SIOUX FALLS, S.D. (KELO) — It can start as a pumpkin on the porch or leaves on the maple tree and can end up in the neighbor’s garden or landscape project.
Sioux Falls residents dump about 12,000 tons of yard waste each year, said Donny Kuper, the sanitary landfill superintendent for Sioux Falls. Those tons are transported to the city’s regional landfill where the compost process turns that waste into black dirt ready for a garden or another project.
The city has two seasonal yard waste dump sites. One on the east side on Chambers Street—just west of Cliff Avenue, west of the Household Hazardous Waste Facility. And one on the west side on North Lyons Boulevard-west of the fairgrounds.
The use has grown over the past several years at a pace of about 200 ton a year. The city opened a new site on North Lyons Boulevard this year that is larger than the site that was located a few blocks down the street in prior years, Kuper said.
The city encourages the use of the drop off site including for pumpkins. “We try to keep pumpkins out of the landfill,” Kuper said.
“With landfilling, you really want to try to extend the life of the landfill as long as possible,” Kuper said. “Some residents may not know that yard waste along with recyclables are actually banned from the landfill, so we try to divert as much material as possible to try to extend the life of the landfill.”
“….Last year we got little over 4,000 ton of material. This year I can foresee us reaching that 5,000-ton range,” Kuper said.
A ton is 2,000 pounds so 5,000 ton is 10 million pounds. Ten million pounds is the weight of 500,000 one-ton pickup trucks.
“It all goes into the landfill where it’s made into compost,” Kuper said. “From start to finish to make compost it takes six to 12 weeks depending on the feedstock.”
Feedstock is the material dropped at leaf and yard waste disposal sites. Carbon material is branches and organic material is yard waste.
The leaves and yard and similar organic waste is mixed in one dump pile.
The city’s compost site is at the landfill next to a hill of already covered landfill waste. There is gas equipment at the top of that hill as the methane gas created at the landfill is used for energy.
But, the compost process creates something different.
The composting process creates nutrient rich material, Kuper said. It also saves valuable space at the landfill, Kuper said.
A big pile of leaf and yard waste is the first step of the compost process. Next to it are about 20 windrows of composting material that are roughly 300-feet long. That’s about 99 yards or the total length of 20 football fields.
A windrow turner moves down those windrows turning the material as part of composting. The machine looks a bit like street sweeper and small combine.
It picks up the material and turns it to add oxygen to it. A stream of steam follows its path.
“(Compost) generates its own heat. It’s much hotter than the ambient air temperature so it releases steam,” Kuper said.
The windrows show the various stages of compost as the material gets darker. As the material breaks-down pieces of plastic and other material can be seen in the windrow.
One of the last steps in the process is to put the compost material through a “screener,” Kuper said.
The screening equipment removes any debris before the material is dropped into a big compost pile.
The final step is to take compost from the big pile and place it in a smaller pile for residents to access.
The pile is held by three concrete sides. A shovel was stuck in the pile, ready for use.