Knowledge (XXG)

Silt fence

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112:) stretched between a series of wooden or metal fence stakes along a horizontal contour level. The stakes are installed on the downhill side of the fence, and the bottom edge of the fabric can be trenched into the soil and backfilled on the uphill side, although it is quite difficult to move the trenched "spoil" from the downside to the upside of the trench. The design/placement of the silt fence should create a pooling of runoff, which then allows sedimentation to occur. Water can seep through the silt fence fabric, but the fabric often becomes "blocked off" with fine soil particles (all sediment-retention devices have this challenge, and none of them "filter" storm water for very long). A few hours after a storm event, the fabric can be "disturbed" in order to dislodge the fines, and allow clean water to flow through. Depending on the protected watershed and erosion, larger soil particles will settle out, ultimately filling the silt fence to the top of the structure; requiring another silt fence above or below it (creating a new ponding area), or for the silt fence to be removed, the sediment removed or spread out, and a new fence installed. The fence is not designed to concentrate or channel stormwater. The fence is installed on a site before soil disturbance begins, and is placed down-slope from the disturbance area. 199:
posts, or posts knocked down. A silt fence top-full of sediment may need maintenance/replacement, but it is a huge success. The fabric may become damaged with holes and tears if construction materials are stored next to or on top of the fence. During various phases of construction at a site, a silt fence may be removed relocated and reinstalled multiple times. It may be difficult to maintain effectiveness of a silt fence under such operating conditions. Location of fences in areas with high flows may lead to fence failures when the installation is not adequately back-filled and properly compacted, and/or the post-spacing is inadequate.
195:(EPA) co-sponsored silt fence efficacy field research through its Environmental Technology Verification Program, and in general, the report found the static slicing method to be highly effective, and efficient. Silt fence effectiveness is best determined by how many hundreds of pounds of sediment are contained behind a given silt fence after a storm event, and not turbidity, etc. as sediment-retention is the end goal, and not a water-quality measurement used in erosion control, for instance. 171: 97: 133:. The metal backing gives the fence increased strength to resist the weight of soil and water which may be trapped by the fence in a large drainage area, and discourages construction site operators from driving vehicles over the fence. However, an improper installation of a super silt fence can create an inadvertent sediment basin when the filter fabric becomes clogged. This typically causes flooding and increased downstream 146: 66: 20: 479: 198:
Silt fences may perform poorly for a variety of reasons, including improper location (e.g. placing fence where it will not pond runoff water), improper installation (e.g. failure to adequately embed and backfill the lower edge of fabric in the soil) and lack of maintenance—fabric falling off of the
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agencies recommend an installation technique called "static slicing" as an improved method for ensuring effectiveness and longevity of a silt fence system on a construction site. The technique involves inserting a narrow blade into the soil with a wedge-type point on its tip to slightly disrupt the
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Silt fence fabrics (geotextiles) tested in laboratory settings have shown to be effective at trapping sediment particles. Although there have been few field tests of silt fences installed at construction sites, these tests have shown generally poor results. (Effectiveness testing involved
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Since 1998, static slicing the material into the ground has proven to be the most efficient and most effective installation method because slicing maintains the soil on both sides of the fence, and is conducive to proper compaction—which is critical to performance, as well. In 2000 the
