultural use) .
Source: Zucconi, F. and M. de Bertoldi. "Specifications for
Solid Waste Compost." BioCycle. 28 (5) :56-61. May/ June
1987.
4 - 25
-------
LTL : less than truck load; and
STN : short tons (2,000 pounds) .
Freight rates are commonly based on two major criteria: cost
and value of service. Cost is influenced by several factors
including:
distance;
shipping weight;
propensity to be damaged;
insurance costs;
potential to damage other commodities;
propensity for combustion or explosion;
ease or difficulty in loading and unloading;
stowability;
excessive weight;
excessive length of trip; and
frequency and regularity of shipment.
Once these factors are assessed as to how they affect the cost
of transporting, the carrier considers the value of service. The
demand for the transportation service is assessed and priced
accordingly.
Transporting recycled materials, in particular compost,
introduces additional complexities. Concern for the cost of
shipping a low economic value material arises. in some cases, the
shipping costs may exceed the economic value of the material being
shipped. Also, since recycled materials often compete with virgin
materials for markets, the freight rate structure could inhibit the
efforts of this and other types of recycling by charging more.
Furthermore, classifications stemming from a definition of the
nature and composition of the material can complicate rate setting
and can serve as a barrier to developing compost markets.
For motor freight, a commodity is classified according to the
National Motor Freight Classification (Classification Description) .
According to this classification, compost is classified as soil,
implying a low value. There are two class rates for compost:
Class 50 LTL and Class 35 TL. The minimum weight used to determine
rates for the material is 40,000 pounds.
A few States, such as Minnesota and North Carolina, have given
compost exempt status from standard classifications, deregulating,
and thereby reducing, the cost of transporting compost. Reduced
transportation costs will expand compost market development.
Rates for the transportation of compost and other soil
amendments via motor carrier generally are filed at the Public
Utilities Commission (PUC) or similar entity of each State.
4 - 26
-------
Motor Carrier
Bagged Compost. The rates usually are flat rates for a 24- to
25-ton truckload. Additional stops are charged at $25-$70 each.
The rates also include a certain amount of time for loading and
unloading (about one hour for each task) . Additional time
requirements for loading or unloading are charged at about $50 per
hour. There is a fee on the order of $25 per load for placing a
tarp over the vehicle's contents.
Typical costs for intra- and inter-State transportation of
bagged compost are presented in Figures 4-1 and 4-2. The graphs in
the figures show that the cost for the intra-State transport is
slightly lower than that for inter-State transport. Furthermore,
as expected, the rates are relatively high for short trips, on the
order of $0.13-$0.70 per ton-mile for trips from 6-50 miles. The
rates decrease to about $0.05 per ton-mile for hauls on the order
of 300 miles or longer.
Bulk Compost. Tariffs for the transportation of bulk compost
have not been established in most States. Estimates of the rates
for transporting bulk compost can be made by using rates charged
for transporting topsoil or composted biosolids as a proxy for
transportation rates for compost.
Topsoil or composted biosolids often are transported in large
dump trucks or in transfer trailers. These vehicles can haul from
20 to 50 cubic yards of material. Charges are assessed on an
hourly basis, and range from $35-$60 per hour. A cursory
nationwide study of rates for transporting compost show that the
rates vary from about $0.08-$0.47 per ton-mile for hauls of 50
miles or less. The rates fluctuate from $0.60 to $0.32 per ton-
mile for distances of 20 to 100 miles and decrease to about $0.05
per ton-mile for distances over 150 miles.
Railroad
Commodities shipped by rail are described in the Federal
Standard Transportation Commodity Code. Compost is not
specifically listed in the Code, but potting media and peat are
listed.
There are not many documented instances when potting media or
any other similar material have been transported by rail. In one
particular case, bagged material was transported about 200 miles.
The rate was $47 per ton for a minimum load of 20 tons, a rate
equivalent to about $0.24 per ton-mile. This rate is more than
four times as high as the cost of shipping a similar distance by
motor carrier.
Estimates for shipping 60-ton loads in box cars and 90-ton
loads in hopper cars range from $11-$17 per ton. These estimates
4 - 27
-------
3.5
c
o
\
o
o
0.3
02
•l
100 200
Trip Distance (miles)
300
400
Figure 4-1.
Intrastate motor carrier rates for bagged compost
(point of origin: Portland, Oregon)
Source: Cal Recovery Systems, Inc. Portland Area Compost
Products Market Study. Prepared for Portland
Metropolitan Service District. Portland, Oregon.
1988.
4-28
-------
§
\
a
o
O
02
100
200 300
Trip Distance miles)
400
500
Figure 4-2. Interstate motor carrier rates for bagged compost
(point of origin: Portland, Oregon)
Source- Cal Recovery Systems, Inc. Portland Area Compost
Products Market Study. Prepared for Portland
Metropolitan Service District. Portland, Oregon.
1988.
4-29
-------
do not include loading and unloading or any additional
transportation that may be required at either end of the trip.
Representatives of railroad corporations have indicated that
it is unlikely that rail transport would be more competitive than
trucks for trips under 100 miles. Generally, a railroad
corporation must have a serious commitment from the customer before
it files with the PUC for a new intrastate commodity rate.
Railroad class rates for materials for which a commodity rate has
not been filed typically are higher than those for motor carriers.
Shipping
In some instances, it may be possible to transport compost by
ship. The shipping can take place in containers or in bulk.
Containerized Cargo. If compost were to be shipped by
container, it would likely be placed in a 20 by 8 by 8 foot ("20-
foot") container with a 20.5 ton weight limit. Although 40 by 8 by
8 foot containers are also available, the compost would exceed the
weight limit before the container was full. Assuming a bulk
density of 800 pounds per cubic yard for compost, about 19 tons
would fit into a 20-foot container.
An official from the Port of Portland (OR) estimated that the
cost of shipping compost would likely be more than $1,100 per
container to Korea and possibly more than $2,000 per container for
other destinations such as India and Saudi Arabia. This is
equivalent to $58-$107.50 per ton. These costs do not include any
inland transportation, loading and unloading charges, or possible
"congestion surcharges" at the destinations (2) .
Bulk Cargo. The alternative to using containers is to
transport the compost in bulk in the hold of a ship. This method
appears to be less expensive than containerized shipping, although
there are many variables which affect the cost. Assuming a total
of 50,000 tons shipped annually in three equal shipments from the
West Coast to Korea under current conditions , one steamship company
estimated the cost at approximately $30 per ton (2) . This rate
assumes current market conditions and fuel prices. The rate
includes loading and unloading, and assumes a loading capability of
about 8,800 tons per day and a discharge capability of almost 2,800
tons per day. It does not include any inland transport.
The steamship transport market is highly volatile. Rates
decreased approximately 50 percent between April and December of
1988. Backhaul rates on steamships are unlikely to be obtained for
compost because little bulk cargo originates in the Far East
destined for the U.S.
Based on current regulations, the present status of the
transportation industry, and the value of compost, it is expected
4 - 30
-------
that transportation for bulk or bagged compost will be carried out
primarily by truck. Proximity to waterways may allow the use of
barges for U.S. transport. Transport of compost by rail may be
competitive in cases where: 1) both the composting facility and
the users are close to a railway; and 2) the distance between the
facility and the users is more than 100 miles.
COMPOST POLICIES
In this section, the various types of policies and regulations
that have been developed pertaining to compost purchase or use are
grouped into three broad areas: 1) those affecting the environment
and 'public health and safety; 2) those affecting composting
program implementation; and 3) those affecting distribution and use
of the compost product. Many of the policies have only recently
been developed (as of 1989) or are still in the developmental
stages.
Policies that protect the environment and public health and
safety are necessary to ensure a compost is safe to use. Policies
that affect composting program implementation are needed to
continue to encourage it as a municipal-level management
alternative. Policies-that affect compost distribution and use are
important to encourage market development of composts that are
produced.
Environment and Public Health and Safety
When policies and regulations pertaining to composting are
discussed, those that affect the environment and public health and
safety are particularly important. Examples of these types of
policies would be those that regulate the siting and operation of
composting facilities and those that affect compost quality.
Environmental and public health and safety regulations related to
the composting of yard trimmings and MSW generally have been the
responsibility of State and municipal governments.
Facility Control. Environmental and health and safety
requirements for composting facilities are often covered by the
regulations in effect for MSW disposal facilities. The primary
foci of the requirements are that the facility be located in a
environmentally suitable area, operated in a safe manner to protect
the environment and public health and safety, and that nuisance
control measures be taken when appropriate. Safety regulations in
the U.S. include fire safety procedures, such as the provision of
hoses and extinguishers around the piles and equipment. Nuisance
control measures generally include vermin and vector control, noise
and odor control, dust mitigation, and litter control procedures.
The length of time that noncompostables are allowed to be stored on
the facility grounds is often limited. Health and safety
requirements at yard trimmings composting sites are less stringent
4 - 31
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and specific than those for mixed MSW composting since these
facilities involve less machinery and handle generally less
putrescible materials. Also, they have a much less likelihood of
receiving household hazardous wastes.
Compost Quality. Compost quality is a function of the
biological, chemical, and physical characteristics of the product.
Efforts to regulate compost quality have approached the task in two
broad ways: 1) regulating the process; and 2) regulating the
finished product.
Control of the composting process begins with regulations
pertaining to acceptable feedstocks. "Incoming materials
contaminated with hazardous materials are not generally accepted
(nor desired) at facilities designed to compost yard trimmings or
MSW for use as an organic soil amendment (3). Source separation of
feedstocks, household hazardous waste collection programs, public
education, monitoring of feedstocks, and preprocessing of the
incoming materials are methods that can be utilized to limit the
potentially hazardous materials entering the composting process.
Legislation passed by the States of Florida and New York
provide examples of two approaches to controlling the feedstocks.
The State of Florida has legislated that household hazardous waste,
used oil, and materials containing asbestos should not be processed
into MSW compost except for small quantities which might normally
be found in household discards. It is the responsibility of plant
operators to reject any loads found containing the household
hazardous waste materials (4). Regulations have been developed by
the State of New York to limit the amounts of household hazardous
wastes entering mixed MSW compost by requiring that a household
hazardous waste collection system be in place in any residential
area serviced by a mixed MSW composting facility. The household
hazardous waste collection system must be approved by the New York
Department of Environmental Conservation and operated according to
the State's Solid Waste Management Facility Regulations.
Utilization of proper composting methods, especially
maintenance of high temperature levels, has been demonstrated to be
effective in destroying pathogens. Similarly, maintaining proper
temperatures during composting destroys weed seeds. At present,
most regulations pertaining to composting methods have been
developed for facilities handling biosolids. Some of these
regulations have also been adapted to MSW composting facilities.
A number of States have developed compost quality standards
which regulate compost products intended for distribution. Most of
the standards were originally developed for biosolids compost, and
adapted to yard trimming and MSW composts, although some are being
developed specifically for this latter group of products. In
addition, labeling standards could be developed so that users
become aware of the product content and quality.
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Regulations regarding the use of composted organic materials
have primarily centered around the public health concern of
possibly introducing potentially toxic compounds into the food
chain. Heavy metals, PCBS, pesticides, herbicides, and other
potentially toxic substances are present in some MSW and,
consequently, can be present in the compost. If this compost is
applied to the land or used as a growing medium in containers, some
amounts of the potentially toxic compounds could be assimilated by
plants and could possibly be transmitted to animals and humans
consuming the crops.
Most compost standards, therefore, limit the concentrations of
potentially toxic materials in the compost product. Regulations in
some States (e.g., Florida) provide different sets of limitations
depending upon the intended use for the product. Composts not
meeting the most stringent limits for toxic materials may be
restricted to use in non-food chain crops, or for land reclamation
or landfill uses.
The State of Florida, in its draft regulations, has developed
guidelines for compost products from yard trimmings, MSW, livestock
manures, and biosolids. In addition to establishing limits for
toxic materials, the State is setting standards for compost
maturity, maximum particle size, and foreign material content.
Standards for composts from yard trimmings and livestock manures in
Florida are less stringent than those for composts from MSW and
biosolids. It is assumed in the State that the concentrations of
heavy metals in yard trimmings compost will be within the limits
specified.
Although the kinds of policies discussed above were developed
to protect the environment and public health and safety, they can
also be a factor in the marketability of the compost product. A
product that can be demonstrated to meet limits for concentrations
of heavy metals, PCBS, herbicides, pesticides, etc., will be more
readily accepted by potential users than one with unknown
concentrations of these substances.
Composting Program Implementation
Policies encouraging the implementation of composting programs
have had a major impact on the increase in the number of composting
facilities. Examples of ways by which government agencies can
increase the number of facilities and thus the volume of materials
being composted are through the development of MSW management
plans, by giving preference in the plans to composting over
combustion and landfilling, by developing recycling goals, by
banning disposal of yard trimmings in landfills, fostering siting
of composting facilities, providing financing and tax breaks, and
compost procurement guidelines. As a result of these programs,
greater quantities of composts are produced and marketed.
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An evaluation of the various policies and programs that can
have an impact on composting has been carried out. The results of
this 1989 evaluation are presented in Table 4-11. As shown in the
table, most of the States in the Industrial, Midlands, Northeast,
and Pacific regions have MSW management plans currently in place.
In the Central region, only one State out of 14 currently has a
plan, and in the Southr only four out of 11. The method utilized
to enforce recycling goals established by each State also varies.
In the Northeast, most of the guidelines are mandatory and carry
with them penalties for noncompliance. Conversely, in the other
regions, the guidelines are mostly voluntary. The table also
presents information regarding the regions in which composting, as
a method to manage municipal organics, is higher on the municipal
solid waste management hierarchy than combustion. Not noted in the
table is the EPA hierarchy, where composting is higher in the
hierarchy than combustion and landfilling. Although relatively few
composting programs are in operation in the South region,
composting is higher on the hierarchy than combustion as a MSW
management method in over one-half of the States.
