OPINION OF THE COURT
ROBERTS, Justice.In this labor dispute between Darby' Borough and its police employees, the Commonwealth Court held that a court of common pleas has no jurisdiction, in an action in mandamus, to order the municipality to perform its contractual duty arising out of a collective bargaining agreement. The Commonwealth Court concluded that the task of enforcing an arbitration award interpreting a collective bargaining *65agreement between parties covered under Act 111 is exclusively within the jurisdiction of the Pennsylvania Labor Relations Board (PLRB). We agree with the common pleas court, appellants Darby police and intervenor PLRB that such a reading of relevant labor statutes and case law authority is erroneous. Accordingly, we reverse the order of the Commonwealth Court, 38 Pa.Cmwlth. 337, 394 A.2d 1298 and remand to the court of common pleas for determination of appropriate relief on the merits of appellants’ complaint.
On September 10, 1975 appellee, the Borough of Darby, and appellants, Darby police, entered into an agreement “concerning terms and conditions of employment of the police officers of the Borough of Darby for the calendar year commencing January 1,1976.”1 Disagreeing as to the proper computation of wages for the year 1977, the parties entered into binding arbitration pursuant to “Act 111,” Act of June 24, 1968, P.L. 237, as amended, 43 P.S. § 217 et seq. On December 20, 1976, the Board of Arbitration entered an arbitration award providing that:
“Commencing January 1, 1977, the annual wage for each police officer shall be increased by Three Hundred ($300.00) Dollars plus a cost of living adjustment for all police equal to the increased cost of living as measured by the C.P.I. for the Philadelphia Region for the twelve month period ending October, 1976, to be added to the base wage.”
*66On February 11, 1977, appellant Geriot,. on behalf of a class of Darby police officers, filed a complaint in mandamus in the Court of Common Pleas of Delaware County. The complaint alleged that appellee was not computing the base wage in accordance with the terms of the collective bargaining agreement,2 and requested the court to order appellee to pay appellants’ wages in conformity with the agreement. Appellants’ position was that although they received the cost of living increase for 1976, this increment was not included in the permanent base wage for computation of 1977 wages.
Appellee filed a preliminary objection, contending that the complaint should be dismissed because “the Plaintiffs have an adequate remedy at law other than an action in mandamus.” Appellees claimed that appellants were seeking judicial, review of the arbitration award, and that such review is exclusively available pursuant to Pa.R.C.P. 247.3 It was *67appellee’s contention that since the 30-day period for filing an “application for review” had lapsed, appellants were barred from relief.
The court of common pleas dismissed appellee’s preliminary objection, holding that (1) appellants were not seeking judicial review of the arbitration award, and (2) that a contractual obligation imposed by law may be enforced against a municipality by an action in mandamus. On appeal, the Commonwealth Court dismissed the mandamus action on the ground that the court of common pleas was without jurisdiction. The Commonwealth Court held that appellants’ exclusive remedy for breach of the collective bargaining agreement was the filing of an unfair labor practice grievance with the PLRB pursuant to the Public Employees Relations Act (PERA or “Act 195”), Act of July 23, 1970, P.L. 563, § 1201(8), 43 P.S. § 1101.1201(8) (Supp. 1979). In so holding the court stated:
“PERA and Act 111 are to be read in pari materia. The exclusive jurisdiction to resolve charges of unfair labor practices is placed in the Pennsylvania Labor Relations Board by Section 1301 of PERA, 43 P.S. § 1101.1301. The reasoning behind this is set forth by Justice Pomeroy, speaking for a unanimous court, in Philadelphia Fire Officers Association v. Pennsylvania Labor Relations Board, 470 Pa. 550, 369 A.2d 259 (1977), reversing, 18 Pa.Cmwlth.Ct. 487, 336 A.2d 477 (1975). ...”
38 Pa.Cmwlth.Ct 337, 338, 394 A.2d 1298, 1299 (1978).
In our view, the Commonwealth Court’s reliance on Philadelphia Fire Officers is misplaced. In that case, this Court held that the PLRA conferred jurisdiction on the PLRB to conduct a representation election in a bargaining unit consisting of fire and police officers. In so holding we sought to avoid the “absurd” result of requiring “employees of the courts of common pleas to conduct elections in firehouses and police barracks and stations.” 470 Pa. at 557, 369 A.2d *68at 262. Accordingly, in Philadelphia Fire Officers, Act 111, which does not cover the subject of representation elections, was read in pari materia with the PLRA.4 Thus read, labor boards would “conduct secret elections through their staffs whose task it is to journey from workplace to workplace for such purpose.” Id., 470 Pa. at 557, 369 A.2d at 262.
Hence, in Philadelphia Fire Officers practical considerations dictated that the PLRA, not the PERA, be read in pari materia with Act 111. Significantly, however, we did not hold that PERA governed the employees covered under Act 111. Rather, we stated:
“We recognize, of course, that employees covered by Act No. Ill are not in any respect covered by P.E.R.A. (Act 195) and that Act 111 provides its own unique, specific procedure, namely, binding arbitration, as the final resort in the event of a bargaining impasse. 43 P.S. §§ 21713— 217.8 (Supp.1976-77).”
Id., 470 Pa. at 558, 369 A.2d at 262.
