Large-Scale Slope Erosion Testing (ASTM D 6459 modified) Flexterra Ultra over Sandy Loam

Transcription

1 Large-Scale Slope Erosion Testing (ASTM D 6459 modified) of Flexterra Ultra over Sandy Loam December 2009 Submitted to: AASHTO/NTPEP 444 North Capitol Street, NW, Suite 249 Washington, D.C Attn: Keith Platte, NTPEP kplatte@aashto.org Submitted by: TRI/Environmental, Inc Bee Caves Road Austin, TX C. Joel Sprague Project Manager

2 December 31, 2009 Mr. Keith Platte AASHTO/NTPEP 444 North Capitol Street, NW, Suite 249 Washington, D.C Subject: Large-scale Slope Testing of Flexterra Ultra over Sandy Loam Dear Mr. Platte: This letter report presents the results for large-scale slope erosion tests performed on Flexterra Ultra hydraulically-applied erosion control product (HECP) over sandy loam. Included are data developed for target rainfall intensities from 2 to 6 in/hr (5 to 15 cm/hr). All testing work was performed in general accordance with the ASTM D 6459, Standard Test Method for Determination of Rolled Erosion Control Product (RECP) Performance in Protecting Hillslopes from Rainfall-Induced Erosion modified as necessary to accommodate hydraulically-applied mulch. The product was allowed to cure on the slopes for approximately 48 hours prior to testing. Generated results were used to develop the following general cover factor (C-Factor) for the tested material: C-Factor Flexterra 3500lbs/acre = for cumulative R Factor < 231 TRI is pleased to present this final report. Please feel free to call if we can answer any questions or provide any additional information. Sincerely, C. Joel Sprague, P.E. Senior Engineer Geosynthetics Services Division Cc: Sam Allen, Jarrett Nelson - TRI

3 Flexterra Ultra HECP over Sandy Loam - Slope Erosion Testing for NTPEP December 31, SLOPE TESTING REPORT Flexterra Ultra HECP over Sandy Loam TESTING EQUIPMENT AND PROCEDURES Overview of Test and Apparatus TRI/Environmental, Inc.'s (TRI's) large-scale slope erosion testing facility is located at the Denver Downs Research Farm in Anderson, SC. Testing oversight is provided by C. Joel Sprague, P.E. The large-scale testing reported herein was performed in accordance with ASTM D 6459 modified as necessary to accommodate hydraulically-applied mulch, on 3:1 slopes using loamy soil test plots measuring 40 ft long x 8 ft wide. The simulated rainfall was produced by ten rain trees arranged around the perimeter of each test slope. Each rain tree has four sprinkler heads atop a 15 ft riser pipe. The rainfall system has been calibrated prior to testing to determine the number of sprinkler heads and associated pressure settings necessary to achieve target rainfall intensities and drop sizes. The calibrated drop size distribution in this test had a 5 percent higher distribution of drops smaller than 1mm than is defined in the standard. This variation as shown in Appendix C is believed to have a negligible effect on the test result. The target rainfall intensities are 2, 4, and 6 in/hr and are applied in sequence for 20 minutes each. Three replicate test slopes covered by the same hydraulically-applied erosion control product (HECP) submitted were tested. The application rate of the HECP was 3500 lb/acre. The product was allowed to cure on the slopes for approximately 48 hours prior to testing. The erosion resistance provided by the product tested is obtained by comparing the protected slope results to control (bare soil) results. Tables and graphs of rainfall versus soil loss are generated from the accumulated data. Hydraulic Erosion Control Product (HECP) The following information and index properties were determined from the supplied products. Table 1. Tested Product Information & Index Properties Product Information and Index Property / Test Units Sampled Product Product Identification - Flexterra Ultra Manufacturing Plant Location - Conover, NC Lot number of sample - 1 Bag Bags Bags Dry Organic Matter Pure Wood Fiber % 74.5 ± 3.5 Moisture % 10.5 ± 1.5 Proprietary Cross-Linked Tackifier % 10 ± 1 Proprietary Crimped, Interlocking Fibers % 5 ± 1 Tensile Strength (ASTM D 6818 modified) lb/in 3.9 Tensile Elongation (ASTM D 6818 modified) % 4.8 Thickness (ASTM 6525 modified) mils 291 Light Penetration (ASTM 6567 modified) % cover 99.2 Water Absorption (ASTM 1117 / ECTC TASC 00197) % Wt Change 695 Mass / Unit Area (ASTM D 6566 modified) osy Note: Index specimens were made using the currently proposed ASTM procedure.

4 Test Soil Flexterra Ultra HECP over Sandy Loam - Slope Erosion Testing for NTPEP December 31, The test soil used in the test plots had the following characteristics. Table 2. TRI-Loam Characteristics Soil Characteristic Test Method Value % Gravel 0 % Sand 45 ASTM D 422 % Silt 35 % Clay 20 Liquid Limit, % 41 ASTM D 4318 Plasticity Index, % 8 Soil Classification USDA Sandy Loam Soil Classification USCS Sandy silty clay (ML-CL) Preparation of the Test Slopes The initial slope soil veneer (12-inch thick minimum) is placed and compacted. Compaction is verified to be 90% (± 3%) of Proctor Standard density using ASTM D 1556 (sand cone method). Subsequently, the test slopes undergo a standard preparation procedure prior to each slope test. First, any rills or depressions resulting from previous testing are filled in with test soil and subject to heavy compaction. The entire test plot is then tilled to a depth not less than four inches. The test slope is then raked to create a slope that is smooth both side-to-side and top-tobottom. Finally, a steel drum roller is rolled down-and-up the slope 3 times proceeding from one side of the plot to the other. The submitted erosion control product is then installed using the spray technique acceptable to the client. For this testing, TRI applied the product to the slopes. Installation of Erosion Control Product on Test Slopes As noted, the submitted erosion control product was installed as directed by the client. For the tests reported herein, the Flexterra Ultra was applied at the rate of 3500 lb/acre. The applied material was allowed to cure for approximately 48 hours prior to testing. Specific Test Procedure Immediately prior to testing, rain gauges are placed at the quarter points (i.e. 10, 20, 30 ft) on the slope. The slope is then exposed to sequential 20-minute rainfalls having target intensities of 2, 4, and 6 inches per hour. All runoff is collected during the testing. Additionally, periodic sediment concentration grab samples are taken and runoff rate measurements are made. Between rainfall intensities, the rainfall is stopped and rainfall depth is read in the three rain gauges, valves are adjusted to facilitate the subsequent rainfall intensity, and empty collection vessels are positioned to collect subsequent runoff. After allowing for sediments to settle, water is decanted from the collected runoff. The remaining solids are used to determine bulk soil loss. Bulk soil loss is measured by drying all collected sediments.

