The complex saga of budget director Bert Lance's personal finances and how he ran two Georgia banks before coming to Washington are all due for a new round of intensive probing as Congress returns from its month-long August recess.

Three congressional committees have scheduled hearings on different aspects of the Lance affair and on the unresolved questions it has raised about the ethics and prudence of certain banking practices that have been revealed.

The embattled director of the Office of Management and Budget will, in effect, be out through an unofficial reconfirmation process as he is asked to justify his behavior and judgment as a Georgia banker when he appears this week before the Senate Governmental Affairs Committee.

The committee, chaired by Sen. Abraham Ribicoff (D-Conn.), approved Lance in the first place last January, and in July, at a one-day hearing, gave him a "a seal of approval" after briefly delving into allegations of improper behavior that had just begun surfacing.

The evidence of Lance's past activities will also be used as a wedge in both the House and Senate Banking committees for legislation designed to tighten certain banking practices, such as loans to insiders and the way banks are bought and sold.

In addition, the Office of the Comptroller of the Currency, which regulates national banks will itself be under scrutiny at the hearings.

At issue will be whether the comptroller's office deliberately white-washed Lance's banking past in a study made before he was confirmed by the Senate, and also whether the comptroller adequately supervised the two Georgia banks Lance headed.

After Congress went on vacation, the comptroller issued a long - but not completed - report resulting from his office's recent investigation.

The report said Lance committed no prosecutable crimes. But it detailed hundreds of thousands of dollars in overdrafts by Lance, his wife LaBelle and other relatives at Calhoun First National Bank when Lance was chairman there and called this an "unsafe and unsound" banking practice that required a cease-and-desist order to remedy.

It also described a pattern of multimillion-dollar personal loans to Lance from banks where his own institutions placed interest-free deposits in correspondent accounts. The report said this "raises unresolved questions as to what constitutes acceptable banking practice."

Still to come are the comptroller's report on whether Lance made personal use of company aircraft when he was head of the Calhoun bank and of National Bank of Georgia in Atlanta.

And there are the as-yet-unrevealed findings of the Internal Revenue Service. It has been investigating why Robert Bloom, who was acting comptroller of the currency last year, did not inform the Senate of Lance's large personal overdrafts in a letter that gave Lance an apparent clean bill of health prior to his confirmation.

The IRShas also been exploring whether any improper intervention caused the Justice Department to drop a criminal case against Lance for bank overdrafts by his 1974 gubernationrial election campaign committee just days before Jimmy Carter announced his nomination as budget director.

The Ribicoff committee will probably hold center stage this week with two days of hearings. On Wednesday Comptroller John G. Heimann will answer questions about his report, and on Thursday, Lance will have a chance to respond.

Stung by criticism over the way it previously handled the Lance matter, the committee can be expected to go over the comptroller's report "almost page by page," according to one committee staffer, and to question Lance about all of the issues that have been raised so far.

The committee will also call Bloom, who is still deputy comptroller of the currency, and John W. Stokes, the former U.S. attorney in Atlanta who terminated the Justice Department's case against Lance last fall.

The financial institutions supervision subcommittee will hold a hearing on Tuesday that will concentrate on Lance's banking activities as, according to subcommittee chairman Fernand J. St Germain (D-R.I.), "part of an ongoing effort to shed light on the need for improvement in the banking codes."

The panel is considering legislation to prohibit loans - like the ones Lance obtained - in which a bank officer uses his institution's correspondent relationship with a bigger bank as leverage for getting personal financing. And it would also like to further restrict the size of loans bank officials can obtain from their own institutions.

St. Germain is also expected to use the hearings to address the continuing question of how adequately the comptroller's office regulates banks and corrects abuses once they are discovered.

Witnesses scheduled on Tuesday are Bloom; Donald L. Tarleton, regional administrator in the comptroller's Atlanta office; Robert Guyton, president of National Bank of Georgia; King D. Cleveland, NBG's former chairman; Calhoun First National Bank chairman Y. Atkins Henderson, and Calhoun president John E. David Jr.

St Germain has left the door open on the subcommittee's objectives, saying he intends to review all aspects of the operation and regulation of the two Georgia banks in recent years "and through succeeding ownership groups."

In the Senate, meanwhile, Banking Committee Chairman William Proxmire (D-Wis.) has scheduled two sets of hearing that will touch on the Lance affair.

On Sept. 16 and 19 his committee holds hearings on reorganizing the way banks are regulated through three federal and multiple state banking agencies, and hopes to cite the two Georgia banks as an example of ineffective regulation.

Three days of hearings beginning Sept. 26 will "focus on specific practices outlined in the comptroller's report, how widespread they are what kind of safeguards regulators have for preventing abuses, and what kind of recommendations they have for preventing a repetition," a Banking Comittee staff member said.

On a recent interview program Proxmire was asked whether the Lance case would provide the impetus for a wave of banking legislation to pass Congress.

"I don't think that bank reform legislation should, or will, really depend on whether or not Mr. Lance stays around," he responded.