The State of New Jersey is an example of the effect policies
can have on composting program implementation. It was the first
State to ban leaves from landfills in 1988. The State now has the
largest number of leaf composting facilities. Since then, a number
of other States have passed similar laws, many of which are
scheduled for implementation over the next few years (see Table 1-
1) . Some States have enacted laws that require source separation
of yard trimmings (e.g., New Jersey and Pennsylvania)
Distribution and Use of the Compost Product
The need to protect the environment and public health and
safety has resulted in policies being developed to regulate
composting facilities and the quality of the finished product. The
growing problem and expense with siting MSW management facilities
has prompted policies aimed at increasing the number of composting
facilities in operation and the volumes of organic materials
composted. Among the three groups of policies being discussed,
those affecting the distribution and use of the product are the
least developed thus far.
As mentioned previously, because of its relatively low
economic value and its low bulk density, the method and cost of
transporting compost from the processing facility to the user is
critical to the marketability of the product. Giving exempt status
to compost for transportation can deregulate the rate charged for
shipment, that, as explained previously in this Chapter, leads to
reduced shipping costs.
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CO
en
Table 4-11
MUNICIPAL SOLID WASTE MANAGEMENT POLICIES
(July 1989)
IN THE SIX STUDY REGIONS
Category
Number of States
Number with MSWM I /
plans currently
in place
Number planning to
have MSWM 1 / plans
in place within
two years
Number of MSWM 1 /
plans providing
mandatory
guidelines
Number of MSWM 1 /
plans providing
voluntary
guidelines
Number which give
composting
higher priority
than combustion
Number which ban
landfilling of
yard trimmings
Central Industrial
14
Midlands Northeast
Pacific
3
2
South
11
(continued)
-------
Table 4-11 (cont.)
List of States
AZ
CO
ID
KS
MT
NE
NV
NM
ND
OK
SD
TX
UT
WY
DE
IN
MD
MI
NJ
OH
PA
WV
IL
IA
MN
MO
WI
CT
ME
MA
NH
NY
RI
VT
CA
OR
WA
AL
AR
FL
GA
KY
LA
MS
NC
SC
TN
VA
U)
1_; MSWM = municipal solid waste management.
-------
Procurement policies that would give preference to purchasing
or using compost, or recycled materials in general, in government-
funded projects could significantly encourage use of the product.
For some States, compost is considered a recycled material. In
California, a State mandate was issued requiring all State agencies
and departments to try to buy compost products if they meet State
specifications and needs.
Policies regarding bid specifications for materials needed by
governmental agencies can also have an effect on developing compost
markets. For example, recent acceptance of yard trimmings compost
as a soil additive by the New Jersey Department of Transportation
increases the potential uses for the product by the State (e.g., in
highway maintenance activities).
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Chapter 4
REFERENCES
Lehmann, T.R. and J.P. Bradshaw, "Over 200,000 Tons Diverted
Each Year." BioCYcle. 31(2):56-58. February 1990.
Cal Recovery Systems, Inc. Portland Area Compost Products
Market Study. Prepared for Portland Metropolitan Service.
Portland, Oregon. 1988.
Zucconi, F. and M. de Bertoldi. "specifications for Solid
Waste Compost." BioCvcle. 28(5):56-61. May/June 1987.
Criteria for the Production and TT.qe of Compost Made from Sol i d
Waste. Florida Department of Engineering Regulations.
Workshop No. 2, Draft Regulations. May 1989.
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Chapter 5
ECONOMIC AND NONECONOMIC BARRIERS
TO DEVELOPING COMPOST MARKETS
While it is important to understand the characteristics of
compost and the benefits from using compost, it is also necessary
to recognize the barriers to developing and/or expanding markets
for using compost. This chapter categorizes these impediments into
economic and noneconomic barriers. By addressing these barriers
(as discussed in Chapter 6) , the benefits from using compost can be
realized more easily.
ECONOMIC BARRIERS
Failure to Identify Potential Markets
Identifying potential markets for the compost product should
be a top priority and ideally should occur prior to actually
producing it. Identifying the markets is important because:
quality requirements for the compost can be determined;
multiple markets may require production of several grades
of compost;
projected amounts of various grades of compost can be
estimated;
pricing structures for various grades of compost and
purchase levels can be established; and
distribution strategies will help determine if bagging is
needed.
Failure to identify markets may result in overproduction or
underproduction of certain grades of compost. This can lead to
excessive stockpiling and shortages of storage space, or,
conversely, the inability to fulfill demand for certain grades of
compost.
Cost Pressures from Competing Products
Compost must be priced competitively (or cheaper) than
competing products. Manufacturers and retailers of competing
products are likely to reduce the cost of their products, if
necessary, to maintain their market share. In addition, competing
products have a reputation for consistency and quality and are
generally readily available. Therefore, if compost is not priced
competitively with competing products, not demonstrated to be of
equal or greater quality, and not available when needed, then its
ability to penetrate existing markets will be impaired.
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Post-processing Costs
Post-processing of compost (shredding, screening, blending/
mixing, bagging, etc.) , although intended to increase the value of
the product, is a potential economic barrier to penetrating certain
markets if it cannot be done cost-effectively. Post-processing
increases production costs which must be recovered through
increased revenues. It may not be necessary to post-process
compost if the primary market is for land reclamation or as a
landfill cover. On the other hand, if the market is nursery use,
for example, then very specific post-processing steps may be
desirable to remove unsightly, unwanted substances (e.g., plastic
film) . Other favorable attributes of a compost for nursery use
include freedom from potentially toxic substances, and suitable
particle size distribution, maturity, water-holding capacity,
organic matter concentration, etc.
Transportation Costs
The cost of transporting compost from the composting facility
to the user has an important influence on successfully developing
markets for compost. This is because compost has a low bulk
density, and is a relatively low value material. Therefore,
transporting compost over long distances may not be economically
viable. Consequently, if prospective markets are far away from the
composting facility, the cost of transportation could inhibit
successful market development of compost. (For a detailed
discussion of transportation costs, refer to the subsection
"Distribution" in Chapter 4.) This relationship between distance
and economic feasibility is a major and decisive factor in the
market development of compost. The longer the distance a product
must be transported, the greater is the cost of doing so.
Ultimately, a Point is reached beyond which it is not economically
feasible to transport the product.
Impacts of Competing Product Capital Investment
Not all equipment used for applying competing products is
suitable for applying compost. Consequently, potential users of
compost who currently use its competing products may have to make
capital investments for equipment suitable for applying compost.
NONECONOMIC BARRIERS
Compost Quality Assurance
Although it could be argued that, theoretically, a demand for
compost exists and only awaits to be tapped, the reality is that a
sizeable part of this potential demand is for a grade of product
higher than that of the "raw compost product." (The terms "raw
product" and "raw compost" pertain here to yard trimmings or
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municipal organics that have been fully composted in the absence of
special control measures and have not been post-processed, e.g.,
screened, for final disposition. This section deals with the "raw
product," because most serious shortcomings are mitigated by the
use of special separation and control measures and post-
processing.) The key factor that prevents "raw compost" (both yard
trimming and MSW compost) from meeting the requirements for the
full spectrum of potential uses, and hence its full market
potential, is insufficient quality assurance. Because yard
trimmings typically make a better feedstock than do other municipal
organics, this shortcoming is less serious with "raw yard trimmings
compost" than it is with "raw mixed MSW compost."
Meeting the full compost market potential demands that the
quality requirements established for three levels of use be met.
Listed in order of diminishing quality needs, the three levels are:
1) horticulture (container nurseries, landscape contractors,
greenhouses, home gardeners) ; 2) field-grown crops (row crops,
field-grown nursery plants, sod); and 3) land reclamation and
landfill cover. See Table 4-1 for the importance of compost
quality parameters to the needs of these three markets.
Horticulture. The following is an example of the list of
needs in the quality assurance category to be met in the production
of a compost suitable for utilization in horticulture: 1)
consistency in physical characteristics and chemical composition
and concentration, and pH levels within the range of 6.5-7.5; 2)
absence of particles larger than about one-half inch, weed seeds,
substances inhibitory to plant growth, microorganisms pathogenic to
plants and animals (including humans); and 3) presence of essential
micronutrients, and C/N ratios between 10/1 and 25/1 (nitrate-
nitrogen, N03-N, is preferable to ammonium-nitrogen, NH4-N) . These
three groups of needs may not always be satisfied simultaneously in
typical composting operations.
Field-grown Crops. Although the needs of field-grown crops
are less rigorous than those for horticulture, they may not
generally be met in typical composts. Reasons for the lower needs
can be traced to the fact that soil serves as a buffer between
plant roots and compost. There are three examples of needs which
the typical composting process might not always be able to meet
simultaneously. These are: 1) particle size less than one inch;
2) pH at 6.0-7.5; and 3) absence of toxic metals and resistant
toxic organics.
Land Reclamation/Landfill Cover. Despite the relatively
potential low quality and lack of quality assurance needs of
compost for land reclamation and for covering landfills, these
markets together may provide only a small fraction of the total
market needed.
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Compost User Attitudes
The attitude toward yard trimmings compost expressed in
previous market development efforts and studies is generally more
favorable than toward mixed MSW compost. An important factor is
the perception that yard trimmings contain no harmful or
objectionable components , and also tend to be source separated (see
Tables 4-6, 7, 8 and 10). This favorable attitude also is fostered
by the collective knowledge of experienced home gardeners. Concern
about plant pathogens is minimal because of the perception that
they are inactivated or destroyed in the composting process. There
is some concern about pesticide residues. The concern is minimized
because legal constraints have significantly reduced the use of
persistent or particularly hazardous pesticides. Time and
composting conditions effectively reduce and may even destroy the
permitted pesticides. With respect to the possibility of weed
seeds, most users are not aware of the fact that weed seeds are
typically inactivated by the composting process and by routine
product quality control (e.g., compost product testing).
Among large-scale consumers (e.g., agriculture, horticultural
and greenhouse enterprises, and local and State agencies) , and
among some small-scale users (e.g. , home gardeners) , the present
attitude toward mixed MSW compost may be characterized by a strong
hesitancy. The hesitancy is the result of: 1) the collective
justified and unjustified negative feelings of the public regarding
mixed MSW composting; and 2) a considerable skepticism and
uncertainty about the compost. The skepticism and uncertainty are
due in part to the general lack of experience with the product.
Because of this lack of experience, a record of continuity of
supply and reasonable uniformity of quality currently is not
available. The skepticism is further aggravated by the presently
insufficiently defined quality assurance. As one example,
skepticism leads to fear of losses from crop failure if the compost
quality is inferior.
Worries and doubts are traceable to the nature of the
feedstock used in mixed MSW composting and to the public perception
that the material is likely to have harmful components that would
become a part of the compost product. Only a long record of
satisfactory experience can convert skepticism into one of
neutrality, and then of a positive attitude. Considerable time may
pass before that record is developed, especially with regard to
large-scale users.
Locations of Markets with Respect to Compost Operations
The nature and characteristics of urban areas are such that,
with some exceptions, the distance between potential users and
composting facilities may be sufficiently great to exert a negative
effect on compost use and the attendant market development. This
situation arises, in part, from the logical tendency to site MSW
5 - 4
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management operations, such as composting facilities, as closely as
is feasible to the generators. The situation with yard trimmings
may be one of the few exceptions, especially those materials
generated from landscaping activities and light agriculture (e.g.,
nurseries and truck farms) . In this case, if composting facilities
are located close to these generators, potential compost users are
likely to be in the vicinity.
Distance exerts two totally different types of effects on the
use of compost. The first effect involves product acceptance and
recognition. Acceptance and recognition of composting and using
compost are necessary preludes to developing markets for the
compost product. The second effect is intertwined with
transportation -- bringing the product to the user.
proximity promotes awareness and recognition. Thus, a
potential user is more likely to know of a compost product produced
in his or her area than of one produced many miles away. This
awareness is a very positive factor favoring the market development
of the product, provided the composting facility is not associated
with unpleasant factors, such as bad odors, traffic congestion,
etc.
For the second type of effect, distance affects availability
of the compost product. The greater the distance, the more the
number of uncertainties. The number and seriousness of
interferences and interruptions between production of the compost
product and its delivery to the user increases with distance. More
importantly, distance may determine the size of the potential
compost market area and greatly influence the ability for market
expansion. The greater the market area, the longer time it may
take to reach the saturation point, i.e., the absorption capacity
of the compost market increases. Furthermore, the larger the
market area, the greater is the potential diversity of compost
users and uses.
In addition, there may be an incompatibility between the
urban area generation of organic materials and the oftentimes rural
nature of potential large compost markets. The difficulty is in
the fact that feed materials for the composting facility may mostly
be of urban origin, whereas large users of the compost product
often may be in a rural or agricultural setting.
Access to Transportation Routes
As stated earlier, access to transportation routes can become
a barrier to developing compost markets because users of the
product are not always in close proximity to the composting
facility. Therefore, before the compost product can be marketed,
it may need to be moved to distribution points that either are
close, or are readily accessible, to the prospective users.
5-5
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In keeping with the three applicable modes of transport, the
transport routes for developing compost markets in bulk are
highway, rail, and water. As described in Chapter 4, serious
competition of rail with truck transport could only occur if
changes were made to existing rail transportation policy. As for
water transport, it may be viable only for communities sufficiently
near navigable waters. Consequently, of the three routes,
currently the highway is perhaps the most available and practical
transportation route on a nationwide basis. Furthermore, with few
exceptions, the product would have to be hauled from the composting
facility to the railway or waterway by truck. The volume of
product per shipment and whether it is shipped in bulk or package
will determine the type and size of vehicle.
The barrier may be further magnified by doing the post-
processing step(s) at a separate facility. This is more likely to
be done if post-processing is expanded to include converting the
compost product into various fractions designed to meet particular
specifications for users in different areas (i.e., markets).
Moreover, such an expansion may be more useful for broadening the
market base of yard trimmings compost by providing more flexibility
in the products and their markets.
The impact of this transportation barrier on the market
development of MSW compost is much greater than that On the
developing markets for yard trimmings compost, simply because the
volumes of MSW compost involved are potentially much larger.
However, in contrast to the greater potential production volume of
MSW compost relative to yard trimmings compost, the actual current
production of yard trimmings compost greatly surpasses that of MSW
compost. Moreover, site restrictions and requirements for yard
trimmings composting facilities are generally less extensive than
MSW composting due to the different feedstocks and processing
steps, and they may be easier to site closer to transportation
routes.
Distribution of the MSW compost will most likely be confined
to bulk deliveries and involve large-volume transportation. AS a
result, as stated earlier, access to adequate transportation
becomes a decisive factor and, accordingly, lack of access can
become a substantial barrier to the developing markets for MSW
compost.
Comparative Availability of Compost
Although the number of yard trimmings composting operations
far exceeds that of MSW composting operations, most of the
individual facilities are comparatively smaller in Size and
somewhat seasonal in operation. Currently, the availability of
yard trimmings compost is highly localized. At present, the
availability of compost satisfies its demand in many areas. The
reason is that the extent of where yard trimmings are generated,
5-6
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and of gardening activity and associated use of composted yard
trimmings, are somewhat interdependent. Long-term availability of
compost is as yet somewhat uncertain, and will remain so until a
sufficient number of composting facilities have been in operation
for a reasonable length of time.
At present, the quantity of MSW compost on the market is
extremely limited and the continuity of supply (i.e., long-term
availability) is uncertain. This uncertainty reflects the current
status of MSW composting in the U.S. That is, no existing MSW
composting (excluding MSW co-composting) facility has been in
continuous operation longer than a few years. As a result of this
uncertainty, the long-term availability of MSW compost is far less
assured than that of competing products, unless and until the MSW
composting situation becomes better established.
Availability could also become a problem if use of high
quality compost products was more vigorously promoted without a
comparable increase in their production. On the other hand, an
oversupply of compost could also develop, such as if large amounts
of low quality compost were made and there were not enough low
quality markets (e.g., landfill cover) available.
Procurement Policies for Compost
Procurement policies relative to markets for yard trimming and
MSW composts are usually associated with those divisions of
Federal, State, and local agencies, public and private
institutions, large business enterprises, and other organizations
that use and procure soil amendments in the performance of their
landscaping and planting projects. These projects may range from
planting, landscaping, and highway right-of-way maintenance, to
land restoration and reclamation.
Usually the procurement policies applied are simple -- namely,
buy those soil amendments that are least expensive, most readily
available, have the most attractive and consistent properties, are
most convenient to apply, and are under no apparent public or
private prohibition. At present, compost may not be available in
many areas to completely satisfy the soil amendment needs of these
procurement agencies. However, with increased composting activity,
compost will become more available. What needs to be determined is
whether the compost will satisfy the other factors (e.g., users'
quality requirements) .
Restrictions on Compost Use
Various government restrictions on use of yard trimming and
MSW compost products are based on their potential impact on public
health and the environment. Particular restrictions are based upon
the level of contaminants, the potential impact on soil, water, and
air resources. Restrictions may be in the form of regulations,
5-7
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specifications, and standards imposed by Federal, State, or local
agencies, or simply may be those dictated by sound resource
management and by plant needs. The current Federal restrictions
pertain mainly to biosolids compost. Restrictions act as barriers
to compost use by way of placing limitations on the amount of
individual application rates, frequency of application, and time
span of an application program. Application limitations may also
be established for a substance introduced by way of the product.
Limitations on application rates based on the potential adverse
impact on a water resource may be determined by the relation
between the concentration of an available fertilizer element (e.g.,
N, P, K) in a soil plus that added by way of the compost and the
amount required by a crop. Generally, fertilizer elements not used
by a crop or otherwise immobilized in the soil are leached to the
ground water, run off to the surface water, or volatilize.
Legal Constraints
Other than a general prohibition against false advertising
(e.g., unfortified leaf compost marketed as a fertilizer), legal
constraints are those that prohibit the production and distribution
of any product which will exert an unduly adverse impact upon the
environment and public safety and well being. It is only
relatively recently that specific legal constraints have begun to
be imposed by individual States. These constraints have been in
the form of regulations regarding maximum permissible
concentrations of certain heavy metals and persistent potentially
toxic organic chemicals in biosolids compost. Standards regarding
weed seed content and degree of maturity are beginning to be set by
government agencies and private entities. However, State and
Federal agencies have been directing their attention mostly to
pathogen, heavy metal, and potentially toxic organic substance
concentrations.
Constraints that have posed the most serious barriers upon
compost use, and perhaps, thereby, compost market development, are
those relating to heavy metals and resistant toxic organics.
Because pathogens are substantially eliminated during the
composting process, the possibility of pathogens being present has
not constituted an insurmountable legal barrier. Federal biosolids
regulations regarding pathogen kill should be satisfied by adhering
to legal stipulations regarding attainment and duration of the high
temperatures during the composting stage (1) .
Legal constraints regarding heavy metals and toxic organics
have restricted the use and consequent market development of
biosolids compost. Mixed MSW compost use may be restricted to a
lesser extent because it too can potentially contain heavy metals
and potentially toxic organics, although generally to a lesser
degree than does biosolids compost. Because contamination with
heavy metals and persistent toxic organics is practically
5 - 8
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nonexistent in typical yard trimmings, very few legal constraints
currently exist regarding the use of yard trimmings compost.
Another legal constraint occurs during inter-State marketing
of compost. The problem is the lack of a uniform legal code (e.g.,
uniform definitions) . As of now, regulations may vary from State
to State. Because of distribution limits associated with
transportation (e.g., distance -- discussed in Chapter 6), this
constraint presently is not a great barrier, except perhaps in
regions along State boundaries and in relatively small States.
Strategies to overcome economic and noneconomic barriers to
increased compost market development are discussed in the following
chapter.
5-9
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Chapter 5
REFERENCES
1. 40 Code of Federal Regulations. Chapter 1 - Part 257,
Appendix II. July 1, 1988 edition.
5-10
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Chapter 6
STRATEGIES TO MITIGATE/OVERCOME BARRIERS
TO DEVELOPING COMPOST MARKETS
In order to take advantage of the potential benefits of using
compost (e.g., improving the soil, enhancing plant growth, and
protecting water resources), economic and noneconomic strategies
will likely need to be fostered and institutionalized at the local,
State, and Federal levels (1) . For example, with passage of the
1990 Farm Bill ("Food, Agriculture, Conservation, and Trade Act of
1990"), there will be a greater role for the U.S. Department of
Agriculture (USDA) in promoting the use of compost, especially by
farmers and the public.
The Farm Bill's section 1456 ("composting Research and
Extension Program") recognizes the potential soil, crop, and water
quality benefits from using compost. According to section 1456,
USDA will:
(1) make information on the potential uses of compost
available to appropriate Federal, State, private
authorities, and the general public;
(2) identify and compile information on State, local, and
foreign government definitions and standards for
processing, handling, and using compost;
(3) conduct research and an assessment of potential uses of
composts produced "on" and "off" the farm, and markets
for the compost;
(4) inform farmers and the general public on benefits of
using, and methods for applying compost; and
(5) consider designating composting as a farm conservation
practice eligible for cost-sharing.
While considering that economic and noneconomic barriers to
developing compost markets may exist, the experience of many
communities indicates that these potential barriers can often be
overcome. This chapter discusses strategies to overcome these
barriers, that will help to build successful programs to develop
and/or expand compost markets.
OVERCOMING ECONOMIC BARRIERS
Identifying Potential Compost Markets
Identifying potential compost markets requires surveying the
local area for those interested in its use and determining their
potential needs as to compost quality and quantity.
Diversification of compost products can increase overall market
opportunities. This allows post-processing and other compost
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production factors (e.g., quantities of different grades of
compost) to be adjusted to meet the markets' needs. Compost has
been successfully marketed in bulk and bag. Bulk sales are
typically for large volume users, and bag sales are typically for
small volume-users. Therefore, there is no single "best" method to
market a compost product.
All potential markets should be considered. In addition, new
uses and applications may be found within a community that were
previously ignored for various reasons, including the expense of
purchasing suitable soil amendments. Also, by identifying uses of
compost on public grounds and projects, communities can avoid the
costs of purchasing other soil amendment products. Experience has
shown that there are many beneficial applications for suitable soil
amendment products within a community that compost can satisfy with
very little (if any) additional cost and labor needed after it is
produced.
Also , compost marketers can promote compost to producers and
suppliers of competing/complementary products as a source of "raw
material" or an ingredient for their products. For example,
topsoil and potting soil producers can mix compost in with their
products to improve the organic content and provide a modest supply
of nutrients in the product. Properly cured compost would be a
suitable ingredient for many competing/complementary products. In
many cases, it may also be a cheaper input material. In many parts
of the country, topsoil is essentially a seasonally available
product. In other areas, adequate topsoil is simply not available
nearby. Therefore, mixing compost into topsoil could extend
existing supplies of topsoil and reduce the expense and need for
transporting topsoil from relatively distant sources.
Overcoming Cost Pressures from Competing Products
Some communities have offered compost free or at reduced
prices initially to attract users and markets. However, others in
the composting industry feel this tends to devalue the product in
the customers' mind (making it difficult to later charge a price)
and recommend that it be sold at a positive price to cover at least
some of the processing and/or transportation costs (2) . Whether or
not a price is charged may also depend on whether the composting
facility is a public or private operation (3). If a price is
charged, a pricing structure can be established to reflect the
purchase quantity and distribution method (3) (4) . For example, a
lower price can be charged to encourage customers to purchase
greater quantities of compost or pick up the compost at the
composting facility.
Recovering Post-processing Costs
Post-processing is generally performed to improve the quality
and/or increase the value of the compost. This may be done to meet
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the quality needs of a specific market, increase the compost's
ability to bear the cost of transportation, or simply to improve
its salability. Post-processing costs are a possible barrier, but
a potentially avoidable one if they are recovered through a higher
selling price for the compost product. The key, here, is to
recognize when and to what extent post-processing is necessary.
This requires an understanding of specific markets' needs as to the
characteristics of the compost (e.g. , particle size, pH,
distribution method, etc.).
If bagging is being considered, an evaluation of the increased
cost versus expected additional revenue should be performed. (As
a rough guide, the average price in 1988 for peat sold in bulk was
$18.14 per ton; for peat sold in packages or bales, the average
price was $24.68 per ton [5]). Wholesale and retail distributors
should be identified. Distribution networks may have to be
established. Transportation modes and costs must also be
considered.
Also, the effectiveness of source separation, the composting
technology used, and the quality control employed will likely
affect the need for, or level of, post-processing. Public
education, separate collection containers, inspection of incoming
compostable materials, and effective up-front facility separation
can prove useful here.
Mitigating Transportation Costs
Various means are available for reducing the cost of
transporting the compost product from the composting facility to
its potential users. Favorable transportation rate structures for
compost would potentially reduce its cost barriers and increase its
use. Thus , adjusting transportation rate structures, such that if
any rate inequities exist they are eliminated (or modified in favor
of the compost product) , could have a significant impact on
increasing compost use.
Shipping compost at lower backhaul rates is another method
that can lower transportation costs. Generally, backhaul rates are
set very low in many areas in order to utilize otherwise empty
return trips, attract freight for return trips, rather than
allowing vehicles to return empty to points of origin. Similarly,
if compost feedstocks (more appropriate for source separated yard
trimmings) are transported to a composting facility (especially one
in a rural site), finished compost could be returned to urban
markets or outlets in the same vehicles provided the vehicles are
cleaned as appropriate (e.g. , to reduce transmittal of weed seeds
to the compost).
It is also possible to increase the value of compost through
post-processing (e.g., by shredding, screening, blending, and/or
bagging) so that it is better able to bear the cost of
6 - 3
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transportation. This is currently done with many competing/
complementary products such as peat and potting soil. The bagged
compost can be given a brand name to develop product identity and
user loyalty. Benefits, uses, and instructions for the compost can
be printed on the bag.
Another means to reduce transportation costs is to locate the
composting facility at, or near, the primary users' location (s) .
This is a viable alternative if a user (e.g., a nursery or farm)
has suitable land area for the composting facility and this area
complies with composting facility siting requirements. Various
advantageous arrangements may then also be possible regarding
provision of labor, equipment, and land.
Finally, most transportation costs can be avoided if markets
are found and developed in the immediate local area. Often, one of
the best markets for compost is within the community in which the
yard trimmings or other municipal organics are generated. This
includes uses in parks, landscaping, home gardens, etc.
Overcoming Impacts of Competing Product Capital Investment
This potential barrier may be difficult to overcome.
Fortunately, it is not applicable to many of the potential markets
for compost. The problem is that even with various incentives to
purchase necessary compost application equipment, a capital outlay
is required, possibly idling some already purchased equipment that
was used for applying the competing product(s) . However, the
equipment used with the competing product(s) may have other uses or
resale value which allows some of the capital investment to be
recovered.
Many States have enacted incentives to encourage the use of
recycled materials, which may (or should) apply to the use of
compost. These include consumption tax credits, sales and property
tax exemptions, grants, and low interest loans. Tax incentives
generally apply to local and/or State taxes. They are an
inducement to invest in new capital but, by themselves, do not
fully compensate for the cost of investment. The same is true with
low interest loans. Grants will generally cover some or all of the
cost for application equipment.
In addition, since this potential barrier typically applies
to certain, perhaps large, users of compost, lower prices may be
offered for substantial purchases of compost.
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OVERCOMING NONECONOMIC BARRIERS
Providing Compost Quality Assurance
Two of the more important tasks, not only for developing a
market for the compost product, but also for maintaining it, are to
establish an acceptable set of compost standards and specifications
and to ensure that the product unfailingly meets those standards
and specifications. The latter task is particularly important
because, as discussed in Chapter 5, deviations in quality lead to
user frustration, and, with commercial users, possibly to financial
losses. Moreover, it is the only way to build a favorable record.
Progress in identifying and implementing measures that improve
compost quality assurance can be made by actively seeking
involvement from potential users on their specific needs and
biological, chemical, and physical qualities they believe are
important or essential. Compost users that should be consulted
include agronomists, farmers, home gardeners, horticulturists,
nurserymen, landscape architects and specialists, municipal and
State park officials, and university agricultural extension agents.
However, the gardening market is strongly influenced by
developments in horticulture-oriented industries. In addition to
the users listed above, public health and environmental protection
agencies and associated professionals should be included.
Arbitrary decisions should be avoided in establishing
specifications, standards, and directives.
Improving the quality of the "raw compost" product by
screening is accompanied by an increase in the size of the rejected
fraction and a lowering of the volume of marketable product. This
problem could be resolved by grading and developing markets for the
product into two or more quality levels, e.g., into top quality,
medium, and general or noncritical use. Another gradation could be
on the basis of unrestricted use (for all uses except perhaps food
crop production); and restricted use (e.g., use only for
reclamation of disturbed land areas or only as landfill cover) .
Several States have established at least one grade for compost, as
well as standards and specifications to be met by each grade (see
Table 4-9) .
Improving Compost User Attitudes
To compete successfully with other soil amendment products,
compost must be shown to be of equal or greater benefit and value.
It is important to stress the benefits of using compost (e.g.,
plant growth improvement, erosion reduction and water quality
benefits, and plant disease suppression) . If a quality compost is
consistently produced, over time it will be able to establish a
positive reputation, such as that currently enjoyed by many
competing products.
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The prevailing attitude toward most composts is generally
favorable. Not only have the many "virtues" of good quality
compost been widely recognized and publicized, they have also been
convincingly demonstrated in many areas. Compost demand can be
further increased by educating new users on the benefits of using
compost and providing application information (6) (7) . For the
present, once good quality compost has been assured, the next step
will be to expand the magnitude of compost production so large
quantities of compost are readily available and used.
There are two important aspects of developing markets for yard
trimmings compost. The first is to maintain a favorable attitude
toward it. An example of an action that could adversely impact
users' attitudes would be the addition to yard trimmings of street
sweepings that have been contaminated by glass shards, metals, and
a variety of other objectionable items. This could adversely
affect product quality and cause users to react unfavorably to the
use of the contaminated product. A favorable attitude can be
strengthened by applying quality assurance measures as discussed in
Chapter 4. Furthermore, working with university agricultural and
cooperative extension services and professional groups (e.g.,
landscapers, agronomists, and farm bureaus) to develop markets and
providing the public and others with technical assistance can
greatly influence compost product acceptance (4) .
The second is to expand the production of yard trimmings
compost to the highest level possible, while still ensuring the
continued availability of, and markets for, the product. In
addition to assuring a continuous supply, lists of suppliers and
their addresses, compost delivery arrangements (if any) , and price
could be made available to the public, landscapers, government
agencies, and others who would use the product. For example,
establishing a local telephone hotline to provide information on
availability, location, price, and use of compost would be helpful
in informing potential users.
Some users of mixed MSW compost have positive attitudes and
others have negative attitudes towards its use. Generally, there
currently seems to be more acceptance for its use for land
reclamation or as a landfill cover than for higher grade uses. For
marketers of compost to increase acceptance of the product, they
need to ensure: 1) the product meets specifications/guidelines
appropriate for the intended use ; and 2) that sufficient quantities
of the product are available for the intended use. This may be
followed by an intensive educational program and the best use of
promotion techniques (6) (7) . Refinements to the product, when
needed, must also be convincingly demonstrated so potential users
are sufficiently reassured as to the improvements. Finally, the
feasibility of making such a demonstration ultimately depends upon
the guaranteed availability of a mixed MSW compost product that
meets all specifications and standards.
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Identifying Locations of Compost Producers and Users
Compost producers should take full advantage of the
recognition factor that accompanies proximity to the composting
facility and which is so essential to successful market development
of any compost product. This can be done by properly operating the
composting facility so it does not become a source of nuisances or
adversely impact the quality of the environment in any way.
Recognition can be furthered through the use of demonstration plots
showing the beneficial effects of compost on plant growth and
production. Another means is to arrange tours of the facility for
the surrounding citizenry.
The negative effects of distance on availability can be
mitigated by establishing a strategic network of distribution
centers where an adequate inventory of compost is maintained. An
additional recourse may be to expand the demand for the product to
the fullest extent possible within the market area allowed by the
distance between the site of the composting facility and the
location of the users. Compost demand can be increased by finding
additional uses for the product or by modifying it to meet new
uses.
Near some of the larger urban areas, sufficiently large
markets for compost may be further away in the rural areas. If
this distance is too great, the cost for transporting the compost
may impede the development of markets in these areas. As a rough
guide, compost may be marketed within 40-50 miles from the compost
processing facility (8) (9) . However, the actual distance would
depend on the quality and value of the compost, form of sale (i.e.,
bag or bulk), access to transport arteries, and type and size of
transport vehicles.
Gaining Access to Transportation Routes
One approach to gain access to transportation routes is to
site composting facilities at, or close to, the primary compost
users, especially long-term, large users. Such locations could be
near farms, nurseries, parks, landfills, etc. Siting must also
take into account transport of the materials to be composted, as
well as the relative costs of land to be used for the composting
facility. As discussed above, strategically located compost
distribution centers may be cost-effective in reducing
transportation costs.
Increasing Comparative Availability of Compost
If the full potential use of yard trimmings compost could be
realized, matching product availability with the seasonal demand
for soil amendments could well become a problem. For the present,
availability of yard trimmings compost in some cases is inadequate,
at least as far as certain users are concerned; other areas are
6 - 7
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experiencing over-supplies of the compost. Very few retail outlets
offer yard trimmings compost, whereas the potential demand for the
product may be large. However, no such dearth of competing
products exists. For example, cow manure, enriched bark compost,
and peat may be available year-round.
Until more MSW composting facilities come into operation,
availability will continue to be one of the barriers to developing
markets for MSW compost. Since the characteristics of the products
are likely to vary between facilities, it is difficult to make
general predictions as to quality and utility. One would expect
that quantities would be greatest in highly urbanized areas because
of the proportionally greater volumes of organic materials
generated and consequently larger composting facilities.
Unfortunately, the potential use of the compost product in such
areas may be able to accommodate only a small fraction of the total
production capacity. Although it follows that unavailability would
no longer be a problem, over- availability could become a serious
one. Near relatively small cities, generation of the organic
materials and the production of compost could be more compatible
with that of demand.
Establishing Procurement Policies for Compost
procurement policies, public or private, that are biased
against composts should be revised by policies unbiased or
favorable to their use. Procurement policies can be implemented
that mandate equal or preferential treatment of composted yard
trimmings and municipal organics in the purchase of soil amendments
and mulches. This type of policy generally provides that the
compost in question be purchased and used if it is no more costly
than competitive materials and if it meets all product
specifications deemed essential.
Complying with Restrictions on Compost Use
The barriers "restrictions on compost use" and "legal
constraints" are closely intertwined. Consequently, many of the
statements made in this section could be applied to the following
section and vice versa.
There are several State laws that restrict compost use (e.g.,
see Table 4-9) . In addition, the EPA and many States have
regulated the use of biosolids compost. These restrictions on
compost use were generally imposed to prevent potential impacts
upon soil, water, and air resources that could adversely affect
public health, crop production, and overall environmental quality.
Because with few exceptions these restrictions are based on
demonstrated tests, first-hand experience, and objective analysis,
any attempt to lessen them to facilitate market development for the
compost product must be examined and evaluated with extreme care.
It should be emphasized, however, that this does not preclude a
-------
continuing evaluation and critical examination of the restrictions
by pursuing a program of careful research and reassessment of past
experience and findings.
Recognizing Legal Constraints
As the state of knowledge regarding compost use advances,
adjustments to compost use restrictions may be needed over time.
Legal constraints on the use of a product or material should be
based solely on the characteristics of that product and not whether
it is a recycled product or virgin material.
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Chapter 6
REFERENCES
1. Kashmanian, R.M.; H.C. Gregory; and S.A. Dressing. "Where
Will All the Compost Go?". BioCYcle. 31 (10) :38-39, 80, 82-83.
2. BioCvcle Staff. "The Present and Future of Compost
Marketing." BioCYcle. 26(5):34-36. July/August 1985.
3. Cox, K. "Expanding Markets for Yard Waste Compost."
BioCvcle. 29(10):64-65. October 1989.
4. Goldstein, N. "Marketing Strategy for Sludge Compost."
BioCvcle. 29(5) :42-43. May/June 1988.
5. Us . Department of Interior. Minerals Yearbook, Volume I:
Metals and Minerals, 1988. 1990.
6. Derr, D.A.; M.C. Varner; and G.J. DiLalo. "Marketing
Potential of Organic Based Fertilizers." BioCycle, 25(3):42-
45. April 1984.
7. Goldstein, N. "He Brings New Life to Compost." BioCYcle.
26(5):37-38. July/August 1985.
8. Alexander, R. "Expanding Compost Markets.'! BioCYcle.
31(8):54-59. August 1990.
9. Cal Recovery Systems, Inc. Portland Area Compost Products
Market Study. Prepared for Portland Metropolitan Service.
Portland, Oregon. 1988.
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Appendix A
EXAMPLES OF EXISTING PROGRAMS AND MARKETS
INTRODUCTION
Composting has become an attractive method in the U.S. to
divert organic materials (especially yard trimmings) from disposal
facilities and produce valuable end products. The number of
facilities in operation, or in the planning or construction stages,
is growing rapidly. The general status of yard trimming and MSW
composting in the U.S. is discussed in the following paragraphs.
Following that, information on the development of compost markets
is presented for a number of existing composting programs. The
information is divided by region, and is intended only to be
representative of the many composting programs and their
corresponding compost markets. The discussions are presented as an
overview of the types of compost market development efforts in the
Us .
Yard Trimmings composting
Composting yard trimmings has been practiced for many years in
the U.S. However, it was not until the late 1980s that this
practice began to attain widespread application. The following
factors are particularly responsible for the growing interest: 1)
recovery and utilization of yard trimmings is an effective means of
diverting substantial quantities of organic materials from
dwindling numbers of, and increasingly more expensive, landfills;
2) the material is easily composted; 3) the required technology can
be minimal; 4) the regulatory requirements have not been too
demanding; and 5) the value of the compost product.
Quantities of yard trimmings generated vary among regions.
The size of the contribution of yard trimmings to a community's
discards into disposal facilities. Results obtained in MSW
composition studies show that yard trimmings may comprise from 5-30
percent (by weight) . The relative contribution of yard trimmings
is also a function of season, climate, vegetation, soils,
population density, and affluence. Typically, the output of grass
clippings and brush is greatest from late spring until mid-autumn.
On the other hand, approximately 70 percent of the annual output of
leaves is typically collected in the autumn.
Composting leaves collected in the autumn is currently the
most frequent type of composting program in the U.S. (1) . These
types of composting programs generally utilize a low-technology
composting process. Market development efforts for leaf composting
programs are usually conducted during a short time period in the
spring and fall, because of the greater need for soil amendments at
those times.
A - 1
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A trend in yard trimmings composting is towards implementation
of more programs that process a mixture of yard trimmings (e.g. ,
leaves and grass clippings) during the year. These yard trimmings
composting programs generally require higher levels of processing
technology and more comprehensive compost market development
programs. Tree trimmings and brush require chipping or shredding.
In addition, improper composting of grass clippings can lead to the
generation of offensive odors.
The compost product is a valuable soil amendment, provided it
is free of objectionable, unwanted substances. It is a source of
organic matter and a modest supply of nutrients.
Municipal Solid Waste Composting
MSW composting was given consideration as a management process
in the U.S. as early as the 1950s. However, in the 1960s, several
factors combined to discourage the prospects for MSW composting.
The primary factors included: 1) an absence of a market for the
compost product; 2) the very low cost of landfill ing; and 3) the
high carbon/nitrogen ratio of MSW in the U.S.
Composting municipal organics, as well as co-composting MSW
with biosolids, currently is receiving a substantial amount of
attention in this country. As of Fall 1989, seven full-scale MSW
composting or co-composting facilities were in operation (2) .In
addition, approximately 40 other facilities were in the planning,
design, permitting, construction, or pilot-scale operation stage.
Table A-l presents a summary of these facilities by region.
With the current high degree of interest in MSW composting,
institutions or agencies should also be cautious before
implementing these programs. If a composting program is
implemented without a full understanding of the MSW stream and the
process itself, problems can be encountered during operation, in
producing a high-quality product, and in developing compost
markets. The quality of the finished product greatly depends upon
the type, efficiency, and thoroughness of the separation process
(including source separation), as well as process and product
guidelines or regulations.
The seven full-scale MSW composting facilities in operation in
the U.S. in 1989 are listed in Table A-2. Capacities of the
facilities range from about ten to a few hundreds of tons per day.
Little detailed information is currently available on the quantity
or quality of the finished compost produced at most of these
facilities. Their output of compost has typically not been
sufficient to permit a long-term definition of the market for their
respective products.
A-2
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Table A-l
STATUS OF MSW COMPOSTING/CO -COMPOSTING
FACILITIES IN THE U.S. (FALL 1989)
Region
Central
Industrial
Midlands
Northeast
Pacific
South
Totals
Consideration Planning 1 /
0
3
10
7
2
4.
26
4
4
16
8
3
6.
41
Operational
0
1
4
0
1
1
Total
4
8
30
15
6
11
74
I/ Includes planning, design, permitting, and construction
stages, as well as pilot-scale or research facilities.
Source: Goldstein, N. "Solid Waste Composting in the U.S."
