Metropolitan Chicago may produce millions of tons of waste, but not all of it stays there.

According to the most recent Illinois EPA waste disposal report, the area, which includes Cook, Kane, DuPage, Will, Lake, Grundy, Kankakee, Kendall and McHenry counties, produced about 20.7 million tons of waste in 2006.

But instead of heading to area landfills, most the waste is being transported to landfills in other parts of Illinois and in some cases, to other states.

“The waste goes in a lot of different directions,” said Bill Plunkett, a spokesman for Waste Management, Inc., the nation’s largest landfill operator. “In recent years, the landfills in the metropolitan area have, one-by-one, reached their capacity and closed.”

Declining landfill capacity, coupled with limited space for new landfills and rapid growth in Chicago’s collar counties, has led Chicago-area waste to be transported to landfills farther and farther away, leading to higher waste disposal costs.

That means trash picked up in Geneva may not be headed directly to a landfill, but to an intermediary, called a transfer station, where it is combined with trash from other trucks and hauled elsewhere by a larger semi-truck trailer to reduce costs.

Trash may be hauled to places like Livingston County Landfill in Pontiac, where much of the Chicago area garbage goes, Plunkett said. Some is transported to northwest Indiana or Kenosha County in Wisconsin.

The long approval process for landfills and the lack of space in Cook County and the collar counties for new landfills have led to the declining numbers in the area, said Steve Garrison, the manager of landfill and storm water field operations for the Kane County Department of Environmental Management.

“The more residential development that takes hold, the harder it is to find the vacant property that meets all the criteria,” Garrison said. That’s why landfills are moving further out, “where there is less impact,” he added.

After Kane County’s Settler’s Hill landfill closed in December 2006, the county has primarily used four transfer stations to transport waste to facilities in Kankakee, Rockford and Pontiac, Garrison said.

Dependence on transfer stations has led to higher waste hauling and disposing costs, said Joy Hinz, an environmental specialist for DuPage County.

Average disposal rates have increased 37.5 percent since 1995, a report from the county found. Costs will likely continue increasing, especially with the skyrocketing cost of diesel fuel, she said.

“It’s a matter of economics, it’s a matter of accessibility to landfills, it’s a matter of availability, but transfer stations have been the answer in this area because they require less space,” Hinz said.

Transfer stations generally become more cost-efficient than direct haul when the landfill is located more than 10 to 12 miles away, she said.

A substantial portion of DuPage County waste goes to the DuKane Transfer Facility in West Chicago and three stations just outside county lines, Hinz said. From there, most of the waste goes to landfills in Lee, Ogle and Morrison counties.

Cook County also relies on its 52 transfer stations, including 16 in the city, to transport its trash, according to the EPA waste disposal report. Transfer facilities in Melrose Park and Elk Grove Village handled the most waste in Cook County during 2006. A landfill in Hillside closed last year.

But some landfills still do exist in the suburban counties.

Most of the garbage in Will County goes to the Prairie View Recycling and Disposal Facility near Wilmington, which is owned by Waste Management. Built on the site of a former military arsenal, the facility receives nearly 2,500 tons of waste per day, plus any arsenal “free waste,” and only accepts waste from Will County, said Dean Olson, waste services manager for the county.

Arsenal “free waste” must be accepted by the landfill at no charge because it is part of a deed from the federal government for obtaining 455 acres of old arsenal property for the landfill.

Other haulers in the county may bring the waste to Envirotech Landfill in Morris, the Livingston County Landfill in Pontiac or the Newton County Landfill in Indiana.

Prairie View’s lifespan is set to expire in 2027, but that doesn’t mean the space becomes useless, said Waste Management’s Plunkett. He points to the Settler’s Hill landfill in Kane County, which still collects enough methane gas from decomposing garbage to meet the electricity needs of half the residents of Geneva.

“Landfills today are community assets, and more and more are being seen in that way,” Plunkett said.

Some states, like Florida and California, have invested in bioreactor landfills, a process in which liquid is injected into the landfill to help speed garbage decomposition, he said.

Landfills in Peoria and Whiteside counties have received EPA permits to use a similar method, Plunkett said. By injecting the liquid-like byproduct of garbage decomposition, called leachate, back into the landfills, decomposition and methane gas generation can be accelerated.

While scientists worry about possible long-term risks associated with liquid waste seeping into groundwater and the increased methane gas production, the Illinois EPA currently has two active applications looking at bioreactors, said Imran Syed, environmental protection engineer for the solid wastes program.

Additionally, closed landfills being used for other beneficial purposes, since they become green spaces, Plunkett said. He points to the old Settler’s Hill site in Kane County, which is located by a golf course and among homes priced around $700,000.

“As landfills mature, people realize they’re a very attractive place to live because of the green space and the openness it offers,” Plunkett said.