5 Flexterra Ultra HECP over Sandy Loam - Slope Erosion Testing for NTPEP December 31, Figure 2. Typical Sampling Figure 1. Rainfall Testing Facility (set up for a control run) Figure 3. Typical Control Result Pictures of slope preparation are shown in Figure 4. Figure 4. Typical Prepared Soil Slope & HECP Application Pictures of the eroded slopes are shown in Figures 5 thru 7.

6 Flexterra Ultra HECP over Sandy Loam - Slope Erosion Testing for NTPEP December 31, Figure 5a. Test Slope #1 At Beginning of 2 in/hr Event Figure 5b. Test Slope #1 At Beginning of 4 in/hr Event Figure 5c. Test Slope #1 At End of 4 in/hr Event Figure 5d. Test Slope #1 Test Run to Completion (20:00) of the 6 in/hr Event Figure 6a. Test Slope #2 At Start of 2 in/hr Event Figure 6b. Test Slope #2 At Start of 4 in/hr Event

7 Flexterra Ultra HECP over Sandy Loam - Slope Erosion Testing for NTPEP December 31, Figure 6c. Test Slope #2 Near End of 6 in/hr Event Figure 6d. Test Slope #2 After Completion of the 6 in/hr Event Figure 7a. Test Slope #3 At Start of 2 in/hr Event Figure 7b. Test Slope #3 At Start of 4 in/hr Event Figure 7c. Test Slope #3 Near End of 6 in/hr Event Figure 7d. Test Slope #3 At Completion of the 6 in/hr Event

8 TEST RESULTS Flexterra Ultra HECP over Sandy Loam - Slope Erosion Testing for NTPEP December 31, Total soil loss and the associated actual rainfall depth measured during the testing are the principle data used to determine the performance of the product tested. This data is entered into a spreadsheet that transforms the rainfall depth into an R-Factor and the total soil loss into soil loss per acre as typically used in the Revised Universal Soil Loss Equation. In accordance with the test procedure, a test is stopped in the event of catastrophic soil loss, as determined by the lab. In such a case, an assumed end-of-test worst-case soil loss based on the control runs is used in lieu of the soil loss just prior to failure. The tests reported herein experienced no catastrophic slope failure. In all cases, the soil loss and associated rainfall data for both protected and control conditions are used to develop a normalized cumulative graph of R-Factor versus C-Factor (R factor = total kinetic energy of the storm (E) times its maximum 30-minute Intensity (I)). The normalized cumulative R-Factor calculated for the target test events: 2 in/hr for 20 minutes + 4 in/hr for 20 minutes + 6 in/hr for 20 minutes, is R = 231. This normalized result facilitates product-to-product comparison of test results at a common point of the storm event. Graphs of R-Factor versus C-Factor for the protected condition and Soil Loss versus C-Factor for the control condition are shown in Figures 8 and 9, respectively. Figure 8 includes the best regression line fit to the test data to facilitate the determination of the C-factor. Linear (R 2 =0.191), power (R 2 =0.186), and exponential (R 2 =0.242) fits were evaluated. Slope # & Product 1 Flexterra Ultra 2 Flexterra Test # (run # - target intensity) Table 3. Summary Data Table Protected Slopes Intensity (in/hr) Runoff (gallons) Cumm. R- Factor Soil Loss (lbs / plot / event) Cumm. Soil Loss (Tons/Acre) Control Soil Loss at Cumm. R-Factor (Tons/Acre) Cumm. C- Factor Test completed with only localized failures Ultra Flexterra Ultra Using the test procedure and data evaluation technique described herein, the C-Factor shown in Table 4 was determined using the following equation: C = m C / 2.78 K where m C = slope of the protected soil loss regression line; and K = the soil erosivity determined from bare soil testing = m K / LSCP Where m K = slope of the bare soil loss regression line; LS = topographic factor = 2.78 for 8 x 40 ft slope; C = cover factor = 1.0 for bare soil; P = management practice factor = 1.0 for bare soil. Table 4. Overall C-Factor Product C-Factor Calculation Flexterra 3500 lbs/acre e x

9 Flexterra Ultra HECP over Sandy Loam - Slope Erosion Testing for NTPEP December 31, C-Factor vs. R-Factor (Flexterra Ultra on TRI-Loam; 3:1 Slope) in/hr: R = C = e x C-Factor y = e x R 2 = R-Factor Figure 8. R-Factor vs. C-Factor Tested Product Soil Loss vs R-Factor (TRI-Loam; 3:1 Slope) Soil Loss (Tons/Acre) C= m / (2.78*K) K = m / (C*2.78) K = / (2.78*1.0) = y = x R 2 = The cummulative R- Factor calculated for the following events: 2 in/hr for 20 min + 4 in/hr for 20 min + 6 in/hr for 20 min, is R = 231and the associated soil loss is 57.9 tons/acre R - Factor Figure 9. R-Factor vs. Soil Loss Control Tests

10 Flexterra Ultra HECP over Sandy Loam - Slope Erosion Testing for NTPEP December 31, 2009 Appendix APPENDIX A RECORDED DATA Test Record Sheets Sediment Concentration Data Runoff Data Soil Moisture Content Soil Loss Tables

