COLUMBIA — For five days in February, Sixth Ward Councilwoman Barbara Hoppe watched smoke linger over parts of the Sixth Ward as piles of wood burned along Rock Quarry Road. Contractors working on The Grove Apartment complex were burning mounds of trees and other vegetation to make room for construction.
"I knew it couldn’t be good for the environment and wondered if there was a better way to recycle the trees," Hoppe said. In February, she requested a report from city staff on the pros and cons of different ways to dispose of trees cleared for development.
The City Council on Sept. 21 reviewed the report and sent it to the Columbia Planning and Zoning Commission and the Public Health and Human Services Department for possible development of an ordinance that could require developers to chip the tree waste rather than burn it.
The report, which remains in the hands of city Planning Director Tim Teddy and Health Director Stephanie Browning, outlined three options for disposing of wood waste:
- Open burning, where the debris is piled up and burned above ground.
- Pit burning, where a pit is dug into the ground and the debris is burned under ground.
- Chipping or shredding, where the wood is ground into chips and used as mulch, compost or to help fuel the bioreactor at Columbia's landfill that captures methane to generate electricity.
The report found that chipping and shredding is three times as expensive as open burning, which would be an added expense for developers, Shane Creech, building and site development manager for the Columbia Community Development department, said.
The wood chips could be used for mulch or erosion control on-site or sold to wood products companies, Creech said.
The report also considered the health effects of burning the wood waste. Browning said the Health Department doesn't know of any local illnesses related to controlled, in-city wood burning, but she said the potential exists.
"Anytime that you are burning something, depending on proximity to people, it can be an aggravating factor in respiratory illness," she said.
The Columbia Fire Department issues local burn permits, and the report found it would prefer that open burning no longer be allowed within city limits.
The city bioreactor adds a twist because it can use wood waste as fuel, Creech said. The Columbia Public Works Department would prefer that developers chip their wood waste and send it to the bioreactor, the report stated.
The report also pointed to an increased local market for wood chips because of MU's new wood-burning boiler and speculated the city could eventually need to pay for waste wood to help fuel the bioreactor.
There is no system in place for the city to pay for wood waste delivered to the bioreactor, Cynthia Mitchell, Columbia's landfill and recovery superintendent, said.
She said enormous piles of surplus wood chips are a common sight at the Parkside Drive and Capen Park mulch sites — the supply, at least for now, is plentiful.
The Columbia Municipal Power Plant and the MU Power Plant use wood chips to fire their boilers, and both have contracts with suppliers. Foster Brothers of Auxvasse will supply all of MU's wood fuel; Missouri Mulch of New Florence supplies the city's wood fuel.
The city's coal-fired boilers require a specific quality in wood, which accounts for 20 percent of each boiler's fuel, according to Christian Johanningmeier, power production superintendent for the city.
The power plant takes only white oak chips, ground up from wood leftover from the manufacturing of barrel staves in New Florence. "We need a consistent quality of fuel for our boilers to operate," Johanningmeier said.
The quality of wood waste cleared for development projects is often unknown, so it is unlikely the city power plant could use it, Creech said.
City Arborist Chad Herwald, who compiled most of the research in the report, is concerned that diseases in trees could be spread by wood chip distribution in mulching projects.
Steve Foster of Foster Brothers said his firm would use wood waste from clearing local sites, as long as the clearing doesn't violate a stipulation in his contract with MU that states: "Buyer will not accept any woody material that was cut or produced in the process of converting forest land to commercial development unless the contractor can document, through a zoning or building permit that such land-use conversion was going to happen anyway."
The MU boiler is equipped for all kinds of wood and so are his company's wood-chipping machines, Foster said. So as long as development sites don't violate the terms of his contract, Foster thinks the agreement with MU would help create a market for local wood waste.