BMP Costing
Cost: There are many factors which will affect costs, from soil conditions to labor rates. Therefore, the USEPA parameters should be considered as estimates only.
BMP Type |
Typical Cost ($/cf, or linear foot) |
Typical Cost ($/BMP) | Typical Application | Reference: |
| Retention and Detention (1) |
0.50-1.00 | $100,000 |
50-Acre Residential Site (Impervious Cover = 35%) |
Adapted from Brown and Schueler (1997b) |
| Constructed Wetland (2) |
0.60-1.25 | $125,000 | 50-Acre Residential Site (Impervious Cover = 35%) |
Adapted from Brown and Schueler (1997b) |
| Infiltration Trench (3) |
4.00 | $45,000 | 5-Acre Commercial Site (Impervious Cover = 65%) |
Adapted from SWRPC (1991) |
| Infiltration Basin (4) |
1.30 | $15,000 | 5-Acre Commercial Site (Impervious Cover = 65%) |
Adapted from SWRPC (1991) |
| Sand Filter (5) | 3.00-6.00 | $35,000-$70,000 | 5-Acre Commercial Site (Impervious Cover = 65%) |
Adapted from Brown and Schueler (1997b) |
| Bioretention (6) | 5.30 | $60,000 | 5-Acre Commercial Site (Impervious Cover = 65%) |
Adapted from Brown and Schueler (1997b) |
| Grass Swale (7) |
0.50 | $3,500 | 5-Acre Residential Site (Impervious Cover = 35%) |
Adapted from SWRPC (1991) |
| Filter Strip (8) | 0.00-1.30 | $0-$9,000 | Filter Strip $0-$9,0003 5-Acre Residential Site (Impervious Cover = 35%) |
Adapted from SWRPC (1991) |
Notes:
(1) Retention and Detention: Cost range reflects economies of scale in designing this BMP. The lowest unit cost represents approx.150,000 cubic feet of storage, while the highest isapprox. 15,000 cubic feet. Typically, dry detention basins are the least expensive design options among retention and detention practices.
(2) Constructed Wetland: Although little data are available to assess the cost of wetlands, it is assumed that they are approx. 25% more expensive (because of plant selection and sediment forebay requirements) than retention basins
(3) Infiltration Trench: Represents typical costs for a 100-foot long trench.
(4) Infiltration Basin: Represents typical costs for a 0.25-acre infiltration basin.
(5) Sand
Filter: The range in costs for sand filter construction is largely due to the
different sand filter designs. Of the
three most common options available, perimeter sand filters are moderate cost
whereas surface sand filters and underground sand filters are the most expensive.
(6) Bioretention: Bioretention is relatively constant in cost, because it is usually designed as a constant fraction of the total drainage area.
(7) Grass Swale: Based on cost per square foot, and assuming 6 inches of storage in the filter.
(8) Filter Strip: Based on cost per square foot, and assuming 6 inches of storage in the filter strip. The lowest cost assumes that the buffer uses existing vegetation, and the highest cost assumes that sod was used to establish the filter strip.
Assume additional 3% year for inflation
Table and language from:
(note: this document also provides up to date costing equations for each BMP)