DESIGN MATRICES FOR EROSION CONTROL BLANKETS FOR MISSOURI HYDROLOGY AND GEOLOGY

Transcription

1 0 0 0 DESIGN MATRICES FOR EROSION CONTROL BLANKETS FOR MISSOURI HYDROLOGY AND GEOLOGY Amanda L. Cox, P.E., Corresponding Author Department of Civil Engineering, Saint Louis University 0 Lindell Boulevard, St. Louis, MO 0 Tel: -- Fax: --; coxal@slu.edu Danny Sommer Department of Civil Engineering, Saint Louis University 0 Lindell Boulevard, St. Louis, MO 0 Tel: --0 Fax: --; sommerdt@slu.edu Ronaldo Luna, P.E. Department of Civil Engineering, Saint Louis University 0 Lindell Boulevard, St. Louis, MO 0 Tel: -- Fax: --; rluna@slu.edu Eric Kopinski Missouri Department of Transportation 0 W. Capitol Avenue, Jefferson City, MO 0 Tel: --0; Eric.Kopinski@modot.mo.gov Word count:, words text + tables/figures x 0 words (each) =, words November, 0

2 Cox, Sommer, Luna, Kopinski 0 0 ABSTRACT To meet federal compliances with the Clean Water Act, erosion control blankets (ECB) are commonly installed on construction sites to control stormwater erosion and assist with reestablishing vegetation following land disturbances along highways. A research project was conducted for the Missouri Department of Transportation (MoDOT) to develop ECB guidelines for slope applications. An ECB design process for conditions representative of Missouri was developed using insight gained through an extensive literature review and the study of common ECB product acceptance and design guidelines. The Revised Universal Soil Loss Equation (RUSLE) was used as the foundation for the ECB design process and minimum performance requirements were established from existing literature. Extensive geologic information was used with ArcGIS to develop a digital map of erodibility for the state of Missouri. Erosivity maps were also developed for Missouri using ArcGIS and a map of the product of erodibility and erosivity was developed. Average values of this product for the different physiographic regions of Missouri were used to develop ECB design matrices. The development of the design matrices accounted for the complexity of ECBs typically being part of a larger stormwater erosion prevention plan. Keywords: Erosion Control Blankets, Stormwater Erosion, Best Management Practices

3 Cox, Sommer, Luna, Kopinski INTRODUCTION Stormwater erosion can produce unstable slopes, inadequate areas for vegetation growth, and pollutants, which may restrict watershed ecology (). During storm events, kinetic energy from rainfall and sheet flow can cause erosion making exposed soil surfaces on slopes particularly susceptible to erosion (). The Clean Water Act (CWA) requires the reduction of pollutants and illicit discharge into the waters of the United States. The Environmental Protection Agency (EPA) mandates states to establish regulations and laws to show compliance to the CWA (). The Missouri Department of Natural Resources (MoDNR) develops these regulations and issues state operating permits for infrastructure and transportation projects for Missouri. MoDOT adheres to the permit requirements including developing a Storm Water Pollution Prevention Plan (SWPPP) for the reduction of pollution which discharges from construction sites (). The SWPPP details best management practices (BMP) to reduce pollution generated from stormwater runoff. Without adequate mitigation, stormwater erosion can result in maintenance and cost issues for overall slope stability and noncompliance to the CWA federal law. A common practice for erosion control is the installation of erosion control blankets (ECBs), which are a type of rolled erosion control product (RECP) comprised of a fiber matrix made of materials such as straw, excelsior, jute, or coconut fiber threaded together by either a photodegradable or biodegradable netting (). Intended to degrade over time, ECBs act as a buffer between stormwater runoff and soil until vegetation is established (). The blanket also promotes growth of vegetation. These multifunctional components make ECBs a popular choice for slope protection (). Appropriate selection of ECBs is critical to their performance in reducing erosion. Slope applications vary by steepness, soil type, and local hydrology. Erosion control performance for a given ECB will vary depending on the site conditions (soil, rainfall intensities, etc.) and standardized performance testing is vital to delineate appropriate applications and limitations of an ECB (). Currently, RECP product approval on MoDOT construction sites references the TxDOT approved products list as its own from its Standard Specifications for Highway Construction (). Additionally, MoDOT does not accept the NTPEP large-scale testing or index tests. MoDOT has further requirements for the applications of ECBs in the Standard Specifications for Highway Construction, in which slope protection applications of ECBs are specified as Table. TABLE Erosion control blanket requirements from MoDOT Standard Specifications for Highway Construction () ECB Type Netting Type Service Life Slope (ft/ft) Type Single, quickly degradable -0 days : or flatter Clay Soil Type Type Single photodegradable months : or flatter Sandy Type Double photodegradable - months : or flatter Clay Type Double photodegradable months : or flatter Sandy Type Double photodegradable months : or flatter Any

