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Line 15:
Line 15: − * Hydrodynamic separators ([[Oil and Grit Separator|oil and grit separators]]) and isolated chamber row as [[Pretreatment| pretreatment]]. − + Line 29:
Line 28: − * Cost for piping from roof to system, parking lot to system and overflow from system are not included in this costing. − * Costs of the control manhole and overflow, and pre-treatment via an OGS (when the facility takes road runoff) are included.
Infiltration Chamber: Life Cycle Costs (view source)
Revision as of 21:55, 22 December 2022
, 1 year ago→Design Assumptions
* Native soil infiltration rates for Full, and Partial Infiltration Design scenarios were assumed to be 20 mm/h and 10 mm/h respectively, and a safety factor of 2.5 was applied to calculate the design infiltration rate.
* Native soil infiltration rates for Full, and Partial Infiltration Design scenarios were assumed to be 20 mm/h and 10 mm/h respectively, and a safety factor of 2.5 was applied to calculate the design infiltration rate.
* Operation and maintenance (O&M) cost estimates assume annual inspections, removal of trash and debris twice a year, and removal of sediment from pretreatment structures annually. Verification inspections are included every 5 years to confirm adequate maintenance, and every 15 years to confirm adequate drainage performance through in-situ chamber system water level monitoring during natural storm events.
* Operation and maintenance (O&M) cost estimates assume annual inspections, removal of trash and debris twice a year, and removal of sediment from pretreatment structures annually. Verification inspections are included every 5 years to confirm adequate maintenance, and every 15 years to confirm adequate drainage performance through in-situ chamber system water level monitoring during natural storm events.
* Infiltration chamber system length of 5 metres and composed of 22 chambers in total.
* Infiltration chamber system length of 5 metres and composed of 22 chambers in total.
* Infiltration chamber system height of 0.762 metres.
* Infiltration chamber height of 0.762 metres.
* 50 mm dia. clear stone aggregate bedding depth (below and above chamber system) of 152 millimetres.
* 50 mm dia. clear stone aggregate bedding depth (below and above chamber system) of 152 millimetres.
* Two (2) maintenance holes providing access to infiltration chamber system inlet and outlet structures.
* Two (2) maintenance holes providing access to infiltration chamber system inlet and outlet structures.
* All cost estimates are in Canadian dollars and represent the net present value (NPV) as the tool takes into account average annual interest and discount rates over the 25 and 50 year operating life cycle periods.
* All cost estimates are in Canadian dollars and represent the net present value (NPV) as the tool takes into account average annual interest and discount rates over the 25 and 50 year operating life cycle periods.
* Unit costs are based on 2018 RSMeans standard union pricing.
* Unit costs are based on 2018 RSMeans standard union pricing.
* Additional costs associated with retrofit or redevelopment contexts is assumed to be 16% of the cost estimate for new (greenfield) construction contexts.
* Additional costs associated with retrofit or redevelopment contexts is assumed to be 16% of the cost estimate for new (greenfield) construction contexts.
** Retrofit construction cost estimates are included in the 'Costs Summary' section for comparison.<br>
** Retrofit construction cost estimates are included in the 'Costs Summary' section for comparison.<br>