After a smooth Day 1, is trouble ahead?

Early Tuesday morning Bill Sanchez pulled his company van into the parking lot of San Antonio's alien legalization center. The six Mexican men who piled out - all wearing the fresh blue shirts of Mr. Sanchez's tree and roofing service, all in the United States illegally - were among the tens of thousands of undocumented aliens emerging from their shadowy lives this week toward what they hope will be a new life of full US citizenship.

``They've been living two different lives here, always looking over their backs,'' said Mr. Sanchez, a native San Antonian who has culled many of his employees from the same Mexican family for more than nine years. Congress has enacted the immigration reform law, he added, ``so let's begin implementation of it.''

The San Antonio center is one of 107 such offices the Immigration and Naturalization Service opened Tuesday to receive illegal aliens for amnesty consideration.

In San Antonio, as across the country, the INS legalization centers opened without the crush - or, by and large, the glitches - that some observers had predicted. ``It pleases me to be able to tell our detractors that we're open, and we're doing it,'' said Richard Casillas, INS district director for San Antonio.

Some offices in Los Angeles reportedly ran out of forms, and there were scattered computer failures, but day one of the year-long application period generally ran smoothly.

But some amnesty program critics maintain that INS provisions for staffing and facilities could yet prove insufficient as this week's stream of aliens turns into an anticipated flood. INS expects nearly 4 million illegals to qualify for permanent residency.

In addition, some immigration experts say major problems loom ahead as these aliens seek help from hundreds of private assistance groups in completing what for many applicants will be a complex process.

``I'm concerned about the understanding of the complexity of this program on the part of the service providers,'' said Wells Klein, director of the American Council for Nationalities Services in New York City.

Hundreds of individuals from various religious, trade union, and community organizations have been hastily trained across the country in recent weeks to help aliens complete their applications, Mr. Klein said. ``This gets into social work. I'm worried there's going to be a weakness in providing quality assistance.''

``It's not like filling out an employment application,'' added Kirke Wilson, executive director of the Rosenberg Foundation in San Francisco. ``It's technically quite demanding.''

Both men said they are especially concerned about a lack of application assistance and accessibility to INS centers for the significant numbers of aliens who live in rural areas of California, Texas, and upstate New York.

Mr. Wilson said he was especially concerned that California, which is believed to have as many as half of the nation's illegal aliens, will be ``unable to handle the numbers expected with the system now in place.'' Reluctance of many organizations to become too closely associated with the INS has led to a lack of application assistance programs, he said. But he added that concern about the quality of help available has prompted a number of statewide legal organizations to consider offering technical assistance.

Tuesday's smooth opening of the legalization centers was attributed in part to the immigration service's last-minute preparations. But a reluctance among aliens to rush to a government agency they have been circumventing for years was certainly a factor.

By late afternoon the San Antonio center had handed out 2,202 applications, all but a handful of which went to Mexican nationals. Only two individuals, one from Guatemala and one from Mexico, had returned completed packets and been issued the temporary work authorizations that are the first step to legal status.

``People are afraid,'' said Omer Bangs, site chief for the San Antonio office. ``But once they see how we're working, that we're not here to deport anyone, then the word will get around and the flow will start.''

Most aliens who did visit the office on the first day said they knew many illegals who were holding back to see how others were treated at the centers. There was speculation that the strongest cases for amnesty would come forward first. One woman said she was picking up an application for a friend who feared the entire operation was nothing but a ruse to trap illegal aliens.

``The INS has a history of setting up sting operations to dupe the undocumented into coming forward,'' said Antonio Cabral, whose United Latin Front staged a quiet protest outside the San Antonio office as aliens trickled inside. ``We're not trying to discourage anyone from applying, but we do want the undocumenteds to know they have to be careful about what they say to the INS.''

Inside, Mr. Bangs held up copies of pages from the landmark 1986 immigration legislation to emphasize its privacy provisions. He noted that information gathered from applicants can only be used for the amnesty decision.

Despite warnings from immigration experts that the applications and their requirements are complicated, many illegals questioned Tuesday said they planned to complete the forms themselves. Still, at the Catholic Family Services office in San Antonio, director Gus Catuogno said his agency was already assisting more than 75 amnesty applicants a day.

``The one thing holding us back is money,'' Mr. Catuogno said. As an INS-designated assistance agency, his service can charge up to $75 per applicant for counseling, and will be reimbursed $15 by INS for each application submitted. But Catuogno said that system is proving a hardship for the assistance organizations.