More than 8 million public workers - ranging from Washington officials to local teachers, firemen, judges and dog catchers - would have their family retirement income cut back under a Social Security "offset" plan now before Senate-House conferees.

The "offset" would hit workers and many retirees in state and local governments in Massachusetts, California, Illinois, Connecticut, O&hio and several other states where public employees are not under Social Security.

Up to now the emphasis on the adverse financial impact of the offset plan has been on federal retirees. But the Senate-passed bill, aimed at endting "windfall" dual retirement benefits, would affect anybody eligible for a public pension who hopes to add to his or her retirement income by applying for benefits - either as a dependent or survivor - of a spouse who worked under Social Security long enough to quality for benefit.

Offsetr would reduce the dependent benefits future retirees are entitled to - based on a spouse's Social Security - doolar-for-dollar based on the amount of the retiree's federal, state or local government pension.

The offset provision is very, very confusing. The Senate approved it; the House did not. Now conferees from both the Senate and House are working out a compromise to the Social Secuityr financing bill that may, or may n ot, provide for offset.

What offset would do, in the language of the Senate report, is this: ". . . social Security benefits payable to spouses and surviving spouses be reduced by the amount of any public (federal, state, or local) retirement benefit to the spouse. The offset would apply only to pensioin payments based on th spouse's own work in public employment that is not covered under Social Security. In general this should assure that dependents's Social Security benefits will not be paid to persons not dependent on the worker."

What that means is that either you, or your spouse, would keep whateve federal, state or public pension you have any Social Security you have earned yourself.

Offset would come into play only when a federal, state or local government retires tried to apply for dependent or survivor benefits based on the Social Security entitlement of a spouse. In that case - and the Senate cstimates it would hit about 85,000 people the first year - the auxiliary Social Security benefit (from your spouse's Social Security earnings) to you would be reduced based on the amount of th public pension or annuity you are drawing.

The effective date of the offset provision, if the Senate plan is approved by the conferees and becomes law, quoting the Senate report, would "become effective with respect to benefits payable for moinths starting with the month of enactment on the basis of appliacations filed in or after the month of enactment."

Public employees who are eligible to collect dependents' benefits from a spouse's Social Security would have to be 62 to apply for them. To get a survivors benefit they would have to be 60. They would not have to retire to be eligible to file, but would have to meet the age requirements and be the spouse of someone eligible for Social Security benefits.

Federal and public unions, and retiree groups are trying to get the conferees to kill the offset plan, or at least to delay it for six months.

Conferees began meeting this week but it could be sometime yet before they get around to voting on the offset language.

Senate sources expect the Senate conferees to stand firm on offset as a means to reduce "windfall" benefits to public retirees who can collect their full pension and any Social Security they earned, plus a dependent or survivor benefit from a spouse.

House members are under heavy pressure to kill or delay the offset, and a major lobbying campaign by the 6 million to 8 million public employees (plus their spouses) who would be affected by offset could change things.

The people who will decide the Social Security compromise are, from the Senate side, Russell B. Long (D-La); Abraham A. Ribicoff (D-Conn.); Gaylord Nelson (D-Wis.); William Hathaway (D-Maine) who replaced Floyd D. Haskel on the conference; Daniel P. Moyniham (D.N.Y.); Carl T. Curtis (R-Neb.); William V. Roth (R-Del.) and John C. Danforht (D-Mo.) who replaced Paul Laxalt (R-Nev.).

House fonferees are Reps. Al Ullman (D-Ore.); James A. Burke (D-Mass.); Dan Rostenkowski (D-III.); Joe D. Waggonner Jr. (D-La.); William R. Cotter (D-Conn.); Abner J. Mikva (D-III.) and Jim Guy Tucker (D-Ark.), Republicans are Barber B. Conable Jr. N.Y.); Bill Archer (Text.); and William M. Ketchum (Calif.).