11 Slope #: 1 DDRF Rainfall Testing SLOPE #1 Target Rain: 2 in/hr Sediment Concentration Grab Samples Followed by Runoff Rate Measurements # Time Date: 4-Dec-09 Start Rain: 12:30 PM End Rain: 12:50 PM 1 12:33 Sampling interval: 0:03 End Runoff: 12:54 PM 2 12:36 Rain Time (min): Test Time (min): :39 Product: Lot #: Flexterra Ultra n/a Descr: lb/acre hydraulically applied mulch 4 12:42 Anchors: none Anchorage: none 5 12:45 TOP OF SLOPE 6 12:48 w c1 = 22.1% (circle "x" for open valves) Set valves to 10 psi. 7 d = 0.71 in x X x x 8 i = 2.13 in/hr P = 10 psi 9 A 10 x 11 B P = 10 psi X 12 x x 13 X P = 10 psi C x 14 x x 15 x D P = 10 psi X 12 x x 13 X P = 10 psi E x 14 x x 15 x F P = 10 psi X x x Runoff Rate Measurements Time to Collect 1 gal, x P = 10 psi G x # Time sec X x x H P = 10 psi x x X x P = 10 psi I x X x X J P = 10 psi x 6 X 7 X 8 d = 0.63 in 9 i = 1.89 in/hr Temp. 63 deg 10 w c3 = 19.6% Hum. 90 % 11 d = 0.78 in 12 i = 2.34 in/hr Average Depth: 0.71 in. 13 w c2 = 20.0% Avg Rainfall Intensity: 2.12 in/hr 14 Notes: 0 mph breeze. Approx 15 gal collected

12 Slope #: 1 DDRF Rainfall Testing SLOPE #1 Target Rain: 4 in/hr Sediment Concentration Grab Samples Followed by Runoff Rate Measurements # Time Date: 4-Dec-09 Start Rain: Sampling 1:00 PM End Rain: 1:20 PM 1 13:02 interval: 0:02 End Runoff: 1:22 PM 2 13:04 Rain Time (min): Test Time (min): :06 Product: Lot #: Flexterra Ultra n/a Descr: lb/acre hydraulically applied mulch 4 13:08 Anchors: none Anchorage: none 5 13:10 TOP OF SLOPE Set valves to 10 psi. 6 13:12 w c1 = 22.1% (circle "x" for open valves) 7 13:14 d = 1.33 in X X x x 8 13:16 i = 3.99 in/hr P = 10 psi 9 13:18 A 10 13:20 X 11 B P = 10 psi X 12 X x 13 X P = 10 psi C x 14 x X 15 x D P = 10 psi X 12 X x 13 X P = 10 psi E x 14 x X 15 x F P = 10 psi X x x Runoff Rate Measurements Time to Collect 1 x P = 10 psi G x # Time gal, sec X x X H P = 10 psi x x X X P = 10 psi I X X x X J P = 10 psi X X X d = 1.5 in i = 4.50 in/hr Temp. 64 deg w c3 = 19.6% Hum. 90 % 11 d = 1.33 in 12 i = 3.99 in/hr Average Depth: 1.39 in. 13 w c2 = 20.0% Avg Rainfall Intensity: 4.16 in/hr 14 Notes: 0 mph breeze. Approx 90 gal collected

13 Slope #: 1 DDRF Rainfall Testing SLOPE #1 Target Rain: 6 in/hr Sediment Concentration Grab Samples Followed by Runoff Rate Measurements # Time Date: 4-Dec-09 Start Rain: Sampling 1:25 PM End Rain: 1:45 PM 1 13:27 interval: 0:02 End Runoff: 1:51 PM 2 13:29 Rain Time (min): Test Time (min): :31 Product: Lot #: Flexterra Ultra n/a Descr: lb/acre hydraulically applied mulch 4 13:33 Anchors: none Anchorage: none 5 13:35 TOP OF SLOPE 6 13:37 w c1 = 22.1% (circle "x" for open valves) 7 13:39 d = 2.08 in X X X x Set valves to 10 psi. 8 13:41 i = 6.24 in/hr P = 10 psi 9 13:43 A 10 13:45 X 11 B P = 10 psi X 12 X X 13 X P = 10 psi C x 14 X X 15 x D P = 10 psi X 12 X X 13 X P = 10 psi E x 14 X X 15 x F P = 10 psi X x X Runoff Rate Measurements Time to Collect 1 X P = 10 psi G x # Time Gallon, sec X x X H P = 10 psi X X X X P = 10 psi I X X X X J P = 10 psi X X X d = 1.89 in i = 5.67 in/hr Temp. 66 deg w c3 = 19.6% Hum. 90 % 11 d = 2.05 in 12 i = 6.15 in/hr Average Depth: 2.01 in. 13 w c2 = 20.0% Avg Rainfall Intensity: 6.02 in/hr 14 Notes: 0 mph breeze. Approx 320 gal collected. Minor slumping during test beginning at 6:

14 Slope #: 2 DDRF Rainfall Testing SLOPE #2 Target Rain: 2 in/hr Sediment Concentration Grab Samples Followed by Runoff Rate Measurements # Time Date: 4-Dec-09 Start Rain: 11:00 AM End Rain: 11:20 AM 1 11:03 Sampling interval: 0:03 End Runoff: 11:23 AM 2 11:06 Rain Time (min): Test Time (min): :09 Product: Lot #: Flexterra Ultra n/a Descr: lb/acre hydraulically applied mulch 4 11:12 Anchors: none Anchorage: none 5 11:15 TOP OF SLOPE 6 11:18 w c1 = 19.8% (circle "x" for open valves) Set valves to 10 psi. 7 d = 0.63 in x x X x 8 i = 1.89 in/hr P = 10 psi 9 A 10 x 11 X P = 10 psi B 12 x x 13 x C P = 10 psi X 14 x x 15 X P = 10 psi D x 12 x x 13 x E P = 10 psi X 14 x x 15 X P = 10 psi F x x x Runoff Rate Measurements Time to Collect 1 x G P = 10 psi x # Time Gallon, sec x X x P = 10 psi H x X x x I P = 10 psi x x X x P = 10 psi J X X 7 X 8 d = 0.87 in 9 i = 2.61 in/hr Temp. 65 deg 10 w c2 = 18.8% Hum. 90 % 11 d = 0.83 in 12 i = 2.49 in/hr Average Depth: 0.78 in. 13 w c3 = 20.8% Avg Rainfall Intensity: 2.33 in/hr 14 Notes: 0 mph breeze from the. Approx 20 gal collected

