In an era of high-tech gadgetry and genetic engineering, Waste Management Inc. of Oak Brook, Ill., has enjoyed a meteoric rise in a field that is more mundane but no less profitable: collecting garbage.

Created 15 years ago by the melding of three rubbish-hauling companies, Waste Management has become the nation's largest waste disposal firm, with revenues last year of $965 million and net earnings of $106 million on operations in 30 states and six foreign countries. Its chairman and president, Dean L. Buntrock, was paid more than $520,000 in salary and bonuses in 1981. Four other officers were paid more than $250,000.

But the firm hauls more than ordinary trash these days. Through its wholly-owned subsidiary, Chemical Waste Management Inc., it is the leading handler of industrial hazardous wastes, with about 15 percent of a $1 billion-a-year market.

In 1975, that market was worth $100 million a year. By 1990, it's expected to be worth $9 billion a year--not counting as much as $40 billion more over the years to clean up inactive dump sites under the federal Superfund law.

Last year, Waste Management entered the low-level radioactive waste market, buying out Chem-Nuclear Systems Inc., owner of the nation's largest radioactive disposal site, near Barnwell, S.C. According to court documents filed by Chem-Nuclear in an attempt to get out of that merger, it was Waste Management's 156th acquisition in 10 years. By year's end, the operations at Barnwell accounted for 5 percent of the corporation's sales and earnings.

Investment analysts call Waste Management "aggressive" and say the firm's "well-planned acquisition program" puts it in solid position to profit from new federal laws regulating the disposal of hazardous industrial byproducts. But critics, including competing firms, have another term for its behavior: "predatory."

In its unsuccessful antitrust lawsuit, Chem-Nuclear contended that Waste Management "has chosen to meet its landfill demands largely through the acquisition of existing sites rather than by developing new, untapped landfill sites." Other antitrust suits are pending in at least two other states.

In recent weeks, the gloss on Waste Management's stock has been dimmed by a spate of allegations that it has profited as much by political connections as by planning. Its largest and most highly regarded waste disposal site, in Emelle, Ala., was an acquisition, from a firm whose founders included Alabama Gov. George C. Wallace's son-in-law. Residents contend that the connection smoothed the way for the site's permit.

In Alabama and Washington, investigators are looking into allegations that James W. Sanderson, a former top Environmental Protection Agency adviser whose law firm represented Chemical Waste Management, intervened in agency decisions on behalf of the firm.

Nor do its troubles end there. Waste Management is the target of a grand jury investigation and a state lawsuit in Illinois, where officials have accused the firm of illegal dumping at its Calumet City site. And the company faces expensive cleanups at several other sites, including Lowry Landfill in Colorado and dumps in Pennsylvania.

Waste Management has denied any deliberate wrongdoing and has launched an aggressive campaign of its own, hiring a team of private lawyers to investigate allegations against it.

A company executive said recently that many of its current problems were purchased along with the dozens of sites it acquired. "We check these things out more carefully now," he said.

Last week, the corporation's investment banking firm released a one-page assessment, noting the company's role in the growing controversy involving the EPA and offering one comment: "Unfavorable publicity expected to produce outstanding buying opportunity."