Accession Number : ADA304936

Title :   Silt Fence Testing for Eagle River Flats Dredging.

Descriptive Note : Special rept.,

Corporate Author : COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH

Personal Author(s) : Henry, Karen S. ; Hunnewell, Susan T.

PDF Url : ADA304936

Report Date : DEC 1995

Pagination or Media Count : 18

Abstract : An estimated 1,000 to 2,000 waterfowl deaths have been noted annually since 1980 in Eagle River Flats (ERF), Alaska, an artillery impact area used by the Army. Waterfowl die because of the ingestion of unburned white phosphorus (WP) particles deposited by incendiary. Remediation of the site is currently being planned, and one of the techniques being considered is the use of a remote-control dredge to excavate WP-contaminated sediment. Dredged material will be placed into a settling pond and allowed to settle until a clear layer of water forms on the top of the sediments. The water will then be released over a weir, across a concrete pad, through a geotextile silt fence to a drain into the ERF. This report describes tests that were conducted to evaluate how well candidate geotextiles for the silt fence retained small particles (less than 0.1 mm in diameter) that were suspended in water being released back into the ERF. The soil used in the tests was collected from ponds to be dredged. The testing program consisted of two parts. Part I tests were standard engineering tests for silt fences, and were used to select a product for further testing. Part II tests simulated field conditions, and were conducted to determine whether the candidate geotextile selected was likely to perform well. In the tests that simulated field conditions, the tests that used geotextiles achieved system filtering efficiencies at 99%, and the geotextile filter reduced the final total suspended solids contained in the water by a factor of 10. Negligible amounts of soil passed the #200 sieve from water that flowed through the geotextile. However, it is also noted that allowing the sediment to settle before decanting the water resulted in system filtering efficiencies in excess of 90% when a silt fence was not used in the test. (MM)

Descriptors :   *ENVIRONMENTAL IMPACT, *POLLUTION ABATEMENT, *DREDGED MATERIALS, *DREDGING, *SILT, *WATERFOWL, PARTICLE SIZE, ARMY FACILITIES, ALASKA, GRAIN SIZE, DIES, SOILS, WATER POLLUTION, POISONING, FILTERS, RIVERS, INCENDIARY AMMUNITION, DEATH, SEDIMENTS, ARTILLERY, FIELD CONDITIONS, PONDS, SWAMPS, DISPERSIONS, GEOTEXTILES, ESTUARIES, WHITE PHOSPHORUS.

Subject Categories : Biology
      Civil Engineering
      Solid Wastes Pollution and Control
      Water Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE