McKUSICK, Chief Justice.

On this appeal by the City of Westbrook, we review the decision of a three-member arbitration panel overturning the City's dismissal of Patrolman Peter J. Blanchette of the Police Department. Blanchette is represented by Teamsters Local No. 48, which has a collective bargaining agreement (Agreement) with the City. The Agreement provides for arbitration of grievances, including those involving disciplinary matters. The arbitrators selected by the City and the Union found the City's disciplinary action against Blanchette unwarranted because the City did not have adequate evidence of Blanchette's alleged breach of duty. The arbitrators awarded Blanchette reinstatement with back pay. Upon the City's application to vacate the award, the Superior Court (Cumberland County, McKinley, J.) affirmed, finding that the arbitrators' decisions both on the procedural arbitrability of the dispute and on its substantive merits were amply grounded in the Agreement. On the City's appeal, we also affirm the arbitrators' award for the same reasons.

Blanchette was accused of tipping off a friend who was to be the subject of a child sexual abuse investigation by the State Police. Blanchette had learned of the investigation at a department meeting during which Chief of Police Ronald Allanach specifically warned the officers that the State Police investigation was extremely confidential, that the subject was known to have personal ties with people in the department, and that any officer who was responsible for a leak of information would be immediately discharged. After word of the sex abuse case by some means reached the subject and after the department internally investigated the leak, Chief Allanach suspended Blanchette with pay. Upon looking further into the matter, Chief Allanach recommended to Westbrook Mayor Philip Spiller that Blanchette be dismissed.

Upon the Union's request, Mayor Spiller held a "Step 2" hearing as required by Article 13(B) of the Agreement. The Mayor issued his decision to fire Blanchette on September 13, 1988. Blanchette filed a formal grievance on the grounds that the City had failed to notify him of his termination within 24 hours in violation of Article 9 of the Agreement, and used excessive discipline in violation of Article 12. The City denied the grievance.

The Union subsequently informed the City that it intended to seek arbitration of the dispute. The City discussed arbitration with the Union and participated in selecting the arbitrators. The Union did not file a written request for arbitration until October 21, 1988. Following two days of hearings, the three-member arbitration panel ruled unanimously that the Union's request for arbitration was procedurally effective, even though made beyond the 10-day period specified by the Agreement, and that the City had violated the Agreement when it disciplined Blanchette without adequate proof that he had indeed leaked word of the State Police investigation.

I. Procedural Arbitrability

On appeal the City contends that the Union's written request for arbitration was untimely and that the arbitrators erred in finding that the City had consented to an extension of time. We have held that "the appropriate standard for reviewing questions of procedural arbitrability is to uphold the arbitrator's interpretation of the procedural provisions of the agreement so long as that interpretation is a rational construction of the contract." Board of School Directors, Maine School Admin. Dist. No. 52 v. Tri-Town Teachers Ass'n, MTA-NEA, 412 A.2d 990, 994 (Me. 1980). See also Saco Valley Teachers Ass'n v. Board of Directors, Maine School Admin. Dist. No. 6, 447 A.2d 72, 74 (Me. 1982).

Article 13(B) of the Agreement outlines the procedure to be used for processing grievances. After the filing of a grievance and a Step 1 hearing, the Union can request and receive a Step 2 hearing with the Mayor. The Mayor's response is due within seven working days of the hearing. If the grievance remains unsettled, Step 3 provides that the Union may, within ten working days after the Mayor's Step 2 response is due, request in writing that the dispute be submitted to arbitration. The lead-in clause of Article 13(B) specifically provides that the applicable time limits may be extended by mutual consent of the parties. See n. 2 above.

Blanchette's Step 2 hearing was held on September 9, 1988. By application of the terms of Article 13(B), the Mayor's response was due on September 20 and the Union's written request for arbitration was due on October 4, 1988. The Union did not file its written request for arbitration until October 21, 1988. The Union argued, however, that because it had made its intent to file for arbitration known to the City before the 10-day notice period had expired and because the City acknowledged that oral notice by discussing arbitration and participating in the selection of arbitrators, the City had effectively consented to an extension of time as permitted by the lead-in clause of Article 13(B). After the evidentiary hearing, the arbitrators ruled:

It seems clear that the Union's intention of proceeding to arbitration was known to the City before the deadline. Testimony indicates, however, that the discussion was informal — the City Solicitor, appearing as a witness, indicated [that] no conclusive or definitive discussion had taken place; a Union witness testified that proceeding to arbitration (Step 3) had been indicated to Management by the Union and that the discussion had occurred within a day or two after the Mayor's letter of September 13.

