When the Justice Department established a Hazardous Waste Section a year and a half ago, its lawyers knew it wouldn't be popular with the chemical industry. They were right.

The section, which is prosecuting as many as 60 violations of waste disposal laws across the country, is the chief target at Justice for the lobbyists in the chemical industry.

"It's going to be very interesting to see how the new administration is going to handle these things," says James W. Moorman, assistant attorney general for land and natural resources in the Carter administration and now a lawyer in private practice. "I don't know what they're going to do but maybe they'll pitch the whole thing out."

Moorman was playing a game popular with about 10 former Justice Department executives these days: Is the Reagan administration going to enforce the nation's laws the way the Carter administration did? Or is new Attorney General William French Smith going to change things to suit the Reagan style, placing less emphasis on enforcing the myriad federal regulations that Reagan campaigned against when he was running for president?

To hear former Justice Department lawyers tell it, the Hazardous Waste Section of the Land Division isn't the only likely target for the Reagan administration. The Environmental Enforcement Section and the Land Acquisition Section could also come under fire. Chances are the Civil Rights Division and the Criminal Division will experience some changes under the new attorney general, who may end up making few changes in the one division that interacts most with private industry: the Antitrust Division.

"I'm like most Republicans, a great believer in free enterprise and competition in the marketplace," Smith told the Senate Judiciary Committee at his confirmation hearing last month. "I will have a strong Antitrust Division."

While everyone expects Smith to have a strong Criminal Division too, most experts on the Justice Department feel he may make some changes. Republicans have never liked the way the Carter administration enforced the Foreign Corrupt Practices Act, feeling that businessmen were being singled out and punished for giving bribes to foreign officials a standard practice in the past.

There may be a Republican push to get the FBI back into chasing bank robbers, which the last three attorneys general left to state and local police. Said one Justice watcher, "Bankers always want more FBI involvement, so you may see the Reagan people at Justice saying that bank robberies are on the rise because the FBI is paying less attention to them."

Civil rights activists will be looking over the new attorney general very carefully.Smith has said he will strongly enforce the civil rights laws, but the Carter administration left office without bringing some major civil rights lawsuits that had been ready for court for months. The biggest is a suit to force the busing of public school students in metropolitan St. Louis, a suit that would involve more than 200,000 students.

"That suit is still ready to go," one Justice source said. " All it needs is the signature of the attorney general."

Most Justice Department watchers expect that Smith will focus most of any changes he plans on the Land Division, which like all the other divisions at Justice still has nobody appointed as its head. Besides prosecuting violators of toxic waste laws, the Land Division enforces all the regulations of the Environmental Protection Agency that Reagan condemned so heartily before the election. It also carries out the land condemnations of the National Park Service, which have been criticized as being too aggressive by Republicans close to Reagan, such as Nevada Sen. Paul D. Laxalt.

"That is an area where my guess is there might be some contention in the future," said former Land Divisio chief Moorman. "I know that when I proposed that the Park Service be allowed to condemn land the way the Army Corps of Engineers does, that really kicked up a storm. Laxalt wanted to know just what kind of orge I really was."