College students anxious to get federally-guaranteed student loans before requirements are tightened next month are flooding Washington-area lenders with applications.

As part of President Reagan's budget-cutting program, beginning Oct. 1 students from families earning more than $30,000 a year will have to meet new requirements--based on need--to be eligible for borrowing under the most popular plan, the Guaranteed Student Loan Program.

"There's an enormous surge going on right now," says Robert Leider of Alexandria, author of the widely-used financial-aide guide Don't Miss Out. "Colleges and lenders are receiving a volume of applications like they've never had before."

The Maryland Higher Education Loan Corporation reports a 105 percent increase in the number of applications for Guaranteed Student Loans (GSL) submitted from April 1 to July 31, 1981, compared to the same period last year.

"A lot of those are probably in response to all the publicity about cuts in the program," says James Leamer, executive director of the state-sponsored loan-guarantee corporation. "Also, as college costs keep increasing, we've been experiencing increased interest in student loans."

College expenses are expected to rise a record 13 to 14 percent this school year, according to a recently-released survey by the College Board. The report says total expenses will average $6,885 at private four-year colleges and $3,873 at public universities.

Students most affected by cuts in the GSL program, notes Leider, are those attending public colleges whose families earn $30,000 to $45,000.

"The new budget cuts," he says, "divide the world into two classes--those who make under $30,000 and those who make over $30,000. If you make under $30,000, life goes on as usual--an undergraduate student may borrow up to $2,500 and a graduate student may borrow up to $5,000 per year at 9 percent interest.

"If a student's family income is greater than $30,000, however, they will be subjected to a 'remaining needs test' (formulated by the U.S. Department of Education and expected to win Congressional approval next week).

"This test calculates the cost of attendance at college--which includes tuition, room, board, books, transportation, pizza and other miscellaneous expenses.

"Then you subtract from that total cost any other aid, like a scholarship, and the 'family contribution'--which is figured by another long form. (The family contribution for a family of four with a $40,000 annual income, he says, is listed at $4,900.) The amount you have left is the 'remaining need.' "

This new "needs-assessment" plan, he says, "will probably knock out middle-income families who are sending their child to a low-cost school like George Mason or the University of Maryland.

"Middle-income families sending students to more expensive schools may still qualify. And those who do qualify must now pay a 5 percent origination fee that goes to Uncle Sam. Instead of getting $2,500, they'll get $2,375."

The other significant change in federal student loans programs, says Leider, is a restructuring of the old Parents Loan Program (PLUS) into the new Auxiliary Loans to Assist Students program, "with the unfortunate acronym ALAS." Under the new program, graduate students and parents can borrow up to $3,000 per year, and "independent" undergraduates can borrow up to $2,500. Beginning Oct. 1, interest on these loans will increase from 9 percent to 14 percent.

Most students seeking loan money for the 1981-82 academic year will have their applications approved before the program changes occur, says Education Department spokeswoman Skee Smith. "Probably 70 percent of the kids who will borrow, will borrow by the end of September."

The key step in avoiding the GSL needs-assessment test, she says, is to make sure the college completes its portion and signs the application by Sept. 30.

Since college financial-aid offices may be swamped, "the earlier you get the application to them," says Leider, "the better. Students who wait to get their tuition bill to apply for a loan, may be out of luck."