1. As used in sections 17-1501 to 17-1505, inclusive, and sections 17-1509 and 17-1511, the word "subdivision" shall mean any tract of land which is divided into five or more parcels, after the effective date of this act, along any existing or proposed street(s), highway(s), easement(s) or right(s)-of-way for sale or for rent as residential lots or residential building plots, and in the county of Suffolk also as business, commercial or industrial lots or building plots, regardless of whether the lots or plots to be sold or offered for sale, or leased for any period of time, are described by metes and bounds or by reference to a map or survey of the property or by any other method of description and regardless of whether the lots or plots are contiguous. A tract of land shall constitute a subdivision upon the sale, rental or offer for sale or lease of the fifth residential lot or residential building plot therefrom within any consecutive three year period, and at this time the provisions of section 17-1505 of this chapter shall apply to all such parcels thereof, including the first four parcels, regardless of whether said parcels have been sold, rented or offered for sale or lease singly or collectively.

2. The word "tract" shall mean any body of land, including contiguous parcels of land, under one ownership or under common control of any group of persons acting in concert as part of a common scheme or plan.

3. "Residential lot" or "residential building plot" shall mean any parcel of land of five acres or less, any point on the boundary line of which is less than one-half mile from any point on the boundary line of another such lot in the same tract, unless any such lot may not legally be used for residential purposes. Without limiting the generality of the foregoing, the term "residential" shall include temporary, seasonal and permanent residential use.

4. For the purposes of this title sewage shall be defined as any substance, solid or liquid that contains any of the waste products or excrementitious or other wastes or washings from the bodies of human beings or animals.