15 Slope #: 2 DDRF Rainfall Testing SLOPE #2 Target Rain: 4 in/hr Sediment Concentration Grab Samples Followed by Runoff Rate Measurements # Time Date: 4-Dec-09 Start Rain: 11:30 AM End Rain: 11:50 AM 1 11:32 Sampling interval: 0:02 End Runoff: 11:54 AM 2 11:34 Rain Time (min): Test Time (min): :36 Product: Flexterra Ultra Descr: lb/acre hydraulically applied mulch 4 11:38 Lot #: n/a Anchors: none Anchorage: none 5 11:40 TOP OF SLOPE Set valves to 10 psi. 6 11:42 w c1 = 19.8% X X x x 7 11:44 d = 1.33 in P = 10 psi 8 11:46 i = 3.99 in/hr A 9 11:48 X 10 11:50 X P = 10 psi B 11 x X 12 x C P = 10 psi X 13 X x 14 X P = 10 psi D x 15 x X 12 x E P = 10 psi X 13 x x 14 X P = 10 psi F x 15 X x x G P = 10 psi X Runoff Rate Measurements Time to Collect 1 x X # Time Gallon, sec x P = 10 psi H x X x X I P = 10 psi X x X X P = 10 psi J X X X d = 1.45 in i = 4.35 in/hr w c2 = 18.8% Temp. 68 deg d = 1.45 in Hum. 90 % 11 i = 4.35 in/hr 12 w c3 = 20.8% Average Depth: 1.41 in. 13 Avg Rainfall Intensity: 4.23 in/hr 14 Notes: 0 mph breeze. Approx. 120 gal collected

16 Slope #: 2 DDRF Rainfall Testing SLOPE #2 Target Rain: 6 in/hr Sediment Concentration Grab Samples Followed by Runoff Rate Measurements # Time Date: 4-Dec-09 Start Rain: 12:00 PM End Rain: 12:20 PM 1 12:02 Sampling interval: 0:02 End Runoff: 12:24 PM 2 12:04 Rain Time (min): Test Time (min): :06 Product: Lot #: Flexterra Ultra n/a Descr: lb/acre hydraulically applied mulch 4 12:08 Anchors: none Anchorage: none 5 12:10 TOP OF SLOPE 6 12:12 w c1 = 19.8% (circle "x" for open valves) Set valves to 10 psi. 7 12:14 d = 2.05 in X X X x 8 12:16 i = 6.15 in/hr P = 10 psi 9 12:18 A 10 12:20 X 11 X P = 10 psi B 12 X X 13 x C P = 10 psi X 14 X X 15 X P = 10 psi D x 12 X X 13 x E P = 10 psi X 14 X X 15 X P = 10 psi F x X x Runoff Rate Measurements Time to Collect 1 x G P = 10 psi X # Time Gallon, sec x X X P = 10 psi H X X X X I P = 10 psi X X X X P = 10 psi J X X X d = 2.20 in i = 6.60 in/hr Temp. 62 deg w c2 = 18.8% Hum. 90 % 11 d = 2.05 in 12 i = 6.15 in/hr Average Depth: 2.10 in. 13 w c3 = 20.8% Avg Rainfall Intensity: 6.30 in/hr 14 Notes: 0 mph breeze. Approx 305 gal collected

17 Slope #: 3 DDRF Rainfall Testing SLOPE #3 Target Rain: 2 in/hr Sediment Concentration Grab Samples Followed by Runoff Rate Measurements # Time Date: 4-Dec-09 Start Rain: 9:30 AM End Rain: 9:50 AM 1 9:33 Sampling interval: 0:03 End Runoff: 9:53 AM 2 9:36 Rain Time (min): Test Time (min): :39 Product: Lot #: Flexterra Ultra n/a Descr: lb/acre hydraulically applied mulch 4 9:42 Anchors: none Anchorage: none 5 9:45 TOP OF SLOPE 6 9:48 w c1 = 20.7% (circle "x" for open valves) Set valves to 10 psi. 7 d = 0.55 in x X x x 8 i = 1.65 in/hr P = 10 psi 9 A 10 x 11 B P = 10 psi X 12 x x 13 X P = 10 psi C x 14 x x 15 x D P = 10 psi X 12 x x 13 X P = 10 psi E x 14 x x 15 x F P = 10 psi X x x Runoff Rate Measurements Time to Collect 1 x P = 10 psi G x # Time Gallon, sec X x x H P = 10 psi x x X x P = 10 psi I x X x X J P = 10 psi x 6 X 7 X 8 d = 0.71 in 9 i = 2.13 in/hr * Temp. 62 deg 10 w c3 = 18.5% Hum. 45 % 11 d = 0.91 in 12 i = 2.73 in/hr Average Depth: 0.72 in. 13 w c2 = 23.0% Avg Rainfall Intensity: 2.17 in/hr 14 Notes: 0 mph breeze from the. Approx 20 gal collected. 15

18 Slope #: 3 DDRF Rainfall Testing SLOPE #3 Target Rain: 4 in/hr Sediment Concentration Grab Samples Followed by Runoff Rate Measurements # Time Date: 4-Dec-09 Start Rain: 10:00 AM End Rain: 10:20 AM 1 10:02 Sampling interval: 0:02 End Runoff: 10:23 AM 2 10:04 Rain Time (min): Test Time (min): :06 Product: Flexterra Ultra Descr: lb/acre hydraulically applied mulch 4 10:08 Lot #: n/a TOP OF SLOPE Anchors: none Anchorage: none 5 10:10 Set valves to 10 psi. 6 10:12 w c1 = 20.7% (circle "x" for open valves) 7 10:14 d = 1.38 in X X x x 8 10:16 i = 4.14 in/hr P = 10 psi 9 10:18 A 10 10:20 X 11 B P = 10 psi X 12 X x 13 X P = 10 psi C x 14 x X 15 x D P = 10 psi X 12 X x 13 X P = 10 psi E x 14 x X 15 x F P = 10 psi X x x Runoff Rate Measurements Time to Collect 1 x P = 10 psi G x # Time Gallon, sec X x X H P = 10 psi x x X X P = 10 psi I X X x X J P = 10 psi X X X d = 1.38 in i = 4.14 in/hr Temp. 61 deg w c3 = 18.5% Hum. 85 % 11 d = 1.42 in 12 i = 4.26 in/hr Average Depth: 1.39 in. 13 w c2 = 23.0% Avg Rainfall Intensity: 4.18 in/hr 14 Notes: 0 mph breeze. Approx 123 gal collected. 15