4 Cox, Sommer, Luna, Kopinski The current method for ECB specification considers only the ECB performance over clay and sand soil types and does not account for state-specific rainfall conditions. The objective for this research was to create design guidelines for appropriate ECB selection for slope applications on MoDOT construction sites. REGIONAL STATE PROCEDURES FOR ECB APPROVAL State procedures for ECB approval and specifications for six state departments of transportation were investigated to assess their approach to ECB guidelines. The states investigated were: Texas, Kansas, Wisconsin, Nebraska, Iowa, and Illinois. These states were chosen because of their proximity to Missouri. MoDOT s acceptance and specification procedures were also noted to compare and observe similarities to the other agencies. Determining acceptable performance values from standardized testing for design is dictated by the intended application. For many departments of transportation, earning acceptance onto an approved products list is required for a certain product to be used for a particular slope and soil type (, 0,, and ). The requirements depend on the state s climate for field performance and practical quality assurance checks from index test results. Several states utilize the Revised Universal Soil Loss Equation (RUSLE) in determining the appropriate ECB for specified slope conditions including slope, soil type, and required service life (e.g. Wisconsin, Nebraska, and Iowa). The RUSLE is an empirical approach for estimating the projected long-term erosion a particular slope may experience for a given soil type, hydrology, slope geometry, land usage, and land coverage (). The RUSLE is an expansion of the Universal Soil Loss Equation (USLE) offering more precision in soil loss estimates (). The RUSLE is presented in Equation where the estimated annual soil loss (A) (tons acre) is equivalent to the product of the rainfall erosivity coefficient (R) ((00ft-tonf in) (acre hr)), the soil erodibility factor (K) (ton acre hr) (00acres ft-tonf in)), the length-slope coefficient (LS), the coverage factor (C), and the practice factor (P). A K R LS C P () The estimated annual soil loss (A) from the ECB is compared to a tolerable annual soil loss which is the maximum amount of soil loss without compromising the land for economical use (). The local hydrology is factored into the equation as the rainfall ultimately induces the erosion, denoted as a rainfall erosivity coefficient (R) (). The soil erodibility factor (K) characterizes the soil s susceptibility for particles to dislodge and transport during storm and rainfall events (). The Agriculture Handbook () empirically determined various soil erodibility factors by soil texture class, organic content, soil structure, and permeability for a.-ft, % slope. The length-slope factor (LS) includes the effect of the steepness and length of slope. The LS factor is computed by Equation for slopes larger than % commonly found on highway construction sites (): N L LS.sin 0.0 (). where θ is the slope angle; and L is the slope length (ft). The constant N is dependent on the steepness of the slope and the RUSLE defines the length slope exponent N by Equation :

5 Cox, Sommer, Luna, Kopinski N () where β is the ratio of rill erosion to inter-rill erosion () which can be determined by using the Equation : sin 0.0 ().0 sin The additional calculations and development involved with the RUSLE constant N is intended to assess steeper slopes typically found on construction projects. However, Lui et al. () found that the RUSLE s theoretical approach overestimates the soil erosion expected on slopes steeper than 0% gradient. Their results show that the USLE s N constant for slopes larger than % of 0. is a more reliable approximation for slopes steeper than 0%. The coverage factor (C) is a coefficient determined by the ASTM D large-scale test (). Because factors such as erodibility of the soil and the hydrology of the region cannot be altered, the selection of an appropriate ECB is critical and often the only parameter which can be controlled for erosion prevention (). For bare-fallow conditions, the C-factor is idealized as.0 (). Highway embankments are often compacted for geotechnical stability, and bare soil conditions of the slope are not considered bare-fallow. Toy et al. (0) recommend a C-factor of 0. for bare soil conditions of compacted soils appropriate for conditions of highway embankments. Land usage and landscape structures such as terracing contribute to the practice factor (P) in the RUSLE. The practice factor is mainly influenced by agricultural techniques and in construction applications (P) is idealized as.0 (). Many construction projects use best management practices to supplement one another () to optimize erosion and sediment control. ECBs are usually supplemented by various BMPs which can be theorized as porous barriers (). Porous barriers have an efficiency in trapping sediment, and the efficiency takes on the practice factor in the RUSLE calculation. Common BMPs and their practice factors are summarized in Table. TABLE Typical practice factors, which can range from zero to one, for common construction best management practices () Porous Barrier Practice Factor Straw Bales 0. Gravel Filters 0. Silt Fences 0. Sediment Basins 0. ERODIBILITY ANALYSIS FOR MISSOURI GEOLOGY The large-scale testing of the TxDOT utilizes various soil conditions to estimate field performance of ECBs (); and some ECBs are only acceptable to be used on certain soil conditions (). The geology of the State of Missouri was investigated to identify common soil characteristics at MoDOT construction sites. The following section describes the process of formulating soil erodibility values (K-values) for use in the RUSLE. The K-values were developed from a MoDNR surficial soil layer map () and information on different soil types in the Geology and Soils

6 Cox, Sommer, Luna, Kopinski Manual (). The K-value determination procedure is outlined in Figure. The K-value analysis utilized ArcGIS in conjunction with geographic soil data layers published by MoDNR (). The map legend described the surficial layers so that appropriate connections to the soil information in the Geology and Soils Manual () could be made. The surficial layers show Missouri to contain the following: alluvium, loess, glacial drift, residuum, bedrock, and surface water.

7 Cox, Sommer, Luna, Kopinski Soil name from manual Determine geographical location from manual description Potential MoDNR surficial map soils Match the parent material/minerals described by the MoDNR map legend Determine if more than one phase of the soil occurs Soil textures If more than one phase occurs, develop all relevant soil textures for each, as listed in the soil manual for each horizon If only one phase occurs, then record all relevant soil texture for that phase for each horizon Soil textures Also include soil textures from corresponding MoDNR map legend to differentiate the two soil phases Separate soil textures Take average of each K-value range from TxDOT report to determine average K-values for each soil texture in a horizon Take average of each K- value range from TxDOT report to determine average K-values for each soil texture in a horizon Soil Texture K-values Calculate any necessary adjustments in the K-value including rock content, organic content, soil structure, and soil permeability Final K-value for soil region FIGURE Flow chart for calculating soil erodibility factors (K) from soil characteristics. Different soil types listed by the MoDNR surficial map have a range of soil textures classified by USDA convention (). The MoDNR surficial map lists the entire range of soil textures for a soil type listed; however, these texture ranges are not region specific. The soil type observed in a particular location may contain only a portion of the soil textures that the description implies.

8 Cox, Sommer, Luna, Kopinski 0 Soils are classified mainly on parent rock material, mineral composition, color, and age of deposition. A more site-specific analysis is necessary to determine more representative soil textures found within a particular location. The Geology and Soils Manual describes specific locations of certain soil textures (). The manual divides Missouri into five physiographic regions: the Ozarks, Western Plains, Glacial Plains, St. Francois Mountains, and the Southeast Missouri Lowlands (Figure ). Each region classifies the soils within the region as alluvial, residual, glacial till, or loess, similar to the classification convention used by the MoDNR surficial map. Names for soils and different soil phases in each region are delineated by soil texture, plasticity, maximum compaction density, silt and clay content, color, and mineral composition. The location of the soil within the physiographic region is also stated allowing for determination of specific soil textures within areas of a soil type. 0 FIGURE Physiographic map of Missouri (). Following the location of soil textures, regional soil erodibility values (K-values) were determined for use in the RUSLE. The Geology and Soils Manual () describes each soil type as several horizons above the bedrock. Each horizon is characterized as a range of soil textures typically encountered. Each also describes important soil traits such as rock and chert content, organic content, permeability, and grain angularity, all contributing factors to developing a K-value for a soil (). For the analysis, the first two horizons were evaluated to determine a K-value for a region. Each horizon has varying thicknesses caused by local topography, erosion, and construction activities. The third horizon, which was not considered, is defined as partially weathered () and lies above the parent bedrock material. The location illustrates the lack of opportunity to experience erosion. The soil properties provided in the manual were compared to the soil features

