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 so 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 by the exercise of the right of eminent domain.
53 P.S. § 57402