Evaluation of Life-Cycle Costs and Cost/Benefit Analysis in Comparing Sewer Replacement versus Sewer Rehabilitation

This paper presents an evaluation of the decision making process for evaluating sewer rehabilitation versus sewer replacement. Historical data from multiple communities were used to evaluate capital cost and life cycle cost of the difference between utilizing sewer rehabilitation versus sewer replacement. A cost and benefit analysis was also performed to determine non-monetary factors which could weigh into the decision making process. Sewer rehabilitation was found to have lower initial capital costs, but life-cycle costs between the two alternatives are similar. Sewer replacement may also present opportunities for other infrastructure improvements and overall cost savings. Prior to performing sewer rehabilitation, a comparison should be made between rehabilitation and replacement, evaluating all factors including capital cost, life cycle costs and overall project benefits.