9 Cox, Sommer, Luna, Kopinski 0 provided by the MoDNR surficial map such as color, parent material, and location. Sommer et al. () provides an example of this calculation for a region s soil erodibility. Erickson () combined the graphical form of the USDA classification with soil erosion to create the Soil Erodibility Triangular Nomograph (Figure ), which aids in the selection of an erodibility factor for any grain size distribution of soil. As illustrated by Figure, erodibility values range from approximately 0.0 to 0. and are dependent on the percentage of sand, silt, and clay in a soil. The graph assumes % overall organic matter content and 0-% rock content. The nomograph is a baseline for erodibility and adjustments for organic content, soil structure, permeability, and rock content can be applied as necessary to determine a representative K-value for a given soil (0). 0 FIGURE Soil erodibility (K-value) triangular nomograph (). The average K-value range for a soil texture was used in the K-value analysis of Missouri to encompass all grain-size compositions of a soil texture. Deductions or additions were addressed based on the appropriate characteristics noted about the horizon. The K-value arithmetic mean of the horizon was calculated and the two horizons were averaged together to determine the final erodibility for the region. Specific K-values for each soil type in the Geology and Soils Manual are identified by Sommer et al. (). Each soil polygon on the MoDNR surficial map was assigned the appropriate K-value. Some soils shown in the MoDNR surficial map encompass a large area and the soil represented in the shape could consist of more than one which was identified in the soils manual. An arithmetic average was taken to account for both soils within these shapes. The K-value map generated from the analysis is shown in Figure which encompasses a range from zero (corresponding to bedrock and bodies of water) to 0..

10 Cox, Sommer, Luna, Kopinski 0 0 FIGURE Missouri soil erodibility map. RECOMMENDATIONS FOR ECB DESIGN SPECIFICATIONS A design approach was developed for ECB specification based on the RUSLE. Site conditions, type of establishment (temporary or permanent), and local geology and hydrology dictate the type of ECB to be used. The recommended design procedure applies the RUSLE in conjunction with ECB C-factors, soil erodibility (K), and rainfall erosivity (R) to estimate an annual soil loss for a given application. To determine erosion control adequacy, the calculated soil loss is commonly compared to a threshold soil loss described as the maximum soil loss without compromising the vegetative growth potential of the land. Ports and Smith () recommend tons/acre annual loss as the maximum threshold for construction sites.

11 Cox, Sommer, Luna, Kopinski 0 ArcGIS was utilized to develop representative erodibility and rainfall erosivity values for each physiographic region in Missouri shown in Figure. The erodibility vector-based layers from Figure were converted into a raster, and the zonal statistic mean was calculated for the average erodibility for each physiographic region from Figure. The region erosivity was performed similarly. The EPA Isoerodent map shown in Figure was georeferenced over the Missouri physiographic map layer. Digitizing the isoerodent map created contours which were interpolated to obtain an erosivity raster. The zonal statistical mean of erosivity was computed to determine the representative region annual erosivity. As the erodibility and erosivity are the only two spatially dependent variables in the RUSLE, combining these variables into one map simplifies the calculation. The product of each physiographic region s respective erodibility and erosivity values (KR factor) were computed. The KR factors were subsequently aggregated into three zones: (Zone ), 0 (Zone ), and (Zone ) as shown in Figure. Zone includes the Glaciated Plains, the Ozarks, and the St. Francois Mountains and assumes all three regions to have a KR factor of. Zone is for the Western Plains, and Zone is the Southeast Lowlands region. 0 FIGURE Isoerodent map of Missouri showing erosivity values (R) with polygons delineating counties (adapted from ()).

12 Cox, Sommer, Luna, Kopinski 0 FIGURE KR zones for ECB design specifications, the Zone KR values range from 0 to (combines three physiographic regions), the Zone KR value is 0, and the Zone KR value is. The RUSLE was applied to each zone to calculate the maximum allowable slope length for each ECB type shown in Table. For product design specifications, the proposed design tool sets tons/acre soil loss as the threshold and solves for the maximum allowable slope length for each type of ECB. It is recommended to use the region of more severe conditions for counties that are located within more than one physiographic region.

13 Cox, Sommer, Luna, Kopinski TABLE Recommended classifications for ECB product approval ECB Type.A Mulch Control Nets.B.C.D Description Material Composition Longevity Netless Rolled Erosion Control Blankets Light-Weight Double-Net Erosion Control Blankets Heavy Double-Net Erosion Control Blankets.A Mulch Control Nets.B.C.D Netless Rolled Erosion Control Blankets Light-Weight Double-Net Erosion Control Blankets Heavy Double-Net Erosion Control Blankets.A Mulch Control Nets.B Erosion Control Blankets Erosion Control Blankets A photodegradable synthetic mesh or woven biodegradable natural fiber netting Natural and/or polymer fibers mechanically interlocked and/or chemically adhered together to form an RECP Natural and/or polymer fibers mechanically bound together by two rapidly degrading, synthetic or natural fiber nettings Processed degradable natural and/or polymer fibers mechanically bound together between two rapidly degrading, synthetic or natural fiber nettings A photodegradable synthetic mesh or woven biodegradable natural fiber netting Natural and/or polymer fibers mechanically interlocked and/or chemically adhered together to form an RECP Natural and/or polymer fibers mechanically bound together by two degrading, synthetic or natural fiber nettings Processed degradable natural and/or polymer fibers mechanically bound together between two degrading, synthetic or natural fiber nettings Maximum Gradient (H:V) Maximum Coverage Factor (C) Maximum Tensile Strength (lb/ft) months : :.0 months : :.0 months : : 0.0 months : :.0 months : :.0 months : :.0 months : : 0.0 months : :.0 A photodegradable synthetic mesh or woven biodegradable natural fiber netting months : :.0 An erosion control blanket composed of processed slow degrading natural or polymer fibers mechanically bound together between two months slow degrading synthetic or natural fiber nettings to form a.: 00.0 continuous matrix An erosion control blanket composed of processed very slow degrading natural or polymer fibers mechanically bound together between two slow degrading synthetic or natural fiber nettings to months : :.0 form a continuous matrix

14 Cox, Sommer, Luna, Kopinski The calculation of maximum allowable slope length assumes one year of blanket usage, and 00% of the annual erosivity. The Type ECBs have a service life of less than one year (three months); therefore an adjusted erosivity was determined. To calculate soil loss for a time interval less than one year, the erosivity index (EI) must be determined for the region (). The EI value corresponds to cumulative annual rainfall percentages for every two weeks throughout the year and linear interpolation is recommended for dates in between the given data (). The percentages represent the fraction of expected annual erosivity that has occurred over the area for a given time period. Five EI areas are located in Missouri, and the most severe three-month period of cumulative annual erosivity of the five areas was used for the Type erosivity value, which was %. The slope and C-factor used in the RUSLE calculation were derived from the ECB type s maximum slope and maximum allowable C-factor from large-scale testing. The soil erodibility values used are for bare-fallow conditions (C-factor of.0) (), and an adjustment is required for a more representative and accurate calculation. For a compacted embankment on construction sites, Toy et al. () recommend a C-factor of 0. for bare soil conditions (0). This 0. for compacted embankments was multiplied by the coverage factor of the ECB for a composite C-factor for the slope. A practice management factor of.0 was used in the calculation of the Type ECBs, which indicates no additional BMPs. The short service life would make the usage of silt fences or wattles less economically practical. Silt fences were assumed for Type, Type, and Type blankets (0.0 Practice Factor). The addition of a silt fence with a Type ECB would extend the maximum length allowable by a factor of four. The resulting lengths were rounded to the nearest five feet and are provided in Table. TABLE Recommended Maximum Allowable Slope Lengths for ECB Types ECB Type Name Maximum Slope (H:V) Maximum Length (ft) Zone Zone Zone A Mulch Control Nets : 0 0 B Netless Rolled Erosion Control Blankets : C Light-Weight Double-Net Erosion Control Blankets : 0 D Heavy Double-Net Erosion Control Blankets : A Mulch Control Nets : B Netless Rolled Erosion Control Blankets : 0 0 C Light-Weight Double-Net Erosion Control Blankets : 0 0 D Heavy Double-Net Erosion Control Blankets : 0 A Mulch Control Nets : D Erosion Control Blankets.: 0 Erosion Control Blankets : 0 0 The maximum allowable slope lengths for the three zones are illustrated graphically in Figures through. The dashed lines designate distances and slopes where an ECB can be used, and the solid line denotes

15 Cox, Sommer, Luna, Kopinski lengths and slope where the ECB is recommended. This style of design matrix was adapted for use based on matrices provided in the NDOR Approved Products List Submittal Procedures (). As shown in the design matrices, many types of ECBs are appropriate for a variety of applications based on the assumption that ECB types are sufficient for any gradient shallower than the maximum specified gradient. Discretion is required by the designer to select the most economical and practical ECB. Because the calculations show that ECB lengths for the : slope gradients are not higher than 0 ft, other forms of erosion control are recommended for this gradient beyond this maximum length. Designers can also manually calculate maximum slope length using the RUSLE procedure, if site specific soil data are known.

