Changes

==Life Cycle Costs==

==Life Cycle Costs==

Below are capital and life cycle cost estimates for the two [[Infiltration chambers|infiltration chamber]] 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 36% of total life cycle costs over the 25-year evaluation period, and increase to 48% of total life cycle costs over the 50-year period, due to increased levels of litter removal, clean out and disposal of collected sediment from the Isolated chamber row (every 4 - 8 years), cleaning out the catchbasin and the [[Oil and Grit Separator|Oil and Grit Separator/Hydrodynamic Separator]] annually.  

Below are capital and life cycle cost estimates for the two [[Infiltration chambers|infiltration chamber]] design scenarios 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 37% of total life cycle costs over the 25-year evaluation period, and increase to 49% of total life cycle costs over the 50-year period, due to cost associated with removal of sediment from the isolated chamber row pretreatment devices every 8 years.