The Justice Department and the state of California filed suit yesterday against 31 individuals and companies to force them to clean up the Stringfellow Acid Pits, a toxic waste dump about 50 miles east of Los Angeles.

Stringfellow, which threatens to contaminate nearby drinking water, has been the focus of a number of allegations of wrongdoing at the Environmental Protection Agency.

The FBI is investigating charges that former EPA administrator Anne M. Burford held up a cleanup grant for the site last summer because she did not want Edmund G. (Jerry) Brown Jr., then governor, who was running for the Senate, to take credit.

The FBI also is looking into perjury and conflict-of-interest allegations against Rita M. Lavelle, a former assistant EPA administrator, because of her role in the Stringfellow matter.

Assistant Attorney General Carol E. Dinkins, head of the Justice Department's Lands and Natural Resources Division, said yesterday, "This is probably the largest and most significant hazardous-waste case the U.S. government has ever filed."

The lawsuit, which seeks to recover $7 million spent on cleanup as well as at least $35 million for future cleanup costs, is against 18 companies who were allegedly the largest waste generators at the dump, four waste-hauling companies and nine former owners.

One of the corporate defendants is Weyerhaeuser Co., whose senior vice president is William D. Ruckelshaus, President Reagan's designee to take over the troubled EPA. Ruckelshaus, who oversees the company's legal division, has said he will not take part in any matter that affects Weyerhaeuser.

Dennis Higman, a spokesman for Weyerhaeuser, said yesterday that the company had dumped only non-toxic starches and printing ink at Stringfellow, but the lawsuit charges that Weyerhaeuser dumped 800,000 gallons of "toxic wastes" there between 1956 and 1972. Dinkins said she is prepared to present evidence that Weyerhaeuser dumped toxic materials at Stringfellow.

According to government documents, the 22-acre site contains 33.9 million gallons of chemical waste disposed of from 1956 to 1972. The wastes include toxic metals such as lead, chromium, nickel and cadmium, and organic chemicals such as chloroform, trichloroethylene and tetrachloroethylene. Several are believed to cause cancer in humans.

The EPA has identified 224 companies responsible for the waste, but Dinkins said the lawsuit includes only the top 18 (which account for 82.5 percent of the wastes), to make the case more manageable. She said other defendants could be added.

The lawsuit said the chemicals have contaminated ground water in the area and threaten a ground water basin that provides drinking water and agricultural irrigation for Glen Avon, a community of 5,000 a mile south of the site.

Dinkins said the EPA will begin a cleanup of the site immediately, using "Superfund" money, with the government suing independently to recover the money. She said Justice is not seeking triple damages from the companies, which is permitted under the Superfund law, because the EPA never filed the required administrative notice.

Dinkins also is negotiating with the Air Force, which is believed to have dumped 3 to 4 percent of the wastes at the site, to pay part of the cleanup costs.

Corporate defendants and their alleged percentage of the wastes at Stringfellow:

Montrose Chemical Corp., 19 percent; Rohr Industries Inc., 11; Hunter Engineering Inc., 7.6; Stauffer Chemical Co., 0.4; Alumax Inc., 0.8. (Dinkins said Stauffer was included because it owns 50 percent of Montrose, while Alumax was a parent company of Hunter from 1963 to 1970.)

General Steel & Wire Co., 6.2 percent; Norris Industries Inc., 5.3; Rockwell International Corp., 5; McDonnell Douglas Corp., 5; Alcan Aluminum Corp., 4.4; RSR Corp., 2.9; Weyerhaeuser Co., 2.3; The Deutsch Co., 2.2; General Electric Co., 2.1; Bridgeport Brass Co., 2; Northrop Corp., 1.9; Rainbow Canyon Manufacturing Corp., 1.9, and Rheem Manufacturing Co., 1.3.