COMPOST TURNING AND AERATION USING WINDROW TURNERS

Revision Date: 5/00
Process Code: Navy/Marines: N/A; Air Force: N/A; Army: N/A
Usage: Navy: Medium; Marines: Medium;Army: Low; Air Force: Low
Compliance Impact: Low
Alternative for: N/A
Applicable EPCRA Targeted Constituents: N/A
Overview: Windrow turners are used to turn and aerate compost in windrows (long extended piles). Windrow turners break up anaerobic pockets in the compost, introduce oxygen, and release heat from the pile. Windrow turners are especially suited for high-volume facilities.

Large windrow turners are typically self-propelled and straddle the windrow, using a cylindrical drum with attached flails to mix the compost. Smaller windrow turners consist of a unit that can be attached to a front-end loader or tractor that is driven between windrows. This side-mounted unit may have the advantage of being more economical for sites that do not require a full-time windrow turner. However, since they turn only half of the pile or windrow, more passes are needed for each pile, which produces an increase in labor hours.

Compost reduces the amount of waste to be disposed. Complete recovery of yard waste will reduce the amount of waste disposed in landfills by an average of 15.9% (EPA, 1994).
Compliance Benefit: Composting will help meet the requirements under Executive Order 13101 requiring executive agencies (e.g. DOD) to incorporate waste prevention and recycling in their daily operations.

States and/or localities may have additional regulations on composting which should be followed. The use of windrow turners or a front-end loader may increase fuels on site which may increase a facility’s need to comply with SARA (40 CFR 355 and EO 12856) reporting requirements and SPCC (40 CFR 112) issues.

The compliance benefits listed here are only meant to be used as a general guideline and are not meant to be strictly interpreted. Actual compliance benefits will vary depending on the factors involved, e.g. the amount of workload involved.
Materials Compatibility:
N/A


Safety and Health: Safety issues for using windrow turners concern the operation of power equipment and health effects of working with decomposing organic matter. Operators should be specifically trained to use the turner. Machinery should not be used if workers are on medication. Proper personal protective equipment (PPE) including gloves, eye protection, respiratory protection, and hearing protection should be used if needed. Consult the base safety office regarding proper PPE and training prior to using mechanized equipment.


Benefits:
  • Turns more cubic yards of compost per hour than a front-end loader.
  • Produces compost with a superior texture relative to that produced by a front-end loader.


Disadvantages:
  • Turner design and size limit windrow dimensions to a maximum of 5 to 7 feet high, and 14 to 18 feet wide at the base.
  • Windrow turners require level surfaces to operate efficiently.
  • Turners can be difficult to move from site to site.


Economic Analysis: Windrow turners cost can vary from approximately $45,000 to $250,000. These units can process from 2,000 cubic yards/hour (requires front-end loader) to 4,000 cubic yards/hour (self-propelled unit). Operating costs, not including labor, are $18/hour to $35/hour.

The cost of constructing and operating a windrow composting facility will vary from one location to another. The capital costs include compost pads, grinder, compost mixer, trommel screen, front-end loader, windrow turner, and offices. The solid waste disposal costs are based on estimates provided by Seymour Johnson AFB:

Assumptions:

  • Process 3000 tons/yr of yard waste, food waste, etc.
  • Produce 1,500 tons/yr of finished compost.Capital Costs: $600,000 (does not include land costs)
  • Solid waste disposal costs: $28/ton
  • Cost to pickup and haul waste to landfill: $50/ton
  • Operating costs (labor and maintenance): $165,000/yr.
  • Avoided topsoil purchases: $25/ton

Annual Operating Cost Comparison of Diversion and Disposal for Windrow Composting

 
Diversion
Disposal
Operational Costs:

Labor and maintenance: $165,000 $0
Landfill costs: $0 $84,000
Transport/waste pickup costs: $0 $150,000
Total Operational Costs: $165,000 $234,000
Total Recovered Income
(Topsoil Savings): 		$37,500 $0
Net Annual Cost/Benefit: -$127,500 -$234,000

Economic Analysis Summary

    Annual Savings for Diversion Method over Disposal: $106,500
    Capital Cost for Diversion Equipment/Process: $600,000
    Payback Period for Investment in Equipment/Process: 5.6 years

Click Here to view an Active Spreadsheet for this Economic Analysis and Enter Your Own Values.
Approving Authority: Approval is controlled locally and should be implemented only after engineering approval has been granted. Major claimant approval is not required.


NSN/MSDS:
Product NSN Unit Size Cost MSDS*
None Identified $  

*There are multiple MSDSs for most NSNs.
The MSDS (if shown above) is only meant to serve as an example.

Points of Contact: Air Force:
Mr. Chuck Schwingler
Seymour Johnson AFB
1095 Mitchell Avenue
Seymour Johnson AFB, NC 27531-2355
Phone: (919) 722-5168
DSN: 722-5168
FAX: (919) 722-5179
 
Navy:
Mr. Wallace Eakes
Naval Facilities Engineering Service Center
1100 23rd Ave.
ESC 426
Port Hueneme, CA 93043-4370
Phone: (805) 982-4882
DSN: 551-4882
FAX: (805) 982-4832

Vendors: Brown Bear Corporation
P.O. Box 29
Corning,  IA   50841
Phone: (515) 322-4220 
  Double T Equipment Manufacturing Limited
Airdrie, Alberta,  T4B 2B8
CA
Phone: (403) 948-5618 
FAX: (403) 948-4780
  Scarab Manufacturing and Leasing, Inc.
White Deer,  TX   79097
Phone: (806) 883-7621 
FAX: (806) 883-6804
  Scat Engineering Division, ATI
Delhi,  IA   52223
Phone: (800) 843-7228 
FAX: (319) 922-2700
  Wildcat Manufacturing Co., Inc.
Box 1100
Freeman,  SD   57029
Phone: (800) 627-3954 
FAX: (605) 925-7536

Sources: Mr. Chuck Schwingler, Seymour Johnson Air Force Base, February 1999.
Double T Equipment Manufacturing Limited, March 1995.
Scarab Manufacturing and Leasing, Inc., March 1995.
Scat Engineering, March 1995.
Wildcat Manufacturing Company, Inc., March 1995.
Illinois Department of Energy and Natural Resources, 1989.
Management Strategies for Landscape Waste - Collection, Composting, Marketing. ILENR/RR-89/09.
Tim Brecheen, Seymour Johnson Air Force Base, July 1996.
Wayne Fordham, Tyndall Air Force Base, July 1996.


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