Caribou, Maine — Six months from now, the ground in this northernmost corner of the Northeastern United States will be frozen solid to depths of more than a yard. The temperature will sink toward minus 40 degrees F. The winds from Quebec will whip snow against the barren potato fields.
That is not exactly the best weather for burying municipal garbage in dumps -- or (as they are now called) "sanitary landfills."
But James Barresi, director of the quasi-governmental Northern Maine Regional Planning Commission here, thinks he has found the answer. He has just been given the green light to build a novel incinerator -- the first of its kind in the nation -- in the border town of Frenchville.
Burning garbage rather than burying it is nothing new, even in a sparsely populated state with plenty of undeveloped land. But most incinerators use No. 6 oil or some other fuel to get up to temperature. Some no longer meet air quality standards. And many simply cannot compete with the lower cost of landfills.
The Frenchville model, however, may revive incinerator interest. "It seems to have every other system beat hands down," says an enthusiastic Mr. Barresi, gesturing towards a drawing of a large hangarlike building with two silos attached. The silos are actually high-temperature refractory incinerators, inspired by sawdust burners now in use in some Western states.
If the plant is completed as scheduled this fall, Mr. Barresi says, it will:
* Reduce waste to only 5 percent of its original volume and 25 percent of its original weight -- producing ash so dense that a cubic yard of it weighs a ton.
* Provide temporary storage for 1,000 tons of ash -- so that the two-acre secure landfill on the site need only be opened up three or four warm days a year to bury the ashes.
* Produce exhaust clean enough to comply with tough air quality standards -- so low in "particulate emissions," says commission planning administrator Kenneth Arndt, that people will be "able to breathe it."
* Provide enough heat to meet the heating needs of the plant itself and of an airport terminal building nearby.
* Cost the participating towns -- Madawaska, Fort Kent, and Frenchville, the three most northerly towns in the Northeast -- only $500,000 to build.
* Use no fuel except the waste itself -- which, the designers say, you can light with a match.
Cost is crucial. The plant, handling 40 tons a day, will be only one-fifth the size of a conventional incinerator opened last spring in Auburn, Maine. That one, however, cost about $4.5 million -- nine times as much.
What makes the Frenchville plan different? Aside from some special design features -- like the ash storage and the idea of pumping liquid residues back into the 1,400-degree F. heat at the top of the burner where they disappear into a puff of gas -- the key lies in the building material.
Most incinerators are steel, lined with a special refractory material. This one will use olivine -- a naturally occurring rock formed largely of magnesium oxide, silica oxide, and iron.
It is found (among other places) in a mountain in Bellingham, Wash., where the Olivine Corporation has been crushing it, casting it into cement modules, and using it to build more than 100 wood-waste burners, some of which have already had seven years of trouble-free operation.
The rock, says Olivine's Corky Smith, will withstand temperatures up to 2,000 degrees F. -- and then cool down overnight without cracking. He recently built a small prototype garbage incinerator, and says that "we can burn it clean as a pin."
The Frenchville plan, however, is not without its critics. So unusual is the design, in fact, that the staff of the Maine Department of Environmental Protection (DEP) originally insisted that the three communities spend another $ 200,000 for a backup landfill in case something went wrong.
"Usually what we do is expect the worst," says the department's Allen Jones. The "worst case," he says, might involve a long shutdown. If that happened, garbage piled at the site could attract enough birds to interfere with air traffic at the nearby airport.
On Aug. 12, however, the DEP board overruled its own staff -- in what some observers see as a decision based more on politics than on design -- and granted a crucial permit.
Why are these three towns interested in this project?"I think the incinerator concept is cheaper than landfills," says Frenchville town manager Dan Martin, "if you're going to operate them legally." The incinerator proposal will shortly come before town meetings in the three communities, but Mr. Martin foresees no difficulties in having it approved.
And if this pioneer operation proves successful? "I expect that the whole northern area [of the state] will install them," says Barresi, with perhaps a little exaggeration.