19 Slope #: 3 DDRF Rainfall Testing SLOPE #3 Target Rain: 6 in/hr Sediment Concentration Grab Samples Followed by Runoff Rate Measurements # Time Date: 4-Dec-09 Start Rain: 10:30 AM End Rain: 10:50 AM 1 10:32 Sampling interval: 0:02 End Runoff: 10:55 AM 2 10:34 Rain Time (min): Test Time (min): :36 Product: Lot #: Flexterra Ultra n/a Descr: lb/acre hydraulically applied mulch 4 10:38 Anchors: none Anchorage: none 5 10:40 TOP OF SLOPE 6 10:42 w c1 = 20.7% (circle "x" for open valves) 7 10:44 d = 2.05 in X X X x Set valves to 11 psi. 8 10:46 i = 6.15 in/hr P = 10 psi 9 10:48 A 10 10:50 X 11 B P = 10 psi X 12 X X 13 X P = 10 psi C x 14 X X 15 x D P = 10 psi X 12 X X 13 X P = 10 psi E x 14 X X 15 x F P = 10 psi X x X Runoff Rate Measurements Time to Collect 1 X P = 10 psi G x # Time Gallon, sec X x X H P = 10 psi X X X X P = 10 psi I X X X X J P = 10 psi X X X d = 2.05 in i = 6.15 in/hr Temp. 59 deg w c3 = 18.5% Hum. 90 % 11 d = 2.09 in 12 i = 6.27 in/hr Average Depth: 2.06 in. 13 w c2 = 23.0% Avg Rainfall Intensity: 6.19 in/hr 14 Notes: 0 mph breeze. Approx 315 gal collected

20 Sample Number 2.12 in/hr avg Test Time, minutes Total Decanted Weight, g Weight, g Dry Weight, g Slope #1 - Sediment Concentration Bottle Weight, g Dry Sediment Weight, mg Total Collected Water Wt., g Total Collected Volume of Water, l Sediment Concentration, mg/l Runoff Sampling Time Time to Collect 1 gal Associated Runoff, gal Associated Sediment Conc, mg/l 4-Dec Associated Solids Loss, lbs AVG = in/hr avg 0.00 Total Solids Lost: Dec AVG = in/hr avg Total Solids Lost: Dec AVG = Total Solids Lost: Solids Loss Prior to Failure, lbs

21 Slope #2 - Sediment Concentration Sample Number 2.33 in/hr avg Test Time, minutes Total Decanted Weight, g Weight, g Dry Weight, g Bottle Weight, g Dry Sediment Weight, mg Total Collected Water Wt., g Total Collected Volume of Water, l Sediment Concentration, mg/l Runoff Sampling Time Time to Collect 1 gal Associated Runoff, gal Associated Sediment Conc, mg/l 4-Dec Associated Solids Loss, lbs AVG = in/hr avg Total Solids Lost: Dec AVG = in/hr avg Total Solids Lost: Dec AVG = Total Solids Lost: 0.72 Solids Loss Prior to Failure, lbs

22 Slope #3 - Sediment Concentration Sample Number 2.17 in/hr avg Test Time, minutes Total Decanted Weight, g Weight, g Dry Weight, g Bottle Weight, g Dry Sediment Weight, mg Total Collected Water Wt., g Total Collected Volume of Water, l Sediment Concentration, mg/l Runoff Sampling Time Time to Collect 1 gal Associated Runoff, gal Associated Sediment Conc, mg/l 4-Dec Associated Solids Loss, lbs AVG = in/hr avg Total Solids Lost: Dec AVG = in/hr avg Total Solids Lost: Dec AVG = Total Solids Lost: 0.27 Solids Loss Prior to Failure, lbs

23 4-Dec-09 Slope #1 Sample Number Test Time, minutes Time per Gallon, sec Interval Time, min Total Time, min Collection Mid-Time, min Runoff Rate, gal/min Associated Runoff, gal Cumulative Runoff, gal 2.12 in/hr end Total Collected Runoff (approx) 4.16 in/hr end Total Collected Runoff (approx) 6.02 in/hr end Total Collected Runoff (approx)

24 4-Dec-09 Slope #2 Sample Number Test Time, minutes Time per Gallon, sec Interval Time, min Total Time, min Collection Mid-Time, min Runoff Rate, gal/min Associated Runoff, gal Cumulative Runoff, gal 2.33 in/hr end Total Collected Runoff (approx) 4.23 in/hr end Total Collected Runoff (approx) 6.30 in/hr end Total Collected Runoff (approx)

25 4-Dec-09 Slope #3 Sample Number Test Time, minutes Time per Gallon, sec Interval Time, min Total Time, min Collection Mid-Time, min Runoff Rate, gal/min Associated Runoff, gal Cumulative Runoff, gal 2.17 in/hr end Total Collected Runoff (approx) 4.18 in/hr end Total Collected Runoff (approx) 6.19 in/hr end Total Collected Runoff (approx)

26 WATER CONTENT DETERMINATION Run #: Slope No. SLOPE #1 SLOPE #2 SLOPE #3 Test Date: 4-Dec-09 4-Dec-09 4-Dec-09 Avg Moisture Content: 20.57% 19.80% 20.74% Location T-1 T-2 T-3 Wt. Of cup + wet soil, g Wt. Of cup + dry soil, g Wt. Of cup, g Wt. Of dry soil, g Wt. Of water, g Water Content, w% 22.1% 19.8% 20.7% Location M-1 M-2 M-3 Wt. Of cup + wet soil, g Wt. Of cup + dry soil, g Wt. Of cup, g Wt. Of dry soil, g Wt. Of water, g Water Content, w% 19.6% 18.8% 18.5% Location B-1 B-2 B-3 Wt. Of cup + wet soil, g Wt. Of cup + dry soil, g Wt. Of cup, g Wt. Of dry soil, g Wt. Of water, g Water Content, w% 20.0% 20.8% 23.0%

