As far as Clarence Long was concerned, Bob Bauman had been downright underhanded.

It was bad enough that Bauman, a Republican congressman from Maryland's Eastern Shore, had openly challenged Long for months over public works project affecting Long's own Baltimore County congressional district.

But then, on Tuesday, Bauman tried a last-minute maneuver to win approval for the project from the House Public Works Committee. And he tried to do it before Long, an influential Democrat, who has spent 17 years on Capitol Hill, could use his muscle to block it.

It didn't work.

Bauman's plan had been to have one of the members of the committee attach an amendment to an omnibus public works bill, giving congressional approval to a plan to dump Baltimore Harbor bottom mud on two small islands in Long's District.

But when the committee met this morning, less than 24 hours after Bauman sent the group a letter requesting the approval, not on congressman offered to amend the bill on Bauman's behalf.

Overnight, Long had made is vehement opposition to the proposal known to one-third of the committee, including a crucial subcommittee chairman. And no-one was willing to oppose the powerful Maryland Democrat.

The dumping issue has been a stubborn snag in plans to dredge a new channel in the Baltimore Harbor.The channel, which would allow the harbor to accommodate large snips carrying more cargo, would give a needed boost to the state's economy.

All state officials, Long included, favor the Dredging. But they had problems figuring out how to dispose of the tons of chemical-laden muck the dredges would pick up.

Over the years, however, most state officials have agreed that the spoil could be dumped on Hart and Miller Islands near the head of the Chesapeake Bay. That might have been sufficient, until a federal judge last fall said congressional approval was needed before they could build a dike to hold the spoil.

If Long has anything to say about it, Congress isn't ever going to approve. As soon as his colleague Rep. Ray Roberts (D-Texas) told him that about the proposal Bauman and Rep. Marjorie Holt (R-Md.) made to the Public Works committee, Long and his staff got to work.

By nine o'clock Tuesday night, they had contracted 15 congressmen on the 45-member Public Works committee and won 15 assurances that Bauman's proposed amendment would not be added to the Public Works bill, which was approved yesterday.

"I've headed them off at this point," Long said yesterday, grinning as he leaned back in his office chair.

Long refused to say which 15 he talked to, or what he said to them. "A few were people I've been helpful to," was all the nine-term congressman would say.

Whatever he may have said, Long had powerful unspoken arguments on his side. For one thing, he is a senior member of the House Appropriations Committee, which controls the money that fuels most House legislation. For another, a congressman who tampers with a public works project in another district puts his own pet projects in jeopardy.

Perhaps for that reason, Bauman attracted only middling supporting for his proposal among the Maryland delegation. Holt was with him, and Democrat Beverly Byron had expressed her support of the Hart-Miller dumping in the past. Bauman also said Democrat Parren Mitchell supports him.

But Baltimore Rep. Barbara Mikulski, a Democrat, has not yet decided whether dumping on the two islands is safe. Furthermore, she thought Bauman was going about things the wrong way.

"He circumvented the normal procedures and rules of the House," she said.

Prince George's Democrat Glady's Noon Spellman is deferring to Mikulski on the issue, since the