EXAMINATION FOR CERTIFIED PROFESSIONAL IN EROSION AND SEDIMENT CONTROL. Resource Booklet. Version A

Transcription

1 EXAMINATION FOR CERTIFIED PROFESSIONAL IN EROSION AND SEDIMENT CONTROL Version A

2 INDEX TO TABLES Index to Maps... 1 Table A Exam Unit Conversion Table... 2 Table B Equations... 3 Table C Slope Length and Steepness Factor LS... 4 Table D Cover Management Factor C... 5 Table E Support Practice Factor P... 6 Table F Estimated Weight of Soils... 6 Table G Runoff Curve Numbers for Urban Areas... 7 Table H Runoff Curve Numbers for Cultivated Lands... 8 Table I Runoff Curve Numbers for Other Ag Lands... 9 Table J Chart for Solution of Runoff Equation February 2015 EnviroCert International, Inc

3 Table A: EXAM UNIT CONVERSION TABLE Length = inchs = feet = yards = miles inch E-05 foot yard mile 63,360 5,280 1,760 1 Area = Sq.In. = Sq.Ft. = Sq.Yds. = Acres = Sq.Miles Square Inch E E-10 Square Foot E E-08 Square Yard 1, E E-07 Acre 6,272,640 43,560 4, Square Mile 4,014,489,600 27,878,400 3,097, Volume = Cu.In. = Gallons = Cu.Ft. = Cu.Yds. = Ac.Ft. Cubic Inch E E-08 Gallon E-06 Cubic Foot 1, E-05 Cubic Yard 46, E-04 Acre Feet 72,271, ,560 1, Liquid Volumes = Ounces = Pints = Quarts = Gallons Ounce Pint Quart Gallon Weight/Mass = Ounces = Pounds = Tons Ounce E-05 Pound Ton 32, February 2015 EnviroCert International, Inc

4 Table B: Equations Revised Universal Soil Loss Equation (RUSLE) A = R K LS C P Where: A = Average annual soil loss per unit area R = Rainfall-runoff erosivity factor K = Soil erodibility factor LS = Slope length and steepness factor C = Cover management factor P = Support practice factor Modified Universal Soil Loss Equation (MUSLE) T = 95(Q p V) 0.56 K LS C P Where: T = Sediment yield, in tons, for specific storm event Qp = Peak flow, in cubic feet per second, for the storm event V = Volume of runoff, in acre-feet, for the storm event K, LS, C and P = as shown above February 2015 EnviroCert International, Inc

5 Table C: Slope Length and Steepness Factor LS Values for topographic factor, LS, for high ratio of rill to interrill erosion.* Horizontal Slope Length (ft.) Slope (%) < * Such as for freshly prepared construction and other highly disturbed soil conditions with little or no cover (not applicable to thawing soil) February 2015 EnviroCert International, Inc

6 Table D: Cover Management Factor C Type of Cover Factor C Percent * None (fallow ground) Temporary Seedings (90 percent stand): Ryegrass (perennial type) Ryegrass (annuals) Small grain Millet or sudan grass Field bromegrass Permanent Seedings (90 percent stand): Sod (laid immediately): Application Rate Tons Per Acre Mulch: Hay Hay Hay Hay Small grain straw Wood chips Wood cellulose * Percent soil loss reduction as compacted/with fallow ground. February 2015 EnviroCert International, Inc

7 Table E: Support Practice Factor P Surface Condition with No Cover Factor P* Compact and smooth, scraped with bulldozer scraper up and downhill. 1.3 Same condition, except raked with bulldozer root rake up and downhill. 1.2 Compact and smooth, scraped with bulldozer or scraper across the slope. 1.2 Same condition, except raked with bulldozer root rake across the slope. 0.9 Loose as a disked plow layer. 1.0 Rough, irregular surface equipment tracks in all directions. 0.9 Loose with rough surface greater than 12 depth. 0.8 Loose with smooth surface greater than 12 depth. 0.9 * Values based on estimates and are provided for illustrative purposes only. P factor values are site-specific and should be developed using data reflecting site conditions. Table F: Estimated Weight of Soils* Soil Textural Class Dry Density (lbs./ft 3 ) clay silty clay, silty clay loam sandy clay, loam, sandy loam clay loam, silt loam sandy clay loam, loamy sands, sands * Data and estimates from published soil surveys, laboratory data and soil interpretation records are to be used where available. Parent materials, soil consistency, soil structure, pore space, soil texture, content of coarse fragments all unit have an influence on weight. February 2015 EnviroCert International, Inc

