(a) If, after a reasonable period of negotiations over the terms of an agreement or after a reasonable time following certification of an exclusive representative, no agreement has been signed, the parties may voluntarily submit to mediation. If, however, no agreement is reached between the parties by 60 days prior to the expiration date of an existing collective bargaining agreement, or, in the case of a newly-certified exclusive representative, within 60 days after negotiations have commenced, both parties shall immediately notify the Board of the status of negotiations.(b) If the parties have not voluntarily agreed to enlist the services of a mediator and less than 30 days remain before the expiration date of the existing collective bargaining agreement, or, in the case of a newly-certified exclusive representative, more than 90 days have elapsed since negotiations began, the Board must appoint a mediator if so requested by the public employer or the exclusive bargaining representative. The mediator shall be chosen from a list of qualified persons maintained by the Board, or upon agreement of the parties, from the Federal Mediation and Conciliation Service, and shall be representative of the public.(c) If the labor dispute has not been settled after a reasonable period of mediation, during which both parties have made a good faith effort to settle their differences, the parties jointly or individually may petition the Board in writing to initiate binding interest arbitration. In lieu of a petition, the mediator may inform the Board that further negotiations between the parties, at that time, are unlikely to be productive and recommend that binding interest arbitration be initiated. The public employer and the exclusive bargaining representative may initiate binding interest arbitration at any time, by mutual agreement.(d) Any costs involved in retaining a mediator to assist the parties in reaching a negotiated agreement shall be paid by the Board. 65 Del. Laws, c. 477, §1; 72 Del. Laws, c. 271, §§ 3, 8; 74 Del. Laws, c. 173, § 1.;