Notes

Outline

Food Waste Diversion at  Correctional Facilities Composting Technologies and Costs Craig Coker Organics Recycling Coordinator DENR/ Div. Of Pollution Prevention & Environmental Assistance

Overview Technology  in Composting Materials Handling Biological Process Optimization Odor Control Capital  Cost Increases with technology Operational Costs Decrease with technology Footprint (Area Required) Decreases with technology (usually)

Technology Classification Low - Tech Windrow Mid - Tech Aerated Static Pile Aerated Compost Bins High - Tech (In-Vessel) Rotary Drum Composters Box/Tunnel Composting Systems Mechanical Compost Bins

Windrow Composting Long, narrow piles agitated/turned regularly Aeration by natural/passive air movement Better suited to larger volumes Composting Time: 3 - 6 Months

Windrow Composting, cont. Equipment Needed Grinder/Shredder Tractor/FEL Windrow Turner tractor-pulled self-propelled Screener Manual labor costs excessive without equipment

Windrow Composting, cont. Footprint One Acre Can Handle 4,000 - 7,000 CY Compost Mix Costs Site Prep -Site Specific Asphalt/Concrete Pad ($12 - $27/square yard) Equipment Grinder/Shredder : $3,500 Tractor/Front End Loader : $50K - $150K Windrow Turner : $30K - $200K Screeners : $50K - $180K

Aerated Compost Bins

Aerated Compost Bins Aeration Through Porous Floor Plates Composting Time: 2 - 3 Weeks Curing Time: 2 Months Durable Materials of Construction Equipment Needed: Front End Loader Vector/Vermin Control Needed With Food Wastes Capacities: 3 - 4 Days Food Waste + Bulking Agent Per Bin

Aerated Compost Bins At Caledonia 12 Bins - Two Rows of 6 Bins Construction Cost - $40,000 Footprint - 50 SF per Bin Capacity of Each Bin - 36 Barrels (35 - gal.) of Food Scraps Blowers - 980 CFM Aeration Plates - 2’ x 2’, $89 Each Filling/Emptying - With Bobcat

Aerated Static Pile Aeration Provided By Mechanical Blowers Can Shorten Composting  time to 3 - 5 Weeks (followed by 30 days curing)

Aerated Static Pile Better Suited to Larger Volumes (landscape debris and food waste) May Not Be Suited to Wastes That Need Mixing During Composting, Like Food Wastes Difficult to Adjust Moisture Content During Composting If Needed Odor Control Difficult With Positive Aeration Less Land Area Than Windrows, Still Labor Intensive

In-Vessel Systems Rotary Drum Composters

Rotary Drum Composters Rotation Mixes, Aerates Compost Mix Second - Stage Curing/Composting Needed Food Waste Grinding and Mixing With Bulking Agent Needed Prior to Feeding Drum Recipe For Drum Composting Food Wastes: 2 Parts Wood Chips 1 Part Sawdust 2 Parts Food Waste

Rotary Drum Composting at Brown Creek Type 616 Greendrum Composter with Patz 9427 Chopper Mounted on Tandem Axle Frame - moveable Footprint - 200-300 SF Daily Loading Rate - 2,000 - 5,000 Lbs/Day Operating Capacity - 11 CY Retention Time - 1 Week, Curing Time - 2 Months Cost -  Approx. $45,000

Box/Tunnel Composting Systems

Box/Tunnel Composting Systems

Auburn Correctional Facility, NY Wright Environmental Model 1500 (Model 750 shown)

Auburn Correctional Composting Capacity: 1500 lbs/day Composting Time: 4 Weeks Curing Time: 1 Month Labor - 2 Inmates Cost: $123,000 Disposal Savings: $33,000 / yr. (4-yr. Payback) Footprint: 50’ Long x 10’ Wide

Mechanical Compost Bins Green Mountain Technologies  “Earth Tub” Modular Design, Batch Operation Capacity: 200 lbs/day Composting Time: 4 Weeks; Curing: 1 Month Footprint: 1 Parking Space Cost: $6,000 Labor: 1 Operator

GMT “Earth Tub” Installations UNC - Asheville (Spring, 1999) Univ. of Georgia Hyatt Regency,  Chicago Vermont DEC Univ. of South Carolina Connecticut DEP Flushing Hospital, NY Texas A&M University

For More Information: Greendrum Rotary Drum Composter Bob Broom, RKB Enterprises  (888) 475-2368 Wright Environmental Tunnel System Paul Roth, Innovative Environmental Systems (757)890-1354 Green Mountain Technologies Earth Tub John DeRham, (802) 368-7291

Summary Factors To Consider In Selecting Technology Available Space Available Labor (Inmate or Staff) Vendor Previous Experience With Same Feedstocks Control of Odors, Vermin, and Vectors Life - Cycle Costs Capital Costs And All O&M Costs Over Expected Life Of System Low - Tech: Lower Capital; Higher Operating Costs High - Tech: Higher Capital; Lower Operating Costs