CONCURRING AND DISSENTING OPINION BY
Judge PELLEGRINI.The majority finds that a provision in an interest arbitration award allowing police officers released from duty to perform union duties shall be paid at the highest-ranking member of the bargaining unit with appropriate longevity is illegal because it purportedly will result in their receiving higher pensions.1 The majority bases that holding on Kirsch v. Public School Employees’ Retirement Board, 929 A.2d 663 (Pa.Cmwlth.2007), appeal granted, 597 Pa. 222, 951 A.2d 257 (2008), where we upheld a Public School Employees’ Retirement Board (Retirement Board) decision that the retirement credit under Section 8102 of the Retirement Code2 is *448based on salary paid “as if’ “or to the same degree in which” the members were in full-time service to the school district and not for any salary paid in excess of that amount.
What the majority misperceives is that we are not being asked to review a Retirement Board decision as to what pension credit a police officer receives for the time he or she was “released for duty” when that police officer retires. At that time, the police officer can present evidence that the amount he or she received under the disputed arbitration provision is comparable to what he or she would receive “as if’ he or she remained on full-time service when such things as overtime and extra-duty time are taken into consideration. The Retirement Board would then make a decision, which could be appealed subject to the normal administrative agency scope of review. Until that occurs, that issue is not before us.
As to the issue before us — whether a board of arbitration can enter an interest arbitration award requiring the Commonwealth to pay a different amount of compensation other than the base amount of salary the union officer would receive — is determined by whether that requires the Commonwealth to do something that it could not do voluntarily.3 Other than the Retirement Code provisions, over which the Retirement Board has sole jurisdiction, the Commonwealth cites no provision, nor can I imagine one, that precludes it from voluntarily entering into an agreement requiring it to pay a police officer released from duty an amount different than its base rate, especially when it is at no cost to the Commonwealth. Because the Commonwealth could agree to the union leave provision voluntarily, there is no basis to vacate the award.
Accordingly, while I agree with the majority’s decision to affirm the “honorable discharge” provision of the arbitration board’s award, I respectfully dissent from that portion of the decision vacating the “union leave” provision.
. The provision of the award that is at issue provides that:
Upon written request by [the Association], Union officers shall be released from duty. Union officers released from duty pursuant to State law shall be paid by the Commonwealth at the amount designated by the [Association] Board of Directors, not to exceed the rate of the highest ranking member of the bargaining unit with appropriate longevity. Any amount paid by the Commonwealth, including the cost of all benefits, shall be reimbursed by the [Association] to the Commonwealth in accordance with law.
. Section 8102 of the Retirement Code defines "Leave for service with a collective bargaining organization” as follows:
Paid leave granted to an active member by an employer for purposes of working full time for or serving full time as an officer of a Statewide employee organization or a local collective bargaining representative under the act of July 23, 1970 (P.L. 563, No. 195), known as the Public Employe Relations Act: Provided, That greater than one-half of the members of the employee organization are active members in the system; that the employer shall fully compensate the member including, but not limited to, salary, wages, pension and retirement contributions and benefits, other benefits and seniority, as if he were in full-time active service; and that the employee organization shall fully reimburse the employer for such salary, wages, pension and retirement contributions and benefits and other benefits and seniority. (Emphasis added.)
24 Pa.C.S. § 8102. The provision applicable here, though, is Section 5302(b)(2) of the State Employees’ Retirement Code, 71 Pa. C.S. § 5302(b)(2), which applies to police officers. It provides, in relevant part:
An active member on paid leave granted by an employer for purposes of serving as an elected full-time officer for a Statewide employee organization which is a collective bargaining representative under the act of June 24, 1968 (P.L. 237, No. Ill), referred to as the Policemen and Firemen Collective *448Bargaining Act, or the act of July 23, 1970 (P.L. 563, No. 195); ... that the employer shall fully compensate the member, including, but not limited to, salary, wages, pension and retirement contributions and benefits, other benefits and seniority, as if he were in full-time active service; and that the Statewide employee organization shall fully reimburse the employer for all expenses and costs of such paid leave ... (Emphasis added.)
. From an appeal of an interest arbitration award, the narrow certiorari standard applies. Under this scope of review, courts are limited to reviewing questions concerning: (1) the jurisdiction of the arbitrators; (2) the regularity of the proceedings; (3) an excess of the arbitrator’s powers; and (4) deprivation of constitutional rights. An arbitrator's powers are limited and cannot mandate that illegal acts be carried out but only that a public employer do that which it could do voluntarily. See Borough of Nazareth v. Nazareth Borough Police Association, 545 Pa. 85, 680 A.2d 830 (1996).