Large Scale Operations

1. Large Scale Operations

2. Funded by the Indiana Department of Environmental Management Recycling Grants Program Developed by the Indiana Rural Community Assistance Program - RCAP Presentation 8:The Composting Toolkit

3. Large Scale Operations • This section will help you to implement the composting techniques discussed in the earlier section on aerobic composting • This section will help you identify the key steps to a large scale operation • This section will help you identify appropriate equipment and appropriately sized equipment

4. Important Questions • What will you do with the finished product? • How much yard waste is available for you to compost? • How much yard waste can you expect to divert? • Will you utilize only yard waste or also food waste and/or biosolids? • Will it be cost effective? • What resources are currently available? • What type of program will you implement? • How are you going to finance the program?

5. Key Steps • Collection • Particle size reduction • Initial material screening (Front-end) • Composting • Regular turning • Finished product screening (Back-end)

6. Sections Within This Chapter • Composting Operations Equipment • Start-up Considerations • Ongoing Operations are covered in the next chapter . . .

7. Composting Operation Equipment

8. Equipment • Many of the pieces of equipment discussed in the “woody waste” management presentation are also useful for composting operations • Size Reduction Equipment: • Chipping and/or Shredding Equipment • Moving Materials / Turning Materials: • Loader • Dedicated Turning Equipment: • Windrow Turner • Sorting Equipment: • Screens

9. Size Reduction Equipment • Size reduction is one of the first critical steps in the composting process. • An optimal particle size is 1 to 3 inches. • The key is maximizing surface area. Sufficient surface area will give the microbes that perform the composting a place to complete their work.

10. Shredding Verses Chipping • The two primary ways size reduction is accomplished is shredding or chipping • Shredding: • Shredders grind the waste by employing a hammer mill to pound trees into shreds. • Chipping: • Chippers use sharpened knives on a disc or a drum to make dimensional chips

11. Shredding Verses Chipping • The two primary ways size reduction is accomplished is shredding or chipping • Shredding: • The primary advantage of shredding is that is maximizes surface area which is optimal for composting. Shredding equipment is also able to handle some contamination from dirt and rocks. • The primary disadvantage of shredding is cost. The equipment to shred is usually much larger than chipping equipment and is significantly more expense to purchase and maintain. • Chipping: • The primary advantage of chipping is that the equipment is smaller, multi-purpose, faster, and less expensive. • The primary disadvantages to chipping is that the composting process will take longer because the chips provide significantly less surface area than shredding equipment. A chipper is unable to tolerate contamination from dirt and debris.

12. Chippers

13. Variations with Chippers • Disc-style chippers are much more common than drum-style chippers. • The disc-style is at this time the “industry standard” • However, at this time there are new developments being made in the drum-style arena. Drums have great promise because they are more compact, yet they can have a larger-diameter opening for feeding materials into the chipper.

14. Variations with Shredders:Tub Grinders • Tub grinders have long been the industry standard in shredding equipment. • Tub grinders have an opening on the top. Materials must be dropped in and rely on gravity to feed the hammer mills. • The primary advantage of a tub grinder is it tends to be faster than other shredders with woody wastes. • The primary disadvantage of tub grinders is they tend to “throw-out” materials which is hazardous to operators as much as within 300 feet of the machine.

15. Shredders: Tub Grinders

16. Variations on Shredders:Horizontal Grinders • Horizontal grinders pull in materials to be processed via a conveyor belt of chain track which feed materials to be shredded into the hammer mill. • Horizontal grinders do not have the tub grinders tendency to “throw-out” materials

17. Shredders: Horizontal Grinders

18. Size Matters • To increase capacity and production, new grinders are getting heavier, with bigger hammer mills. The largest models now approximate the size and weight of a railroad freight car and cost well over half a million dollars. • Smaller tub-grinders weigh around 80,000 pounds. Larger tub-grinders weigh over 110,000 pounds. Horizontal grinders often weigh approximately 100,000 pounds. • The lighter the machine, the more you will sacrifice longevity • The thickness of steel determines how soon the machine will require welding to remain in one piece. Extra weight reduces vibrations in turn reducing wear and tear.