27 SLOPE #1 - Sediment Weights Total Dry Sediments: in/hr Collected Typ. TSS in Wt. Of pan + wet soil, lb Decanted Wt. Of pan + dry soil, lb 0 Collected Runoff, lb/gal Wt. Of pan, lb 0 Wt. Of dry soil, lb Wt. Of water, lb Water Content, w% #DIV/0! Total Wet Sediments, lb - Collected Sediments, gal % dry solids Dry Collected Sediments, lbs Total Dry Sediments: in/hr Collected Typ. TSS in Wt. Of pan + wet soil, lb Decanted Wt. Of pan + dry soil, lb 0 Collected Runoff, lb/gal Wt. Of pan, lb 0 Wt. Of dry soil, lb Wt. Of water, lb Water Content, w% #DIV/0! Total Wet Sediments, lb - Collected Sediments, gal % dry solids Dry Collected Sediments, lbs Total Dry Sediments: in/hr Collected Typ. TSS in Wt. Of pan + wet soil, lb Decanted Wt. Of pan + dry soil, lb 68.6 Collected Runoff, lb/gal Wt. Of pan, lb 1.2 Wt. Of dry soil, lb Wt. Of water, lb Water Content, w% 0.0 Total Wet Sediments, lb - Collected Sediments, gal % dry solids Dry Collected Sediments, lbs Add'l Soil Collected after Major Slumping at 8:30 Not Measured

28 SLOPE #2 - Sediment Weights Total Dry Sediments: in/hr Collected Typ. TSS in Wt. Of pan + wet soil, lb Decanted Wt. Of pan + dry soil, lb 0 Collected Runoff, lb/gal Wt. Of pan, lb 0 Wt. Of dry soil, lb Wt. Of water, lb Water Content, w% #DIV/0! Total Wet Sediments, lb - Collected Sediments, gal % dry solids Dry Collected Sediments, lbs Total Dry Sediments: in/hr Collected Typ. TSS in Wt. Of pan + wet soil, lb Decanted Wt. Of pan + dry soil, lb 0 Collected Runoff, lb/gal Wt. Of pan, lb 0 Wt. Of dry soil, lb Wt. Of water, lb Water Content, w% #DIV/0! Total Wet Sediments, lb - Collected Sediments, gal % dry solids Dry Collected Sediments, lbs Total Dry Sediments: in/hr Collected Typ. TSS in Wt. Of pan + wet soil, lb Decanted Wt. Of pan + dry soil, lb 0 Collected Runoff, lb/gal Wt. Of pan, lb 0 Wt. Of dry soil, lb Wt. Of water, lb Water Content, w% #DIV/0! Total Wet Sediments, lb - % dry solids Dry Collected Sediments, lbs Add'l Soil Collected after Major Slumping at 5:00 Collected Sediments, gal Not Measured

29 SLOPE #3 - Sediment Weights Total Dry Sediments: in/hr Collected Typ. TSS in Wt. Of pan + wet soil, lb Decanted Wt. Of pan + dry soil, lb 0 Collected Runoff, lb/gal Wt. Of pan, lb 0 Wt. Of dry soil, lb Wt. Of water, lb Water Content, w% #DIV/0! Total Wet Sediments, lb - Collected Sediments, gal % dry solids Dry Collected Sediments, lbs Total Dry Sediments: in/hr Collected Typ. TSS in Wt. Of pan + wet soil, lb Decanted Wt. Of pan + dry soil, lb 0 Collected Runoff, lb/gal Wt. Of pan, lb 0 Wt. Of dry soil, lb Wt. Of water, lb Water Content, w% #DIV/0! Total Wet Sediments, lb - Collected Sediments, gal % dry solids Dry Collected Sediments, lbs Total Dry Sediments: in/hr Collected Typ. TSS in Wt. Of pan + wet soil, lb Decanted Wt. Of pan + dry soil, lb 0 Collected Runoff, lb/gal Wt. Of pan, lb 0 Wt. Of dry soil, lb Wt. Of water, lb Water Content, w% #DIV/0! Total Wet Sediments, lb - Collected Sediments, gal % dry solids Dry Collected Sediments, lbs No Major Slumping

30 Flexterra Ultra HECP over Sandy Loam - Slope Erosion Testing for NTPEP December 31, 2009 Appendix APPENDIX B TEST SOIL Test Soil Grain Size Distribution Curve Compaction Curves Veneer Soil Compaction Verification

31 November ASTM D 6459 Target Loam Plasticity (ASTM D 4318) Liquid Limit: 41 Plastic Limit: 33 Plastic Index: 8 Soil classifies as a sandy silty clay (ML-CL) in accordance with ASTM D 2487 Percent Finer DDRF ASTM D 6459 Blended Test Soil Particle Size (mm)

32 November 2009 Proctor Compaction Test 130 Sample No.: DDRF Blended Test Soil 125 Test Method: ASTM D Method A Maximum Dry Density (pcf): Dry Density (pcf) Optimum Moisture Content (%): Moisture Content (%)

