Gustavus Adolphus College



Compost and food waste recycling—ideas for Gustavus

18 April 2010

Jim Dontje

a. Student Senate resolution (see below) and other expressions of support

b. Background information: preconsumer versus post consumer, 2005 to 2008 average: 175.5 tons/year (961.6 lbs/day), tipping cost of $ 12,550 ($71.50/ton); St. Olaf in-vessel system cost about $160,000

c. Regulatory issues: internal source of feedstock and internal use of compost less regulated; city limits versus county

d. Technical approaches to composting

|Method |Infrastructure |Labor |Advantages |Challenges |

|Open pile/windrow |Concrete pad or bard ground,|Daily tending |Cheap and easy to start up |Run off, vermin, odor, |

| |run off catchment, hauling | | |labor |

| |and turning equipment | | | |

|Covered pile/windrow |Same as open pile but add |Daily tending |More control of process, |Vermin and odor still |

| |simple cover like hoop | |especially water management |an issue, Possible |

| |house. Possible to use | | |worker safety in |

| |smaller catchment basin | | |structure; higher costs|

| | | | |and regulatory issues |

|In-vessel |Fully engineered system with|Less daily management |Good control of process, |High capital cost |

| |containment and material |(mostly daily loading and |little runoff, fewer vermin | |

| |transport |unloading) |issues | |

|Vermicomposting |Vermicomposting trays and |Daily loading and unloading |Cool process, can be |Leachate management; |

| |material handling equipment;|of product |relatively odor free; less |larger area |

| |simple structure and | |bulky product |requirement; heating |

| |environmental control | | |energy |

Some alternatives to composting:

Anaerobic digestion: The products are biogas (methane and carbon dioxide) which can be used directly to heat water and low solids/low odor liquid that can be pumped and land applied. Amenable to mechanical loading and unloading. Process takes place in sealed vessel. This is done at the Northern Plains dairy west of town althought at a much larger scale. The challenge is to find equipment at our size—most of what is available is much larger. This means we would probably have a research project on our hands if we pursued this.

Feed it to the pigs. The Stillwater schools do (or have in the past) done this (). The waste must be hauled and cooked, which raises costs and energy use, but if we found a close by partner this has some potential.

Develop a third party composting partner. This isn’t really an alternative to composting, but rather a different way to get the job done. The city will eventually need a new site for its yard waster composting operation. A small business could be developed around the revenue stream from our food waster and the cities yard waste. This could reduce our hauling distance but not our tipping fees. The money would be spent locally, however.

APPENDIX A

Compost Committee Resolution

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Adopted:

GUSTAVUS ADOLPHUS STUDENT SENATE, April 11, 2011

WHEREAS, maintaining environmental sustainability is a Tier 1 objective of Gustavus Commission 150, we, the Gustavus Adolphus College Student Senate,

RECOGNIZE, over half of students and faculty polled think composting is a necessity on campus;

PROCLAIM, 94% of those polled would support and use a composting policy if one were implemented;

ACKNOWLEDGE, Director of Dining Services Steve Kjellgren in his pledge to fully support implementing any infrastructure needed in a composting system;

RESOLVE, to submit the Student Senate Compost Committee’s data and infrastructure plans;

URGE, the College to consider these plans and requests to implement one of them in order to create a composting system at Gustavus Adolphus College.

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