BioCycle. 30 (11) :32-37 . November 1989.
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Table A-2
OPERATIONAL MSW COMPOSTING/CO-COMPOSTING
FACILITIES IN THE U.S. (FALL 1989)
Location
Delaware
Wilmington
Florida
Sumter County
Minnesota
Fillmore County
Lake of the Woods
County
St. lCloud
Washington
Skamania County
Wisconsin
Portage
Type of System
In-vessel
Windrow
Windrow
Windrow
In-vessel/drum
Windrow
In-vessel/drum
Material Added
to MSW
Biosolids
None
None
None
Biosolids
None
Biosolids
Source: Goldstein, N. and B. Spencer. "Solid Waste composting
Facilities ." BioCYcle. 31(l):36-39. January 1990.
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Composting Other Organic Materials
In addition to programs that compost yard trimmings and the
other municipal organics, a number of programs have been
established throughout the U.S. to compost other organic materials.
Examples of these materials include horse manure, dairy manure,
chicken manure, potato processing by-products, and seafood
processing by-products. These types of programs are generally more
limited in number and tend to be much more dependent upon the types
of local industry and the types of organic materials these
industries produce.
EXAMPLES OF COMPOSTING PROGRAMS BY REGION
Central
The Central region consists of the largest number of States
(14) and has a total population of approximately 39,000,000. The
States which comprise this region are: Arizona, Colorado, Idaho,
Kansas, Montana, Nebraska, Nevada, New Mexico, North Dakota,
Oklahoma, South Dakota, Texas, Utah, and Wyoming.
The States in the Central region have the fewest active
composting projects. This may be due to the fact that the region
covers a large area of land that is not densely populated. In
addition, the landfilling cost is relatively inexpensive and there
is an absence of legislative measures discouraging landfilling.
The Central region has a sizeable agricultural industry which could
absorb compost products.
Boulder. Colorado. Boulder County and the City of Boulder
have supported a wood chipping project since 1985. Woody material
is collected during the regular "spring cleanup" program. The
material is processed through a tub grinder and reduced to wood
chips from one to three inches in size. During 1986, the project
diverted 9,000 cubic yards of woody material from the landfill, and
produced 3,250 cubic yards of wood chips (3) (4) .
Lincoln, Nebraska. A program was begun in June 1988 to use
"biodegradable" cornstarch plastic bags in the collection of yard
trimmings for composting. The compost from the program's first
year was unmarketable due to the presence of nondecomposed bag
pieces, so it was spread on a closed landfill and disked in.
The City has an agreement with the University of Nebraska to
conduct tests on the bags and the compost. The series of tests
also include an analysis of pesticides and herbicides in the
leachate. Local nurserymen, landscapers, and sod farmers have
expressed an interest in using the compost (5) .
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Omaha, Nebraska. The City of Omaha is using a closed landfill
as a site for a pilot-scale yard trimmings composting program. In
1987, the breakdown of the yard trimmings accepted was 60 percent
leaves and 40 percent tree trimmings and other yard trimmings. In
1989, most of the material collected was grass clippings.
In the past, the material has been stockpiled at the landfill
from April to November. Then in November, the materials are
shredded and put into windrows. The windrows are turned twice
during the composting process with front-end loaders.
In 1987, all of the compost product was used by the City's
Parks Department. Currently, the finished compost is taken to a
central park in bulk form, where residents can pick up the product
free of charge. The material is used primarily as a mulch and soil
amendment (6) .
Industrial
The Industrial region consists of eight States and, except for
the South, has the largest population of the regions defined for
the study -- 52,000,000. The eight States are: Delaware, Indiana,
Maryland, Michigan, New Jersey, Ohio, Pennsylvania, and West
Virginia.
The MSW management policy for the State of Michigan
establishes a range of 8 to 12 percent as a goal for diverting yard
trimmings from disposal by composting. In early 1989,
approximately one percent of Michigan's MSW was being composted in
about 100 leaf and/or yard trimmings composting programs throughout
the State (7).
The State of New Jersey has the largest number of leaf
composting facilities in operation. As of March 1988, there were
175 operational leaf composting facilities in the State (8) . The
primary end uses for leaf compost are: residential gardening,
topsoil companies, nurseries, and public works and parks
departments. Other uses include land reclamation and landfill
cover. Most municipalities in New Jersey are giving the compost
away to residents and charging a nominal fee to bulk users (9) .
Wilmington. Delaware. The Delaware Reclamation Plant in
Wilmington is owned by the Delaware Solid Waste Authority and has
been operational since 1984. The facility is designed to process
about 1,000 tons of mixed MSW per day. Processing includes size
reduction, air classification, magnetic separation, and screening
to recover metals and glass and to produce a refuse-derived fuel.
In addition, the process also generates about 225 tons of residue
(primarily paper and plastic). The residue is mixed with an equal
amount of biosolids (about 20 percent total solids) and then
introduced into one of four reactors for composting. The material
is held in the reactor for five to seven days during which time it
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is mixed and aerated. The humus from the reactors is dried to
approximately a 15 percent moisture content and then screened to
remove plastic, glass, and metallic particles. The screened
product is pelletized for marketing.
Early analysis of the compost produced by the facility
indicated that the material contained PCBS in the range of 4 to 5
parts per million. These concentrations ruled out the original
plan to market the product as poultry litter. Present markets
being developed include horticulture, lawn fertilizer, and
hydroseeding operations.
The product was brought to market in 1989 under the name
"Fairgrow." The facility has received a permit from the Department
of Natural Resources and Environmental Control to sell the compost
to landscapers, nurserymen, and groundskeepers at large
corporations, cemeteries, golf courses, schools, etc. The product
is not permitted for sale to the general public in Delaware and
cannot be used on vegetable gardens because of regulations on heavy
metal content in the compost.
The selling price for the compost in 1989 was $4.50 per cubic
yard; delivery cost is provided at an additional cost. To
encourage first-time users, the operator, Fairfield Service
Company, offers the first truckload (up to 20 cubic yards) free of
charge. Printed materials are provided to users which include a
description of the product, its properties, uses, application
rates, and restrictions (10)- (15) .
Montgomery County. Maryland. Montgomery County received
18,200 tons of leaves for composting in windrows in 1989. A
windrow turning machine is used to turn the piles. The compost is
screened and is tested for weed seeds and heavy metals. The
finished compost is sold mainly to landscapers and nurseries for
$7.50 per cubic yard, in minimum loads of 10 cubic yards. Peak
market demand for the compost occurs in the spring. The fall
season is the second highest demand period. Compost not sold in
the spring may need to be stored at the composting facility for up
to six months to be sold through the fall.
In summer 1989, the County undertook a pilot program to add
grass clippings to its leaf composting program. With the inclusion
of grass clippings, the County will monitor the finished compost
for pesticide content (16).
Traverse City. Michigan. After an ordinance was passed in
1986 which banned the burning of combustibles within City limits,
a leaf composting program was started in 1987. Loose leaves are
collected and formed into windrows. Traverse City plans to
incorporate grass clippings and possibly fruit processing by-
products into its composting program. The City plans to sell the
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compost to the public in bulk form (by the cubic yard, the bushel,
or pickup truck load) (7) (17).
Essex County. New Jersey. In 1987, Essex County, New Jersey
set up a leaf composting program to process the leaves generated by
approximately 12 towns in the County. In addition to the central
site, 9 or 10 municipal sites are also operated in the area.
Incoming loads are monitored at a gate, and only clean loads
are accepted. Plastic bags are not allowed, although paper bags
are. During the 1988-89 season, approximately 60,000 cubic yards
of leaves were brought in, and 15,000 cubic yards of compost were
produced.
The County composts the leaves in windrows. During the first
year of operation, the piles were turned with a front-end loader.
A windrow turner was purchased during the second year. The leaves
undergo 12 to 16 months of processing, and are turned three to five
times during this period. No screening or other post-processing is
done.
Prior to beginning the program, the County and towns agreed
that each town would be responsible for taking their "share" of the
finished compost. The share was estimated to be approximately one-
third of the volume of leaves dropped off at the site. This ratio
was later changed to one-fourth because a larger reduction in
volume was experienced than originally anticipated.
The towns are provided with a list of approximately 15 markets
that would take the compost for free (or at a nominal cost of $1
per ton) if delivered. Most of the markets on the list are
farmers. The list also includes an urban gardening program h
Newark and use by the landfill for revegetation and landscaping
(not cover) . A large share of the compost is used by the towns
themselves. According to the County, the problem is not in finding
a market for the material; the problem is in getting each town to
transport its share to the available market.
No laboratory analyses have been conducted on the product. No
restrictions are placed by the County on the use of the product
because they feel the compost belongs to each of the towns, rather
than to the County. According to a County representative, if a
higher quality compost was produced, it could be more attractive to
residents and would be easier to market (18) (19).
Franklin Township. New Jersey. Middlebush Compost, Inc. has
been composting leaves in Franklin Township since early 1987.
Because of restrictions imposed by the State Department of
Environmental Protection, the facility is only allowed to accept
leaves as feedstock for the composting operation. TO maintain a
quality end-product and keep processing costs down, the facility
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does not accept leaves in plastic bags. The finished compost is
passed through a three-eighth to half-inch screen.
The leaf compost is subjected to a range of laboratory
analyses including pH, organic matter content, and a range of
nutrients (see Table A-3). These results are published and made
available to prospective buyers. Middlebush Compost has also
developed instructions for the application of the product and makes
this information available to buyers as well. Recommended
application rates and instructions vary depending on the intended
use of the product.
Middlebush Compost, Inc. was selling compost at $10 per cubic
yard screened and $6 per cubic yard unscreened in 1989. About 20
percent of the compost was used by a landscaper who combined it
with soil to make topsoil. The remaining 80 percent was sold to
other landscapers, developers, nurseries, garden centers, and
homeowners for use as a potting soil, a soil amendment, or as mulch
for water retention and weed control, and was also used to cap
landfills. In order to establish markets, at first the company
gave the product away and conducted a full marketing campaign. By
the end of 1989, they were able to sell all of their product. In
order to fully meet market demand, the company would like to
increase production (20)- (22) .
Parlin, New Jersey. Alternate Disposal Systems, Inc. (ADSI)
shreds tree stumps and other woody materials from over 100
communities. Following its shredding process, ADSI Sells fine
mulch for $12 per cubic yard, coarse mulch for $10 per cubic yard,
and topsoil (attached to the stumps) for $10 per cubic yard,
primarily to landscapers. ADSI also sells fill material (from
crushed rock) (23) .
Wrightstown. New Jersey. Woodhue, Ltd., operates a privately-
run facility in Wrightstpwn, New Jersey to compost various mixes of
leaves, brush, tree trimmings, food processing by-products, and
livestock manures. Unwanted substances are hand-picked from the
incoming material. The feedstocks are placed in windrows where
temperature is monitored to determine the turning frequency.
Laboratory analyses are conducted at the beginning, middle,
and end of the composting process. On-going analyses include
testing for pH, heavy metals, and nutrient content. Other
analyses, such as for herbicides and pesticides, are conducted
periodically.
The compost is passed through a trommel screen to improve the
quality of the product. The finished compost was being sold for
$12 per cubic yard in bulk, excluding cost of delivery in 1989.
Markets were agriculture, residential home gardening, and
commercial users (nurseries, landscapers, etc.) . The New Jersey
Department of Transportation has recently accepted the compost
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Table A-3
TEST RESULTS - MIDDLEBUSH COMPOST, INC.,
FRANKLIN TOWNSHIP, NEW JERSEY
Soil
Properties
Color
pH
Organic matter (percent)
Specific conductance (CEC),
micromhos/cm
Texture I /
(USDA Classification)
% Sand (2.0-0.05 mm)
% Silt (0.05-0.002 mm)
% Clay (<0.002 mm)
Available nutrients:
(Ib per acre)
Nitrogen (N03 and NH4)
Phosphorus
Potassium
N03
NH4
Ca
Mg
Zn
Fe
Mn
B
— S04
Cl
cu
Total carbon
Total nitrogen
C/N ratio
Leaf Compost
Mixed with Sand
Dark gray brown
7.3
18.0
300
Sandy loam
76
20
4
51 (medium)
33 (medium)
205 (high)
15.7
35.3
2,255
42
29
107
19
7
19
14
7
10.1
0.75
13.5/1
Leaf
Compost
Black
7.8
51.0
730
Organic soil
60 (medium)
36 (medium)
150 (medium)
26.8
33.2
2,290
19
20
59
33
16
30
39
3
28.3
1.66
17/1
I I The texture was tested by the hydrometer method. The soil
separates (particles) listed "here reflect the size
distribution of the inorganic as well as the organic
fractions.
Source: Middlebush Compost, Inc.
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product as a soil additive. Use by counties and municipalities in
the area is being explored (24) (25) .
Cleveland. Ohio. The Greater Cleveland Ecological Association
serves 16 communities, operates six composting sites, and composts
approximately 250,000 cubic yards of leaves in windrows each year.
Laboratory analyses have been conducted on cation exchange
capacity, pH, heavy metals (lead and cadmium) , and nutrient content
(nitrogen, phosphorus, and potassium) by the Ohio State University.
The Association sells compost in four ways:
1. Bag and bushel--people bring their own containers; cost
is $0.75 per bushel.
2. Bulk load pickup--customers' trucks are loaded for
$13.50 per cubic yard.
3. Home delivery--2 cubic yard minimum, 10 cubic yard
maximum, sold at $55.10 for 2 cubic yards and $178.30 for
10 cubic yards including delivery and taxes. For out-of-
County delivery, there is an added $20 charge.
4. Bagged in plastic one-cubic yard bags. These are sold
through distributors who deal with the nursery and
landscaping industries.
A discount is given for semi-truckloads delivered to
landscapers and commercial growers to encourage the use of compost
on lawns and in potting media for nursery stock. All of the
compost has sold out every year.
