Chesapeake Assessment Scenario ToolCAST
Olivia H. DevereuxInterstate Commission on the Potomac River Basin
GOALS FOR CAST
Provide a mechanism for the states to get inputand commitment from multiple federal and local jurisdictionsGuaranteethat calculations are consistent and replicableCreatetransparencyIntegrate data in a uniform format for WIP and Milestones
Maryland Department of the Environment requested thatICPRB developMAST to facilitate their WIP 2 processCBRAP and MD General FundsVirginia Department of Conservation and Recreation asked thatICPRB customize MASTto meet Virginia’sneeds (VAST).Chesapeake Bay Program requested thatICPRB develop CAST to apply MAST to the entire watershed.CBRAP funding to MD wasexpandedTetra Tech hired ICPRB to perform training
Consistent with EPA Phase 5.3.2 and WIP Phase IIConsistent process for WIP teamsApproved and interim BMPsConsistent input scale
Facilitate an adaptive process, scenario development is iterativeServe as a data management systemFacilitate stakeholder involvement, show implications of decisions
Reporting – Watershed Model
Builds load reduction strategies (by local area)Identifies the BMPs that give the greatest load reductionsSpecifies the extentthese BMPs are to be implementedMeetsthe allocationsComparesamong scenariosProducesCBP Scenario Builder model inputsAssesses WIPsand 2-Year Milestones
METHODOLOGY FOR BMP CALCULATIONS
CAST calculates all BMPs identically to CBP’s Scenario Builder except for Animal BMPsAnimal BMPs affect the amount of manureCAST calculates manure lbs based on user-selected BMP implementation level, same as Scenario BuilderDistribution of manure lbs based on regressionsThree classifications of manuredirect deposit manure (pasture land uses only)storage loss manure (AFO/CFO)stored manure (crop and pasture land)
BMPs that increase stored manure, which is then applied to crops and pasture
AlumLagoon CoversAWMSMortality Composting
BMPs that decrease total manure
Dairy Precision FeedingPoultry PhytaseSwine Phytase
Based on user’s selection of % Implementation of theseBMPs and the interaction effects with nutrient management, CASTcalculates the amount of manureThe regression equations translate themanure into a loading rate by FIPS, LU, and TN or TP.
MAINTAINING CONSISTENCY WITH THE CHESAPEAKE BAY PROGRAM
Change on Nov. 30, 2011 to Scenario Builder:Street Sweeping may now only be entered in terms of Mechanical Monthly as acres on an annual basis or in terms of pounds of sediment removed. Note that mechanical monthly has a nitrogen, phosphorus, and sediment benefit whereas street sweeping-pounds only has a sediment benefit.Changes on Dec. 7, 2011 to Scenario Builder:Poultry injection and dairy manure infection are no longer allowed on nursery.Crop irrigation management is no longer available for alfalfa, nutrient management alfalfa, hay without nutrients, hay with nutrients, nutrient management hay, and pasture.
VALIDATION USING 2009 PROGRESS
Most of the error is on agricultural land uses. Urban land uses match within +/- 1%.
State Specific Practices
MD—Heavy Use Area Concrete Pads – PoultryVA—Conservation No Till implemented in two ways
CHANGES TO SCENARIO BUILDER AND THE WATERSHED MODEL
Using multiple models strengthens all models. Comparisons between MAST/CAST/VAST and Scenario Builder/Watershed Model led to changes to Scenario Builder and/or the Watershed Model including:Processing of agricultural forest buffers, agricultural grass buffers, agricultural wetland restoration and urban forest buffers in Scenario Builder when these BMPs are submitted as a percent. There were also problems with the processing of these upland efficiencies of these BMPs, regardless of how they are submitted (acres or percent). Fixed by CBP last week.Comparisons of CAST with Scenario Builder also showed that the BMP StreetSweepFt is not given credit in Scenario Builder.Working with Maryland and the Chesapeake Bay Program, we updated MD urban data in both MAST and the Watershed Model.There was an error in the Watershed Model that involved pulling data from a previously run scenario where BMPs were not specified. This led to the incorrect base loads that were initially used in MAST/CAST/VAST.The Watershed Model was changed so that groups of overlapping BMPs were better defined, preventing issues related to over-crediting certain BMPs. (This fix needs still to be implemented in Scenario Builder, but is controlled for in the WSM).
Users input acres or percent implementationBMP costsData QualityP on AFO/CFOGarret County Sediment delivery factorImproved estimation of animal BMPsAdditional testingSpeed—upgrade tool to accommodate increased usage, larger scenariosShow results as percent implementation, not just loadsContinued technical support and updating documentation
Olivia H. DevereuxInterstate Commission on the Potomac River Basin/ Potomac Valley Conservancy District301email@example.com