19. Variations with Shredders:Stump Grinders • These are specialized machines designed specifically to pulverize tree stumps in place down to a specific depth. • It is easier to pulverize a stump in the ground than to pull it out and grind it. • This would more commonly be used in on-site wood waste management than in composting operations separate from where the woody waste is generated.

20. Loaders

21. Loaders • The front-end loader is the single most important piece of equipment for large scale composting facilities. • It may be the only piece of equipment needed for operations for smaller communities. • The loader moves materials around the site and can be used as the turning equipment for windrows as well.

22. Windrow Turner

23. Windrow Turners • Windrow turners are designed specifically to turn and aerate compost in a windrow. • There are both self-propelled models and models that require a tractor to pull them. • The advantage of windrow turners is they thoroughly turn and mix materials and do so more quickly than front end loaders can. • This superior mixing produces a superior compost product. • Their primary disadvantage is the added cost of purchasing an additional piece of equipment for a composting operation.

24. Screens

25. Screens • Plastic, cloth, wire mesh, deck (flat), disc, grizzly, orbital, star, and trommel screen. The many varieties of screens.

26. Screening • Large scale composting facilities will nearly always employ some form of screening. • If your facility plans to SELL finished compost a screen is essential. When paying for the finished compost, people demand a quality of finished product that simply can’t be obtained without screening. • If a community has strong controls on the front end of their process such as strong litter control, strong compliance on not allowing plastic bags, then the community may be able to get by without a screen if the end product is given away.

27. Screening • Removal of contamination • Proper sizing of starting and finished product • Material passing through a screen is generally referred to as “undersize” • Material that remains on the screen surface is generally referred to as “oversize”

28. Cost Effectiveness ofWindrow Composting • That equipment looks expensive! I thought you said this was cost effective! • First, compare these to the costs of landfill equipment or MRF equipment. • Second, select equipment appropriate to your size operation. • Third, form partnerships!

29. Form Partnerships • Bartholomew County SWMD contracts with a private contractor who provides tub grinder services. The District pays an hourly rate for the equipment. The contractor maintains the equipment and Bartholomew is simply one of many clients for the contractor. • Northeast Indiana SWMD owns a tub grinder and uses it at five composting sites over a four county area.

30. Start-up Considerations

31. Start-up Considerations • Facility Location • Facility Type • Site Characteristics • Customer Access • Collection Options • Drop-off • Curbside • Out-of-system Users

32. Operational Considerations • Hours of Operation • Staffing • Equipment • Site Requirements • Fee Schedule • Program Budget

33. Site Layout • Office • Drop-off Area • Chipping/Shredding Area • Mulch / Woody Waste Storage Area • Composting Area • Screening Area • Equipment Service and Storage Area

34. Operation Plan and Procedures • Composting Registration • Site and Traffic Plan • Administrative Procedures • Safety Procedures • Materials Processing Procedures • Testing Requirements • Maintenance Procedures • Marketing Plan

35. Example Site Layout

36. Compost Facility Registration • Compost facilities that process more than 2,000 pounds of vegetative matter during a year are required to register with IDEM. • Registered facilities must then submit an annual report to IDEM in regard to the volume of materials processed in the previous year. • Registration is valid for five years and may be renewed.

37. Compost Facility Registration • The registration must include the following components: • A legal description of the site • A topographic map of the site • A description of the composting facility and who it will serve • An estimate of the yearly volume to be processed • A registered Indiana compost facility may not: • Be located within 200 feet of a potable water supply • Be located within 200 feet of a existing residential structure • Be located within a 10-year floodplain • A registered Indiana composting facility must: • Keep compost five feet from the water table • Manage leachate and runoff generated by the compost site • Control dust, odor, and noise

38. White Papers • Don’t reinvent the wheel (or the compost pile in this case) • Composting tool-kit white paper topics include: • Facility Siting Guidelines • “How to” for Navigating Compost Facility Registration Process • Start-up and operation logistics recommendations • Guidelines for identifying appropriately sized equipment

39. QUESTIONS?

40. Thank You! • Additional Questions, Comments, or You Think You Have A Potential Pilot Community • Please Feel Free to Contact Me: Mark W. Davis Technical Assistance Provider Rural Community Assistance Program Office: 1-800-382-9895 Wireless: (812) 320-0720 E-mail: mdavis@incap.org