A project has been approved by County Commissioner Clarence Brown and is currently in development stages for a gas collection and control system to be installed at all three phases of the landfill. This system will take advantage of the naturally occurring release of gases that can then be harnessed for the sale of renewable energy and carbon credits. According to the Environmental Protection Agency, 12 similar sites exist in the state and 519 across the country.
Gas trapped beneath the Bartow County landfill, through sample tests, has been estimated to be composed of about half methane and half carbon dioxide with small parts of other gases such as nitrogen and oxygen. The valuable piece of this equation is the methane. Through horizontal and vertical wells drilled into the landfill, perforated pipes funnel gas to a central collection site where the fuel is harvested, putting to use the about 350 tons of waste collected in Bartow each day.
The end use for landfill gas is determined by the methane content of the gas. Preliminary tests show positive findings and Bartow County Solid Waste Department Director Rip Conner said he is "very confident" in the sufficiency of methane levels.
"Ideally there's going to be enough [methane] where -- and we're pretty positive it's going to happen -- ideally the methane will be enough to where we can flare it," Conner said. "Once we start flaring it we'll do two things: we'll start creating carbon credits and we'll also take gas samples and ideally there's going to be enough volume and quality of methane that will power a modified diesel engine. And that engine in turn will power a generator which will produce electricity and then we'll sell that to either Georgia Power or the city of Cartersville."
The process known as flaring is where methane is burned off, creating heat that can potentially create useful energy while destroying the harmful greenhouse gas. Profits from the sale of both carbon and renewable energy credits as well as the sale of electricity will depend solely on the volume and quality of the methane produced, but estimates show a considerable opportunity for revenue. The profit margin for Bartow County is virtually 100 percent due to a partnership with Montauk Energy of Pittsburgh, Penn. According to the company's website, they pioneered the first landfill gas project in the U.S. in the early 1970s. With Montauk making the monetary outlay for infrastructure investment estimated about $700,000 to $1 million, Bartow County will receive a portion of all proceeds from the project.
"It's estimated, and I think it's a very conservative estimate, but it's estimated that the county over the next 20 years can make between $8 million and $12 million in revenue from all of this and the biggest thing about it is that we aren't investing a single cent into this project," Conner said.
The benefit of revenue production is purely ancillary to original goals. County officials began research for the project with the aim of reducing and removing landfill gases to prevent gas migration. This problem arises when landfill gases build up and leach to other areas through the process of diffusion. Environmental damage is compounded when landfill gases migrate off of the controlled landfill property. In an effort to prevent migration, Bartow County sought solutions culminating in the gas collection and control system and an entity that will be known as Bartow LFG LLC.
"Our goal starting into this process was concerned with the methane gas that they produce -- landfills always deal with that -- and you can just burn it off and if we had done that we would have had some cost of infrastructure and we wouldn't have produced this revenue. ... We were thinking that at least we could break even," said Steve Bradley, Bartow County administrator. "We see it for us as a good opportunity to accomplish our original goal, which was to get rid of the methane gas that we needed to get rid of but also to produce some revenue to the county as well."
The project is currently being developed to produce digital 3-D images of gas pockets. The oldest section of the landfill, phase one, was opened in 1978 and closed in 1991. Conner added that methane is typically produced for 20 to 25 years after disposal, which led to concerns over remaining methane content. An initial boring taken in phase one to a depth of 35 feet showed significant volumes of gas with a high concentration of methane, Conner said. With phase one reaching depths of about 75 feet, estimates on methane content are hopeful for all phases.
"There's a lot of methane generation still being produced in phase one which is a nice surprise because the garbage has been in there for so long that methane generation should be ebbing but there's still a lot of methane there," Conner said. "The real question mark was phase one and that is because it is so old. There's no way we were expecting 60 percent [methane]. I wouldn't say it is all producing 60 percent but we found a pocket of 60 percent methane."
When dealing with combustible gases such as methane, safety precautions are built into all projects. Montauk will handle the gas delivery system feeding the flare, keeping parameters within the lower -- and upper -- explosive limits to maintain safe levels of gas and oxygen to reduce risk. As for the flame itself, it is unknown at this time if it will be visible outside of the landfill.
Preliminary plans have the installation of the system slated to occur in November or December. This long-term project will continue as a viable source of revenue and a means of landfill gas extraction for many years, Conner said.
"The basic contract [with Montauk] is for 20 years -- but this landfill, as designed, has about 35 years left here with future expansion," Conner said. "This place will be producing methane for 50 to 60 years."