Default unit cost estimates are provided for each state and the Chesapeake Bay Watershed. The Chesapeake Bay Watershed is an average of all states. Costs are provided as a starting point to use for creating your own cost estimates of various BMP scenarios. Costs are estimated in 2010 dollars. Capital and opportunity costs are amortized over the BMP lifespan and added to annual operations and maintenance (O&M) costs for a total annualized cost.
Costs are annualized average costs per unit of BMP (e.g.: $/acre treated/year). The formula is:
- annual costs = (capital * annualization factor) + O&M costs + (land * annualization rate)
- annualization factor = i/((1+i)^n - 1) + i
- i = annualization rate, which is always 5%
- n = period of annualization (also called lifespan)
Edit Cost Profiles
You can log into CAST and edit the costs by creating your own Cost Profile. CAST provides costs associated with each scenario using the cost profile you select. The data available in the Cost Profiles is summarized to include the capital, operations and maintenance, and opportunity costs.
BMP costs included in CAST are developed by contractors to the EPA and are in 2010 dollars.The original costs were reviewed with the states who provided input. Additional BMPs were approved by the Chesapeake Bay Program Partnership since the original TMDL costs were determined. The data source of all BMPs are provided in the downloadable files below by sector.