Human Biology 103 class tour of Rapid City Municipal Solid Waste Recycling and Composting Facility, Fall Term, November 18, 2003 Instructor, Jim Taulman

 

Mr. Jerry Wright, Superintendent of Solid Waste Operations, very generously donated his time and gave us a comprehensive tour of his recycling and composting facility. A previous class had toured the recycling operation last fall, so we were most interested in the newly completed composting facility on this tour. This composting facility just began operation during Spring 2003.

 

 

Students attending this tour were, left to right, Sonya Little-Dubray, Paul White Bull (behind Mr. Wright), Violette Bear Runner, Cindy Mesteth, Cathy White Face, Nick Tilsen, Amia Moore, and Alsie LeBeau.

 

The Municipal Recycling Facility (MRF) serves about 80,000 people in the greater Rapid City area and takes in about 175 tons of garbage per day. About 100 tons of that material consists of organic kitchen waste that now goes through the composting facility, instead of having to be disposed of in the landfill.

 

About 13,000 tons of yard waste are also composted and processed into a variety of grades of compost and mulch, which are sold at the MRF facility. In 2003 about $75,000 will be generated in revenue from yard compost sales.

 

 

The Solid Waste Operations are funded by user fees paid by residential customers and landfill scale customers; no taxes are required to support operations.

 

The recycling and composting activities of the MRF will extend the useful life of the current landfill out past the year 2050. Without recycling, the landfill would have had to be closed in 2027. Further benefits of the recycling effort include energy savings and environmental protection resulting from the remanufacture of products from recycled materials compared to obtaining new raw materials and processing those into new products.

 

Organic waste coming into the plant is fed to a conveyer belt that takes it through the sorting room above where non-organic refuse items are manually removed.

 

 

The material then proceeds to these large rotating mixers that pulverize and thoroughly mix the organic wastes.

 

 

The mixed and pulverized organic material is then piled in these channels that run the length of the composting building, where they have water and a solid waste component added to promote the decomposition of organic material. An ingenious stirrer, or turner, crawls along the channels keeping the material well aerated and uniformly mixed.

 

 

During the month-long decomposition process, in which the organic material is becoming nutrient-rich compost, gasses emitted from the microorganisms metabolic processes are filtered through a large outdoor wood chip filter. The resulting odors are so well absorbed that one can only detect a faint musty smell right next to the filter area.

 

 

After the composting process is complete, a final filtering step is carried out in which any remaining bits of plastic or other non degradable materials are removed.

 

 

The final product is a nice-looking mulch suitable for garden or agricultural applications. Though the organic compost is not being actively marketed at this time plans are to create additional revenue for the MRF by selling the material as a farm or garden soil enrichment additive.

 

We got some great ideas about the ecological and economic benefits to be derived from this pioneering effort by Jerry Wright and the Rapid City MRF. We left even more motivated to be diligent in our recycling efforts, saving aluminum and tin cans, plastic and glass containers, and cardboard, to bring to the center for recycling. We also talked about the possibility of starting community organic gardens on the Pine Ridge Reservation.