Dodge County: Compost case study

Type of project

Source-separated organic material collection from three sectors: schools, commercial and residential

Organization description

  • Organization: Dodge County, Minn.
  • County size:  440 square miles
  • Population: 20,243 in census year 2010

Project purpose/goals

Dodge County was interested in determining the long-term sustainability of source-separated organics collection services. To accomplish this they targeted three sectors: schools, commercial businesses and residents.

Materials targeted

  • School sector: food waste, milk cartons, wood chips
  • Commercial sector: bakery, deli and produce
  • Residential: food and garden waste

School sector project

The EARTH team (Environmental Awareness and Responsibility at Triton High) collected cafeteria food waste and wood chips from its shop classes. The school houses K-12, however only grades 6-8 participated in the program due to constraints on lunchroom staff. About one 5-gallon bucket of food waste was generated each day. In addition to food waste collection, the school also collected milk cartons for recycling.

The School purchased three JORA compost tumblers. Each day the EARTH team collected the 5-gallon bucket and brought it outside to the compost tumbler. They added sawdust and wood chips to mix with the food waste. Despite the tumbler being insulated, the bins did freeze and collection of food waste was temporarily suspended for about three months.

The finished compost was used to amend soils in the school garden and in the spring of 2012 the first-graders used the compost to plant flowers to take home.

Prior to this project, the school’s environmental science class conducted a waste sort of the waste generated for elementary, middle and high school lunches. The teacher met with the kitchen staff during the initial planning and again for the implementation. The teachers and staff supervising the lunch times were sent an email about the project and how they could help with collection efforts.

The EARTH team informed the students at a back-to-school assembly and subsequently through their public address system. They also developed a display that was located in the main lobby.

Commercial/Business sector

Dodge County staff met with licensed haulers to gage initial interest in their participation. Alli Rolliff worked with Dodge County to solicit area businesses to participate in an organics collection program. Initially two grocery stores and two restaurants were recruited. However, one grocery store, located in Olmsted County, was not able to participate due to a solid waste ordinance in Olmsted County. One of the restaurants dropped out because of a language barrier. As a result, the grant was used to purchase outdoor collection bins and compostable bags.

Erdman’s grocery store collected organics from the bakery, deli and produce departments. Additionally, a local hog farmer picked up food waste in a separate container. The hog farmer was not part of the grant and did not weigh their food waste.

Residential sector

Dodge County pre-sold 42 backyard compost bins through a cooperative sale with Olmsted County. The sale was advertised through the local Shopper newspaper. All the bins were pre-ordered and pre-paid to control costs. Residents picked up the bins at the Dodge County Courthouse.

A follow-up survey was mailed to the residents with a 29 percent response rate. Most of the respondents were using the bin and about half were using the bin daily. The average amount of food waste composted each week was three gallons. Residents reported they liked the reduction in kitchen waste and the quality of the finished compost. The only drawback reported was that composting attracted flies.

Partnerships

  • School sector: District administration, teachers, EARTH team, kitchen staff, and the custodial staff.
  • Commercial sector: Haulers and area businesses
  • Residential: Olmsted County and Zumbro Watershed District

Project timeline

June 28, 2010 to June 30, 2011

Cost/budget

  • School sector:
    • County purchased three JORA compost tumblers: $1800
    • County in-kind staff time: $700
  • Commercial sector
    • Collection bins: $974.83
    • Compostable bag liners: $2,494.69
    • County in-kind staff time: $1,000
  • Residential sector:
    • 42 Earth Machine compost bins: $820
    • County in-kind staff time: $700

Measurable results

  • School sector:
    • Four tons of material per year was diverted to onsite school composing
    • Four metric tons of carbon dioxide equivalent abated
  • Commercial sector:
    • From August 2010 to June 2011 41.18 tons of organics waste was diverted. This does not include the amount of food diverted by the hog farmer.
    • 36 metric tons of carbon dioxide equivalent abated
  • Residential sector
    • An estimated 25.2 tons of food waste per year from 42 residents
    • 22 metric tons of carbon dioxide equivalent abated

Lessons learned

Dodge County met with the city councils to discuss the program. Some cities were not able to participate due to financial issues.

Olmsted County’s ordinance restricting exporting food and non-recyclable paper eliminated the opportunity for commercial and institutional organization in participating in this project.

Increasing route density is key to the success of a commercial organics program

Further information

For further information contact Dodge County Environmental Services at 507-635-6273.