Copper, zinc bonanza 'neath Maine's pines?

On the surface, this nameless township 18 miles from the nearest highway looks much like the rest of northern Maine: fir trees, fireweeds, and the abandoned shacks of former logging operations.

Eight hundred feet beneath, however, lies a billion dollars.

That is the estimated value of the 36 million-ton "massive sulfide" deposits of copper and zinc at the Bald Mountain site here.

So far, there is nothing here but a clearing, a small man-made pond, and a lot of exploratory drill holes capped with chunks of tree trunks.

But if production begins as forecast in 1984 or '85, this isolated site could have far-reaching effects:

* It could help reduce US dependence on imported copper. Copper is a strategic metal crucial to electrical applications and stockpiled by the US government for defense purposes. In 1980, the United States imported about 14 percent of its copper needs along with 60 percent of its zinc, which is most commonly used to galvanize steel, according to the US Bureau of Mines.

* It could be the bellwether of an entirely new industry in Maine: heavy mining. The state has some small mineral and gemstone mines -- as well as rock quarries and peat-harvesting operations. But "Maine is new to the mining industry," says state geologist Walter Anderson. He foresees other significant finds in a 60-mile-wide volcanic belt angling down from the New Brunswick border into northern New Hampshire. Molybdenum, gold, nickel, and uranium are among the likely discoveries.

* It could have a significant impact on the local economy. Portage, a rural lakeside village that triples in size with summer tourists, may have to absorb some of the 200 to 300 employees needed over the 20-year life span of the mine -- setting up what some are concerned could be a "boom and bust" cycle.

* It could realign the state's economy as the Bald Mountain site forces Maine to develop a minerals policy that allows mining while protecting the environment of this nature-conscious state.

Now under discussion by a legislative committee is a bill submitted by Gov. Joseph E. Brennan establishing a "severance tax" -- a levy on nonrenewable resources removed from the state. Such taxes now are being hotly debated in the coal-rich Western states, which see such revenues as a way to compensate for the necessary environmental unpleasantness of large-scale mining operations.

The exact figure attached to the severance tax, however, is still a bone of contention between the state and the mining companies. The current proposal calls for a tax of roughly 2 percent, says geologist Anderson.

The mining companies, however, feel that is too high. "The deposit is no bonanza," says Ronald Howes, as his four-wheel-drive pickup truck bounces toward Bald Mountain over a lumber road. He is the environmental coordinator for Superior Mining Company (a subsidiary of Superior Oil in Houston), which is a partner in the Bald Mountain project with LL&E Mining Inc., a subsidiary of Louisiana Land & Exploration Company.

"The economics are very marginal right now," says Mr. Howes, noting that copper has slipped from last year's price of $1 a pound (when the $1 billion figure was used for the in-ground value) to about 75 cents a pound. He fears that the wrong severance tax figure could render the site not worth developing.

Another cost arises from environmental regulations. Big mining hs a bad name among many conservationists. Superior has already spent more than $600,000 on environmental planning, conducting air- and water-quality tests, and taking fish , bird, and mammal counts -- in marked contrast to the Great Northern Paper Company, which has not come under the same scrutiny and has left frequent marks of its clear-cutting operations on the landscape around Bald Mountain.

But an earlier controversy -- about whether some Class A streams in the area could be downgraded to Class B so that water from the mining process could be discharged into them -- may now be resolved. The plan to be filed early next year (when the mining companies apply for state and federal permits) will include a 17-mile pipeline to the Class B Aroostook River.

To the relief of those who worry about air-quality standards, the Bald Mountain site is too small to warrant the construction of a smelter. Even so, the 1,000-acre site will require, says Howes, "way in excess of $150 million" to develop. The crushed ore will be shipped by rail to the coastal town of Searsport, where it will then be sent to a smelter.