The Association has plans to begin a pilot program to compost
mixtures of wood chips and grass clippings. Prior to
implementation of the program, they will subject the_ grass
clippings to laboratory analysis for pesticides. The finished
compost will also be tested to determine how the chemicals are
broken down during the composting process (26) (27) .
Toledo. Ohio. In 1987, the City disposed of 40 percent of its
leaves, used 10 percent unprocessed, and gave away 50 percent
unprocessed. In order to conserve landfill space, a full-scale
effort to obtain users for all of the unprocessed leaves was
launched. As a result, in 1988, 100 percent of the 300,000 cubic
yards of loose leaves collected were given away. Approximately 90
percent of that amount was delivered to a quarry under an agreement
with the City to take at least two-thirds of the leaves collected
during the three-year period, 1988 to 1990. The quarry has
purchased a shredder and is composting the leaves for land
application.
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The City offers to deliver leaves free of charge to large
users near Toledo. In addition to the quarry, users include a
large greenhouse operation that composts the leaves and uses them
as a soil amendment. A large canning operation located in Toledo
has also agreed to accept leaves for agricultural use (28) (29) .
Allegheny County. Pennsylvania. Mount Lebanon, in Allegheny
County, has been composting leaves for 17 years. The leaf
composting operation averages over 10,000 cubic yards per year.
Compost produced is used in parks and on the City's golf course,
and is sold to residents for approximately $.50 per bushel.
Allegheny County is planning to set up a series of composting
areas in City parks. Finished compost would be made available to
municipalities and Parks Departments. Municipalities could use the
compost or sell it to residents (30)-(32) .
Midlands
Illinois, Iowa, Minnesota, Missouri, and Wisconsin are the
States comprising the Midlands region. The five States have a
combined population of approximately 29,000,000.
In the State of Illinois, composting is one of the alternative
methods for dealing with MSW that is being encouraged. A report
issued by the Illinois Department of Energy and Natural Resources
states that an estimated 70 percent of the State's MSW stream is
compostable. The following components are included: yard
trimmings, other municipal organics, biosolids, livestock manures,
and agricultural residues (33) .
Chicago. Illinois. During 1987, Chicago experimented with
approaches to composting yard trimmings by windrowing various
combinations of grass clippings, leaves, and brush. in the fall of
1988, 700 tons of leaves were collected and composted in windrows.
During 1989, the City expanded its pilot testing to include: grass
collection tests, paper bag collection and processing, and
"biodegradable" plastic bag collection and processing. The
feedstocks to the test programs have been brush chips, grass
Clippings from early spring 1989, and leaves from Fall 1988.
Laboratory analyses of the compost from the test programs have
been conducted by the University of Illinois. Tests include heavy
metals, herbicides, pesticides, and nutrients. In addition to
these analyses, growth tests will be undertaken by the University.
On July 1, 1990, State regulations went into effect that ban
yard trimmings from landfills and require source separation of
these materials by homeowners. The City planned to implement a
full-scale program to compost grass clippings and tree trimmings by
that time (34)- (36) .
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Urbana and Champaign. Illinois. An Intergovernmental Solid
Waste Disposal Association has been formed by the neighboring
cities of Urbana and Champaign, and by Champaign County. The
Association agreement requires that the three member agencies fund
and operate a yard trimmings recovery facility that was begun in
1986 by the City of Urbana.
In 1987, the facility received and processed 5,200 tons of
yard trimmings from residents and landscapers from the two cities
and the County. The facility processes incoming brush into wood
chips, heavy wood into firewood, and leaves and grass clippings
into compost. The incoming brush is shredded by a tub grinder.
The resulting wood chips are sold retail to individual customers or
wholesale to landscapers, nurseries, and greenhouses. Large pieces
of wood (more than 6 inches in diameter) are split into firewood
and sold to the public.
The leaves and grass clippings are placed in windrows and
composted for use as mulch. The City of Champaign also collects
bagged leaves during the fall and Christmas trees for inclusion in
the composting operation. The compost is available free of charge
to the public, cities, and parks. It is sold to wholesalers,
landscapers, and nurseries. During the fall of 1988, the City of
Urbana introduced a curbside yard trimmings collection program
using cornstarch plastic bags (37) (38).
Will and Lake Counties. Illinois. Land and Lakes Company is
currently operating three leaf composting sites using the results
of a Rutgers University leaf composting research project as a basis
for its operations. About 300 cubic yards of leaves are processed
each week in windrows. The windrows are turned often, and moisture
is added to accelerate the composting process.
The finished compost product is named "Compsoil." It is
available free of charge to residents, and is also used as landfill
cover. The County plans to implement a program in which compost
will be available free to residents who drop off yard trimmings at
the landfill, at a ratio of 4-to-l by volume.
Some preliminary laboratory analyses have been completed on
the leaf compost. Included in the tests were pH and nutrient
content. To further market the product, the County feels the
chemical content of curbside collected yard trimmings needs to be
analyzed (30) (39) .
Afton. Minnesota. Composting Concepts in Afton, Minnesota
currently operates a 20-acre site to compost leaves and grass
clippings for residents of Woodbury, North St. Paul, and various
small communities.
A program using "biodegradable" corn-starch plastic bags that
are clear in color was begun in April 1989. Since the bags are
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clear, unwanted substances can be seen before yard trimmings are
added to the composting operation. Consequently, they experience
very little contamination in the process itself (except for
remaining plastic bag shreds which are screened out) .
The test phase for the cornstarch bags is being run in
cooperation with various public agencies including the University
of Minnesota, Minnesota Department of Agriculture, and Minnesota
Pollution Control Board. No laboratory results on the finished
compost were available at the time of this study. No compost could
be moved off-site until May 1990. Local nurseries and growers have
expressed interest in buying the bulk product (40).
Carver County. Minnesota. A number of yard trimmings
composting sites are operating in Carver County. In rural
locations, the yard trimmings are dropped off at community
composting sites/ These materials are collected at curbside in the
more urban areas of the County and composted at a centralized
facility. The sites accept only leaves, grass clippings, and
garden residues. No brush, woody tree parts, or other organic
materials are permitted as a normal practice.
At the rural drop-off sites, the yard trimmings are composted
in windrows. The compost is generally given back to the area's
residents.
The central composting facility is located at the University
of Minnesota's landscape arboretum. The 10,000 cubic yards per
year of yard trimmings received at the site are processed using a
relatively low-technology windrow composting method. Water is
added occasionally and the windrows are turned on the average of
two to three times during the composting process. Composting time
ranges from 12-18 months. The product is screened before
distribution.
In return for the use of the site, the University receives
about one-half of the finished compost product for use at the
arboretum. During 1989, approximately 500 cubic yards of compost
were sold by the County to one landscaper and two-golf courses in
the area. The selling price was $12 per cubic yard, including
delivery.
Carver County has conducted laboratory analyses of nutrient
content, pH, heavy metals, and C/N ratio. The University of
Minnesota has also conducted plant growth studies. Weed seeds
initially were a problem, but it has been alleviated by altering
the composting procedure. After composting is completed, the top
six inches of the windrows are removed and composted again.
Beginning January 1, 1990, yard trimmings (leaves, grass
clippings, prunings, and garden trimmings) were banned from
landfill disposal in the seven-County metropolitan area of
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Minneapolis-St. Paul. Experiments are currently being conducted
with larger quantities of grass clippings in the composting medium
in order to allow for the increased amounts of grass clippings that
will be collected as a result of the ban. The County is also
experimenting with other materials including shredded newspaper in
the compost feedstock (41)(42).
Fillmore County. Minnesota. The Fillmore County Resource
Recovery Center in Preston, Minnesota was built in 1987 and is
composting the municipal organics. Because there are separate
programs in the area already composting their yard trimmings, these
materials are not typically received at the Fillmore MSW composting
facility. Recyclable and oversized material are removed prior to
composting. Approximately 15 tons per day are composted in
windrows. After composting, approximately 40 to 50 percent of the
material is screened out as rejects. Various laboratory tests have
been conducted by the University of Minnesota on the finished
product.
The primary purpose for implementing the MSW composting
program was to reduce the County's reliance on landfilling.
Therefore, the operators do not have a plan to sell the product at
this time. Most likely it will be available free of charge to
users who are willing to pick it up. Orchards and agriculture are
markets that have expressed an interest in using the product. The
operators of the facility are recommending that the compost be used
in conjunction with commercial fertilizers and be applied at a rate
of about 20-25 tons per acre.
Due to the very wet weather during the 1988-89 winter, the
compost was not ready to distribute for spring planting in 1989 as
planned (10) (43) (44) .
Hennepin County. Minnesota. In Hennepin County, Minnesota,
yard trimmings from residents and landscapers are formed into
windrows up to 12 feet in height. A mechanical turner is used to
aerate and grind the material.
During the period April through November 1989, 146,000 cubic
yards of yard trimmings were collected. Of this, approximately
52,000 cubic yards were processed into compost at the County's
site. After screening through a quarter-inch screen, the compost
is either used by the County's Parks Department or redistributed to
municipalities. The municipalities then make the compost available
to residents free of charge, picked up in bulk form.
The remaining 94,000 cubic yards of yard trimmings were
distributed as follows: 66,000 cubic yards to private companies
interested in producing compost; 18,000 cubic yards to County parks
for landscaping; and 10,000 cubic yards to a local farm for
landspreading. Laboratory tests are conducted annually for heavy
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metals (lead, cadmium, mercury), pesticides, and nutrient content
(45) .
Swift County. Minnesota. A 20 ton-per-day MSW composting/
recycling facility is currently under construction in Swift County,
Minnesota. When the facility began operation in May 1990, source
separated MSW was tipped at the facility in the form of either
recyclable, compostables, or nonprocessibles.
Initially, compost use will be limited to landfill final cover
and selected County projects until environmental and plant growth
studies are completed (46).
Monroe. Wisconsin. In Monroe, Wisconsin, grass clippings are
composted with leaves. According to the City, the two materials
composted together produce a higher quality compost than either
composted separately.
Between 6,000 and 12,000 pounds per day of grass clippings are
collected during the summer months. They are piled on land the
City owns adjacent to the airport runway and later mixed with
leaves for composting. No laboratory tests are conducted.
Truckloads of the finished compost are delivered to users free
of charge. The compost is used by the Parks Department, and is
distributed to landscapers, a golf course, and farmers. According
to the City, the current demand for the product "far exceeds the
supply."
The City is currently experimenting with composting the yard
trimmings with dewatered biosolids from the local wastewater
treatment plant. The compost would be added to fields as a soil
amendment (47)(48).
Portage. Wisconsin. A mixed MSW/biosolids co-composting
facility has been in operation in Portage since September 1986.
The facility processes 30 tons per day of mixed MSW in an in-vessel
operation. After composting, the product undergoes fine screening,
resulting in 15 to 20 percent of the material being rejected.
The primary purpose for composting the mixed MSW and biosolids
is to conserve landfill space. No commercial markets are currently
being pursued. The compost is used as landfill cover. Previous
testing has shown the product suitable for this use.
The Wisconsin Department of Natural Resources has required the
facility to conduct field studies for landspreading. In compliance
with these requirements, the compost currently is being spread on
test plots at several concentrations. During 1990, crops will be
grown and tests will be conducted on metal uptake and leachate
(10) (49) (50) .
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Northeast
The Northeast region has a population of approximately
31,000,000 and is comprised of the following seven States:
Connecticut, Maine, Massachusetts, New Hampshire, New York, Rhode
Island, and Vermont.
In Massachusetts, approximately 200,000 tons of leaves were
estimated to be composted from the autumn 1988 season. Still
another 700,000 tons of leaves reportedly were disposed at
landfills and waste-to-energy plants (28) .
Wellesley. Massachusetts. The City of Wellesley, in
cooperation with the City of Newton, operates two yard trimmings
composting facilities. One of the facilities accepts yard
trimmings from landscapers. Approximately 3,000 cubic yards per
year of compost are produced at this site. The compost is used by
the highway division for landscaping.
The second composting facility is at the City's Recycling and
Disposal Facility. At this site, the general public may drop off
yard trimmings at no charge. The 4,500 cubic yards per year of
compost produced at this site are marketed as a soil amendment.
The City is currently pursuing various methods of advertising the
compost. Advertisements are being placed in local newspapers in
the early fall and spring. In addition, the City is planning to
broadcast advertisements on cable television.
Laboratory testing currently is being conducted by the
University of Massachusetts. The analyses will determine the
presence of heavy metals, NPK, trace elements, and the organic
content of the compost. A pH of approximately 7 has been reported
(51) .
Fort Fairfield. Maine. A project was begun by the Maine
Department of Agriculture to demonstrate the composting of potato
processing by-products and cull potatoes. Local farmers and
industry Provided equipment and feedstocks. The compost feedstock
is comprised of the cull potatoes and by-products, wood ash, paper
mill biosolids, and sawdust.
During the demonstration program in 1989, 484 tons of compost
were produced. According to Al Dixon, Town Manager, the product is
a "nice organic product, smells like dirt, and is pretty as peat."
The compost is being tested by a local farm on oats, peas,
potatoes, and broccoli crops at various application rates. The
same crops are being grown on fields without compost. Tests will
be conducted on the compost product, soil samples, and the crops
over a period of three years.
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The town plans to expand the program to produce over 2,000
tons of compost in 1990. Future plans are to market the compost in
bulk to the farming community (52) (53) .
Thomas ton, Maine. The State Department of Environmental
Protection has permitted a 23-acre site in Thomaston, Maine to
compost fish processing by-products. North Atlantic Products has
been involved with pilot composting programs since 1987, and began
operation in Thomaston in June 1989. The material is mixed with
sawdust and mechanically turned. The company expects to produce
500 tons of finished compost by November. The product is
undergoing laboratory analysis for NPK and trace elements. The raw
materials are being tested for heavy metals. North Atlantic
Products is actively seeking more markets for both bagged and bulk
sales, and plans to market the product under the name "Sea Green"
(54) (55) .
