1. Presented to the National Park Service,
National Capital Region Sustainability Advisory Group
November 9th, 2010, Washington, DC
Composting 101
By Brenda Platt
Institute for Local Self-Reliance
www.ilsr.org
2. Outline
What is composting
Benefits of composting
Composting systems
State of composting in our region
Model programs elsewhere
Compostable biobased food service ware
Thoughts for compost operations planning
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3. What is composting?
Composting is the aerobic, or oxygen-requiring,
decomposition of organic materials by microorganisms
under controlled conditions.
During composting, the microorganisms consume oxygen.
Active composting generates heat, carbon dioxide, and
water vapor.
Composting reduces the volume and mass of the raw
materials while transforming them into a valuable soil
conditioner.
Source: Robert Rynk et al, On-Farm Composting Handbook, 1992.
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7. Recommended Conditions
Variable Recommended Range
Initial C:N 25:1 to 40:1
Moisture content 50% to 60%
Oxygen concentration >>5%
Temperature 131-149 deg F
Initial bulk density <1,100 lbs/cubic yard
Particle size 1/8 to 2 inches
pH 5.5 to 8.0
Source: Greg Evanylo, Dept. of Crop and Environmental Science, Virginia Tech, Better
Composting School 2010.
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8. Composting involves numbers
Feedstock accounting
Recipe development
Collection and manipulation
of physical, biological and
chemical measurements
Site size calculations
Labor and financial numbers
Source: “Introduction Better Composting School,” R.E Graves, Penn State, October 2008
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9. Benefits of Composting
Creates a rich nutrient-filled material, humus,
Increases the nutrient content in soils,
Helps soils retain moisture,
Reduces or eliminate the need for chemical fertilizers,
Suppresses plant diseases and pests,
Promotes higher yields of agricultural crops,
Helps regenerate poor soils,
Has the ability to cleanup (remediate) contaminated soil, and
Can help prevent pollution and manage erosion problems.
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10. U.S. Municipal Waste Disposed
T e x t i le
6 % G la s
Paper and paper 7%
24%
M e ta l
9%
(http://www.epa.gov/epaoswer/non-
Source: US EPA, 2007 data
Y a r d t r im m i
hw/muncpl/msw99.htm)
7%
W oo
F o o d sc ra
8%
19%
O th e r m a te r
2%
169.2 million tons in 2007 P l a s t ic
18%
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11. Composting = Local
Organics do not ship well
Composting is small-scale
Compost products are used locally
Jobs are local
Dollars circulate within local economies
Local = good for local economies
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12. Compost Applications
landscape and nursery
agricultural and horticultural
vegetable and flower gardens
tree and shrub planting
sod production and roadside
projects
wetlands creation
soil remediation and land
reclamation
sports fields and golf courses
sediment and erosion control
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14. Compost System Comparison
Method Cost Labor Management Rate of
Composting
Passive/Static Low Low Low Low
Windrow Low-Med Med-High Med Low-Med
Aerated Static Low-Med Med Med Med
Pile
In-vessel Med-High Low High High
Source: Jactone Arogo Ogejo, Biological Systems Engineering, Virginia Tech,
Better Composting School 2010.
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15. Typical composting times for selected
combinations of methods and materials
Method Materials Composting Time Curing Time
Passive Leaves 2-3 years NA
Windrow Leaves, manure, + 2-6 months 1-4 months
amendments
Aerated Static Pile Sludge + wood 3-5 weeks 1-2 months
chips
In-vessel rotating Sludge + 3-8 days 2 months
drum municipal solid
waste
Source: Greg Evanylo, Dept. of Crop and Environmental Science, Virginia Tech, Better
Composting School 2010.