8 Table G: Runoff Curve Numbers for Urban Areas 1 Cover description Curve numbers for hydrologic soil group Cover type and hydrologic condition Average percent impervious area 2 A B C D Fully developed urban areas (vegetation established) Open space (lawns, parks, golf courses, cemeteries, etc.) 3 : Poor condition (grass cover < 50%) Fair condition (grass cover 50% to 75%) Good condition (grass cover > 75%) Impervious areas: Paved parking lots, roofs, driveways, etc. (excluding right-of-way) Streets and roads: Paved: curbs and storm sewers (excluding right-of-way) Paved: open ditches (including right-of-way) Gravel (including right-of-way) Dirt (including right-of-way) Western desert urban areas: Natural desert landscaping (pervious areas only) Artificial desert landscaping (impervious weed barrier, desert shrub with 1- to 2-inch sand or gravel mulch and basin borders) Urban districts: Commercial and business Industrial Residential districts by average lot size: 1/8 acre or less (town houses) /4 acre /3 acre /2 acre acre acres Developing urban areas Newly graded areas (pervious areas only, no vegetation) Idle lands (CN s are determined using cover types similar to those in Table M). 1 Average runoff condition, and Ia = 0.2S. 2 The average percent impervious area shown was used to develop the composite CN s. Other assumptions are as follows: impervious areas are directly connected to the drainage system, impervious areas have a CN of 98, and pervious areas are considered equivalent to open space in good hydrologic condition. CN s for other combinations of conditions may be computed using figure 2-3 or CN s shown are equivalent to those of pasture. Composite CN s may be computed for other combinations of open space cover type. 4 Composite CN s for natural desert landscaping should be computed using figures 2-3 or 2-4 based on the impervious area percentage (CN = 98) and the pervious area CN. The pervious area CN s ae assumed equivalent to desert shrub in poor hydrologic condition. 5 Composite CN s to use for the design of temporary measures during grading and construction should be computed using figure 2-3 or 2-4, based on the degree of development (impervious area percentage) and the CN s for the newly graded pervious areas. February 2015 (210-VI-TR-55, Second Ed., June 1986) 7

9 Table H: Runoff Curve Numbers for Cultivated Agricultural Lands 1 Cover description Curve numbers for hydrologic soil group Cover type Treatment 2 Hydrologic condition 3 A B C D Fallow Bare soil Crop residue cover (CR) Poor Good Row crops Straight row (SR) Poor Good SR + CR Poor Good Contoured (C) Poor Good C + CR Poor Good Contoured & terraced (C&T) Poor Good C&T + CR Poor Good Small grain SR Poor Good SR + CR Poor Good C Poor Good C + CR Poor Good C&T Poor Good C&T + CR Poor Good Close-seeded SR Poor or broadcast Good legumes or C Poor rotation Good meadow C&T Poor Good Average runoff condition, and Ia = 0.2S. 2 Crop residue cover applies only if residue is on at least 5% of the surface throughout the year. 3 Hydrologic condition is based on combination of factors that affect infiltration and runoff, including (a) density and canopy of vegetative areas, (b) amount of year-round cover, (c) amount of grass or close-seeded legumes in rotations, (d) percent of residue cover on the land surface (good > 20%, and (e) degree of surface roughness. Poor: Factors impair infiltration and tend to increase runoff Good: Factors encourage average and better than average infiltration. February 2015 (210-VI-TR-55, Second Ed., June 1986) 8

10 Table I: Runoff Curve Numbers for Other Agricultural Lands 1 Cover description Curve numbers for hydrologic soil group Cover type Hydrologic condition A B C D Pasture, grassland, or range continuous Poor forage for grazing. 2 Fair Good Meadow continuous grass, protected from grazing and generally mowed for hay. Brush brush-weed-grass mixture with brush Poor the major element. 3 Fair Good Woods grass combination (orchard Poor or tree farm). 5 Fair Good Woods. 6 Poor Fair Good Farmsteads buildings, lanes, driveways, and surrounding lots. 1 Average runoff condition, and Ia = 0.2S. 2 Poor: < 50% ground cover or heavily grazed with no mulch. Fair: 50 to 75% ground cover and not heavily grazed. Good: > 75% ground cover and lightly or only occasionally grazed. 3 Poor: < 50% ground cover. Fair: 50 to 75% ground cover. Good: > 75% ground cover. 4 Actual curve number is less than 30; use CN = 30 for runoff computations. 5 CN s shown were computed for areas with 50% woods and 50% grass (pasture) cover. Other combinations of conditions may be computed from the CN s for woods and pasture. 6 Poor: Forest litter, small trees, and brush are destroyed by heaving grazing or regular burning Fair: Woods are grazed but not burned, and some forest litter covers the soil. Good: Woods are protected from grazing, and litter and brush adequately cover the soil. February 2015 (210-VI-TR-55, Second Ed., June 1986) 9

11 Table J, Chart for Solution of Runoff Equation February 2015 EnviroCert International, Inc