Nothing in this act shall be construed as estopping the Commonwealth or any district attorney from proceeding in courts of law or equity to abate pollution forbidden under the laws of the Commonwealth or to abate nuisances under existing law. Nothing contained in this act shall in any way abridge or alter rights of action or remedies now or hereafter existing in equity or under the common law or statutory law, criminal or civil. No provisions of this act shall be construed as estopping the Commonwealth, persons or municipalities, in the exercise of their rights under the common law or decisional law or in equity, from proceeding in courts of law or equity to suppress nuisances, to abate any pollution now or hereafter existing or to enforce common law or statutory rights.