57:. Silt fences are widely used on construction sites in North America and elsewhere, due to their low cost and simple design. However, their effectiveness in controlling sediment can be limited, due to problems with poor installation, proper placement, and/or inadequate maintenance. 137:. Most super silt fence specifications are outdated, requiring the trenching installation method, which has been shown to be highly susceptible to "washing out" under the fabric due to improper back-filling and inadequate compaction. 115:
Sediment is captured by silt fences most often through ponding of water and settling, rather than filtration by the fabric. Sand and silt tends to clog the fabric, and then the sediments settle in the temporary pond.
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recommend or require the use of a reinforced fence, sometimes called a "super" silt fence or an enhanced silt fence, on some construction sites. This design uses filter fabric reinforced by a wire mesh or
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Sprague, C.J. (1999). "Assuring the Effectiveness of Silt Fences and Other Sediment Barriers." Proceedings of Conference 30, International Erosion Control Association, Nashville, TN. pp. 133-154.
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soil upward, while simultaneously inserting the silt fence fabric into the slot with a moving pivot, while the machine is moving forward. This step is followed by mechanical
532: 316: 404:. Erosion and Sediment Control Manual (Report). Washington, D.C.: District of Columbia, Department of Energy and Environment. September 2017. pp. 93–96. 298: 304:. Virginia Erosion and Sediment Control Handbook (Report) (3rd ed.). Richmond, VA: Virginia Department of Environmental Quality (VA DEQ). 1992. 398: 187:.) Other studies and articles about silt fence usage and practice document problems with installation and maintenance, implying poor performance. 365: 192: 586: 581: 509: 416: 544: 78: 504:. Washington, D.C.: Environmental Technology Evaluation Center (EvTEC); Civil Engineering Research Foundation. 2001. 478:
Barrett, Michael E.; Kearney, John E.; McCoy, Terry G.; Malina, Joseph F. Jr.; Charbeneau, Randall J. (March 1996).
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Environmental Technology Verification Report for Installation of Silt Fence Using the Tommy® Static Slicing Method
434: 218: 85:, which are designed to retain sediment in place where soil is being disturbed by construction processes (i.e., 596: 591: 213: 90: 385:
Development Document for Final Effluent Guidelines and Standards for the Construction and Development Category
180: 170: 96: 496: 485:(Report). University of Texas at Austin, Center for Transportation Research. Research Report 1943-2. 73:
Silt fences are often installed as perimeter controls. They are typically used in combination with
505: 361: 342:(Report). Stormwater Best Management Practice. Washington, D.C.: EPA. 2012. EPA 833-F-11-008. 130: 35: 252: 159: 134: 105: 82: 24: 255:(Report). Cincinnati, OH: U..S. Environmental Protection Agency (EPA). EPA 600/R-04/185. 223: 145: 74: 54: 575: 208: 125: 43: 457:
Developing Your Stormwater Pollution Prevention Plan: A Guide for Construction Sites
19: 456: 86: 39: 251:
Stevens, Ellen; Barfield, Billy J.; Britton, S.L.; Hayes, J.S. (September 2004).
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Installation detail for a silt fence with specifications recommended by US EPA
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Designing for Effective Sediment and Erosion Control for Construction Sites
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An Evaluation of the Use and Effectiveness of Temporary Sediment Controls
299:"Chapter 2. Erosion and Sediment Control Principles, Practices and Costs" 422:(Report). Baltimore, MD: Maryland Department of the Environment. 1994. 34:, sometimes (misleadingly) called a "filter fence," is a temporary 417:
1994 Maryland Specifications for Soil Erosion and Sediment Control
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Filter Fence Design Aid for Sediment Control at Construction Sites
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in nearby streams, rivers, lakes and seas from sediment (loose
