Cost estimates that site planners can use to compare the relative construction and maintenance costs for structural best management practices are excellent for purposes of comparison. However, it is recommended that construction and maintenance budgets should be based on site specific information. Utilizing the table below and cost estimation worksheets for either bioretention or surface sand filter will allow designers to more accurately estimate the cost of a filtration BMP.

Cost components for filtration practices.
Link to this table

Implementation Stage Primary Cost Components Basic Cost Estimate Other Considerations
Site Preparation Tree & plant protection Protection Cost ($/acre) x Affected Area (acre) Removal of existing structures, topsoil removal and stockpiling
Topsoil salvage Salvage cost ($/acre) x Affected Area (acre)
Clearing & grubbing Clearing Cost ($/acre) x Affected Area (acre)
Site Formation Excavation / grading X-ft Depth Excavation Cost ($/acre) x Area (acre) Soil & rock fill Hauling material material, tunneling
Hauling material offsite Excavation Cost x (% of Material to be hauled away)
Structural Components Under-drains Under-drain cost ($/lineal foot) x length of device Pipes, catchbasins, manholes, valves, vaults
Vault structure (for media filters) ($/structure)
Media (for media filters) Media cost ($/cubic yard) X filter volume (cubic yard)
Inlet structure (for vegetative filters ($/structure)
Outlet structure (for vegetative filters) ($/structure)
Site Restoration Filter strip Sod cost ($/square foot) x filter strip area Tree protection, soil amendments, seed bed preparation, trails
Soil preparation Topsoil or amendment cost ($/acre) x Area (acre)
Seeding Seeding Cost ($/acre) x Seeded Area (acre)
Planting / transplanting Planting Cost ($/acre) x Planted Area (acre)
Annual Operation, Maintenance, and Inspection Debris removal Removal Cost ($/acre) x Area (acre) x Frequency (2x / 1yr) Vegetation maintenance, cleaning of structures
Sediment removal Removal Cost ($/acre) x Area (acre) x Frequency (1x / 5yr)
Gate / valve operation Operation Cost ($) x Operation Frequency (2x / 1 yr)
Inspection Inspection Cost ($) x Inspection Frequency (6x / 1 yr)
Mowing (for some vegetative filters) Mowing Cost ($) x Mowing Frequency (4x / 1 yr)

Surface sand filter cost estimate worksheet.
Link to this table

Project Title
Project Number
Description Units Quantity Unit Cost Total Estimated Price
Site Preparation
Tree removal - up to 12" diameter each $350.00 $0.00
Clear and grub brush square yard $1.50 $0.00
Tree protection - temp. fence lineal foot $3.00 $0.00
Topsoil - 6" depth, salvage on site square yard $4.50 $0.00
Site Formation
Excavation - 6' depth square yard $8.00 $0.00
Grading square yard $1.50 $0.00
Hauling off-site - 6' depth square yard $10.00 $0.00
Structural Components
Underdrain - with pea gravel and geotextile lineal foot $400.00 $0.00
Inlet structure each $1,500.00 $0.00
Sand filter media - 18" depth square yard $15.00 $0.00
Outlet structure each $3,000.00 $0.00
Site Restoration
Sod filter strip lineal foot $1.50 $0.00
Soil preparation square yard $5.00 $0.00
Seeding - above outlet elevation square yard $0.50 $0.00
Subtotal $0.00
10% Contingencies $0.00
Subtotal $0.00
Apply MN Location Factor $0.00
Annual Operation and Maintenance
Debris removal per visit $50.00 $0.00
Mowing per visit $150.00 $0.00
Sediment removal per yeart $500.00 $0.00
Gate / valve operation per visiit $125.00 $0.00
Erosion repair square yard $75.00 $0.00
Inspection pper visitt $125.00 $0.00
Subtotal $0.00
Apply MN Location Factor $0.00
Minnesota Location Factors
Bemidji 0.963
Brainerd 1.003
Detroit Lakes 0.962
Duluth 0.991
Mankato 0.990
Bemidji 0.963
Minneapolis 1.035
Rochester 0.983
St. Paul 1.000
St. Cloud 1.002
Thief River Falls 1.042
Willmar 0.961
Windom 0.935

Note: Suggested unit costs are based on RS Means prices for Spring, 2005, then factored into an area basis based on typical design features for Constructed Wetlands BMPs. To be used for preliminary cost estimation

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This page was last edited on 29 December 2022, at 02:11.