The 95th Congress called it a session and went home Thursday night after a busy year that saw the passage of 24 private laws; 210 public laws, and nearly a thousand assorted resolutions - but not the waterway toll bill.

And so the waterway bill, S.790 - which would require barge lines to pay some fee for their use of federally maintained inland waterways - will be held over for final Senate action sometime after the second session begins next year.

Just a few weeks ago the waterway bill had seemed almost certain to emerge as a waterway act before the end of the 95th's first session. Both the House and Senate had voted for some kind of waterway charge, and the question remaining before the Senate was no longer "whether" but simply, "How much?"

But late in October the barge bill ran aground on a Senate schedule crowded with more urgent legislation. And when the majority leader, Robert C. Byrd (D-W.Va.), finally offered to squeeze in a waterway vote to somewhere, senators on both sides of the issue turned him down - because neither side was sure it had enough votes to prevail.

With the final Setate vote delayed until late January at the earliest, various groups of lobbyists were meeting here to plan their efforts to pressure the members of Congress on their home turf during the interlude between sessions.

The barge industry, which has reluctantly come to the realization that some form of waterway charge is imminent, was building a campaign to push for Senate approval of the House bill, which established a relatively moderate fuel tax for the barges.

The railroads, the barge lines' arch competitors, were gearing up for a nationwide lobbying drive to convince the Senate to vote again for a much stiffer user charge plan that had passed the Senate by a narrow margin in June.

Although senators and lobbyists on both sides were insisting that they had no interest in a compromise solution, just about everybody involved in the battle had privately prepared his own version of a waterway bill that would fit somewhere between the House and Senate plans.

But nobody in Congress knew precisely where an acceptable compromise might be found. In fact, nobody in Congress would know, because the final arbiter of an "acceptable" waterway charge will be President Carter - and he doesn't seem to have made up his mind.

Carter holds the key to the waterway bill because he has promised to hold up federal funding for a major new barge facility - Locks and Dam 26, at Alton, Ill. - unless Congress establishes a "substantial" waterway fee.

The barge industry sorely wants that Alton project, and has told its supporters in Congress to vote for a waterway fee in order to win Carter's support.

But the bargemen cannot tell their congressional friends how large a fee to vote for, because Carter has not yet said just what he would consider "substantial."

That question is a subject of dispute within the Carter administration.

The Department of Transportation, which has jurisdiction over barge traffic, has been urging the President to accept just about any fee that Congress decides to pass. Since the inland waterways have been toil free since the birth of the republic, the transportation experts say it is enough to establish the concept of a barge charge this year. The toils can always be raised later, they say.

But in the White House, a youthful corps of analysts in the President's Domestic Council and the Office of Management and Budget is taking a harder line. The Alton project offers leverage that will force Congress to approve a hefty waterway fee, as the analysts see it. The President should hold out for a significant barge charge.

Eventually, the President will have to resolve the issue and tell Congress what a "substantial" waterway fee might come to. For now, though, Congress has adjourned, and Carter will have plenty of time to mull over his position on S.790.