Brookhaven and Holtsville. New York. The Department of
Highways in Brookhaven composts approximately 200,000 cubic yards
of leaves annually, using windrows, at the Holtsville Ecology site
and Manorville Transfer Station.
During initial operations, plastic bags had been creating
problems in the composting operation, both in clogging processing
equipment and reducing the quality of the finished product. In
1987, the Highway Department purchased 400,000 paper bags and
offered them free to residents. According to the operator, the
pilot program demonstrated that curbside collection of paper bags
was more convenient and efficient than with plastic bags, and that
the paper bags decomposed as quickly and inexpensively as
composting loose leaves.
Laboratory analyses were conducted by Cornell University for
heavy metal contamination during the paper bag pilot study. All
test results were acceptable according to the standards established
by the U.S. EPA for biosolids composting. Currently, only pH is
tested for at the Ecology site.
Approximately 50-75 percent of the compost produced is given
away to residents for use in gardens and on lawns. Small bags are
given to Girl Scout troops and other groups for potted plants. The
compost is used by the local garden club and in the community
garden. The remainder is used for municipal projects (35) (52) (56) .
Islip, New York. In September 1988, Islip expanded its yard
trimmings composting program to a full-size operation. The town
anticipates processing at least 70,000 tons per year of grass
clippings, leaves, and tree trimmings.
Yard trimmings are collected at curbside, and are received at
the facility primarily in plastic bags. They are then shredded,
trommel screened, windrowed, and turned periodically. The trommel
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has recently been added to the process and is expected to be able
to remove approximately 90 percent of the plastic in the feedstock.
Laboratory analyses conducted on the compost have been very
favorable. The finished compost is usually given away. Currently,
it is available to residents and local landscapers on a first-come,
first-serve basis. The town is in the process of providing 25,000
cubic yards to develop a golf course in the area. At the present
time, market demand exceeds the available supply.
The town is exploring potential commercial markets such as
turfgrass growers, landscapers, and other users of soil amendment
products. It is uncertain at this time as to whether the product
will be marketed in bag as well as bulk form (54) (57).
Saratoga Springs. New York. The horse manure and bedding from
the Saratoga Springs Raceway are composted and sold as "Saratoga
Organic." The Saratoga Springs Raceway houses over 1,000 horses on
the premises, which generate 150 to 200 cubic yards per day of
manure and bedding material. The composting operation is conducted
inside a building over a two-week period. Forced aeration,
controlled via computer, is used to maintain proper oxygen levels.
The flow of oxygen is controlled by computer, based on data from
temperature probes inserted in the piles. Laboratory analyses have
been conducted by Cornell University. The finished compost is
shredded, but not screened. It is bagged and sold to both retail
and wholesale markets (58) (59) .
Scarsdale. New York. Yard trimmings have been composted in
the City of Scarsdale since the mid-1960s. Currently, the City
works with a local nursery to compost approximately 35,000 cubic
yards per year of yard trimmings and distribute the product. The
yard trimmings are delivered throughout the year.
Leaves are composted (aerobically) in windrows. Grass
clippings, shrubs , and tree trimmings are composted (anaerobically)
in cells for five years.
In return for a share of the finished product, the nursery
assists in turning the windrows and provides storage space for the
finished compost. The City uses as much of the screened compost as
it needs. Twice a year (spring and autumn) the City sponsors
giveaway weekends, during which time bulk compost is available free
of charge to residents. The remaining compost is marketed by the
nursery as mulch and is also blended in potting soil and topsoil.
The nursery sells the compost products both in bulk and in bags.
Laboratory testing is conducted by the nursery (60) (61) .
A - 1 9
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Pacific
The Pacific region has the fewest States of any of the regions
defined for the study. It consists of California, Oregon, and
Washington, with a combined population of approximately 35,000,000.
Davis. California. The Davis Waste Removal Company has been
composting yard trimmings generated in the City of Davis since
December 1981. During the first five years of operation,
approximately 10,500 tons (225,000 cubic yards) of loose brush and
leaves were collected and processed. Approximately 4,875 tons
(15,600 cubic yards) of compost were produced. Of this, 1,175 tons
were sold and the remaining 3,700 tons were given to residents of
Davis. Of the compost that was sold, the primary market was local
landscapers.
The yard trimmings are collected at curbside using a "claw."
Unwanted substances are removed, and the material is shredded,
formed into windrows, and turned every two weeks.
The company has had laboratory analyses conducted on the
compost. The results during the first five years showed that they
were unable to produce a consistent product. The average
composition analysis of the compost during those years was as
follows:
Moisture (%) 60
Total solids (%) 40
Volatile solids (%) 34
Carton/nitrogen ratio 45:1
Carbon (%) 22
Nitrogen (%) 0.48
Phosphorus (%) 0.16
Potassium (%) 0.24
The finished compost product currently is available in bulk
form at no cost to residents. According to a representative from
the company, problems with the quality of the finished compost have
been encountered, primarily due to a lack of control of the
incoming feed stream and the high C/N ratio. Because of these
problems, the facility now composts primarily leaves (62)(63).
Palo Alto. California. The City of Palo Alto's yard trimmings
composting program began full scale in 1979. in 1988, 22,000 cubic
yards of material were received at the facility, and 8,799 cubic
yards of compost were produced. The type of materials accepted are
clean plant trimmings. The material is processed through a tub
grinder and then formed into windrows. Turning is done with a
bulldozer at least once per month.
The product is produced for eventual cover of a 146-acre
landfill to convert it into a park. The compost will be mixed with
A - 2 0
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dirt at a ratio of l-to-2. Use of the compost for landfill cover
will displace material that would need to be purchased at a cost of
approximately $15 per cubic yard (64)-(66).
San Mateo. California. The City of San Mateo began its yard
trimmings composting program in April 1982. Yard trimmings
composted included garden and tree trimmings. Incoming loads were
checked for conformance with a published list of acceptable
materials. The site attendants had the authority to reject
unsuitable materials such as food scraps, rotten or odorous
materials, plastic or paper containers, pet animal manure, diseased
or infected materials, and poisons or hazardous wastes.
The materials were then size reduced and formed into windrows.
The windrows were then aerated. During the 1986-1987 fiscal year,
41,000 cubic yards of raw materials were processed to produce
27,000 cubic yards of compost. Some laboratory analyses of the
product have been conducted, including organic content and nitrogen
content. Approximately 150 cubic yards per year of the product
were used by the Parks Department as a soil amendment with
favorable results. Most of the compost was stockpiled with the
intention of using it in the development of a 35-acre landfill site
into the Shoreline Park.
As of September 1989, San Mateo was no longer accepting yard
trimmings for composting. The site had accumulated a stockpile of
compost in excess of its needs for the Shoreline Park, and is
selling the excess at $6.50 per cubic yard to customers who will
pick it up at the site. Topsoil providers and the general public
are the primary customers. Approximately 3,000 cubic yards were to
be used by the Parks Department in municipal projects during 1989
(67)-(69).
Portland. Oregon. There are two major producers of yard
trimmings compost in the Portland area: Grimm's Fuel Co. and
McFarlane's Bark, Inc. In addition, East County Recycling Co. size
reduces through shredding yard trimmings into a mulch.
At the Grimm's facility, yard trimmings are size reduced and
piled. The shredded product is aerated during the composting
period, screened, and the oversized material is shredded again.
Grimm's markets the compost alone and also blends it with sandy
loam and barkdust.
The yard trimmings received at McFarlane's are stockpiled in
preparation for processing. The material is shredded and heaped
into piles, and allowed to compost for three to six months. Prior
to selling the product, the material is shredded and screened. The
compost is blended with sawdust in a 9-to-l ratio before selling.
Both Grimm's and McFarlane's have targeted three major
markets: residential customers, landscapers, and nurseries.
A - 2 1
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Grimm's has been actively trying to produce a material of
consistent, reliable quality to be used as a potting medium in the
nursery industry. The shredded yard trimmings produced by East
County Recycling are given free of charge to residents (70)- (72) .
Kina County, Washington. Pacific Topsoils, near Seattle,
composts grass clippings, leaves, and prunings from various parts
of King County. Incoming yard trimmings are visually inspected for
plastics, rocks, etc., shredded to accelerate the composting
process, and formed into windrows. Some of the compost is screened
and sold as a decorative ground cover to be used in place of bark.
It is marketed under the name "Pacific Garden Mulch." Pacific
Topsoils also blends the compost with the company's other soil
amendment products and in its topsoil. The company concentrates on
the commercial landscaping market, although other markets are
targeted as well.
Laboratory analyses for organic content, soil fertility, and
macronutrients and micronutrients are conducted quarterly. The
company recommends that the compost be applied to the soil in a
three- to six-inch layer (22) (73)- (75) .
Seattle. Washington. A Seattle city ordinance states that
yard trimmings must be source separated. The City's composting
programs are designed to handle 75 percent of the yard trimmings
typically disposed of. In 1989, Seattle implemented a three-
pronged approach to diverting yard trimmings: 1) backyard
composting; 2) curbside collection City-wide; and 3) self-haul for
a discounted tipping fee.
The City is encouraging backyard composting of yard trimmings
by giving composting bins to homeowners. in its first year,
starting in September 1989, the program planned to distribute 6,000
composting bins to Seattle residents. The bin is delivered by a
composting instructor who provides the resident with a one-hour
home consultation explaining how to use the bin, helping the
resident set the bin up for use, assessing their yard trimmings
generated.
Another facet of Seattle's backyard composting program is the
Master Composter Program, which was begun in 1985. Since then, 75
master composers have received training and four backyard
composting demonstration sites have been developed around the City.
The program is projected to reach 70,000 households over a span of
seven years.
Seattle's curbside collection program for yard trimmings was
implemented City-wide in January 1989. Yard trimmings are
transported to a centralized composting site. AS of September
1989, no saleable product had been produced at that composting
site. The anticipated current market value for the compost end
product was $2.00 per cubic yard.
A - 2 2
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The self-haul program began operation in January 1989, and is
available at both of Seattle's transfer stations. During the first
seven months of 1989, residents and businesses dropped off almost
7,000 tons of yard trimmings at the sites (35) (76)-(79) .
South
The South is the largest region in this study in terms of
population. The eleven States in the region, which have a combined
population of approximately 56,000,000 are: Alabama, Arkansas,
Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina,
South Carolina, Tennessee, and Virginia.
Gentry. Arkansas. In Gentry, manure from broiler chickens is
composted in windrows. The finished product is marketed to sod
farmers, landscapers, and golf courses (80) .
Ft. Lauderdale. Florida. The City of Ft. Lauderdale, in
Broward County, operates a composting plant to process biosolids,
using trimmings from commercial tree surgeons and wood chips as
bulking agents. The facility is designed to process 35 tons per
day (250 cubic yards per day) of biosolids cake in reactors and
accepts 1,000 to 1,500 cubic yards per week of yard trimmings.
Small amounts of the compost have been used by nurseries and
the general public. The Soil and Water Conservation District is
currently considering use of the product. Local environmental
restrictions have made landspreading very difficult (81) (82).
Perry. Florida. America's largest blue crab scrap composting
project receives most of the crab processing residues generated in
the Florida panhandle. The crab scrap deliveries, averaging 13
tons per day, are mixed with sawdust, pine bark, shredded leaves,
brush, other yard trimmings, and other locally available
carbonaceous materials. The material is placed in windrows
outdoors and turned frequently over a two-month period, followed by
curing for two months.
The crab compost is screened and then marketed under the
"Suwanee River Natural Organics" label for $25 per cubic yard bulk,
or $3 per 40-pound bag wholesale to local nonprofit groups (e.g.,
4-H, garden clubs) for use as a fund raiser. The compost is also
sold as high-quality potting soil which is sold at retail for $6
per 40-pound bag.
The University of Florida is conducting field trials and
growth studies, and the seven local Soil and Water Conservation
Districts are helping to introduce the compost to local farmers
(83) .
Sumter County. Florida. A windrow composting facility to
process mixed MSW has been on-line since mid-1988 in the County.
A - 2 3
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The facility is operated by U.S. Waste Recovery. Information from
the County and the operators indicates that 50-70 tons of
residential and commercial discards are received each day.
The composting process is begun by passing the material
through a flail mill designed to break open bags and packages, thus
allowing their contents to mix with the remainder of the MSW
stream. The incoming material is then subjected to magnetic
separation to remove ferrous metals. Aluminum and other inert
matter are removed manually. The remainder of the material is
size-reduced to an approximate two by two-inch particle size.
The shredded product is transferred to a composting pad where
it is stacked in windrows, and a bacterial implant is added. The
finished product is being tested for organic matter, pathogens, and
heavy metals.
As of October 1989, no compost had been marketed. Plans are
to sell the material to nurseries as an alternative to peat, to
soil amendment dealers, and to contractors for landscaping near
roadways. Market development efforts were being delayed until
State guidelines for compost are finalized by the Florida
Department of Environmental Regulation (84) (85) .
Mecklenburg County. North Carolina. The County is currently
conducting a yard trimmings recycling program in which woody
material is shredded into mulch. Approximately 200-300 tons per
day of the materials are received at the facility. The mulch is
used by the Board of Education, Public Works Department, and the
Parks and Recreation Department. Additionally, over one-half of
the mulch is sold to the public at $6 per cubic yard, picked up at
the site.
In 1990, the County plans to implement a full-scale yard
trimmings composting program at two sites. Approximately 375,000
cubic yards per year of yard trimmings will be processed. In
addition to continuing to shred woody materials into mulch, leaves
and grass clippings will be composted in windrows.
Mecklenburg County is currently exploring markets for the
compost. The County hopes to market the product in bulk to large
end-users such as nurseries and greenhouses (86) (87).