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16. Yard Debris Composting Is
Well-Established in DC Region
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18. Regional Composting Facilities
Annual Total Acreage
Composting Facility Serves
Throughput Acreage Used
Arlington County Facility
Arlington County, Fairfax County 5,212 3 3
[Arlington, VA]
City of Alexandria temp site
Alexandria 4,480 2
[Alexandria, VA]
City of College Park, only fall leaves
City of College Park DPW from: Berwyn Heights, Cottage City,
2,800 5 4.5
[College Park, MD] Edmonston, Laurel, New Carrollton,
Riverdale Park, Univ. of MD
City of Takoma Park City of Takoma Park, Montgomery
2,000 1
[Takoma Park, MD] College
Loudoun Composting
Loudoun County, Fairfax County 55,000 25 12
[Chantilly, VA]
Prince George’s County Yard Waste
Prince George's County, Anne Arundel
Composting Facility (Western Branch) 66,000 200 47
County (10K tons)
[Upper Marlboro, MD]
MES Dickerson facility
Montgomery County 77,000 118 49
[Dickerson, MD]
POGO Organics District of Columbia, City of Rockville
35,757 125 10
[Olney, MD] (tree service contract)
Prince William County (Balls Ford)
City of Manassas, Fairfax County,
facility 55,000 30 15
Prince William County
[Manassas, VA]
Recycled Green
Howard County 20,000 30 12
[Woodbine, MD]
The Reichs Ford Road Yard Trimmings
Frederick County 9,922 30 15
[Frederick, MD]
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19. Materials Collected
Jurisdiction Materials Collected Set-Out Requirements Frequency of Collection
Leaves, Wood/Branches, Garden Trimmings (only in spring and
Arlington County Paper bags, Compostable Bags Weekly
fall), Brush
City of Alexandria Leaves n/a Seasonal (end October to January 1)
Leaves, Grass Clippings, Wood/Branches (<5'), Garden
City of College Park Paper bags, Durable containers Weekly
Trimmings (<5'), Brush
City of Falls Church Leaves, Grass Clippings, Garden Trimmings Brown compostable bags that are 30 gal size Weekly (Mondays)
City of Greenbelt Leaves, Grass Clippings, Garden Trimmings (<4'), Brush Paper bags, Durable containers Weekly (Fridays)
Leaves, Grass Clippings, Wood/Branches (<4' L, <3" D),
City of Manassas Paper bags, Durable containers Weekly (Mondays)
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Garden Trimmings
Leaves, Grass Clippings, Wood/Branches (<4’ L, 3” D), Garden
City of Takoma Park Paper bags, Durable containers Weekly
Trimmings, Brush
Seasonal (end-Novemeber to mid-
District of Columbia Leaves Rake leaves to curb
January)
Fairfax County Leaves, Grass Clippings, Wood/Branches (<4‘ L, 6” D), Brush Paper or plastic bags, Durable containers Weekly/Hauler-dependent
Frederick County Leaves, Grass Clippings, Wood/Branches (<8' L, 6" D), Brush N/A, since self-haul to facility N/A
Leaves, Grass Clippings, Wood/Branches (<4’ L, 4” D), Garden
Howard County Paper or plastic bags, Durable containers Weekly
Trimmings , Brush, Pallets, Manure
Loudoun County Leaves, Grass Clippings, Garden Trimmings (<3'), Brush Paper bags, Durable containers Hauler-dependent
Leaves, Grass Clippings, Wood/Branches (<4' L, <4" D), Paper bags, Durable containers w/ county "Yard
Montgomery County Weekly
Garden Trimmings, Brush Trim" labels
Prince George's Leaves, Grass Clippings, Wood/Branches (4' L, 3" D), Brush, Heavy-duty paper or plastic bags, Durable
Weekly
County Thatch containers
Prince William County Leaves, Grass Clippings, Garden Trimmings, Brush, Stumps Paper or plastic bags, Durable containers Hauler-dependent
27. Scope of your operations?
What are your goals?
Composting only NPS generated material?
What types and quantities of materials?
Collection service?
Processing on-site? Decentralized or a regional site?
Deliver to a non-NPS site?
Process into value-added product?
Sales and marketing or product? Income generating?
Delivery and application of compost?
Use only on NPS properties?
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28. Issues to consider
Know your feedstocks: what, quantity, source
Can you make a recipe to produce good compost?
Cost/income
Regulations
Siting issues (availability, neighbors, traffic, dust,
noise, water, stormwater management, size,
security, zoning, permits, set backs, accessibility,
utilities)
Compost needs to be cured = space
Managing the compost process = trained operators
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29. Managing the compost process
Good management can make or break the operation
Minimize odors and other environmental impacts
Make best use of materials, equipment, and labor
available
Good operator who understands the compost process
and knows how to troubleshoot
Temperature is the primary
yardstick of the composting
process
Pathogens/aspergillus fumigatas
Source: Jactone Arogo Ogejo, Biological Systems Engineering,
Virginia Tech, Better Composting School 2010.
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30. Equipment considerations
Types of materials to be processed
Quantity of material
Processing methods
Surface
Capacity and space
optimization
Available money
(or ability to acquire)
Anticipated growth
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31. Equipment
Moving materials
Aerating/turning
Grinders
Mixing
Watering
Screening
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35. Compost Regulations
MD Dept. of Agriculture
regulates product
MD Dept. of the Environment
regulates process, including air
and water pollution
Local jurisdictions regulate
zoning, site prep, buildings, noise,
odor
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36. Contact
Brenda Platt
Institute for Local Self-Reliance
bplatt@ilsr.org
www.ilsr.org
202-898-1610 ext 230
Institute for Local Self-Reliance
