1. February 28, 2006 Stormwater BMP Performance U.S. EPA Chesapeake Bay Program Urban Stormwater Workgroup

2. BMP Performance

3. Why evaluate BMP performance?  20 years worth of effort has evolved into a $1 billion/year spending to improve water quality among the three Bay region states and the District of Colombia;  Bay region population of 16 million people is growing at a rate of 100,000 people/year;

4. Cost Effective Strategies for the Bay December 2004; Chesapeake Bay Commission “Developed lands are a major contributor of nutrient and sediment loadings to the Chesapeake. Yet none of the measures to deal with the impacts of development come up on the list of the most cost effective actions to help meet the 2010 nutrient goals.” “This is because the corrective actions in urban and suburban areas will be expensive, difficult to measure, and effective only over the long term.” “Data shows that the urban and suburban sources of the nutrient and sediment load to the Bay are the only sources where the load is growing.”

5. Status Quo!? “Bay’s dead zone is biggest in 20 years” Chesapeake Bay Program 10/3/05 “Estimated $19 billion price tag for Bay restoration as outlined in the Chesapeake 2000 agreement.” Chesapeake Bay Commission’s January 2003 Report, The Cost of a Clean Bay. (represents a 4 fold increase in order to reach the 2010 goal!) Algae bloom; York River, 9/9/05 Courtesy Bill Portlock, Chesapeake Bay Foundation

6. Chesapeake Bay Watershed  64,000 mi 2  6 States & District  16 million people

7. Virginia Stormwater BMPs Min. Std. 3.06: Retention Basins Min. Std. 3.07: Extended Detention Basins Min. Std. 3.08: Detention Basins Min. Std. 3.09: Constructed Wetlands Min. Std. 3.10: Infiltration Min. Std. 3.11: Bioretention Min. Std. 3.12: Intermittent Sand Filters Min. Std. 3.13: Grassed Swales Min. Std. 3.14: Vegetated Filter Strips Min. Std. 3.15: Manufactured BMP Systems V wq ; V ce ; Flooding-Q 10, Q 50 ;

9. Maryland Stormwater BMPs BMP Group 1:Stormwater Ponds BMP Group 2:Stormwater Wetlands BMP Group 3:Infiltration Practices BMP Group 4: Filtering Practices BMP Group 5: Open Channel Practices BMP Group 6:Non-structural practices (LID?) WQ v ; Re v ; Cp v ; Q p ; Q f 80% removal of TSS; 40% removal of TP; when designed, constructed, and maintained in accordance with the MD Stormwater Design Manual

10. District of Colombia Stormwater BMPs BMP Group 1: Filtering Systems BMP Group 2: Infiltration Practices BMP Group 3: Storage Practices BMP Group 4: Storm Water Ponds BMP Group 5: Storm Water Wetlands BMP Group 6: Open Channel Practices V w ; Qp 2 ; Qp 15 ; Q f ; Median % removal: TSS, TP, TN, Cu, Zn

11. BMP Removal Efficiency (%) BMP Type Bay Prog. TN TP TSS MD TN TP TSS VA TN TP TSS DC TN TP TSS A Wet Ponds Wetlands 30 60 80 - 40 80 40 80 - 40-65 - - 30 - 32 49 79 26 43 83 B Dry Detention Hydrodynamic 5 10 10 - - - - 20 - - - - - - ? C Dry Ext. Det. 30 20 60- - -- 35 -- - - D Infiltration 50 70 90- 40 80 - 50-65 -42 100 - E Filtering 40 60 85- 40 80- 50 -49 65 - Grassed Swale - - -- * *- 15 - - 29 68 Veg. buffer- - -- * *- 10 -- - -

12. Percent Removal Regulatory goal of protecting downstream resources uses percent removal as a compliance tool. Performance Goal: XX Percent removal of:  Water Quality (first Flush) Pollutant Load  Individual Storm Pollutant Load  Annual load of TSS, TP, TN, etc.

