Runoff and Erosion Testing at the Stormwater Academy Laboratory at UCF

1. 2009 H2O and Erosion Control Workshop, March 12-13, 2009 Runoff and Erosion Testing at the Stormwater Academy Laboratory at UCF Manoj Chopra, PhD, P.E., Sai Kakuturu, PhD, Mike Hardin, MSEnvE Stormwater Management Academy University of Central Florida, Orlando

2. Outline of Presentation • Introductory Remarks • Erosion and Sediment Control Testing Laboratory • Project 1 – Fertilizer Runoff and Groundwater Pollutants Study • Project 2 – Runoff Characterization Studies

3. SWMA Erosion Lab

4. Evaluation of Pollution Levels Due to the Use of Consumer Fertilizers under Florida Conditions Sai Kakuturu, Ph. D. University of Central Florida, Orlando

5. BACKGROUND • Establishing and sustaining good quality turf is essential for preventing erosion of highway slopes • Excessive turf fertilization is causing leaching of nutrients and pollution of surface and ground waters • Recent legislative measures (county ordinances, Clean Water Act of NPDES) intend to minimize nutrient leaching by stipulating limits on fertilization practices • FDOT needs to evolve improved fertilizer regimes for simultaneously • preventing pollution due to nutrient leaching • maintaining high quality turf for aesthetic beauty and for preventing soil erosion

6. THE PROBLEM • Changed fertilizer regimes stipulating lower nitrogen (N), little or no phosphorous (P) • Need for quantifying concentration of nutrients in leachate and run-off from FDOT roads • Necessity to understand the effect of highway embankment slopes on nutrient concentrations • Development of BMPs for optimum use of fertilizers to minimize pollution and at the same time for promoting the growth of highway turf and thus preventing soil erosion

7. What we are doing at UCF:Rainfall and Pollution Evaluation • The rainfall simulator is used for creating storms of chosen intensity and duration • The rainfall intensities chosen for this study are: (a) 0.5 inch/hr (b) 1.0 inch/hr, and (c) 3.0 inch/hr (the choices are based on Harper’s study) • The leachate and run-off collected both during and after the 1-hour storm • Chemical analysis of leachate carried out and will be used in mass balance studies

8. What we are doing at UCF:Slopes and Soils • Tests are conducted on three slopes to represent typical slopes of highway embankments, 1 in 2, 1 in 3, and 1 in 4 • Tests are conducted using two soil types to represent typical soils available in Florida for highway construction, AASHTO A-3 (central/southern Florida) and A-2-4 (northern Florida) • The soil beds are prepared following standard procedures for turf establishment on highway slopes

9. What we are doing at UCF:Grasses and Fertilizers • The grass types are: • Argentine Bahia on AASHTO A-3 soil • Pensacola Bahia on AASHTO A-2-4 soil • Sod tiles established on the prepared soil test bed. • One unfertilized test bed tested for each soil type to quantify the nutrient leaching from virgin Florida soils • The fertilizers selected are: • 10-10-10 and 12-3-6 to represent previous practices • 16-0-8 (SR) to represent changed practices • The prime objective is quantifying reduction in concentration of nutrients due to changed fertilizer regimes

10. Implementation and Expected Outcomes • This project is being implemented at the UCF’s Stormwater Management Academy Laboratory (SMARTLab) • Quantitative evaluation of new fertilizer regimes in terms of nutrient leaching from highway slopes • Effect of soil type and rainfall intensity on nutrient leaching • Basis for developing best management practices (BMPs) for effective fertilization of highway turf while minimizing nutrient pollution of waters to meet NPDES regulations and prevent soil erosion • Dissemination of research results to state agencies

11. Runoff Characterization Studies Mike Hardin and Nicole Runnebaum. University of Central Florida, Orlando

12. Background • Stormwater management is necessary to prevent flooding, protect surface waters, and minimize health hazards associated with sitting water • Stormwater infrastructure is designed using hydrologic models • Inputs: rainfall, infiltration, and evapotranspiration • System response: water levels, flow rates, flow directions, etc…

13. Problem • SCS CN method good for large events but underestimates small events • Little data exists on runoff from non-vegetated urban surfaces • Particularly for small storm events, i.e. < 1 inch • Field measurements difficult due to lack of controlled conditions • Model integrity is effected • Lack of reliable data on amount of rainfall excess available for runoff and infiltration

14. Objectives • Research Goals: • Measure runoff from rainfall events on representative impervious urban surfaces • Place the collected data within a quantitative cause-and-effect relationship between surface cover, time of year, slope, and rainfall variability • Testing areas & Slopes • Asphalt and Concrete • 0.2 %, 2 % • Roofing Shingles and Barrel Tiles • 5 %, 25 %, 50 % • Sod • 0.2 %, 5 %, 50 %

21. Sample points: 9

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29. Sample points: 18

30. Simulated Sample Points: 9 Natural Sample Points: 23

31. Simulated Sample Points: 9 Natural Sample Points: 23

32. Simulated Sample Points: 9 Natural Sample Points: 23

33. Simulated Sample Points: 9 Natural Sample Points: 23

34. Simulated Sample Points: 9 Natural Sample Points: 23

35. Simulated Sample Points: 9 Natural Sample Points: 23

36. Questions and Discussion !