16 Cox, Sommer, Luna, Kopinski Type A B C D A B C D A B Zone Name Mulch Control Nets Netless Rolled Erosion Control Blankets Light-Weight Double Net Erosion Control Blankets Heavy Double-Net Erosion Control Blankets Mulch Control Nets Netless Rolled Erosion Control Blankets Light-Weight Double Net Erosion Control Blankets Heavy Double-Net Erosion Control Blankets Mulch Control Nets Erosion Control Blankets Slope Steepness : : : :.: : 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ Erosion Control Blankets FIGURE ECB design matrix for Zone, solid line identifies lengths that the erosion control blanket is recommended for use, dashed line identifies lengths for which the erosion control blanket can be used but may not be the optimal choice.

17 Cox, Sommer, Luna, Kopinski Type A B C D A B C D A B Zone Name Mulch Control Nets Netless Rolled Erosion Control Blankets Light-Weight Double-Net Erosion Control Blankets Heavy Double-Net Erosion Control Blankets Mulch Control Nets Netless Rolled Erosion Control Blankets Light-Weight Double-Net Erosion Control Blankets Heavy Double-Net Erosion Control Blankets Mulch Control Nets Erosion Control Blankets Slope Steepness : : : :.: : 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ Erosion Control Blankets FIGURE ECB design matrix for Zone, solid line identifies lengths that the erosion control blanket is recommended for use, dashed line identifies lengths for which the erosion control blanket can be used but may not be the optimal choice.

18 Cox, Sommer, Luna, Kopinski Type A B C D A B C D A B Zone Name Mulch Control Nets Netless Rolled Erosion Control Blankets Light-Weight Double-Net Erosion Control Blankets Heavy Double-Net Erosion Control Blankets Mulch Control Nets Netless Rolled Erosion Control Blankets Light-Weight Double-Net Erosion Control Blankets Heavy Double-Net Erosion Control Blankets Mulch Control Nets Erosion Control Blankets Slope Steepness : : : :.: : 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ 0-0' 0-0' 0'+ Erosion Control Blankets FIGURE ECB design matrix for Zone, solid line identifies lengths that the erosion control blanket is recommended for use, dashed line identifies lengths for which the erosion control blanket can be used but may not be the optimal choice.

19 Cox, Sommer, Luna, Kopinski 0 CONCLUSIONS AND RECOMMENDATIONS A research project was conducted to develop recommendations for ECB design guidelines unique for Missouri's geology and hydrology. A surficial investigation was performed to determine soil erodibility values throughout the state. An ECB design process was developed based on an application of the RUSLE and different zones associated with erodibility and erosivity. A design-matrix tool was developed by calculating the maximum allowable slope length for each ECB type and incorporating erodibility and erosivity coefficients that are representative of Missouri geology and hydrology characteristics. As ECBs are generally only one component of a stormwater pollution prevention plan, the design guidelines and associated matrices were developed to account for other commonly used BMPs. The use of the design matrix, which is based on generalized conditions, is intended for convenience when site-specific data are not available. If the data are available, the engineer can conduct the site-specific ECB design calculations directly using the RUSLE with the available data and provided guidelines.

