midterm

1. Site and Operations Redesign of Composting
Facility for City of Columbia
Rachel Cron, Shelby Green, Carrington Moore, Alena Senf, & Mallory Ware
Clemson University, Clemson, SC
October 24th, 2019

2. Overview
● Introduction
○ Background
○ Rationale
○ Objectives
○ Approaches
● Literature Review
● Materials and Methods
● Results
● Take Home Messages
● Acknowledgments

3. Introduction

4. Background: Site Description
Previously was a landfill
90 acre property
● Compost facility → 32-acres
● Human Society → 8-acres
● Jurisdictional Streams → 50 acres
● FEMA Flood Zone → 42.4% of 50
acres
Figure 1. Project Site located at 110 Humane Society Lane, Columbia, SC

5. Figure 2: Existing
composting facility in
Colombia

6. Images From On-Site Visit
Figure 3: Figure 4:
Figure 5: Figure 6:

7. Background: Current Facility Operations
● Annual capacity
○ 15,000 cubic yards of material
● Hands-off composting technique
○ Takes over 1 year to complete
● Yard clippings and woody material
○ Considered “non-organic”
● Only 1 full time employee
● Low, to no profit from sales
Figure 7. Yard trimmings being collected for compost
facility https://www.columbiasc.net/solid-waste/yard-trimmings

8. Rationale
● 40 million tons of food sent to landfills in 2015
● Food waste not included in currently operation
● Composting food waste would reduce landfill waste by 30%
● City’s carbon footprint lowered
● Local connections provide consistent food waste
● Compost quality improved
● Secure a profitable market for finished compost

9. Objectives
The main objective of this project is to redesign a compost facility for the City of
Columbia. The specific objectives are to:
1. Evaluate alternative methodologies for incorporating food waste into the facility’s current
compost operations
1. Redesign the site layout and modify operational procedures based on chosen methodology
1. Increase the facility’s profitability

10. Task 1: To modify site operations by
➢ Converting the facility to include
food waste
➢ Evaluating the methodologies of
covered/open static aerated
windrows, covered/open turned
windrows, or in-vessel reactors
➢ Selecting the best methodology
➢ Determining maintenance procedures
for compost methodology
➢ Selecting necessary equipment for
compost methodology
➢ Securing a waste hauling service
➢ Quantifying compost capacity
➢ Specifying mixing procedures for
feedstocks.
Task 2: To redesign the site layout
by determining
➢ Entrance and exit locations
➢ Product, contaminant, equipment,
and waste storage areas
➢ Operations building
➢ Operating pathways
➢ Grading for runoff management
with minimal excavation
➢ Stormwater design including a
retention pond
➢ Windrow spacing and dimensions
➢ Any additional site requirements
necessary for permitting.
Task 3: To form local
partnerships in order to
maintain consistent
feedstock sources and
optimize marketability of
final compost product. The
facility will need to have an
estimate on annual organic
compost production as well
as operating costs and
maintenance expenses.
Approaches

11. Disciplinary Collaboration
***Insert Venn Diagram****

12. Overall Steps for Project Completion
Figure 8:

13. Literature Review

14. Compost Information
Basics of compost:
What is compost used for?
Why is compost good for soil?

15. Composting Processes
Phases of Microbial Growth:
● Mesophilic
○ Microorganisms initially breakdown feedstock
○ Moderate temperature between 20-40 deg. C
○ Breakdown causes temperature to rise into thermophilic range
● Thermophilic
○ Breakdown of more complex compounds
○ Lasts from 30-over 100 days depending on process
○ Pile gets up too and stays above 55 deg. C
■ Pathogens killed
● Cooling
○ Mesophilic bacteria dominate
○ Develop maturation of product
○ Typically lasts around a week

16. Facility Type
● Type 1
○ Yard trimmings and landscaping debris
○ Compostable bags
● Type 2
○ Animal manure
○ Food waste (no meat)
■ Can take cooked meat from plate scrapings
● Type 3
○ Sludges
○ Fats, oils, and grease
○ Other organic residuals

17. Composting Technologies: Turned Pile/
Windrows
● Collect compost into long piles
called windrows
● Regularly turn the pile in order
to promote decay
Figure 10:
https://i.pinimg.com/originals/6b/a6/66/6ba666e0b1f332edc1c014f9996fecf3.jp
g

