Casper's landfill appears to be the envy of many Wyoming dumps.

Its newly lined bottom, a recent state Department of Environmental Quality requirement, prevents garbage from contaminating groundwater.

Many other Wyoming dumps don't have the plastic lining, and are turning to the Casper landfill to safely store their garbage. That in turn, could prevent future garbage rate hikes for Casper residents.

"We are going to use Casper because the DEQ is requiring a landfill to be permitted to double line their landfills," said Don Cuin, the Rawlins landfill superintendent. "It is very expensive to do that but less expensive when you have a larger operation."

This means it will be cheaper for Rawlins to package their own garbage and truck it 120 miles to Casper for storage rather than line their own landfill and continue burying it there.

A lining is made of high density poly ethylene geomembrane. Essentially, it's the same material as your average heavy lawn and leaf bag, only roughly 20 times thicker.

As more communities consider using Casper's landfill for their garbage, such a move could prevent Casper residents' bills from rising, said Cynthia Langston, Casper's solid waste division manager.

"It's economy of scale," Langston said. "It's like going to Sam's Club and buying two cases of cereal, which ends up being cheaper than buying one."

The city owns 1,700 acres of land north of the landfill, providing enough space for another 1,000 years of landfill life, even with regionalization.

"The advantage to the city of Casper is there's no transportation, and so a low tipping fee," Langston said. The tipping fee is how much trucks are charged per ton for garbage. "The environmental liability is also greatly reduced with a lined landfill."

Casper has the largest lined facility in the state. Cheyenne and Gillette lined expansion parts of their cells but don't have entirely lined cells, said Langston.

Lining a garbage pit means instead of leachate -- liquid produced from garbage breakdown -- potentially contaminating groundwater, it is siphoned off into a pipe and pumped to the wastewater treatment plant.

Douglas is also considering using Casper's landfill for their garbage within the next five to ten years, said City Administrator Bobbe Fitzhugh.

"We as a city fully expect to end up with a recommendation to regionalize and close our local landfill in Douglas and transport our waste to a regional facility in Casper," Fitzhugh said. "We expect the data will show that one large central landfill will be less expensive than developing our own lined facility."

Fitzhugh said Douglas may still use their landfill for demolition waste and other waste that doesn't require a liner.

Montana, Colorado and Utah already use a regional landfill concept, Langston said.

Contact city reporter Christine Robinson at (307) 266-0639 or christine.robinson@trib.com