Striking city garbage collectors defied a judge's order to return to work today to clean up 15 emergency dumps around the city that he said posed "a clear and present danger to the health and safety of the citizens."

Mayor W. Wilson Goode said he would seek a contempt citation against the 2,500 garbage collectors in court Friday morning. If the citation is issued and the workers still refuse to return, Goode said, he will call in private contractors to replace them.

This was the 17th day of the strike by city employes. More than 13,000 white- and blue-collar workers have participated, and more than 9,000 were still not working today, but the absence of the garbage collectors is most noticeable.

All around Philadelphia, mounds of trash and debris are forming as people drive up and heave bags and cardboard boxes full of garbage, old mattresses, rusted bicycles, battered furniture and diaper cartons onto the ever-rising heaps.

Fifteen of these piles are emergency dumps designated by Goode at the start of the strike. Some garbage has also been dumped on the streets and along roads on the outskirts of the city; the downtown area is mostly clear.

Common Pleas Court Judge Edward J. Blake ordered the garbage collectors back to work specifically to clean up the emergency dumps. If private contractors are hired, Goode said, they will do the same. The mayor said he does not expect normal garbage collection to begin soon.

The president of District Council 33 of the American Federation of State, County and Municipal Workers (AFSCME), Earl Stout, said he had told the garbage collectors to return to work but was unable to force them to do so. Goode also threatened to fire the workers if they continued to refuse to return. Told today that pickets had scoffed at the threat, Goode said, "Tell them to try me."

Strikers reacted angrily to Goode's statements. Craig Wise, a sanitation supervisor and union member, said if private contractors crossed the picket lines "it will be very ugly."

Goode said in a statement this evening that the city's personnel department has begun screening candidates to replace the striking sanitation workers permanently.

At a hearing that led to the back-to-work order, officials said citizens were endangered by fighting between people who want to dump trash and people who live near the newly created dumps. Tapes of such confrontations were shown.

Police are posted around the clock at the emergency dumps, and have closed at least one because of protests from people who live not far from the heap, which sprawls along a median strip.

Also today, Judge Blake issued a back-to-work order to about 850 workers at city health centers. Their contract has been settled but, citing solidarity with the garbage collectors, they have not been working.

Thomas Cronin, head of District Council 47 of AFSCME, which represents the health workers, said they would obey the order and return to work.

Contract negotiations between the city and District Council 33 stopped after the back-to-work order Wednesday, but Jim Jamison, director of communications for the city, said telephone calls are being exchanged to try to resume them.

District Council 33 represents 11,130 blue-collar workers. District 47 represents 2,220 white-collar workers.

Nearly 40,000 tons of garbage has piled up, rotting and settling in the impromptu dumps.

When Goode named the emergency dumping grounds, citizens were asked to bring well-wrapped household garbage to the dumps if necessary, keeping as much as possible at home.

The 15 dumps are located in city parks, empty lots, on median strips and in parking lots. They settle and seep when it rains, stink when it's hot and have gathered populations of insects and animals, including raccoons, opossums, rabbits, deer, rats, snakes, turtles and frogs, according to one observant dumper at a site in Pennypack Park.

Residents of Summerton, in the northeast section of the city, rebelled upon discovering a pile one resident said was "as big as a house" 100 feet from their front doors, only a few hours after Goode desigated a median strip there as a dump.

"We didn't want it here," said Joanne Eife firmly as she and a half dozen neighbors sat in a circle of lawn chairs around the garbage.

Since July 2, the day after the strike started and the garbage began mounting, the Summerton residents have maintained a 24-hour watch to prevent additions to the pile.

They swat the flies and burn sticks of incense to counter the offensive smell. Since the residents began protesting, police have maintained a 24-hour vigil at the Summerton site.

Although it is not officially closed, the police have been helping to direct carloads and truckloads of trash to other dump sites.

Some dump visitors appear pleased with the Philadelphia system. "We saw several New Jersey and New York plates" on cars delivering garbage, said Margaret Kozempel, one of the garbage-guarding committee.

Other entrepreneurs, she said, have been collecting one dollar for each bag of trash they haul away to the dumps.

Kozempel said the committee has to keep an eye out at night for dumpers so determined that they move police barricades and drive toward the dump with their lights out.

"But we spot them by their brake lights," she said.