18. Composting Technologies: Active Aeration
○ Pile is placed on pad with small holes
■ Air can be forced through by a
blower
■ Air can be pulled through by
suction based on negative pressure
created beneath the pad
○ Both ways of aeration can be combined
for more effective homogenization
Figure 11:
http://compost.css.cornell.edu/MSWFactSheets/msw.fs2.html

19. Composting Technologies: In-vessel
○ Uses some form of enclosure (called
drums)
■ Enclosed aerated static piles
■ Agitated vessels
○ Generally improved moisture control,
temperature control, and odor control
Figure 12:
https://www.ecoponics.com.sg/wp-content/uploads/2016/05/In-vessel-
Composter.jpg

20. Retention Pond Design
● Purposes
○ Manage stormwater and erosion of sediment from site
○ Avoid nutrient overload in nearby waterways
○ Preserve local infrastructure
● Primary components
○ Inlet/forebay → Diversion of water from site to pond
○ Basin → Flow control, partial temporary storage, partial
treatment storage
■ Littoral shelf → Encourage plant life to anchor
bank of pond
○ Emergency spillway → Preparation for large storms
○ Outlet → Properly deliver water away from pond
Figure 9:

21. Charleston County Case Study
● Fast turnaround
○ Finished compost in 45 days
● Municipal or commercial trucks deliver
waste
● Waste processed through grinders
● Deposited into one of 70 windrows
● Space between rows for loader and
water trucks
○ Moisture and temperature closely monitored
● Trommel removes large pieces
● Generates 60,000 tons of compost per year (primarily composed of yard
waste)
Figure 12: Provided by the City of Columbia

22. Greenville County Case Study
● Designed to have annual capacity of 12,000
tons of compost
● Partnered with Atlas Organics
○ Food waste collection service
○ Compost production service
○ Compost quality testing through third party
● Residential waste material accepted
● Organic farming approved
● Primarily food waste/woody biomass
○ No biosolids or manure
● 45-day process
1) Forced aeration
2) Windrow
3) Screening
Figure 13: Provided by the City of Columbia

23. Advantages & Disadvantages Compost
Technologies

24. Materials and Methods

25. Pile Dimensions
● Capacity: 15000 yd3
○ Breaks into 49 total piles
● Total acreage of composting portion is 10 acres
● 20 ft spacing between each pile
Figure 14:

26. Material Mass Balance of the Composting
Process
Where…
● BVS = biodegradable volatile solids (kg/day)
● Xs = wet weight (%)
● Vs = organic content (%)
● Ks = degradability (%)
● Ss = substrate amount (kg/day)
● NBVS = nonbiodegradable volatile solids
(kg/day)
● WAT = water component
● ASH = ash component
● WATSO = water component of product solids
(kg/day)
● WATP = water product during composting
(kg/day)
Figure 15:

27. Material Mass Balance of the Composting
Process
Where...
● NBVS = nonbiodegradable volatile solids (kg/day)
● WAT = water component
● ASH = ash component
● PS = product solids (kg/day)
Figure 16:

28. Material Mass Balance of the Composting
Process
Where...
● DGASO = dry gas out
● DAIRI = dry air in
Figure 17:

29. Results

30. Material Mass Balance
Figure 18:

31. Proposed Site Layout
Figure 19:

32. Acknowledgements

33. We would like to thank...
Deb Sahoo, Senior Engineer/Subject Matter
Expert/Task Leader at Woolpert
Holly Elmore, Founder & CEO, Elemental Impact
Chantal Fryer, Senior Manager, Recycling Market
Development at Department of Commerce
David Paul, Co-founder, CIO at CompostNow Inc.
Kim Charrick, Sustainable Management of Food
including Food Recovery Challenge for Hospitality
Sector at US EPA
Mary Pat Baldauf, Sustainability Facilitator; City of
Columbia, SC
Jim Lanier, President/CEO at Earth Farms Organics
Douglas Oflaherty, VP of SC Restaurant and Lodging
Association
Britt Faucette, Director of Research and Technical
Services
Wesley Harrison, Senior Engineer for City of Columbia
Samantha Yager, Solid Waste Assistant
Superintendent at City of Columbia
Will Sagar, Southeast Recycling and Development
Council
Brenda Platt, Director of Composting for Community at
Institute for Local Self-Reliance
Nora Goldstein, Editor at BioCycle
Richard Chesley, Manager at S.C. Department of

34. Takeaway Messages

35. Takeaway Messages

36. Thank you!