33 Compaction Worksheet ASTM D 1556 Calibration Date: 8/16/2009 Sand Used: Pool Filter Sand Volume Measure: Liquid Volume, V m (cm 3 ): 425 Wt. of Sand to Fill Known Volume: Total Wt (g) Pan Wt (g) Net Wt (g) Trial #1 (g) Trial #2 (g) Trial #3 (g) W a (g) Density of Sand, ɣ sand (g/cm 3 ) = W a / V m = 1.53 Wt. of Sand to Fill Cone: Total Wt (g) Cone Wt (g) Net Wt (g) Trial #1 (g) Trial #2 (g) Trial #3 (g) Wt. of Sand in Cone (g): Field Data Date: 11/4/2009 Soil Data: Wt. of Wet Soil + Pan (g) Wt. of Dry Soil + Pan (g) Wt. of Pan (g) 14.5 Wt. of Wet Soil, W' (g) Wt. of Dry Soil (g) Wt. of Water (g) Water Content, w (%) Volume Data: Sand Used: Pool Filter Sand Unit Wt. of Sand, ɣ sand (g/cm 3 ) = 1.53 Wt. of Jug & Cone Before (g) = Wt. of Jug & Cone After (g) = Wt. of Sand Used (g) = Wt. of Sand in Cone (g) = Wt. of Sand in Hole, W (g) = Volume of hole, V h (cm 3 ) = W / ɣ sand = Density Calculation: Wet density, ɣ wet = W' / V h (kn/m 3 ) = 1.83 Wet density, ɣ wet = W' / V h (lb/ft 3 ) = Dry density, ɣ dry = ɣ wet / [1 + w] (kn/m 3 ) = 1.54 Wet density, ɣ wet = W' / V h (lb/ft 3 ) = Max Std. Proctor Dry density (kn/m 3 ) = Opt. Moisture via Std. Proctor density (%) = Compaction as % of Std. Proctor = 92.3%

34 Flexterra Ultra HECP over Sandy Loam - Slope Erosion Testing for NTPEP December 31, 2009 Appendix APPENDIX C RAINFALL DATA Raindrop Size Distribution Rainfall Calibration

35 50.00 Raindrop Size Distribution July % of Raindrops by Mass mm mm mm mm mm Rainfall Intensity, in/hr

36 TRI/Environmental, Inc. A Texas Research International Comp DDRF Rainfall Calibration Slope 1: 2 in/hr Rainfall (target) Date: 22-Jul-09 Start Time: 3:00 PM End Time: 3:15 PM Test Time: min. (circle "x" for open valves) TOP OF SLOPE x x X x P = 10 psi A x d = 0.25 in 1 2 d = in X P = 10 psi i = 1.00 in/hr B i = 1.50 in/hr x d = 0.5 in 3 4 d = 0.5 in x x i = 2.00 in/hr C i = 2.00 in/hr P = 10 psi X x d = 0.5 in 5 6 d = 0.5 in x X P = 10 psi i = 2.00 in/hr D i = 2.00 in/hr x x d = 0.45 in 7 8 d = 0.55 in x x i = 1.80 in/hr E i = 2.20 in/hr P = 10 psi x x d = 0.5 in 9 10 d = 0.5 in X X P = 10 psi i = 2.00 in/hr F i = 2.00 in/hr x x d = 0.5 in d = 0.5 in x x i = 2.00 in/hr G i = 2.00 in/hr P = 10 psi x x d = 0.55 in d = 0.5 in X xp = 10 psi i = 2.20 in/hr H i = 2.00 in/hr x X d = 0.5 in d = 0.5 in x x i = 2.00 in/hr I i = 2.00 in/hr P = 10 psi x x d = in d = 0.5 in X xp = 10 psi i = 2.50 in/hr J i = 2.00 in/hr X X d = 0.25 in d = 0.5 in X i = 1.00 in/hr i = 2.00 in/hr Approx. Bottom Catch: 95 gal Average Wind: 0 mph Average Depth: 0.48 in. Average Rainfall Intensity: 1.91 in/hr Christiansen Uniformity Coefficient: 88

37 TRI/Environmental, Inc. A Texas Research International Com DDRF Rainfall Calibration Slope 1: 4 in/hr Rainfall (target) Date: 22-Jul-09 Start Time: 4:00 PM End Time: 4:15 PM Test Time: min. (circle "x" for open valves) TOP OF SLOPE x x X X P = 10 psi A X d = in 1 2 d = 1.00 in X P = 10 psi i = 3.50 in/hr B i = 4.00 in/hr x d = 1.00 in 3 4 d = 1.00 in X x i = 4.00 in/hr C i = 4.00 in/hr P = 10 psi X X d = 1.00 in 5 6 d = 1.00 in x X P = 10 psi i = 4.00 in/hr D i = 4.00 in/hr x x d = 1.25 in 7 8 d = 1.00 in X x i = 5.00 in/hr E i = 4.00 in/hr P = 10 psi X x d = 1.25 in 9 10 d = 1.00 in x x P = 10 psi i = 5.00 in/hr F i = 4.00 in/hr x X d = 1.25 in d = in x X i = 5.00 in/hr G i = 3.50 in/hr P = 10 psi x x d = in d = 1.00 in X x P = 10 psi i = 4.50 in/hr H i = 4.00 in/hr X X d = 0.75 in d = 1.00 in x X i = 3.00 in/hr I i = 4.00 in/hr P = 10 psi X x d = 0.75 in d = in X X P = 10 psi i = 3.00 in/hr J i = 3.50 in/hr X X d = 0.5 in d = in X i = 2.00 in/hr i = 3.50 in/hr Approx. Bottom Catch: 190 gal Average Wind: 0 mph Average Depth: 0.97 in. Average Rainfall Intensity: 3.88 in/hr Christiansen Uniformity Coefficient: 87

38 TRI/Environmental, Inc. A Texas Research International Com DDRF Rainfall Calibration Slope 1: 6 in/hr Rainfall (target) Date: 22-Jul-09 Start Time: 5:00 PM End Time: 5:15 PM Test Time: min. (circle "x" for open valves) TOP OF SLOPE x X X X P = 10 psi A X d = 1.25 in 1 2 d = 1.4 in X P = 10 psi i = 5.00 in/hr B i = 5.60 in/hr X d = 1.5 in 3 4 d = in X x i = 6.00 in/hr C i = 5.50 in/hr P = 10 psi X X d = 1.75 in 5 6 d = 1.4 in X X P = 10 psi i = 7.00 in/hr D i = 5.60 in/hr x X d = 1.65 in 7 8 d = 1.45 in X x i = 6.60 in/hr E i = 5.80 in/hr P = 10 psi X X d = in 9 10 d = 1.55 in X X P = 10 psi i = 7.50 in/hr F i = 6.20 in/hr x X d = 1.75 in d = in x x i = 7.00 in/hr G i = 4.50 in/hr P = 10 psi X x d = 1.65 in d = 2.00 in X X P = 10 psi i = 6.60 in/hr H i = 8.00 in/hr X X d = 1.45 in d = 1.5 in X X i = 5.80 in/hr I i = 6.00 in/hr P = 10 psi X X d = 1.35 in d = 1.5 in X X P = 10 psi i = 5.40 in/hr J i = 6.00 in/hr X X d = in d = 1.25 in X i = 3.50 in/hr i = 5.00 in/hr Approx. Bottom Catch: 290 gal Average Wind: 0 mph Average Depth: 1.48 in. Average Rainfall Intensity: 5.93 in/hr Christiansen Uniformity Coefficient: 87

