Uncle Sam's million-plus white collar workers will soon learn what new performance standards -- of quality, speed and quantity -- they must meet to get pay raises, or simply to hold on to their jobs.

President Carter's sweeping civil service reforms have, so far, concentrated on the upper reaches of the bureaucracy. Changes are already being made via the Senior Executive Service, the produce-or-perish, bonus-or-boot corps of federal supergraders. And big changes are coming for the government's huge 200,000 middle-management group in Grades 13, 14 and 15. They soon will be placed under a merit pay system that is a wildly new concept for government.

For the ordinary civil servant, however, civil service reform is something one reads about of an evening if there are no sleeping pills handy. The extent of reform, so far, for the typical GS buck private has been to watch bosses squirm, quit or scoot ahead. But within the next few months the brave-new-world of corporate-style management is about to be applied to the U.S. government, which has never suffered such before.

When Congress passed the Civil Service Reform Act, it gave the Carter administration greater control over the hiring, firing, mobility and reward system for top career executives. In response, an astonishing number retired early. And Congress approved a controversial, untested merit pay system. It is designed -- for better or worse -- to force mid-management types to earn annual raises rather than get them automatically like rank-and-file workers. That merit pay system goes into effect no later than October 1981. Some agencies will try it this year.

While concentrating on the top levels of the federal pyramid, however, Carter aides are also eager to introduce tough new management controls down to the lowest levels. They plan to do it by eliminating the current system under which employes qualify automatically for regular 3 percent longevity raises simply by being rated "satisfactory" by their bosses.

In its place, the Civil Service Reform Act requires agencies to set up new job performance standards and to establish "critical elements" within those jobs. Failure to meet one of those "critical elements" -- as yet undefined in agencies -- would be enough to deny employes longevity pay raises. At present 90 to every 100 employes who came due for longevity raise gets it -- a "satisfactory" ratio the administration believes may be too high.

"Under the current system, employes become eligible for an automatic 3 percent longevity raise every year during their first three in-grade-steps of service; every two years over the next three steps; and a raise every third year in each of the final three steps in grades.

To make sure the employes are performing up to par, the administration has authorized a rating system -- flexible enough to be tailored to individual agency standards -- that bosses will use to decide who gets raises in addition to the regular, statutory October boosts.

The multimillion-dollar question -- one that affects every one of the 300,000 civil servants here -- is who determines those standards. Carter aides say Congress intended for management to set them in consultation with employes.

Federal unions have argued that something as important as performance standards cannot be left to management alone. Unions want the right to bargain with management over the standards. Management -- knowing the bargaining can only result in "weaker" standards -- says no bargaining.

The issue of the negotiability of performance appraisal systems, and critical job elements, is now before the Federal Labor Relations Authority. If the FLRA buys the management argument, the unions will certainly take it to court. If the unions win, the government will appeal.

Both sides predict the end off the world if the other wins.

If the FLRA upholds management's right to set those standards (and courts go along), federal workers could be in for a real jolt next time they come up for a performance rating. If it gives unions the right to negotiate those standards, federal managers claim it will gut the program Carter promised the American people, when he said he wanted to make it easier to punish or get rid of "incompetents."