53 Pa. Stat. § 4662
The term "private sewer" is applied to main sewers that are not constructed by and under the supervision of the department of public works.
The term "house-sewer" is applied to that part of the main drain or sewer extending from a point five feet outside of the outer wall of a building, vault or area to its connection with public sewer, private sewer or cesspool.
The term "house drain" is applied to that part of the main horizontal drain and its branches inside the walls of the building, vault or area, and extending to and connecting with the house sewer.
The term "soil-pipe" is applied to any vertical line of pipe extending through the roof, receiving the discharge of one or more water-closets, with or without other fixtures.
The term "waste-pipe" is applied to any pipe receiving the discharge from any fixtures except water-closet.
The term "vent-pipe" is applied to any pipe, extending through the roof, provided to ventilate the system of piping, and to prevent trap syphonage and back pressure.
The term "plumbing fixtures" are receptacles intended to receive and discharge any liquid water or water carried wastes into a drainage system or treatment works with which they are connected.
The term "safe or special waste pipe" is supplied to any waste pipe receiving the discharge from any fixtures or drainage appliance, with or without water supply, not connected directly with the drainage system.
The term "dwelling" applies to any building which is designed for, or occupied in whole or in part as, the home, residence or sleeping place of one or more persons, either permanently or transiently.
The term "one family dwelling"--A separate building designed for or occupied exclusively by one family.
The term "two family dwelling" (duplex)--A separate building designated for, or occupied exclusively by, two families, one above the other, or an interior accessible door or passage way.
The term "tenement-house" is any house or building, or portion thereof, which is intended or designated to be occupied as a home or residence for three or more families living in separate apartments, and doing their cooking upon the premises.
53 P.S. § 4662