39 TRI/Environmental, Inc. A Texas Research International Com DDRF Rainfall Calibration Slope 2: 2 in/hr Rainfall (target) Date: 22-Jul-09 Start Time: 6:00 PM End Time: 6:15 PM Test Time: min. (circle "x" for open valves) TOP OF SLOPE x x X x P = 10 psi A d = 0.5 in 1 2 d = 0.5 in x i = 2.00 in/hr B i = 2.00 in/hr P = 10 psi X x d = 0.55 in 3 4 d = 0.75 in x X P = 10 psi i = 2.20 in/hr C i = 3.00 in/hr x x d = 0.55 in 5 6 d = 0.65 in x x i = 2.20 in/hr D i = 2.60 in/hr P = 10 psi X x d = 0.5 in 7 8 d = 0.55 in x X P = 10 psi i = 2.00 in/hr E i = 2.20 in/hr x x d = 0.5 in 9 10 d = 0.5 in x x i = 2.00 in/hr F i = 2.00 in/hr P = 10 psi x x d = 0.5 in d = 0.5 in X x P = 10 psi i = 2.00 in/hr G i = 2.00 in/hr x X d = 0.5 in d = 0.5 in x x i = 2.00 in/hr H i = 2.00 in/hr P = 10 psi x x d = 0.5 in d = 0.5 in X x P = 10 psi i = 2.00 in/hr I i = 2.00 in/hr x X d = 0.45 in d = 0.5 in x X i = 1.80 in/hr J i = 2.00 in/hr P = 10 psi x d = 0.5 in d = 0.5 in X i = 2.00 in/hr i = 2.00 in/hr X Approx. Bottom Catch: 105 gal Average Wind: 0 mph Average Depth: in. Average Rainfall Intensity: 2.1 in/hr Christiansen Uniformity Coefficient: 92

40 TRI/Environmental, Inc. A Texas Research International Com DDRF Rainfall Calibration Slope 2: 4 in/hr Rainfall (target) Date: 22-Jul-09 Start Time: 6:30 PM End Time: 6:45 PM Test Time: min. (circle "x" for open valves) TOP OF SLOPE x x X X P = 10 psi A d = 0.95 in 1 2 d = 0.95 in X i = 3.80 in/hr B i = 3.80 in/hr P = 10 psi X X d = 1 in 3 4 d = 1.5 in x X P = 10 psi i = 4.00 in/hr C i = 6.00 in/hr x x d = 1 in 5 6 d = 1.25 in X x i = 4.00 in/hr D i = 5.00 in/hr P = 10 psi X X d = 1 in 7 8 d = 1 in x X P = 10 psi i = 4.00 in/hr E i = 4.00 in/hr x x d = in 9 10 d = 1 in x x i = 4.50 in/hr F i = 4.00 in/hr P = 10 psi x x d = in d = 1 in X x P = 10 psi i = 4.50 in/hr G i = 4.00 in/hr X X d = 1 in d = in x X i = 4.00 in/hr H i = 4.50 in/hr P = 10 psi x x d = 1 in d = 1 in X X P = 10 psi i = 4.00 in/hr I i = 4.00 in/hr X X d = 0.95 in d = 1 in x X i = 3.80 in/hr J i = 4.00 in/hr P = 10 psi X d = 0.95 in d = 0.75 in X i = 3.80 in/hr i = 3.00 in/hr X Approx. Bottom Catch: 205 gal Average Wind: 0 mph Average Depth: in. Average Rainfall Intensity: in/hr Christiansen Uniformity Coefficient: 91

41 TRI/Environmental, Inc. A Texas Research International Com DDRF Rainfall Calibration Slope 2: 6 in/hr Rainfall (target) Date: 22-Jul-09 Start Time: 7:00 PM End Time: 7:15 PM Test Time: min. (circle "x" for open valves) TOP OF SLOPE x X X X P = 10 psi A d = 1.5 in 1 2 d = in X i = 6.00 in/hr B i = 5.50 in/hr P = 10 psi X X d = 1.55 in 3 4 d = in X X P = 10 psi i = 6.20 in/hr C i = 8.50 in/hr x X d = 1.75 in 5 6 d = 2 in X x i = 7.00 in/hr D i = 8.00 in/hr P = 10 psi X X d = in 7 8 d = in X X P = 10 psi i = 7.50 in/hr E i = 5.50 in/hr x X d = 1.5 in 9 10 d = 1.5 in x x i = 6.00 in/hr F i = 6.00 in/hr P = 10 psi X x d = 1.55 in d = 1.5 in X X P = 10 psi i = 6.20 in/hr G i = 6.00 in/hr X X d = 1.5 in d = 1.5 in x X i = 6.00 in/hr H i = 6.00 in/hr P = 10 psi X X d = 1.5 in d = 1.5 in X X P = 10 psi i = 6.00 in/hr I i = 6.00 in/hr X X d = 1.45 in d = 1.5 in X X i = 5.80 in/hr J i = 6.00 in/hr P = 10 psi X d = 1.25 in d = 1.00 in X i = 5.00 in/hr i = 4.00 in/hr X Approx. Bottom Catch: 305 gal Average Wind: 0 mph Average Depth: 1.54 in. Average Rainfall Intensity: 6.16 in/hr Christiansen Uniformity Coefficient: 90