This letter is in response to the utilization of the Silt-Saver Belted Silt Retention Filter (BSRF) system on the RIverwalk of Highlands development site located in Highlands, North Carolina. McGill Associates was contracted by Riverwalk to help mitigate existing impacts to the Cullasaja River. McGill Associates did not design the original sediment and erosion control plans, and became involved with the project after the Town of Highlands issued several Notice of Violations (NOVs) on the development site.
One particular area of interest was the discharge of sediment laden and turbid waters directly to the Cullasaja River which is designated as Trout waters. The mitigation plan for these impacts included adding sediment basins, adding check dams, adding turf reinforcement matting, stabilizing the site, and utilizing BSRF.
The BSRF was particularly effective in minimizing the sediment/turbidity plume that was visible in the Cullasaja River. Prior to installing the BSRF, the BMPs being utilized included traditional wire backed silt fence and straw bales. The properly installed BSRF system is more effective than the wire backed silt fence that was installed per the original set of erosion control plans and is still providing effective sediment removal from the discharge to the Cullasaja River. Please refer to the attached photos that demonstrate the effectiveness of the BSRF as compared to traditional wire backed silt fence and straw bales.
McGill Associates, P.A.
J.P Johns, PE
University of California Berkeley
COLLEGE OF LETTERS AND SCIENCE DEPARTMENT OF EARTH AND PLANETARY SCIENCE
307 McCONE HALL, MC4767
BERKELEY, CALIFORNIA 94720
Telephone: (510) 642-3993
FAX (510) 643-9980
To Whom It May Concern:
It is a pleasure to be writing a letter of praise for Siltsaver™ fabric, which we used extensively during a field expedition to a small cirque glacier in the Canadian Rockies this summer. Our group spent two months studying the motion and melt of the West Washmawapta Glacier, British Columbia, as part of a collaborative project funded by the National Science Foundation. The group includes scientists from UC Berkeley, Macalester College, University of Alberta Edmonton and the United States Geological Survey. Over three field seasons, we hope to gain insight in the mechanics of small glaciers and how they are able to create cirques (the amphitheater shaped basins frequently found at the head of glacial valleys).
Our camp's water supply is a small meltwater stream exiting the glacier, which carries silt-laden water and other organic detritus (algae, insects, etc.). We were concerned that consuming silt for two months would cause health problems and, accordingly, went in search of a filter system that 1) could process large quantities of water rapidly (our camp supports up to 8 researchers at a time), 2) is inexpensive, 3) would not clog quickly, and 4) is designed for macroscopic matter rather than microscopic contaminants such as giardia.
We first became aware of Siltsaver™ fabric a month before our expedition and immediately became excited by its potential. It met all the criteria listed above and came in sheets large enough that we could customize its size and shape for use in our camp. Ultimately, we used square sections ~50 em across to cover 5 gallon buckets, but other systems (say, over a Nalgene bottle) could easily be implemented if necessary.
By allowing us to avoid using microfilters, iodine, or boiling water, Siltsaver™ fabric saved us hours of work preparing water for consumption. It took less than 5 minutes to supply our entire water needs for three days. We are very grateful we discovered Siltsaver™ and highly recommend it to any outfit or organization that requires silt filters for outdoor activi .
John W. Sanders Graduate Student
Department of Earth and Planetary Science UC Berkeley
The silt saver units were used on the Route 359 relocation project. This project was a segment of the PPTA project of which we were a 33% owner (Jamestown 2007 Corridor Constructors). We used the units as a test site for VDOT's evaluation of the units. I fully endorse the units, they did an excellent job during one of the worst hurricanes to hit Williamsburg in decades. Our project was adjacent to the Colonial National Park, Jamestown Island and tidal waters of the James River.
Andy Curtis CPESC #216
In August, 2003 Curtis Contracting agreed to try the Silt Saver on the entrance road into Jamestown Festival Park, a project to improve the entrance prior to the 2007 celebration of the 400th Anniversary of the establishment of the first permanent English colony in the western hemishpere at Jamestown. Shortly after the installation a hurricane came through and did significant damage to the graded slopes and roadbed. The Silt Saver protected open inlets from receiving significant amounts of sediment when the inlets were overtopped with sediment-laden water from the heavy rain that accompanied the hurricane. An inspection following the storm revealed the Silt Saver still in place and functioning while the rest of the project was being cleaned up.
James R. Barrett, C.P.E.S.C
Regulatory and Compliance Manager
Virginia Department of Transportation