By its own terms, PERA excludes police and fire officers from coverage by the Act:
“ ‘Public employe’ or ‘employe’ means any individual employed by a public employer but shall not include . those employes covered under the act of June 24, 1968 (Act 111), entitled ‘An act specifically authorizing collective bargaining between policemen and firemen and their public employers; providing for arbitration in order to settle disputes, and requiring compliance with collective bargaining agreements and findings of arbitrators.’ ”
Act of July 23, 1970, P.L. 563, § 301, 43 P.S. § 1101.301(2). Section 1201(a)(8) of the PERA, which was viewed as controlling by the Commonwealth Court, has no application to *69proceedings initiated under Act 111.5 PERA, through § 1201(a)(8), governs enforcement of “grievance” arbitration awards. It does not encompass so-called “interest” arbitration which is the subject of the present action.6 Thus the conclusion of the Commonwealth Court, that enforcement of a collective bargaining agreement incorporating a final and binding arbitration award may only be enforced through the filing of an unfair labor practice pursuant to § 1201 of PERA, is manifestly incorrect. The Commonwealth Court’s result ignores the “unique and specific procedures” provided in Act 111 which were tailored by the Legislature to the specific requirements of the employment relations of municipalities and police and fire labor forces.
The remedy of mandamus is available against a municipality where there is a clear contractual right, arising out of a collective bargaining agreement, to be enforced. See Christian v. Johnstown Police Pension Fund, 421 Pa. 240, 218 A.2d 746 (1966) (contractual obligation imposed by law may be enforced by either mandamus or assumpsit); see also, Dombrowski v. Philadelphia, 431 Pa. 199, 245 A.2d 238 (1968) (because of contractual relationship between former employee and municipality, mandamus action by former employee is available to ensure financial soundness of mu*70nicipality’s retirement system). Here, the collective bargaining agreement, incorporating the cost of living increase provided for in the arbitration award, gave rise to a binding contractual duty on the part of appellee. Thus a judicial determination of a breach of that contractual obligation is properly remediable by mandamus. The order of the Commonwealth Court to the contrary is reversed and the case is remanded to the court of common pleas for proceedings to determine the merits of appellants’ claim that the collective bargaining agreement was breached.
Order of the Commonwealth Court reversed and the case remanded to the Court of Common Pleas of Delaware County-
NIX, J., files a dissenting opinion.. Paragraph one of the collective bargaining agreement provides:
“1. Wages and Cost of Living: Beginning January 1, 1976, the annual wage for each officer shall be increased by $350.00 plus the percentage of increased cost of living as measured by the C.P.I. for Philadelphia during the 12 months ending October, 1975. Said cost of living is incorporated in and shall become part of the basic wage as of January 1, 1977. By way of illustration the basic wage of a patrolman on January 1, 1976, will be computed as follows:
1975 Basic Wage $13,160.15
1976 Standard of Living Increase 350.00 Cost of Living Increase
(assuming hypothetically that during the 12 months ending 10/75 the cost of living increase is 5%) 675.00
TOTAL $14,185.50’
. Paragraphs 6 and 7 of appellants’ complaint in mandamus allege:
“6. The defendant has not, as of January 1, 1977, been computing the plaintiffs’ base wage in a manner or fashion contemplated by the 1976 Collective Bargaining Agreement, in that they have not incorporated the cost of living, as measured by the C.P.I. for Philadelphia during a 12 month period ending October, 1975, into the basic wage as of January 1, 1977, in computing the basic wage for each of the police officers for the Borough of Darby for the year commencing January 1, 1977.
7. Despite requests made on behalf of the pláintiffs for the inclusion of the cost of living aforesaid as part of the base wage for 1977, and as agreed to by the Council for the Borough of Darby in the agreement Exhibit “A” aforesaid, the defendant has failed, ■refused to perform the duties imposed upon them in connection with the payment thereof.”
. Pennsylvania Rule of Civil Procedure 247 provides:
“Review of Arbitration Awards in Local Public Employment Disputes:
(a) Review of an award of arbitrators appointed in conformity with an Act of Assembly to arbitrate a dispute between a public employer and employe not within the scope of Rule 703 of the Pennsylvania Rules of Appellate Procedure shall be sought exclusively in the courts of common pleas. The application for review shall be filed within thirty (30) days after the date of the award of the arbitrators.
(b) The order of a court of common pleas under subdivision (a) of this rule shall be subject to appeal to the Commonwealth Court in the manner prescribed by Chapter 9 of the Pennsylvania Rules of Appellate Procedure.
*67Adopted June 23, 1976, effective July 1, 1976.”
See also Washington Arbitration Case, 436 Pa. 168, 259 A.2d 437 (1969).
. “Statutes in pari materia
(a) Statuteá or parts of statutes are in pari materia when they relate to the same persons or things or to the same class of persons or things.
(b) Statutes in pari materia shall be construed together, if possible, as one statute.”
Act of November 25, 1970, P.L. 707, added December 6, 1972, P.L. 1339, § 3, 1 Pa.C.S.A. § 1932 (Supp. 1964-1978).
. Section 1201(a)(8) provides:
“Public employers, their agents or representatives are prohibited from refusing to comply with provisions of an arbitration award deemed binding under § 903 of Article IX.”
Section 903 provides:
“Arbitration of disputes or grievances arising out of the interpretation of the provisions of a collective bargaining agreement is mandatory. The procedure to be adopted is a proper subject of bargaining with the proviso that the final step shall provide for a binding decision by an arbitrator or a tri-partite board of arbitrators as the parties may agree. Any decisions of the arbitrator or arbitrators requiring legislation will only be effective if such legislation is enacted.”
43 P.S. § 1101.903.
. “Grievance” or “contract interpretation” arbitration contemplates the disputed interpretation of an existing contract. “Interest” arbitration contemplates an inability of the parties to agree on the terms of a collective bargaining agreement. See generally, J.D. Thrush, Pennsylvania Public Employe Labor Relations, 231-32 (1st Ed. 1977).