Food Waste Diversion at Correctional Facilities Composting Technologies

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

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

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

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

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

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

Aerated Compost Bins

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

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

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

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

In-Vessel Systems Rotary Drum Composters

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

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

Box/Tunnel Composting Systems

Box/Tunnel Composting Systems

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

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

Mechanical Compost Bins b b b b 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 b b b b 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: b b b 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 De. Rham, (802) 368 -7291

Summary b 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