Customers at Safeway food stores in the Washington area will get more than their usual share of $2 bills with their change during the next six months.

Under an agreement made with the Treasury Department earlier this month, all 165 Safeway stores in this area and in Delaware and southern Pennsylvania have begun distributing $2 bills in large numbers to their customers.

Although the agreement with Safeway and with Grand Union, a New York state-based chain was not announced until yesterday, a Treasury official said the $2 bills had been distributed at some Safeway stores as early as Nov. 7. The bills will be used extensively in 24 Grand Union stores in New York beginning Jan. 1.

The program is part of an effort by Treasury to encourage use of $2 bill. The bill was reissued on April 13, 1976, the birth date of Thomas Jefferson, whose likeness appears on the bill.

Since then, the Bureau of Engraving and Printing has issued 527 million $2 bills, but only about 220 million of them are in national circulation. It had originally been hoped that the $2 bill would cut in half the number of $1 bills being printed.

"Right now 60 per cent of bills printed by the Bureau of Engraving and Printing are $1 bills," Terry Marksberry, special projects officer for the operations department at Treasury explained. "If that keeps up, we're going to have to build a whole new engraving and printing building in a few years just to print $1 bills."

Marksberry said despite the problems it has had in distributing the $2 bill, the Treasury Department was still hoping that the bill - along with a new $1 coin - would combine to cut in half the number of $1 bills being printed. And if the Safeway and Grand Union experiment works out, he said, the program to encourage the use of the $2 bill will be expanded into other areas.

If the program is successful, the government could save between $5 and $6 million in printing costs.

Safeway and Grand Union will be asked to distribute the bills during "normal day-to-day" transactions. In other words, a customer getting $18 in change will not be given nine $2 bills, but probably will get at least one.

A similar experiment in Portland, Ore., resulted in a 2,000 per cent increase in the use of the $2 bill there.

"Nobody will actually declare it a failure or a success" a spokesman said. "They may be desirable, but they're not necessary.That's how many people feel. They're getting along well without it."