13. Performance Goals  Volume / Flow Rate  Removal Mechanism / Particle size distribution  Influent / effluent concentrations  Maintenance

14. Flow Rate Particle Size DistributionInfluent Concentration

15. Ideal Stormwater BMP Acceptance Policy GOAL:  Characterize, with a reasonable level of statistical confidence, an emerging technology’s effectiveness in removing pollutants from stormwater runoff for an intended application  Compare test results with vendor’s claims

17. Strategy for Reciprocal State Acceptance of Environmental Technologies December 2000 Six State Memorandum of Understanding Massachusetts Pennsylvania New Jersey New York California Illinois And accepted by Virginia Supported by: Interstate Technology & Regulatory Cooperation Workgroup Environmental Council of States

18. Tier II Guidance The Technology Acceptance and Reciprocity Partnership (TARP) Protocol for Stormwater Best Management Practice Demonstrations August 2001 Updated July 2003 Endorsed by Massachusetts Pennsylvania New Jersey California Maryland Virginia

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21. Ideal Stormwater BMP Acceptance Policy  Treatment Objectives  Performance Goals  Application and Approval Process  Application Format  Field Evaluation Project Plan (QAPP)

22. Treatment Objectives Water quality parameters  Solids  Nutrients  Hydrocarbons (oil & grease)  Metals  Pesticides  Bacteria

23. Technical Review Committee  Program goals and oversight  Application review  Revisions and response to comments  Formal acceptance of Designated Use.

24. Application and Approval Process  Preliminary Acceptance  Application package  Performance Claims based on treatment objectives and performance goals  Performance demonstration in laboratory setting

25. Laboratory Studies Designate commercially available surrogate (such as Sil-Co-Sil 106, 250, etc.) to simulate regional sediment distributions: silt loam, sandy loam, etc.

26. Application and Approval Process (cont.)  Use Designations  Pilot Level Designation (# yrs) oLimited or no lab data oEnables Field Testing with limited installations  Limited Use Designation (# yrs) oLab data oLimited or no installation history oEnables Field Testing with limited installations  Conditional Use Designation (# yrs) oEstablished History in the Region oLab & non-local field data to provide confidence oRequires implementation of a monitoring program following an accepted QAPP  General Use Level Designation oPermanent approval level

27. Application Format  Technology description  Treatment Objectives and Performance Goals  Appropriate land use applications  Design criteria/Sizing  Construction  Costs  Operation and Maintenance  Reliability  Robustness

28. Development of a Quality Assurance Project Plan (QAPP)  Project Organization and Schedule  Project Team  Consultants  Technical Advisor  Sampling Design  Site Selection  Pre-Sampling Activities  Equipment  Field QA/QC  Method Quality Objectives  Data Management  Data Review  Verification and Validation  Reporting

29. Other Issues to be addressed  Reporting performance  Net annual load reduction  Average removal  Removal during design storm  Storm Characteristics  # of storms  Minimum storm depth  Antecedent dry period  Sampling issues  Storm coverage  # of aliquots  Analytical parameters

30.  Storm Prediction  Equipment Operational  Inlet and Outlet  Batteries  Rain Gage  Event Occurrence  Dry Storms  Sample Hold Times  What can go wrong… Sampling Issues

31. Individual Storm Report

32. Load vs. Concentration  Do EMC’s represent BMP performance?  Smoothing of removal efficiencies underestimate performance at higher concentrations  Coarser and heavier particles represent high mass loads which may dominate performance calculations

33. Performance Goals Findings from the International Stormwater BMP Database (The Water Report - August 2004): BMP pollutant removal performance is best assessed by determining: 1)How much stormwater runoff is prevented?; 2)How much of the runoff that occurs is (or is not) treated by the BMP?; 3)Of the runoff treated, what is the effluent quality?

34. Statistical Analysis of Influent and Effluent Data: Efficiency Ratio Linear Regression of loads Line of Comparative Performance Effluent Probability Method Reference Watersheds Must account for overflow and bypass.

35. BMP Performance

36. Why do we need an acceptance policy?  Lack of specificity often leads to decision making based on price;  Lack of specificity tends to be exploited in competitive market situations; They are all competitive situations!  TMDLs will drive requirements for BMPs;  Accountability.

37.  New Jersey (TARP)  Washington D.C.  North Carolina (PEP)  Virginia (TARP)  Pennsylvania (TARP)  Maryland (TARP)  West Virginia  New York Current Status: