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Composting Pilot Study

Wright-Pierce worked closely with the City of Lewiston to conduct a pilot study to collect and compost organic waste separated from municipal solid waste. The City was seeking ways to reduce waste management costs and increase its waste diversion rate, which was 43 percent in 1995.  Although biosolids from Lewiston are composted at the Lewiston-Auburn Sludge Composting Facility, composting of the municipal solid waste stream was limited to tree leaves. 

A small-scale pilot study was conducted to determine if separation, collection and composting of residential and commercial organic waste could save the City money.  Approximately 600 single-family homes, four restaurants, one hospital and one school participated.

The primary goal of the study was to determine participation and waste diversion rates.  This was the first study of its type to be carried out in Maine. The State Planning Office provided funding because the Lewiston study will assist other communities in establishing similar programs.

Training programs for residential, institutional  and commercial study participants provided instruction about what qualify as organic waste products and how it should be collected.

Waste volumes and contamination levels were recorded during collection.  Following collection, the material was weighed, ground and then composted at the Lewiston-Auburn Sludge Composting Facility.  Samples at various stages of processing were collected and analyzed.

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Project Highlights

Background

Lewiston’s solid waste program was viewed as a model for the collection and composting of organic waste because most of its solid waste is disposed of in a landfill. There was incentive to compost additional material to extend the life of the landfill.

Pilot Study Facts

  • Participants included 600 single family homes, four restaurants, one hospital, one school
  • Collection of organic waste carried out once a week for a six week period
  • 30%-50% participation
  • 7.5 tons of residential waste collected represents approximately 7 percent of the total waste volume for participants
  • Actual recoverable organic waste volume much higher than 7 percent and would be expected to increase over time