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SANITARY SEWER EVALUATION
Air Force Center for Engineering and the Environment
Andersen Air Force Base, Guam
EA conducted a sanitary sewer evaluation survey to inspect and evaluate the sanitary sewer lines and manholes at the Main Base portion of Andersen Air Force Base.
EA performed a physical inspection and line cleaning for each segment of sanitary sewer lines. The inspection process consisted of identification of pipe size, shape, and material; identification of origin manhole and destination manhole, and length of the line being inspected; and identification of pipe condition and evidence of failure (i.e., cracks, offset joints, corrosion, structural condition, alignment, consistency of grade, and evidence of infiltration). Each manhole associated with line cleaning and inspection was visually inspected to determine the physical condition of the manhole and associated pipe segments. When areas were identified that were receiving flow from unidentified sources, dye testing was performed to either confirm suspected flow path or determine flow path. Sanitary sewer line conditions were visually inspected using closed circuit cameras. The line conditions were recorded and compiled onto DVDs. DVDs allowed for later detailed viewing that was necessary to accurately complete the lines inspection reports.
EA evaluated inspection data, and provided findings and recommendations to improve the sanitary sewer system. This sanitary sewer evaluation survey was originally scoped to investigate approximately 200 manholes and 47,000 linear ft of sanitary sewer lines, including a forced main. However, as the project progressed, savings in field activities allowed for a second and third phase of investigations to be performed. As a result, surveys of an additional 48,219 linear ft of piping and 206 manholes were completed at no additional cost.