73 Pa.C.S. § 6104

Where it is reasonably impracticable, in the judgment of the board of commissioners, in any part of the sanitary sewer system to carry sanitary sewers along the lines of public streets or highways, the board of commissioners may locate and construct as much of the sanitary sewers as is necessary through private lands and may acquire the necessary land or right of way for this purpose by gift, purchase or the exercise of the right of eminent domain.