1. IDEAL Stormwater BMP Modeling Framework May 8, 2007 Brian T. Bates, PE

2. Woolpert IDEAL Demonstration  History/Background of IDEAL  Modeling Approach  State of the model  Demo  Discussion Integrated Design and Evaluation Assessment of Loadings Model

3. Woolpert IDEAL Demonstration An OCRM Dilemma  Compliance with Antidegradation & TMDLs  Needed an explicit BMP model −Model Hydrology & Hydrualics and pollutant yield from urban areas. −Estimate BMP performance. −Base predictions on accepted predictive procedures. 20022003200420012000 1999

4. Woolpert IDEAL Demonstration IDEAL Initiated  Woolpert hired by OCRM  Scope of Model  Literature review  Watershed Framework  Post Construction BMP Design Aid Manual and IDEAL Spreadsheet 2001 20022003 20042005

5. Woolpert IDEAL Demonstration IDEAL Development  Primary Researchers Dr Bill Barfield – Oklahoma State University Dr. John Hayes – Clemson University

6. Woolpert IDEAL Demonstration IDEAL OCRM version  BMP Trapping Sedimentology and soil isotherms  Hydrology Single storm and Total annual runoff  4 pollutants  3 BMPs  Pond routing  Single watershed  Post-construction

7. Woolpert IDEAL Demonstration Pervious Imp Pervious and Unconnected Impervious Impervious Directly Connected Impervious BMP Dry/Wet Detention Basin Outflow From Watershed Watershed Modeling Framework

8. Woolpert IDEAL Demonstration Rainfall Statistics Growing Season P=0.664 AMC 1 P=0.797 AMC 2 P=0.104 AMC 3 P=0.100 Dormant Season P=0.336 AMC 1 P=0.543 AMC 2 P=0.231 AMC 3 P=0.226 12 Storms 0.25’’ to 10.5’’ Values for Greenville, SC Precip Amount Prob P

9. Woolpert IDEAL Demonstration Sediment Yield  Pervious Areas - MUSLE  Impervious Areas - EMC Approach − EMC varies with type of impervious area − Modeling dependability improves as local data is collected  Model Sediment Size Distribution − Used to determine sediment trapping in Vegetated Filter Strip and in ponds − Nutrients and bacteria are sorbed on the exchange phase of the clay particles, hence need to know concentration of clay size particles − Pervious areas based on CREAMS equations − Impervious areas based on NURP data

10. Woolpert IDEAL Demonstration Nutrient and Bacteria Loading  Modeling Nutrients − Yield based on event mean concentrations (EMCs) for each chemical − EMCs vary based on land use  Modeling Indicator Bacteria − Yield based on event mean concentrations (EMCs) for bacteria − EMCs highly variable National average ~ 15,000 number/100ml Depends a great deal on presence of pets, wildlife, leaky sewers, etc

11. Woolpert IDEAL Demonstration BMP Trapping  Predicts trapping of sediments in ponds through overflow rate calculations for 5 particle classes.  Predicts nutrient trapping by settling of particulate matter and sorbed portion on trapped active clay content of the sediment by isotherms.  Predicts bacteria trapping using isotherms and mortality  VFS trapping uses the KY VFS model

12. Woolpert IDEAL Demonstration IDEAL OCRM Model Limitations  Only for use on the SC coast  Limited outlet configurations  Numerous spreadsheet constraints  Untested BMP algorithms  No resuspension, denitrification, direct loading on BMP, or bacteria growth.

13. Woolpert IDEAL Demonstration  Woolpert hired by County  Isotherms and Rainfall Analysis  Continue to use spreadsheet Greenville County 2002 20012003 20042005

14. Woolpert IDEAL Demonstration Greenville County 2003 20012002 20042005  Dry pond verification study

15. Woolpert IDEAL Demonstration Greenville County 2004 20012002 20032005  VB GUI developed  Bioretention cell research begun  Multiple watersheds  Literature review −Swales & Engr. Devices

16. Woolpert IDEAL Demonstration Greenville County Sept 20012002 20032005  EPA BMP Design Manual EPA/600/R-04/121 2004

17. Woolpert IDEAL Demonstration Greenville County 2005 2006 2002 20032004  Bioretention cell added and revised −Greenhouse study −Greenville Co. study

18. Woolpert IDEAL Demonstration Greenville County

19. Woolpert IDEAL Demonstration Greenville County 2005 2006 2002 20032004  Bioretention cell added and revised −Greenhouse study −Greenville Co. study  FC loading function

20. Woolpert IDEAL Demonstration Greenville County

21. Woolpert IDEAL Demonstration Greenville County 2006 2005 2002 20032004  Sand filter and bioswale added  Conceptual algorithms developed for engr. devices  Conveyance routing algorithms −Pipe, Channel, Simple translation  Model presented to EPA Region 4  VB GUI revised to current layout −Distributed Jan 2007 to GC engineers

22. Woolpert IDEAL Demonstration Greenville County  Object oriented VB.net “Drag n Drop” version

23. Woolpert IDEAL Demonstration Ongoing Improvements  Technical Advisory Group −Barfield and Hayes −Dr. John Sansalone –University of Florida −Dr. Bob Pitt –University of Alabama −Mike Borst – EPA-Office of Research & Development −Mark Schlautman – Clemson University −Khaled Gasem – Oklahoma State University  Enhanced Bioswale research with EPA-ORD, Edison, NJ  User’s Manual

24. Woolpert IDEAL Demonstration Summary of versions OCRM Spreadsheet VB.Net PollutantsSediments, Nutrients, Bacteria Watersheds1200+ BMPsWet/Dry Ponds, VFS Wet/Dry Ponds, VFS, Bioretention cells, Sand filter ConveyancesNone Pipes, channels, and translation only Isotherms & Rainfall Analysis SC CoastGreenville Co.

25. IDEAL DEMONSTRATION

26. Woolpert IDEAL Demonstration Uses  BMP design for small to large development projects  TMDL compliance  Antidegradation restrictions  Watershed master planning  LID design

27. Woolpert IDEAL Demonstration Future Enhancements  Expansion of Isotherms  Bacteria growth function  Rainfall statistics  Engineered device algorithms development  Bioswale algorithm revision  Conveyance design functionality  GIS/CAD interface  Optimization  Large scale watershed considerations  Performance enhancement and user support  Continue to use best science available

28. Questions?