The Senate Intelligence Committee, which has been secretly assessing for more than a year America's ability to monitor the new SALT treaty, will report next week that the pact's provisions can be verified, informed sources said yesterday.

According to these sources, the Intelligence Committee's positive finding will be endorsed by an "overwhelming" majority of the committee's membership, crossing a broad political spectrum from liberal Democrats to Sen. Barry Goldwater (R-Ariz.).

Several hawkish members of the committee who oppose the strategic arms limitation treaty will declare that it is not entirely verifiable by U.S. intelligence, these sources said. The senators reportedly include Jake Garn (R-Utah) and Henry M. Jackson (D-Wash.).

The Intelligence Committee's endorsement is regarded by the Carter administration and senators who are supporting SALT II as important, though both acknowledge that verification is not the issue it once was in many senators' minds.

A few months ago, many in the Senate predicted that the SALT vote would hinge on members' perception of the adequacy of America's photo satellites and eavesdropping devices to pick up any Soviet violations of the treaty. Since then several new issues have arisen in the SALT debate, detracting attention from verification. Also, Goldwater and others have already stated publicly that they thought the treaty could be verified.

The Intelligence Committee is now scheduled to report its findings to the Foreign Relations Committee late next week. The report has been delayed several times -- most recently, it is said, to allow the Intelligence Committee to say something about the relationship between American intelligence concerning Cuba and verification of SALT II.

Some senators have asked how the United States could verify Soviet compliance. with the arms pact if it was unable to detect the presence of a Soviet "combat brigade" in Cuba for a number of years. Senior intelligence officials have said the two are not directly related.

Anticipation of the positive report from the Intelligence Committee is one basis for hopes among administration officials that the SALT debate is about to take a favorable turn for the White House.

Another new source of pro-treaty sentiment, officials hope, will be the influence of officials from North Atlantic Treaty Organization countries, who have already quietly begun lobbying the Senate, calling SALT II crucial for the future of NATO cooperation and modernization.

For example, the West German defense minister, Hans Apel, is in Washington and meeting with key senators. Apel is stressing the need for Senate approval of SALT II to avoid the possible collapse of NATO efforts to agree on sweeping modernization and expansion of the alliance's nuclear arsenal in Europe, according to informed sources.

A key NATO meeting on these improvements is scheduled for December, Apel notes, and Senate defeat of SALT could all but scuttle it. According to these sources, the German does not dwell on the merits of SALT II itself, but rather on the political significance of a U.S. failure to follow through on such an important treaty.

Carter administration officials hope to be able to convince wavering senators that a vote against SALT would amount to a vote against modernization of NATO nuclear forces, on the grounds that the NATO allies won't be interested in such modernization if they perceive the United States as incapable of conducting policies needed to lead the alliance.

Democratic members of the Foreign Relations Committee met yesterday to discuss rules and procedures for the "markup" of the treaty, now scheduled to begin on the afternoon of Oct. 15. During the markup the committee will consider amendments, reservations or understandings, and decide whether to approve the treaty for action by the full Senate. This process could take two weeks.

Sen. John Stennis (D-Miss.) chairman of the Armed Services Committee, said yesterday that his panel will resume its separate hearings on SALT next week.

On the floor yesterday, seven senators joined in a planned discussion on the Cuban issue, all of them declaring that it should not be allowed to interfere with consideration of SALT II.

Several said the administration had mishandled the flap, but all agreed it was not of great significance. Claiborne Pell (D-R.I.) said he hoped the Cuban troops issue "will fade into the global and national insignificance it deserves."

Sen. Edward Zorinsky (D-Neb.) said, "for the last several weeks Chicken Little has been loose in Washington, but no, the sky is not falling." The Cuba issue should not impede consideration of SALT, Zorinsky said.

Sens. Thomas F. Eagleton (D-Mo.), John H. Chafee (R-R.I.), Alan Cranston (D-Calif.), Charles McC Mathias (R-Md.) and Don Riegle (D-Mich.) also took part in this discussion.

Minutes before they spoke, Sen. John Tower (R-Tex.), took the floor to denounce President Carter's proposals for dealing with the Soviet troops in Cuba. "The series of measures to be taken are all on our side and are empty of content or tangible result," Tower said. "The Soviets are required to do nothing."