Paul Nolfo was just fed up. To get to his Manhattan job as a computer specialist he walked out of his apartment in Jersey City, hustled his way through a subway, jumped on a bus, and then boarded a train. "It was not a simple hour," Nolfo said.

So when his employer, the American Diabetes Association, decided to establish an office in Alexandria last month, Nolfo moved, too.

Now he sleeps a little later, commutes almost hassle-free in a car pool, and arrives in Alexandria 20 minutes after leaving his Falls Church home.

Nolfo is one of thousands of workers being drawn to the Washington area to fill an estimated 185,900 jobs that have been created or will be created in the second half of this decade. The Metropolitan Washington Council of Governments reports that the most intense growth -- an increase of almost 40 percent from 1985 through 1990 -- will occur in Alexandria.

The American Diabetes Association, like many organizations, relocated in the Washington suburbs because of their proximity to the Capitol and three major airports, the mass transit system and the cost of living.

"In New York, we knew we weren't getting the most effective use of our donor dollars," said Caroline A. Stevens, the association's assistant executive vice president. "We evaluated cities for two years and chose Alexandria," she said, "because it was close to the government and other associations -- a networking goes on among people dealing with the same issues -- and we got a good financial arrangement."

What type of work the newcomers do, how they get to work, where they live and how many schoolchildren they will have might have far-reaching effects on the region, say local government, housing, transportation and education officials.

"We are putting together the implications now," said John C. McClain, the Council of Governments' director of information services. "We are trying to tell governments what they should be prepared for in the way of schools, transportation systems, new bus links to Metro, parking . . . . "

"What it means is the District is changing from being a government town to a private sector town," said Douglas M. McCabe, associate professor of industrial and labor relations at Georgetown University.

McCabe said the radical change in the number of private sector jobs has turned metropolitan Washington from a one-company paper-pushing town into a cosmopolitan international city.

From 1980 through 1985 the private sector service economy overtook the federal government as the area's major employer, and a large chunk of the forecasted job growth is in technical, legal, hotel, fast food and other service jobs. "A lot of the jobs will be professional," said G. Barton Middleton, executive director of the Alexandria Chamber of Commerce. "But they will bring grocery stores that employes can go to at lunchtime, and dry cleaners and restaurants . . . . "

While the region's population increase from 1985 through 1990 is not expected to be much greater than the increase from 1980 through 1984 -- a projected 170,000 increase compared with a 162,000 increase -- the number of jobs is expected to jump by 185,900, or 26,300 more than generated in the first half of the 1980s.

So, for the first time in planning officials' recent memory, new jobs are expected to top the number of new residents attracted to the region, bringing in workers from the outer counties and beyond.

"I have 50 full-time employes who travel 200 miles a day -- 100 each way -- to get to work," said Garnet N. Kaufman, president of the Kaufman Group, a construction subcontractor and consultant firm based at Dulles International Airport. "Because you can't get to Dulles by a Metro, it's hard to get people from the District, so they're coming from Winchester Va. ."

In Alexandria, where the biggest percentage employment increase is projected, city and Council of Governments officials expect only about 1,000 new residents by 1990, while the number of new jobs may exceed 28,500.

The projections are based on figures supplied by local government planners who estimate future employment by looking at proposed site plans and new construction.

"The rub is that although there is a significant number of new nonprofessional jobs, the potential employes cannot afford to live here," Alexandria Mayor James P. Moran said. "They'll have to commute from rural areas."

The average monthly rent in Alexandria for a two-bedroom apartment is $660, and the average single-family house costs $126,400. With the increased demand of the high-paid executives who staff the 150 national associations and the scores of computer and high technology firms that have recently located in Alexandria, real estate agents say housing costs will continue to grow.

"We looked all over Alexandria, but it was too expensive," 30-year-old Nolfo said of himself and his wife, Jeanmarie Mara. "For $90,000 we found a three-bedroom house with a basement in Falls Church."

What the bulging work force will do to the region's congested roads has started a tug of war between residents who have had enough road building and engineers and others who say development demands more.

In Alexandria, many residents say they are tired of Fairfax County and outer county commuters traveling through their compact city as they head to the District. And many say they are unwilling to finance and to put up with the inconveniences of the city-proposed widening of Duke Street and extension of Eisenhower Avenue to accommodate the increasing pool of nonresidents working in the city.

"This is going to mean we'll have additional problems and challenges with traffic," said the chamber's Middleton . "But I'd rather have this than no traffic and a ghost town."

The solace to taxpayers is that the booming job market will pump tens of millions of new dollars in property and sales taxes into local governments and, depending on federal cutbacks, possibly lower tax rates.

There is also hope that the boom will help reduce unemployment. Area planners say that although most of the new jobs are professional -- association executives, lobbyists, computer technicians and consultants -- there will be a significant number of jobs requiring less skill.

"If we don't find a way to match the unemployed with these jobs, we will never have a better opportunity," Moran said.

Yet matching the jobless with the jobs has proved to be costly.

D.C. Mayor Marion Barry has found some success with a job training and transportation program designed to fill suburban jobs with the District's unemployed, but since June the District has spent $127,940 to help 794 people get temporary, part-time or full-time positions.

As Alexandria City Manager Vola Lawson sees the job boom, it is a challenge to "share the prosperity with unskilled persons who need training and employment."

As Paul Nolfo sees it, it was a chance to escape the New York City subway as he turned 30.