568:—An Erosion and Sediment Control Video Education Resource 462:(Report). Washington, D.C.: EPA. 2007. EPA 833-R-060-04. 387:(Report). Washington, D.C.: EPA. 2009. EPA 821-R-09-010. 559: 322:(Report) (3rd ed.). VA DEQ. 1992. p. III-19. 162:, setting of fence posts, and attaching the fabric. 533:"Research and Testing of ESC Products and Methods" 562:—Professional Association, Publications, Training 433:Carpenter, Thomas; Sprague, Joel (Jul–Aug 2002). 317:Virginia Erosion and Sediment Control Handbook 23:Silt fence installed up-slope of a vegetated 16:Sediment control device on construction sites 8: 246: 244: 69:Silt fence installed on a construction site 473: 471: 469: 560:International Erosion Control Association 351: 349: 331: 329: 379: 377: 415:"Section H - 26.0: Super Silt Fences". 240: 104:A typical fence consists of a piece of 100:Chain link supported "super" silt fence 360:. Santa Barbara, CA: Forester Press. 124:Some government jurisdictions in the 7: 193:U.S. Environmental Protection Agency 543:(6). Forester Media. Archived from 531:Brzozowski, Carol (Sep–Oct 2004). 435:"Silt Fence Installation Efficacy" 275:Brzozowski, Carol (Nov–Dec 2006). 14: 439:Grading and Excavation Contractor 399:"Section 3.2: Super Silt Fence" 1: 108:filter fabric (also called a 356:Fifield, Jerald S. (2004). 141:Static slicing installation 613: 587:Environmental soil science 315:"Spec. 3-05. Silt Fence". 277:"Silt Fence Installation" 219:Nonpoint source pollution 582:Earthworks (engineering) 214:Geotechnical engineering 61:Design and installation 181:total suspended solids 179:measurements for both 175: 150: 149:Static slicing machine 101: 70: 27: 516:CERF Report No 40565. 173: 148: 99: 68: 22: 445:(5). Forester Media. 287:(7). Forester Media. 176: 151: 102: 81:, as well as with 71: 28: 566:WatchYourDirt.com 367:978-0-9707687-3-5 42:sites to protect 604: 548: 547:on 12 June 2017. 517: 515: 503: 493: 487: 486: 484: 475: 464: 463: 461: 453: 447: 446: 430: 424: 423: 421: 412: 406: 405: 403: 395: 389: 388: 381: 372: 371: 353: 344: 343: 341: 333: 324: 323: 321: 312: 306: 305: 303: 295: 289: 288: 272: 266: 263: 257: 256: 248: 131:chain link fence 120:Super silt fence 83:erosion controls 36:sediment control 612: 611: 607: 606: 605: 603: 602: 601: 597:Water treatment 592:Water pollution 572: 571: 556: 551: 537:Erosion Control 530: 526: 524:Further reading 521: 520: 512: 501: 495: 494: 490: 482: 477: 476: 467: 459: 455: 454: 450: 432: 431: 427: 419: 414: 413: 409: 401: 397: 396: 392: 383: 382: 375: 368: 355: 354: 347: 339: 335: 334: 327: 319: 314: 313: 309: 301: 297: 296: 292: 281:Erosion Control 274: 273: 269: 264: 260: 250: 249: 242: 237: 205: 168: 160:soil compaction 143: 122: 75:sediment basins 63: 38:device used on 17: 12: 11: 5: 610: 608: 600: 599: 594: 589: 584: 574: 573: 570: 569: 563: 555: 554:External links 552: 550: 549: 527: 525: 522: 519: 518: 510: 488: 465: 448: 425: 407: 390: 373: 366: 345: 325: 307: 290: 267: 258: 239: 238: 236: 233: 232: 231: 226: 224:Sediment basin 221: 216: 211: 204: 201: 167: 164: 142: 139: 121: 118: 79:sediment traps 62: 59: 15: 13: 10: 9: 6: 4: 3: 2: 609: 598: 595: 593: 590: 588: 585: 583: 580: 579: 577: 567: 564: 561: 558: 557: 553: 546: 542: 538: 534: 529: 528: 523: 513: 511:0-7844-0565-4 507: 500: 499: 492: 489: 481: 474: 472: 470: 466: 458: 452: 449: 444: 440: 436: 429: 426: 418: 411: 408: 400: 394: 391: 386: 380: 378: 374: 369: 363: 359: 352: 350: 346: 338: 332: 330: 326: 318: 311: 308: 300: 294: 291: 286: 282: 278: 271: 268: 262: 259: 254: 247: 245: 241: 234: 230: 227: 225: 222: 220: 217: 215: 212: 210: 209:Geosynthetics 207: 206: 202: 200: 196: 194: 188: 186: 182: 172: 166:Effectiveness 165: 163: 161: 156: 147: 140: 138: 136: 132: 127: 126:United States 119: 117: 113: 111: 107: 98: 94: 92: 88: 84: 80: 76: 67: 60: 58: 56: 53: 49: 45: 44:water quality 41: 37: 33: 26: 25:stream buffer 21: 545:the original 540: 536: 497: 491: 451: 442: 438: 428: 410: 393: 357: 310: 293: 284: 280: 270: 261: 197: 189: 177: 152: 123: 114: 103: 87:land grading 72: 40:construction 31: 29: 337:Silt Fences 576:Categories 235:References 229:Stormwater 110:geotextile 91:earthworks 89:and other 52:stormwater 32:silt fence 185:turbidity 135:pollution 106:synthetic 203:See also 508:  364:  55:runoff 502:(PDF) 483:(PDF) 460:(PDF) 420:(PDF) 402:(PDF) 340:(PDF) 320:(PDF) 302:(PDF) 155:state 153:Some 50:) in 506:ISBN 362:ISBN 183:and 77:and 48:soil 93:). 578:: 541:11 539:. 535:. 468:^ 441:. 437:. 376:^ 348:^ 328:^ 285:13 283:. 279:. 243:^ 30:A 514:. 443:4 370:.

Index


stream buffer
sediment control
construction
water quality
soil
stormwater
runoff

sediment basins
sediment traps
erosion controls
land grading
earthworks

synthetic
geotextile
United States
chain link fence
pollution

state
soil compaction

total suspended solids
turbidity
U.S. Environmental Protection Agency
Geosynthetics
Geotechnical engineering
Nonpoint source pollution

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