20 Cox, Sommer, Luna, Kopinski REFERENCES. Kelsey, K. (00). Use of the Revised Universal Soil Loss Equation on an Event-by-Event Basis. Steven's Point, College of Natural Resources University of Wisconsin-Steven's Point.. Lal, L. (00). Soil Degradation by Erosion. Land Degradation & Development, Vol., No., pp. -.. EPA. (00). Developing Your Stormwater Pollution Prevention Plan. Washington D.C., Environmental Protection Agency.. MoDOT. (0). Stormwater Pollution Prevention Plan. Jefferson City, Missouri Department of Transportation.. Caltrans (). Soil Stabilization Using Erosion Control Blankets. Construction Storm Water Pollution Prevention Bulletin. Sacramento, CA, California Department of Transportation.. Bhatia, S. E. (00). Comparison of Geosynthetic Rolled Erosion Control Product (RECP) Properties between Laboratories. International Conference on Scour and Erosion. San Francisco, ASCE, pp. -.. ECTC. (00). A Technical Guidance Manual Terminology, Index, & Performance Testing Procedures for Rolled Erosion Control Products. Roxborough, Erosion Control Technology Council.. MoDOT. (0). Section 0 Geotextile. General Provisions and Supplemental Specifications to 0 Missouri Standard Specifications for Highway Construction. Jefferson City, MO.. IDOT. (0). IDOT Standard Specifications for Road and Bridge Construction 0. Springfield, IL, Illinois Department of Transportation. 0. KDOT. (0). Standard Specifications for Road and Bridge Construction. Topeka, Kansas Department of Transportation.. NDOR. (00). Approved Products List Submittal Procedures. Lincoln, Roadside Stabilization Unit, Nebraska Department of Roads.. WisDOT. (0). Wisconsin Department of Transportation Standard Specifications for Highway and Bridge Construction. Madison, WI, Wisconsin Department of Transportation.. TxDOT. (0). Changes to Approved Products List (APL) for Erosion Control Devices. TXDOT White Paper: Changes to APL. Austin, TX, USA, Texas Department of Transportation.. OMAFRA. (0). Universal Soil Loss Equation Fact Sheet. Guelph, Ontario Ministry of Agriculture, Food and Rural Affairs.. Spaeth, K. et al. (00). Evaluation of USLE and RUSLE on Estimated Soil Loss on Rangeland. Journal of Range Management, Vol., No., pp. -.. USDA. (). Predicting Soil Erosion by Water: A Guide to Conservation Planning with the Revised Universal Soil Loss Equation. Washington D.C., U.S. Government Printing Office.. USDA-ARS. (). Predicting Rainfall Erosion Losses: A Guide to Conservation Planning. Washington D.C., Agriculture Handbook No. United States Department of Agriculture.. Liu et al. (). Slope Length Effects on Soil Loss for Steep Slopes. Sustaining the Global Farm. West Lafayette, IN, International Soil Conservation Organization, pp. -.

21 Cox, Sommer, Luna, Kopinski ASTM. (0). ASTM D Standard Test Method for Determination of Rolled Erosion Control Product (RECP) Performance in Protecting Hillslopes from Rainfall-Induced Erosion. West Conshohocken, PA, American Society for Testing and Materials International. 0. Toy et al. (). Guidelines for the Use of the Revised Universal Soil Loss Equation (RUSLE) Version.0 on Mined Lands, Construction Sites, and Reclaimed Lands. Denver, Office of Surface Mining Reclamation and Enforcement, U.S. Department of the Interior.. USDA-ARS. (00). RUSLE User's Reference Guide. Washington D.C., U.S. Department of Agriculture.. Fitfield, J. (). What are Acceptable Sediment Yields from Sites Undergoing Construction? Proceedings of Conference XXII, International Erosion Control Association, Orlando, FL, pp Li, M. H. (0). Comparing Erosion Control Products' Performance Results from Field and Large-Scale Laboratory Testing. Indian Geotechnical Journal, Vol., No., pp. -.. TXDOT/TTI Sediment and Erosion Control Laboratory. (0). Final Performance Analysis. Austin, Texas Department of Transportation.. MoDNR. (00). Missouri Environmental Geology Atlas 00. Rolla, MO.. Missouri State Highway Commission. (). Geology and Soils Manual. Jefferson City, Missouri State Highway Commission.. Bureau of Plant Industry. (). Soil Survey Manual Agriculture Handbook No.. Soils and Agricultural Engineering Soil Survey Staff. Washington D.C., US Government Printing Office.. Sommer, D., Cox, A.L., and Luna, R. (0). Evaluation of Erosion Control Blanket Properties and Test Criteria for Specification and Design. Technical report submitted to the Missouri Department of Transportation, July, pp.. Erickson, A. (). Aids for Estimating Soil Erodibility - K Value Class and Soil Loss Tolerance. Salt Lake City, USDA Soil Conservation Service. 0. Bursztynsky et al. (). Erosion and Sediment Control Handbook. New York, McGraw Hill, Inc.. Ports and Smith. (). Maryland Highway Erosion and Sediment Control: Evaluation and Future Directions. Land Application of Waste Matter. Des Moines, Soil Conservation Society of America, pp. -.. EPA. (0). Stormwater Phase II Final Rule: Construction Rainfall Erosivity Waiver. Washington D.C.