In Westmoreland Intermediate Unit # 7 v. Westmoreland Intermediate Unit # 7 Classroom Assistants Educ. Support Pers. Ass'n, PSEA/NEA, 595 Pa. 648, 939 A.2d 855 (2007), our Supreme Court affirmed the use of the essence test, but decided that it must be subject to a narrow exception that allows a court to vacate an arbitrator's award if it violates the public policy of the Commonwealth. More specifically, we hold that upon appropriate challenge by a party, a court should not enforce a grievance arbitration award that contravenes public policy. Such public policy, however, must be well-defined, dominant, and ascertained by reference to the laws and legal precedents and not from general considerations of supposed public interests. Westmoreland Intermediate Unit I, 595 Pa. at 666, 939 A.2d at 865-66.