Seven of every 10 government workers in grades 13, 14 and 15 will be put under a tough, untested merit pay system that will force them, for the first time, to compete for pay raises.

Competition will be especially fierce in Washington, the headquarters town. Federal officials figure 125,000 GS 13 through 15 people will be under merit ppay this year or by the fall of 1981. Merit pay is part of the President's civil service reform. Salaries for those grade jobs range from $29,375 to $50,112.50.

A number of agencies will begin merit pay this October. Designated employes will be guaranteed only half the percentage pay raise set for other civil servants. To get more, they will have to compete with agency peers under job performance appraisal systems that will vary from agency to agency.

Example of how it will work: Suppose the October federal white collar pay raise is set at 6.2 percent, the amount Carter has budgeted. Federal workers in Grades 1 through 12 would get the full 6.2 percent. But GS 13 through 15 individuals under merit pay would be guaranteed only 3.1 percent. To get more than that they would have to be rated better than satisfactory. Top achievers could get up to 12 percent or 13 percent, depending on funds available to their agency and competition from fellow merit pay personnel.

The deadline for having merit pay systems set up and ready to go is October 1981. But a number of agencies -- Office of Personnel Management, Department of Health and Human Services (formerly HEW) and the Small Business Admnistration -- will implement merit pay this October. Individual agencies will decide which employes are either "supervisors" or "management officials" and subject to merit pay.

HHS, one of the mjaor employers here, has 16,000 GS 13 through 15 workers. It figures about 9,000 will be put under merit pay.

Most of the 9,000 slated for merit pay competition are here, or in Social Security headquarters in Baltimore. The new Department of Education will not begin merit pay until 1981.

HHS officials believe most of their supervisory -- management personnel in GS 13 through 15 will get the satisfactory ratings, and the full amount of the October increase. Money taken from those who don't measure up -- and get only half the regular raise -- will be used to award bigger pay raises, of up to 14 percent or more, to individuals who get outstanding ratings. In other words, the more people who "lose," the more money for the winners in the merit pay race.

The percentage of GS 13, 14 and 15 people put under merit pay will vary by agencies. Navy, also one of the metro area's biggest employers, plans to put 90 percent or more of its eligibles under merit pay. Some agencies will designate fewer people for merit pay. The government-wide average will be 71 percent.

Interest in merit pay is keen here for a very simple reason. Washington has more people who will be in it. Two merit-pay sessions coming up are worthy of note. They should shed some light on how the system is supposed to work, but the people who are designing it and who will run it.

On May 29 an outfit called FED 42 will hold an open forum on merit pay. FED 42 is a new group made up of GS 13, 14 and 15 personnel (hence its numerical name). A lot of them are concerned about how merit pay will work.

Jule Sugarman, deputy director of the Office of Personnel Management, will head up an OPM team of experts on merit pay.He is one of the architects of the system. Leonard Burchman, president of FED 42, will act as the auditorium of the HHS North building. Time is 11:30 a.m. Call Burchman on 376-6733 for details.

On May 20, the D.C. Chapter of International Personnel Management Association will have an afternoon session 3:30 p.m. to 5 p.m.) with top agency officials talking about their merit pay plans. Panelists include Fred Newman, Army's personnel chief; Donna Beecher of HHS personnel; Fred Kistler of the OPM and Howard Messner, Office of Management and Budget's assistant director for management improvement. Place is the Commerce auditorium. Call Tim Connelly next week on 377-3203 for information.