Food and Dining Composting
at Clark University
Dave Schmidt
NACUBO
April 1st 2008
Why Compost?
• Close the loop
• Divert waste from landfills
• Reduce emissions
Genesis
• Student group project, spring 2006
• Focused on waste from Clark Dining
Services
• Proposed the installation of Earth Tubs
• Taken up by the Sustainability Task Force
in fall 2007
• Committee formed to conduct analysis
Annual Baseline Scenario
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35 Yard roll-off compactor
$150 / month for service charge = $1800
$115 per lift, once a week = $5980
$77 per ton = $18,249 (237 tons / year)
Earth Tub Scenario
• Purchase 3 Earth Tubs = $30,000 total
• Material can be cured and stored at
arboretum, used on grounds
• Students estimated 57 tons diverted ~
savings of $4,400 / year
• Reduce pickup schedule to once every 2
weeks ~ savings of $3,000 / year
• Roughly 4 year payback
Earth Tubs - Bowdoin
Earth Tubs – Harraseeket Inn
Fatal Flaws
• Insufficient space on loading dock
• Odor issues and proximity to Admissions
We Care Scenario
• Tip at We Care Composting Facility
• Increase materials that can be composted
• Use existing waste hauler’s service and
container
• Divert trash to a nearby compactor
• Increased hauling costs ~ $200 per lift
• Decreased per ton fee to ~ $60
• No significant net cost increase
Planning
• Summer 2007
• Scope – one building
• Committee of building occupants, dining
service managers, and Physical Plant staff
• Developed plans for infrastructure, cost
handling, and procurement
Implementing
• New bins
• Purchase compostable cutlery and service
ware
• Divert trash from other buildings
• Design educational campaign targeting
– Dining Services staff
– Building users
Operations - Collections
Collect materials from:
– Food preparation
– Post consumer waste
– Containers within the building
Operations – Modular Bins
Operations - Collection
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Operations - Education
Operations - Education
Operations – We Care
• Handle all organic and biodegradable
material, including waxed and soiled OCC
• Auger extracts plastic bags
• Prohibit “sharps” – anything that can
puncture the skin of a worker
• Type 1 compost – permitted for unlimited
distribution
Data
• Online at the end of August
• As of February 1st, 145 tons collected
• Clark delivers a premium mix, only 5% is
trash
• Composting program has offset 44% of
total daily trash
Emissions
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Clean Air Cool Planet Carbon Calculator
Daily waste handled in Mass Burn Facility
137 tons of trash generates (15) MT CO2e
Mass Burn less CO2 intensive than grid
137 tons of compost generates (25) MT
CO2 e
• Clark’s approach: consistent with WRI
Take Away Points
• Onsite = potential savings
– Reduced pickup schedule and tipping fees
• Offsite = no net costs or added labor
– Lower fee / ton balances higher lift fee
• Opportunity in a change in dining service
• Form committee of stakeholders early
• Substantially divert waste stream