Giving credence and greater weight to the Union's position that Management was aware of the Union's intention to proceed to Step 3, is the discussion between City and Union officials about the choice of arbitrators and their joint decision to use the Maine Board of Arbitration and Conciliation, an alternative under Article 13, Section B, Subsection b. According to the Agreement, the alternative selected had to be mutually agreed to by the parties. No testimony, evidence, or objections indicate that this provision of the Agreement was not followed.

Thus, it must be concluded that the City knew of the Union's intention to proceed to arbitration — discussion between the City and the Union led mutually to the decision to follow the alternative described in Article 13, B. b., in selecting arbitrators at Step 3.

It is also noted that the Agreement specifically allows for extension of time limits by mutual consent, as indicated by the emphasized phrase in the opening sentence of Section B. . . . The Agreement does not state the extension must be in writing.

By entering into discussion with the Union and then jointly selecting who should arbitrate the grievance, the City in effect concurred with the Union in waiving the time limits at Step 3, an extension allowed under the Agreement. Thus, the City's objections to arbitrability because of violation of the timeliness provision is not convincingly argued.

The panel's analysis is a rational construction of the Agreement. By virtue of the City's actions, the arbitrators concluded that the City had notice of the Union's intent to seek arbitration and on that basis began discussions preliminary to the Step 3 proceeding. The Agreement does not require that an extension of time for requesting arbitration be in writing, nor that consent to an extension of time be in writing. On these facts the arbitrators could rationally conclude that the City had joined the Union in extending the Union's time for formally requesting arbitration pursuant to the agreement. See Tri-Town Teachers Ass'n, 412 A.2d at 994.

The City argues that this interpretation of the time-extension provision of the Agreement places it in a no-win situation. If the City refused to discuss arbitration with the Union because of the Union's failure to serve a timely written request, the City contends that it might be charged with violation of the Agreement or with a "prohibited practice" under Maine labor law. If, on the other hand, the City discussed arbitration despite the Union's failure to make a timely written request for arbitration, then the City could be held to have waived the timeliness argument in later hearings before arbitrators and courts. This argument is at best unconvincing. In the circumstances of the present case, the City had the obligation just as soon as the timeliness issue arose, namely, upon the expiration of the 10-day notice period, to inform the Union that it would assert the time-bar in any upcoming arbitration. Having done so, the City would have effectively preserved its objection to the Union's failure to make a timely arbitration request and the time-bar issue would itself be adjudicated in any later arbitration. Here, however, the City did nothing to preserve the issue. Rather, the City, knowing of the Union's intent to seek arbitration, participated in selecting the arbitrators. The arbitrators' finding, in these circumstances, that the City effectively consented to an extension of time to file the formal arbitration request, is a rational interpretation of the evidence in the context of the underlying Agreement. Nothing more is required for that finding to withstand our review.

II. Substantive Arbitrability

The City's substantive contention on appeal is that the arbitrators exceeded their authority under Article 13(B)(c), the supersession clause, when they substituted their judgment for the City's and reinstated Blanchette. With regard to such contentions, we have declared that:

The standard for review of whether an arbitrator exceeds his authority is a narrow one. We will "conclude that an arbitrator exceeded his powers by travelling outside the agreement . . . [only] `if all fair and reasonable minds would agree that the construction of the contract made by the arbitrator was not possible under a fair interpretation of the contract. . . .'"

Granger Northern, Inc. v. Cianchette, 572 A.2d 136, 139 (Me. 1990) (citations omitted). See also Bureau of Maine State Police v. Pratt, 568 A.2d 501, 505 (Me. 1989); Westbrook School Comm. v. Westbrook Teachers Ass'n, 404 A.2d 204, 209 (Me. 1979).

After hearing all the evidence against Blanchette, the arbitrators concluded that by taking disciplinary action that was not supported by adequate evidence, the City had taken unwarranted disciplinary action against Blanchette and so had violated the Agreement. On the basis of that violation alone, the arbitrators substituted their judgment for that of the City and ordered Blanchette's reinstatement with back pay. Article 13(B)(c) permits the arbitrators to make this decision only if they found "that the City acted arbitrarily, in bad faith, without reason and in violation of the specific terms of this [A]greement." The City contended, and continues to contend on this appeal, that the Agreement must be interpreted to require the arbitrators to find all four grounds before substituting their judgment for the City's and that because the arbitrators found only that the City had violated the Agreement, they were not empowered to override the City's judgment in discharging Blanchette.

After careful consideration, the arbitrators rejected the interpretation of the supersession clause urged by the City. They reasoned:

Article 13, Section B, Subsection c . . . states, "Grievances involving disciplinary action, lay-offs, demotions and transfers shall be subject to the grievance procedure, but no arbitrator shall have the power to substitute his or her judgment for that of the City to overrule the decision of the City unless he/she finds that the City acted arbitrarily, in bad faith, without reason and in violation of the specific terms of this agreement." . . . The first of the two criteria are essentially procedural safeguards while the fourth — violation of the specific terms of the agreement — goes to the substantive heart of the matter. The third condition, "without reason," is so vague and full of diverse meanings as to be useless as a standard for conduct or for evaluating that conduct.

The City argues that the use of the word "and" as a conjunction meant that all four criteria must be met in order to overrule the City's decision to discharge the Grievant. In other words, that Arbitrators would have to determine that the City acted in an arbitrary fashion, in bad faith, without reason and in violation of specific terms of the Agreement. In extending this reasoning to its logical conclusion, credulity is stretched to the breaking point. What if the City did not act in arbitrary fashion, or in bad faith or without reason (whatever that means) but still violated specific terms of the Agreement? According to the City's interpretation, the grievance would have to be denied because the Union could not establish that all four of the conditions had been violated. Discipline would have to be upheld no matter how trivial or serious the City's violation of the Agreement might have been. Such an interpretation reduces the Agreement to an empty document and it is difficult to imagine [that] negotiators on either side intended the meaning the City has given Article 13. Thus, Article 13 must be discounted as a standard in evaluating actions which resulted in this grievance.

(Boldfaced emphasis added; underlined emphasis in original)

The supersession clause is an obvious attempt to limit the authority of the arbitrators, and the City and the Union could have used language that would unambiguously limit the arbitrators' authority in the way here advocated by the City. Our review of the arbitrators' decision, however, is limited to the determination of whether "all fair and reasonable minds would agree that the construction of the contract made by the arbitrator[s] was not possible under a fair interpretation of the contract. . . ." See Granger Northern, 572 A.2d at 139. The arbitrators carefully reasoned that the critical "and" in the supersession clause must be read in the disjunctive to give the parties' intended effect to the Agreement; they could rationally conclude that a violation of the Agreement, enumerated as one of the grounds for arbitral supersession of the City's decision, was enough by itself to empower them to exercise their independent judgment on the disciplinary question. Although their construction of the Agreement might not be that which we as an original matter would reach, we cannot say that it is so unreasonable as to be impossible under a fair interpretation of the contract.

By their submission of disputes to arbitration under the Agreement, the parties made the arbitration panel the proper forum to interpret the language in the supersession clause in a way consistent with the entire Agreement. Because their construction of the supersession clause is a plausible one, we must defer to this decision as a legitimate exercise of the arbitrators' authority. See Caribou Board of Education v. Caribou Teachers Ass'n, 404 A.2d 212 at 215 (Me. 1979) ("In making the determination whether an arbitrator has exceeded his authority the agreement must be broadly construed, and all doubts will usually be resolved in favor of his authority"). "It is, after all, the arbitrator's construction of the contract that was bargained for and only where there is manifest disregard of the contract will we disturb the award." Bureau of Maine State Police v. Pratt, 568 A.2d at 505.

The entry is:

Judgment affirmed.

ROBERTS, WATHEN, and BRODY, JJ., concur.