Columbia May Trash Electricity
Other parts of the city landfill use what is called the "dry tomb" method where liquids are kept out of the trash and methane gas is burned off. The new bioreactor cell will add liquids to the trash to make more methane and break down trash more quickly.
Columbia also wants to take yard waste and move it from the city compost pile to the bioreactor landfill because adding more yard waste means more methane more quickly. However, state officials said that's a bad idea because compost from yard waste benefits the environment.
"One thing to keep in mind is that, when you compost yard waste, it can be made into a beneficial product that can be used to replenish the soil," explained Jim Hull of the Department of Natural Resources. "Placing it in a landfill, once it decomposes and composes methane, and that's used for energy, it's gone."
Putting yard waste into a landfill is illegal but, with or without the yard waste, the city said the bioreactor will produce enough methane to benefit Columbia. The bioreactor will be the 4th cell at the Columbia landfill, and the city will eventually build two more cells.