WESTLEY, CALIF. -- Tires. Lots of tires.

Round ones, flat ones, big ones, little ones, black ones, white ones, thin ones, fat ones, plain ones, fancy ones, old ones, very old ones -- 42 million tires stretching as far as the eye can follow over gulleys and ravines of yellow-brown San Joaquin Valley hills, so distorting the sense of size and distance that they look like little gray Cheerios poured out for breakfast.

Here, in the midst of the most old tires ever assembled in a single place, a small group of entrepreneur-environmentalists and a giant corporation have erected their solution for a civilization awash in garbage: Burn it to run your dishwasher.

The 15-megawatt power plant dedicated last week near this little valley town has begun to nibble at the monstrous tire pile. At 800 tires an hour, 19,200 a day, 7 million a year, the new Modesto Power Plant could lap up every last one of the tires in six years.

To the distress of some neighbors, the plant's proprietors intend to preserve Ed's Tire Disposal, the business that built the pile over 20 years, and thus postpone that tireless day. Otherwise, they point out, the tires would just pile up somewhere else.

An estimated 2 billion old tires lie in America's dumps and on its roadsides, with more than 200 million added every year. They are nonbiodegradable, in normal conditions indestructible. They attract mosquitos and rats and cause fires that can smolder -- like a 1983 blaze in a tire dump near Winchester, Va. -- for months.

The creators of the Modesto plant envision similar operations in several parts of the country. This $41 million plant was built by General Electric with German technology under the direction of an infant New York firm called the Oxford Energy Co. Its makers say it will provide enough electricity for 15,000 homes for at least the next 15 years.

It is the first plant in the world to operate full-time on nothing but whole tires, plopped two at a time without shredding or other preparation into two boilers roaring at more than 2,000 degrees Fahrenheit.

Because half the plant is devoted to pollution control equipment, and because the combustion temperature is so high, plant officials say it will emit little smoke or odor -- and three byproducts, steel from belted tires, gypsum and zinc, will be sold. No smoke or odor was detectable as the plant operated near full power last week.

If Robert Colman, Oxford Energy's 39-year-old president, has his way, this will be the fate of much of the world's trash over the next several decades. Many big-city landfills are within five years of overflowing, and for years experts have called for radical new approaches to waste recycling.

"We have not yet responded to the crisis in the United States," Colman said. Efforts to build trash-fueled power plants have hit many political obstacles, including neighborhood objections, and this plant in a relatively empty part of the valley has drawn the ire of local residents and environmentalists.

The Ecology Action Educational Institute, a nonprofit group in Modesto, has objected strenuously to Stanislaus County's decision to clear the plant without an environmental impact report. The group's executive director, Gordon E. Hart, said that despite reports citing no harmful pollution from a similar German plant, the Modesto plant is three times as large and operating under different environmental laws.

The Oxford Energy executives, Hart said, seem to be "personifications of 1980s entrepreneurs," and "I don't wish them any ill." But he is not impressed by the lack of odor or smoke from the plant, which has been burning at near full power this week.

"You don't determine long-term and subtle environmental impacts with your senses," he said, adding that environmentalists "are skeptical of experimental technology because we have been sold a bill of goods in the past."

Although some real rubber still goes into most tires, they are principally made from petroleum-related products and have many potential uses in the eyes of the recycling industry. Skip Scherer, spokesman for Goodyear Tire & Rubber Co., said his company has invested $1 million in a small firm using shredded tires to supplement wood fuel in paper mills and other industrial plants. Added to asphalt, the recycled tire material can increase the life of roads.

Rubber Research Elastomerics Inc. of Minneapolis turns old tires into a rubber compound used in carpet backing and other products. Dumped into the ocean, tires make useful reefs and breakwaters, "but unfortunately that doesn't require a heck of a lot of tires," Scherer said.

The Oxford Energy group, said General Electric executive Clemens Thoennes, "had the initiative and the vision to see that here was a virtually free fuel and find a way to use it."

Gordon Marker, a New England economist, was putting together small hydroelectric projects when he joined Colman, an investment banker, and several others to create Oxford Energy in early 1984. Marker was concerned about U.S. energy policy, "that we were importing so much energy and exporting so little."

The energy deficit, with the huge surplus of waste, struck the small group as an opportunity. Furthermore, new federal laws had begun to require utilities to buy power from the kind of small, independent operations the new company might be able to build.

Oxford discovered a successful whole-tire power plant in the little town of Landau, West Germany, where energy was produced with little pollution. Oxford bought rights to the technology from the Gummi-Mayer Co. and persuaded GE, which sent a platoon of engineers to check out the process, to build the plant.

A broker told the group about Ed Filbin's huge dump in the hills of western Stanislaus County. Filbin, a tall man who wore jeans, boots and a cowboy hat to the dedication ceremony, started his tire disposal business 20 years ago to earn cash for his 6,000-acre family cattle ranch. It made a profit, but a small one. When Oxford proposed to lease his land and burn his tires, he readily agreed.

Colman is optimistic, despite some local resistance, about similar plants planned for Connecticut and New Hampshire. Oxford Energy is also about to build one California power plant fueled by rice hulls and straw and developed plans for another burning municipal trash.

"With dedication and hard work," Colman said at the ceremony, "we will not be interred in our own garbage."