Watching over the workplace. The issue of drug tests on the job pits deeply held notions of personal privacy against an employer's obligation to keep assembly lines safe and to ensure the quality of goods and services. As the use of drug tests spreads, `dignity' is becoming a crucial watchword.

`NO one will ever make me do that again,'' said Susan Register with great emotion in her voice. ``I'll never humiliate myself that way again.'' Ms. Register, a quality-control inspector at Georgia Power's Vogtle nuclear plant, was a target of her employer's spot check drug-testing program. She ended up being fired - for ``insubordination.'' And she has taken the matter to court.

The young woman had agreed to cooperate in a test to see if a sample of her urine would indicate that she was taking narcotics. She said she willingly complied, at first, because she did not use drugs. But when she was required to repeat the process several times under non-private and what she considered debasing circumstances, she rebelled and walked out on the examination. Her privacy was invaded and the whole thing was demeaning to her, she said.

Register and four of her co-workers at Georgia Power say their names came up on a drug ``hot line'' (as suspected narcotics users) only after they challenged some of the company's safety regulations at the nuclear plant. Now the American Civil Liberties Union, in defense of the five, is charging the company with retaliation for the employees' complaint to the Nuclear Regulatory Commission.

Georgia Power has denied these allegations and defended its procedures as sound, sure, and protective of individual liberties. Furthermore, it believes its urinalysis tests have sharply curbed drug use among employees and resulted in better plant safety.

The Register case is getting national publicity as part of the growing - and heated - debate over drug testing in the workplace.

It is only one of a dozen or more now being litigated in courts around the nation. All raise basic questions about constitutional privacy rights of workers and the responsibility and obligations of employers. Privacy vs. safety and quality

Unions and employee groups - buoyed by civil liberties organizations - generally oppose drug testing as an invasion of workers' privacy and a violation of Fourth Amendment protections against ``unreasonable searches and seizures.'' Also they point out that such a requirement - if not strictly regulated - can be used by management as an overt threat to recalcitrant workers and to regulate off-the-job behavior.

Further, they warn, as do many scientists, that drug tests are often inaccurate - and faulty results can lead to unjust discipline or dismissal and the branding of innocent employees as drug users.

Management groups that employ these tests say, however, that they have an obligation to all workers to maintain a high standard of safety and production. And by identifying employees who use drugs, they insist, they not only are able to improve the atmosphere in the workplace but to help individuals purge themselves of a habit or addiction.

It is also argued by advocates of urinalysis that drug tests are no more intrusive on an individual's privacy than routine physical examinations, fingerprint checks, and other background screening required for many jobs.

Within this framework, these questions, among others, are surfacing:

Should testing be required at all? And if so, should it be random or required of all employees of a given company?

Should any distinction be made between government workers and those in the private sector?

Should testing be confined to those in special occupations - such as airline pilots, nuclear workers, and those in government who hold security clearances?

Should testing be made only after establishing ``reasonable cause'' or suspicion of drug use?

Should test results be confirmed by independent sources?

Should positive evidence of drug use be used as grounds for immediate dismissal or as an opportunity for companies to refer employees to rehabilitation programs?

Alan F. Westin, a Columbia University professor of public law and government who has written widely on the subject of privacy and has done extensive studies with industry in related areas, stresses that it isn't the drug tests themselves but how they are used that is important.

``Technology doesn't change a good workplace into a bad one,'' he says.

Professor Westin adds that an employer has a right to know what to expect from a worker on the job. And he cites statistics that indicate ``anywhere between 5 percent and 25 percent of workers have some form of alcohol or drug abuse problem.'' Public sector vs. private sector

The privacy expert makes a clear distinction between public and non-public companies when it comes to drug testing.

``Private employers are at liberty to do as they please,'' Westin says. But he adds that most are looking for a balance between their desire to weed out drug users and the need to preserve morale by protecting workers' privacy rights. ``Potential legal liability is also driving them,'' he points out.

Westin says that in the public sector, wholesale random testing is ``probably not going to be accepted... [It] cuts across the grain of individual liberties.'' He advocates drug screening for people holding special jobs - such as nuclear workers.

But he also says there is an overriding ``moral'' factor that should encourage an employer to offer treatment to - rather than dismiss - drug offenders.

``If he simply pushes these people out, tens of thousands will be unemployed. It would do harm to the whole society by throwing them on the rubbish heap,'' Westin explains.

Norman Dorsen, a New York University law professor and president of the American Civil Liberties Union, does not rule out drug testing. But he says the ``nature of the intrusion [on an individual's privacy] must be carefully weighed against governmental [or safety] interests.''

``Employers must be willing to forgo some information,'' Mr. Dorsen adds. He says he sees ``restraint as a product of sophisticated awareness to a free society.''

David Cole of the New York-based Center for Constitutional Rights makes a distinction between what an employee is doing on and off the job.

``We should address work performance, not drugs,'' he says. Mr. Cole, a civil rights lawyer, allows that national-security and public-safety considerations might dictate testing in some situations.

``However, there is a constitutional principle,'' he stresses, ``that if we're going to infringe on the fundamental right of privacy, it must be done in the least intrusive way.'' Breadth of corporate drug testing

Current estimates show that about one-third of the nation's largest corporations - and about 17 percent of all companies - conduct some form of drug or alcohol tests on employees.

Most companies lean toward screening prospective workers. But many also test current employees. Some that have recently adopted the procedures concede that they have been prodded by President Reagan's call for a nationwide war on drugs.

The Boeing Company, which plans to start testing new applicants in February, says it will take careful precautions to avoid faulty results. Among other things, it will check to see if applicants who test positive use prescription medicine, which could account for the result.

Second of three articles. Tomorrow: Privacy and technology.