What to do with trash has been the burning question as the closing of Middle Point Landfill looms, and the county commission is now considering a plan to turn solid waste into an energy source that may be consumed inside Rutherford County.
The Rutherford County Commission’s Public Works Commission last Tuesday heard a presentation by Mark Brown, CEO of WastAway, a McMinnville company. Officials had toured the solid waste processing plant in July as part of an ongoing study of landfill closure options. Public Works Chairman Mike Kusch said that when he toured the WastAway site in Warren County, he did not smell any odors outside the building.
After the presentation, the committee asked Brown to prepare an agreement to allow the company to prepare a proposal to the county. Any contract over $10,000, which would include a project of this scope, must be put out to bid, said Mac Nolen, the county’s solid waste director. He said probably no other company would be able to match the bid since it will be based on WastAway’s proposal.
Brown asked the committee to agree to a 90-day contract that would cast WastAway as the exclusive vendor so it can approach potential clients to buy the solid fuel. The company would receive a $50,000 upfront fee that would be refundable if WastAway cannot meet the county’s goals, which the company will present in a study. If the proposal meets the goals, the fee would be rolled into the cost of equipment, he said. The only way the county would lose the money would be if WastAway’s proposal met the goals but the commission decided not to approve the deal, he said.
Under the WastAway model, trucks transport solid waste to an industrial-type building, where the trash is tipped into the inside of the building so it can be processed. This includes food waste. The waste is shredded, ground, sorted and separated. Recyclable materials are removed.
Ninety percent of all the waste is diverted from the landfill, Brown said. Seventy percent of the waste is turned into fuel; the remainder is either water or “inerts” like glass and rocks, which will be sent to the landfill. The remaining plastics, cardboard, paper and other organics are mixed into a confetti-like material before being exposed to a continuous-feed high-pressure steam “Hydrolizer” which sterilizes the substance, he said. The process takes half an hour.
The material is considered to have a high BTU (British thermal unit), a measurement of heat, Brown said. It may be burned similar to wood pellets or coal, so it is ideal for use in coal plants. If the county were to produce “green power,” it would serve as an incentive to attract industries that want to use environmentally friendly electricity, Brown said.
Rutherford County would have the option of either operating the center or hiring a vendor, Brown said. The operation is structured to where it needs to charge a tipping fee and to sell the end product to pay for itself. A tipping fee of $40 per ton was mentioned as an option, but that may change.
Both Brown and Kusch acknowledged that finding an end-user is critical.
Kusch said, “With this technology, as a county we could run the system if we chose or pay a company to run it. That’s an intriguing thing to think about. Do we as a county want to be in the solid waste business?”
The school system could be a major end-user, said Brown. He said he can work with Middle Tennessee Electric Membership Corp. to create a process in which the fuel is burned locally and diverted to the schools. MTEMC would charge a small fee for the use of its network, but that would be less expensive than buying the power off the grid from the Tennessee Valley Authority, he said. Also, there are a handful of large companies or other institutions that could set up their own generation system for electricity or steam generation.
The committee discussed inviting the City of Murfreesboro to join the venture.