segment
(50) Treatment works phase or segment. A treatment works phase or segment may be any substantial portion of a facility and its interceptors described in a facilities plan under 35.2030, which can be identified as a subagreement or discrete subitem. Multiple subagreements under a project shall not be considered to be segments or phases. Completion of building of a treatment works phase or segment may, but need not in and of itself, result in an operable treatment works. (51) Useful life. The period during which a treatment works operates. (Not design life which is the period during which a treatment works is planned and designed to be operated.) (52) User charge. A charge levied on users of a treatment works, or that portion of the ad valorem taxes paid by a user, for the user's proportionate share of the cost of operation and maintenance (including replacement) of such works under sections 204(b)(1)(A) and 201(h)(2) of the Act and this subpart. (53) Value engineering. A specialized cost control technique which uses a systematic and creative approach to identify and to focus on unnecessarily high cost in a project in order to arrive at a cost saving without sacrificing the reliability or efficiency of the project.