About BayFAST



What is BayFAST?

Chesapeake Bay Facility Assessment Scenario Tool (BayFAST) is a web-based nitrogen, phosphorus and sediment load estimator tool that streamlines environmental planning. Users specify the boundaries of a parcel, and then select Best Management Practices (BMPs) to apply on that parcel. BayFAST builds the scenario and provides estimates of nitrogen, phosphorus, and sediment load reductions.

For more technical details see the full documentation.

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Why use BayFAST?

BayFAST enables each facility in the watershed to develop a plan for meeting a load allocation. BayFAST provides the facilities with opportunities for “on-the-fly” estimates of load reductions.

BayFAST allows users to understand which BMPs provide the greatest load reduction benefit and the extent to which these BMPs can be implemented. Based on the scenario outputs, users can refine their BMP choices in their WIP planning.

BayFAST facilitates an iterative process to determine if Total Maximum Daily Load (TMDL) allocations are met. Scenarios may be compared to each other, TMDL allocations, or the amount of nitrogen, phosphorus, and sediment from the Watershed Implementation Plan (WIP) or a current annual progress scenario.

BayFAST scenarios closely replicate the results of the Chesapeake Bay Program’s (CBP) Watershed Model. Other available tools have assumptions that may be different from those used in the Watershed Model for developing the current TMDL. Since the Watershed Model is used to assess the jurisdictions’ progress toward meeting the TMDL allocations, consistency with the Watershed Model is critical.

  • Uses CBP-approved BMPs and efficiencies
  • Consistent with the CBP Phase 5.3.2 Watershed Model and updates
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Who benefits from using BayFAST?

BayFAST is based on the CAST family of tools which have been used by multiple local jurisdictions and states for the Phase II WIPs, 2013 and 2015 Milestones and even local TMDLs. Any user may see the source of the data that was used in developing the TMDL and the state’s most recent annual progress scenario, Milestone and WIP. This allows involvement of the counties and other local planners in the Bay TMDL. BayFAST is easily accessible on-line with no need to install specific databases or software. All who request a login are granted one.

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What are BayFAST’s outputs?

BayFAST estimates of load reductions for point and nonpoint sources include: agriculture, urban, forest, and septic loading to the edge of a fourth order stream and loads delivered to the Chesapeake Bay. BayFAST stores the parcel boundaries and data associated with each BMP as well as the load for each sector and land use. With these data tables, BayFAST also serves as a data management system. Thus, users may quantify the impacts of various management actions while improving local management decisions.

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Why was BayFAST developed?

The first version of BayFAST was launched in March 2014 to provide individual federal facilities within the Bay watershed with a tool to provide input into the TMDL WIP process. The U.S. Environmental Protection Agency (EPA) issued a TMDL in 2010 for the Chesapeake Bay based on allocations established by the states. The jurisdictions that drain to the Chesapeake Bay include New York, Pennsylvania, West Virginia, Maryland, Delaware, District of Columbia, and Virginia. The states agreed that it would be more efficient for states to allocate responsibility within their respective political boundaries, and for EPA to issue one overall TMDL that reflected each state’s allocation. Since planning happens at a more local scale, such as county, some states downscaled the allocation to the county level. BayFAST allows that process to extend to the parcel level.

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How is information entered into BayFAST?

BayFAST is designed to be useful to people with a general knowledge of BMPs. Knowledge of models or BMP load reduction calculations is not necessary. BayFAST is available on-line to users with a login and password, which may be requested from the website.

Data is entered into BayFAST in the following sequence:

  • The user selects the boundaries of a parcel on a map using a "point and click" interface.
  • The user creates or modifies the basic features of a scenario as applied to the parcel. BayFAST draws upon the same data sources as the Chesapeake Bay Program Partnership models to populate the parameters of the scenario based on user selections. The user can build a new scenario or import features of an existing scenario. The user may opt to share the scenario with other users on the system.
  • The user establishes costs of BMPs, or can use the EPA- defaults provided defaults.
  • The user adds BMPs to the scenario using separate screens with options for urban, septic, forest, agriculture, animals, and manure transport. The user may edit the BMP selections at any time to modify the scenario.
  • The user selects calculate and the loads and costs are provided on screen and in downloadable tables.
  • The user also may compare scenarios.

Users may choose to enter BMPs on actual acres or number of septic systems. The number of available acres changes depending on the other BMPs in the scenario. For example, the forest buffer BMP removes acres from one land use and converts it to forest. This means that there are fewer acres for other BMPs in the original land use. More information on the sequence of BMP application is found in the BayFAST technical manual file posted under documentation.

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How is BayFAST different from the other CAST family of tools?

BayFAST allows users to define the boundaries of a parcel and the land use areas within that parcel, and then to build scenarios for those user-defined parcels. The CAST family of tools requires users to select land areas for scenarios based on land-river segments within the Bay watershed and to use the land use areas defined by the Chesapeake Bay Program. MAST is a Maryland specific version of CAST. MAST has some Maryland-specific geographies available through the interface.

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How do the load estimates produced by BayFAST agree with those produced by the Chesapeake Bay Program Partnership Watershed Model?

The Watershed Model does not produce load estimates at the parcel level. Over larger geographic areas, the builders of BayFAST regularly assess the fit between the load estimates and the Watershed Model. For a very large number of land-river segments within the watershed under a range of BMPs, the fit is 95% or better. Download the latest detailed report under resources on the documentation page.

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Who develops and maintains BayFAST?

The Chesapeake Bay Facility Assessment Scenario Tool (BayFAST) was first developed in 2014 by Jessica R. Rigelman of J7 LLC and Olivia H. Devereux of Devereux Environmental Consulting, with funding provided by the U.S. Environmental Protection Agency (EPA). The immediate need was to provide federal facilities within the Chesapeake Bay Watershed with a tool to provide input into the TMDL Milestone development process. For more information about the developers visit the Contact Us page.

With continued funding from the U.S. EPA, the functionality of BayFAST will be expanded to serve multiple needs for environmental planning in the Chesapeake Bay Watershed.

Future enhancements are developed with input from the states and local jurisdictions, the Chesapeake Bay Program, federal facilities managers, and the EPA. The tool will continue to evolve to meet the needs of users.

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