SUMMARY
The results of the assessment of existing composting programs
and markets show that there is a considerable interest in
composting in the United States. The interest seems to be driven
largely by economic and regulatory factors, as well as for
environmental reasons. The markets for the finished product vary
A - 2 4
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from uses by public entities, to wholesale and retail sale, to
residents and commercial markets.
A summary of the characteristics of this study is presented in
Table A-4. The data in the table show that there seems to be a
rough correlation between the tipping fee for landfill disposal and
the number of operational composting programs. The highest average
tipping fee was $58 per ton in the Northeast region. This region
had one of the highest number of composting projects. On the other
hand, the lowest average tipping fees were $9 and $14 per ton in
the Central and South regions, respectively. As of April 1989, the
Central region had only seven yard trimmings or MSW composting
projects, and the South had six.
Another factor that plays a critical role in the number of
composting programs is regulating materials to be disposed of.
Several States in the Industrial, Midlands, and Northeast regions
have passed legislation to ban the disposal of yard trimmings in
landfills. A discussion of the regulatory factor was presented in
the section entitled Policies in Chapter 4.
A - 2 5
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Table A-4
CHARACTERISTICS OF THE SIX STUDY REGIONS
(July 1989)
I
to
Number of States
Population in 1987
(millions)
Population density
(population/square mile)
Average landfill tipping
fee ($/ton) 1 /
Number of yard trimmings
composting programs
Number of operational
MSW composting programs
List of States
Central
14
39
26
9
7
0
AZ
CO
ID
KS
MT
NE
NV
NM
ND
OK
SD
TX
UT
WY
Industrial
8
52
235
28
354
1
DE
IN
MD
MI
NJ
OH
PA
WV
Midlands
5
29
91
20
135
4
IL
IA
MN
MO
WI
Northeast
7
31
278
58
134
0
CT
ME
MA
NH
NY
RI
VT
Pacific
3
35
110
29
15
1
CA
OR
WA
South
11
56
110
14
5
1
AL
AR
FL
GA
KY
LA
MS
NC
SC
TN
VA
(continued)
-------
Table A-4 (cont.)
i/ Average of tipping fees reported in Pettit, C.L. "Tip Fees Up More Than 30% in
Annual NSWMA Survey." Waste Aae. 20(3):34-39. March 1989.
Sources: Glenn, J. and D. Riggle. "Where Does the Waste Go? -- Part I." BioCycle.
30(4) :34-39. April 1989.
Goldstein, N. "Solid Waste Composting in the U.S." BioCycle. 30 (11):32-37.
November 1989.
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Appendix A
REFERENCES
1. Glenn, J. "The State of Garbage in America: Part 1."
BioCvcle. 31(3):48-53. March 1990.
2. Goldstein, N. "Solid Waste Composting in the U.S.."
BioCYcle. 30(11) :32-37. November 1989.
3. Solid Waste Management in the Denver Region. Prepared by the
Solid Waste Task Force. 1986.
4. Personal communication with Trish Kenney, City of Boulder.
1989.
5. Personal communication with Gene Hanlon, City of Lincoln.
1989.
6. Personal communication with Dan Slattery (1987 and 1989) and
Marty Crater (1989).
7. Goldstein, J. "10 Percent 'Off the Top' for Composting."
BioCYcle. 30(2):26-27. February 1989.
8. "Operating Leaf Compost Facilities in New Jersey." Prepared
by the New Jersey Department of Environmental Protection.
March 22, 1988.
9. "Options for Municipal Leaf Composting." BioCvcle. 29(9) :38-
43. October 1988.
10. Diaz, L.F. and C.G. Golueke. "Compost Experience in the USA."
Presented at the International Symposium on Compost Production
and Use. Italy. June 1989.
11. "The Delaware Reclamation Plant." Delaware Solid Waste
Authority. 1988.
12. "Fairgrow Easy Reference Chart." Fairfield Service Company.
1989.
13. "Giving Nature a Hand." NCC Business. October 1989.
14. Personal communication with John Neyman, Delaware Solid Waste
Authority. 1989.
15. Personal communication with Rebecca Roe, Fairfield Service
Company. 1989.
16. Personal communication with Doreen Cantor, Montgomery
County. 1990.
A - 2 8
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17. Personal communication with representatives from Traverse
City. 1989.
18. "N. J. County Seeks Ways to Get Rid of Compost." Recycling
Times. May9 , 1989."
19. Personal communication with Paul Petto, Essex County, New
Jersey. 1989.
20. Meade, K. "Waiting for the Leaves to Fall." Waste
n-n-o-K-r^n^oo pP 34-38, March 1989.
21. Personal communication with Matthew Vastano, Middlebush
Compost, Inc. 1989.
22. Taylor, A.C. and R.M. Kashmanian. Yard Waste Composting: A
Study of Eight Programs. Us . Environmental Protection
Agency. Office of Policy, Planning and Evaluation; Office of
Solid Waste and Emergency Response. EPA/530-SW-89-038. April
1989.
23. Personal communication with Patrick Kennedy, Alternate
Disposal Systems, Inc. 1990.
24. Salimando, J. "Woodhue Compost. . .or Wouldn't You?" Waste
Age, 20(5):63-64. May 1989.
25. Personal communication with Joe Hayes, Woodhue, Ltd. 1989.
26. Logsdon, G. "A Business-like Approach to Leaf composting."
BioCycle. 30(3):22-24. March 1989.
27. Personal communication with Edward Janesz, Greater Cleveland
Ecological Association. 1989.
28. "News Breaks. " Waste Aae. 20(3) :28. March 1989.
29. Personal communication with Steven Hayden, City of Toledo.
1989.
30. " Slants and Trends." Solid Waste Report. 20(14) :105. April
3, 1989.
31. Personal communication with Don Berman, Allegheny County.
1989.
32. Personal communication with Jim Caine, Mount Lebanon. 1989.
33. Illinois Department of Energy and Natural Resources.
Composting Municipal Solid Waste. Undated.
34. "Regional Roundup." BioCycle. 29(3) :11. March 1988.
A - 2 9
-------
35. O'Brien, J.K. "Prospects for Year-Round Composting of
Municipal Yard Waste." Resource Recovery, pp. 26-27.
February 1989.
36. Personal communication with Doug Ziesemer, City of Chicago.
1989.
37. Darling, J.S. "Twin Cities Tackle Their Waste Problems
Together." World Wastes. Undated.
38. Personal communication with Laura Marshall, Intergovernmental
Solid Waste Disposal Association. 1989.
39. Personal communication with Harry Morris and Jim Embroso, Land
and Lakes Company. 1989.
40. Personal communication with Richard Eisinger, Composting
Concepts. 1989.
41. Personal communication with Michael Lein, Carver County. 1987
and 1989.
42. "Yard Waste Disposal is Banned in Metro Area." Carver County
Solid Waste Newsletter. October 1989.
43. Personal communication with Neil Bremseth, Fillmore County
Resource Recovery Center. 1989.
44. Fillmore County Resource Recovery Center. Agricultural Use of
Solid Waste Compost. 1988.
45. Personal communication with Bill Brenna (1987 and 1989) and
Paul Kroening (1989), Hennepin County.
46. Cal Recovery Systems, Inc. Pilot source separation program
for Swift County, Minnesota. 1989.
47. "Composting Projects for Grass Clippings" BioCycle.
29(5) :47. May/June 1988.
48. Personal communication with Nate Klassy, City of Monroe.
1989.
49. Personal communication with Surgit Saini, Wisconsin Department
of Natural Resources. 1989.
50. Personal communication with Tom Pinion, Portage Department of
Public Works. 1989.
51. Personal communication with David Pilkington, Department of
Public Works. 1989.
A - 3 0
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52. "Regional Roundup." BioCvcle. 30(6):13,15. June 1989.
53. Personal communication with Al Dixon, Town Manager. 1989.
54. "Regional Roundup." BioCycle. 30(4) :19. April 1989.
55. Personal communication with Ron Jackson, North Atlantic
Products. 1989.
56. Personal communication with Timothea Nalepa, Holtsville
Ecology Site. 1989.
57. Personal communication with Dr. Stewart Bruckner, Department
of Environmental Control. 1989.
58. Personal communication with personnel from Saratoga Springs
Raceway. 1989.
59. Logsdon, G. "Racetracks Bet on Composting." BioCycle.
29(3):38-39. March 1988.
60. Personal communication with Jim Rice, City of Scarsdale.
1989.
61. Rice, J.E. "Leaf Bagging vs. Curb Collection." BioCycle.
29(2):30-31. February 1988.
62. Gertman, R. Davis Waste Removal Company Compost Program.
Undated.
63. Personal communication with Paul Geisler (1987) and Ken
Sheppard (1989), Davis Waste Removal Company.
64. Personal communication with Russ Reisierer, City of Palo Alto.
1987 and 1989.
65. "Municipal Recycling Programs: Potential for Waste Management
and Energy Savings." Energy Task Force of the Urban
Consortium for Technology Initiatives. Denver, Colorado.
1985.
66. "City of Palo Alto Composting Program." February 1989.
67. Department of Public Works, City of San Mateo. Compost
Material Guide. 1984.
68. Bergeron, A.T. "6,000 Tons Diverted: Recycling Plant
Materials." BioCycle. 29(2):29-31. February 1989.
69. Personal communication with Vernon Ficklin, City of San Mateo.
1989.
A - 3 1
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70. Cal Recovery Systems, Inc. Portland Area Compost Products
Market Study. Prepared for the Portland Metropolitan Service
District. Portland, Oregon. 1988.
71. Personal communication with Rod Grimm, Grimm's Fuel Co. 1988.
72. Personal communication with representatives from McFarlane's
Bark Co. 1988.
73. Johnson, B. "Kirkland Recycling Program Gets Unexpected
Success." World Wastes. 32(2): 26-27. xFebruary 1989.
74. Personal communication with Dave Foreman, Pacific Topsoils.
1987.
75. Personal communication with Dorran McBride, Pacific Topsoils.
1989.
76. Johnson, B. "Public Participation Helps Seattle Set Recycling
Goal." World Wastes. 32(2): 20, 22. Undated.
77. Personal communication with Carl Woestendiek, Seattle Solid
Waste Utility. 1989.
78. "Seattle's Backyard Composting Program. " Seattle Solid Waste
Utility. 1989.
79. "Yard Waste Program Update - August 1989." Seattle Solid
Waste Utility. 1989.
80. Personal communication with Les Hileman, University of
Arkansas (retired) . 1989.
81. Personal communication with John Jackson, Ft. Lauderdale
Compost Plant. 1989.
82. "Private Role Grows in Yard Waste Composting." BioCYcle.
28(9):36-38. October 1987.
83. Personal communication with Clark Gregory, Woods End
Laboratory. 1990.
84. Personal communication with Mike Olson, U.S. Waste Recovery.
1989.
85. Personal communication with Gary Breeden and Tommy Hearst,
Sumter County. 1989.
86. "New Emphasis on Yard Waste." BioCycle. 28(8) :42-46.
September 1987.
A - 3 2
-------
87. Personal communication with Allen Giles and Brenda Bardner,
Mecklenberg County. 1989.
A - 3 3
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Table A
CHARACTERISTICS OF THE SIX STUDY REGIONS (Fall 1991)
Central Industrial Midlands Northeast
Number of States
Population in 1987
(millions)
Number of yard trimmings
composting programs
Number of operational
MSW composting
programs
Number of States that
ban yard trimmings
from landfills
Number of States with
recycling laws
List of States
14
39
35-45
3
0
3
AZ
CO
ID
KS
MT
NE
Nv
NM
ND
OK
SD
TX
UT
WY
53
524
1
5
8
DE
IN
MD
MI
NJ
OH
PA
WV
5
29
341
9
5
5
IL
IA
MN
MO
WI
7
31
432
0
3
7
CT
ME
MA
NH
NY
RI
VT
Pacific
5
39
35
2
0
3
AL
CA
HI
OR
WA
South
11
57
40
3
4
6
AL
AR
FL
GA
KY
LA
MS
NC
SC
TN
VA
(continued)
-------
Table A (cont.)
Sources: Goldstein, N. Personal communication. October 1991.
Glenn, J. and D. Riggle. "The State of Garbage in America: Part I"
BioCvcle. 32(4):34-38. April 1991.
Howson, C. "Recycling Laws Impacting at State Level." Waste Tech News.
October 1991.
Kashmanian, R. Personal communication. March 1992.
-------
Table B
OPERATIONAL MSW COMPOSTING/CO-COMPOSTING FACILITIES IN THE U.S. (Fall 1991]
Type of System Capacity (TPD)
Location
Arizona
Pinetop-Lakeside
Delaware
Wilmington
Florida
Escambia County
Pembroke Pines
Sumter County
Iowa
Des Moines
Kansas
Coffeyville
Minnesota
East Central Solid
Waste Commission
Fillmore County
Lake of the Woods
County
Pennington County
Prairieland
St. Cloud
Swift County
Eweson
Fairfield
Windrow
Buhler
Windrow
Windrow
Windrow Raw MSW
Daneco
Windrow
Windrow
Lundell w/ windrows
OTVD w/ agitated bed
Eweson w/ agitated bed
Windrow
12 MSW; 5 biosolids
250-350 processed MSW;
70 biosolids (dry)
130MSW; septage
660 MSW
120 design (50 actual)
192 MSW; 115 biosolids
(wet); 38 yard trimmings
80 MSW
250 MSW
18 MSW
10 MSW
10 (RDF residuals)
100 MSW
100 MSW
25 MSW
(continued)
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Table B (cont. )
Oregon
Portland Dano w/ windrows 600 MSW
Texas
Hidalgo County Windrow 150 MSW
Washington
Ferndale Eweson w/ agitated bed 300 MSW
Wisconsin
Portage Digester w/ windrows 16 MSW; biosolids
Sources: Goldstein, N. and R. Spencer. "Solid Waste Composting in the
United States." BioCycle. 31(11): 46, 48-50, November 1990.
Goldstein, N. Personal communication. October 1991.
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