Bioretention Data
(illustration courtesy of the Low Impact Development Technical Guidance Manual for Puget Sound)
What does Bioretention cost, and how what is the efficiency of pollutant removal?
Bioretention can be economical. In new construction, costs can be slightly greater than landscaping but may be as little as $500 per site, excluding planting and design costs. This, of course, depends on scale, construction rates, and other conditions, such as soil type.
The USEPA suggests that retrofits typically cost more, with $6,500 as a base price.
As with any stormwater management strategy, the question often arises, "Who pays?"
As a point of interest, this technology can actually create profit margins in new construction: a recent 200 unit development in Prince County, Maryland, the implementation of on-site bioretention allowed the developer to forgo a land intensive retention pond; as a result, additional lots were sold which created a realized profit $4,000 per lot. * (For more costing and background please download the EPA document below)
The following is a published EPA guideline with regard to performance:
*Taken from the EPA document EPA 832-F-99-012
Note: this document also contains design scope and relevant background information.