As Howard County approaches the day when there will be no more room to dump waste at its Alpha Ridge landfill, officials have begun searching for alternatives.

Opened in 1980, the Alpha Ridge landfill is expected to last the county until the year 2003, maybe a couple of years longer if residents recycle more of their waste.

But already, county officials are meeting with their counterparts in Carroll, Frederick and Washington counties to find a solution to a problem the counties have in common.

One idea is for the counties to share landfills, incinerators and recycling plants.

County executive candidate Gil South has another idea. The Republican from Mount Hebron said the county should consider mining its existing landfill to extract recyclable materials, such as old cans and plastic bottles.

South said the idea has worked well in one southwest Florida county. By spending about $300,000 on mining and excavation equipment Collier County has saved its taxpayers millions of dollars.

"I think it's a fantastic concept that no one is really paying enough attention to," South said.

Robert E. Fahey, Collier County's solid waste director, agrees. "We think we have shown how a landfill can be used as a processing facility" instead of a decaying dump, he said.

Mining begins at the Collier County landfill when most of the organic garbage has turned to compost, Fahey said. Workers then use specially adapted mining equipment to sift through the compost, pulling out plastics, metals and glass that have not deteriorated. These items then are stockpiled for sale as recyclables.

Recently, Collier County was able to sell about 44 million pounds of discarded plastics for about 2 cents a pound, or $880,000, Fahey said. The county also is negotiating with plastic producers who want to build a processing plant nearby to accept the refuse.

Fahey said the county also saves its residents money by extending the life of its landfill and keeping tipping (dumping) fees low. Finally, Collier County is able to use the composted material as fill dirt on open landfills, freeing it from having to buy the dirt.

Howard County has no problem acquiring free dirt from builders in the area. But the county could extend the life of its landfill, keep its tipping fees low and make money from the recyclables, South said.

Charles Ecker, who will face South in the GOP primary, said, "I think we need a comprehensive landfill solution. And landfill mining might or might not be an option."

Howard County officials said they have heard of the idea but that the concept is too new for them to know whether it could be a long-term solution.

"There's just not enough known about it," said John O'Hara, chief of the county Bureau of Environmental Services.

It may be that digging into an existing landfill causes more problems than it solves, O'Hara said. First, excavation could expose workers to hazardous materials. Or it could ignite a pocket of methane trapped within the landfill. The explosive gas is a common byproduct of decomposing wastes.

"There's also the downside that exposing landfill material to the elements could create more leachate and odor," O'Hara said.

Leachate is the watery residue from percolating garbage that sinks to the bottom of the landfill. The county is spending $52 million over the next five years to install a liner at the bottom of its landfill to collect and dispose of the residue. Installing the liner is a state environmental requirement to protect ground water.

Finally, O'Hara wonders whether there is a big enough market to buy recyclables that have been contaminated by other wastes.

"Already many companies have established some fairly stringent guidelines for what they will accept," O'Hara said. "It is a pretty big problem to overcome."