| Below are capital and life cycle cost estimates for the three [[bioretention]] configurations over 25 and 50 year time periods. The estimates of maintenance and rehabilitation (life cycle) costs represent net present values. | | Below are capital and life cycle cost estimates for the three [[bioretention]] configurations over 25- and 50-year time periods. The estimates of maintenance and rehabilitation (life cycle) costs represent net present values. Operation and maintenance costs are predicted to represent between 25 and 30% of total life cycle costs over the 25-year evaluation period, and increase to approximately 40% of total life cycle costs over the 50-year period, due to filter media bed rehabilitation costs assumed to be required after 25 years of operation. |