Two federal lawmakers from New Jersey demanded that the Army Corps of Engineers hold a hearing on a dredging permit it had already issued after following all the rules. They got the hearing. But it didn't fit the mold they were used to.

In the past, hearings on dredging permits in New Jersey and New York were largely one-sided affairs. A handful of people would attend from the port, make their points, and sit quietly. Hundreds of local residents, whipped into a frenzy of fear by a publicity-savvy activist group, would show up and vent their anger. Anti-dredging placards waving, they would cheer, boo and shout catcalls, depending on what point a speaker was making. Organizers would root them on.The latest hearing, which took place Monday at Fort Monmouth, N.J., didn't proceed like that at all. It was a true two-sided hearing. And it left no one in any doubt that there is a large number of people who passionately support the Port of New York and New Jersey and a rational approach to keeping it alive and well.

More than 2,000 longshoremen from both sides of the Hudson River, riding some 50 buses that their International Longshoremen's Association locals chartered for the occasion, traveled to Fort Monmouth to speak out for the future of the port.

It was a trip into hostile territory. Once again, the activist group had stirred up public alarm, promoting the erroneous impression that a dredging project will result in a flood of toxic waste washing over New Jersey beaches. Local newspapers had come out against the project and a talk-radio station inveighed noisily against it, playing up calls that opposed the project and giving short shrift to those that supported it.

The longshoremen, concerned for their future and acutely aware of the opposition to them, weren't shy about making their feelings known. In fact, they expressed themselves clearly and very loudly - just as hundreds of people on the other side of the issue usually do, and did again on Monday.

But the dockworkers and their leaders weren't the only people to show support for the port. Port businesses came and spoke. Other businesses and business groups came, too, including the New Jersey State Chamber of Commerce and Nation's Port, a new business-labor coalition. Officials from other unions and the head of the New Jersey State AFL-CIO, Charles Wowkanech, also spoke out.

They all came to remind hearing officials of the port's hefty economic benefits to the region, including jobs and support for environmental programs.

So did Rep. Robert Menendez, D-N.J., whose calm words sounded especially good when compared to the harangues of his colleague, Rep. Frank Pallone, D-N.J., a dredging-disposal foe who - with Sen. Robert Torricelli, D-N.J., who wasn't there - pressured the Corps into holding the hearing.

It was a raucous two-part session that began in the afternoon, and many of those who signed up to speak never got the chance. By the evening portion, tensions were high. Shortly after 8 p.m., a local mayor came to the podium and denounced the longshoremen. As ILA Executive Vice President Al Cernadas attempted to calm his people, he was heckled. Cernadas sharply warned that dredging opponents needed to keep their people in line, too.

Col. William Pearce, district engineer, quickly cut the hearing short. The record will be kept open into February for written comments.

At the heart of the matter is the use of a federally approved ocean site several miles off Sandy Hook, N.J., for dredged material. It's a contentious issue that was supposed to have been resolved in 1996 in a compromise agreement by Vice President Al Gore. The accord shut the decades-old site to contaminated dredged material. But it allowed clean material - so called Category I mud - to continue to go to the site as a cap for material dumped there years ago.

Clean Ocean Action, the activist group that set off a dredging crisis in the early 1990s over use of the site, praised the agreement. So did Pallone, who helped the group negotiate it.

But apparently the Gore agreement was little more than a temporary tactical accommodation to them. They now oppose the use of the site for mud from two dredging projects in New York City, including the one that was the focus of the hearing.

The mud from both projects has passed the Category I tests and, as an Environmental Protection Agency official put it in a letter to New Jersey Gov. Christine Whitman, it ''meets the spirit and intent of the 1996 agreement.'' But the activist group disagrees. It says the government changed the standards after the agreement was reached, lowering them. Federal officials say that's just not true. Nevertheless, the group has backed out of the agreement and now wants new standards - its standards. And it's playing the public-fear card to get them.

New Jerseyans still remember with horror the late 1980s, when sewage, garbage and medical waste washed up on their beaches. It's entirely understandable that they don't want it to happen again - ever.

Dredged material isn't sewage, garbage or waste. It will not wash up on their beaches from a site several miles at sea. And the material in question has met detailed federal standards for suitability for placement at the ocean site; in fact, it's well within those standards.

But it's not hard for skillful activists to juxtapose the issues of dredged material and beaches in the public mind. That's what has happened here. The result is a highly fearful public - one that's being cynically used to promote a group's agenda, but one that's too worried to care.

It's a pity the Gore agreement was deep-sixed by the ocean-disposal opponents, bringing back to life the controversial dredging issue it had laid to rest.

But the issue has been revived. And it's good to see longshoremen, port businesses and many others support the port so strongly. It will be even better to see them continue their efforts, as they'll have to do if a rational approach is to prevail.