2020 Eugene Wastewater Master Plan Chapter 6: Basis of Cost Estimates 46 <br />Chapter 6 - Basis of Cost Estimates <br />PURPOSE <br />This chapter provides estimated construction costs for wastewater lines, wastewater pump stations, and <br />pressure lines. <br />GENERAL <br />The estimated costs presented in this chapter are primarily for development of long-range financial <br />plans. Major new interceptors, trunk wastewaters lines, pump stations, and pressure lines that may be <br />constructed during the next 20 years are described in Chapter 7. This chapter shows the basic unit prices <br />used to estimate the construction costs for these future wastewater projects. <br />WASTEWATER CONSTRUCTION COSTS <br />Wastewater construction cost estimates are based on the 1998 Local Wastewater System Development <br />Study completed by CH2MHill and have been adjusted to an Engineering News-Record (ENR) cost index <br />of 11281, which was the average adjustment for 2019. This method was verified by comparing adjusted <br />estimates to values from more recent cost estimating software. <br />The estimated costs per foot are shown for pipes from 6-inch through 72-inch diameters and for trench <br />depths in 5-foot increments. The costs are estimated for two typical construction situations as shown in <br />Table 6-1 and Table 6-2. The costs include a complete construction package for the main wastewater <br />line, including manholes, excavation, pipe bedding, pipe materials, pipe laying, pipe zone backfill, <br />appropriate trench backfill, air-pressure testing, TV inspection, and pavement removal and repair in the <br />trench area where required. <br />The tables show costs for projects of average construction difficulty. When special conditions exist, such <br />as high ground water, unstable trench, difficult traffic control, etc., costs should be increased. Costs for <br />building service connection lines and other special features, such as pavement overlays beyond the <br />trench area, also must be added if a more complete project estimate is needed. <br />