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Terra-Tubes Fiber Filtration Tubes (FFTs) are engineered composites of wood fibers, man-made fibers and performance-enhancing polymers— all encased in heavy-duty, knitted cylindrical tubes. This revolutionary filtration medium is available as a superior polymer delivery system or as stand alone, high performance fiber tubes to accommodate specific applications, including:
- Slope Interruption Devices (SIDs)
- Channel/Ditch Flow Checks
- Bio-Swale/Storm Water Treatment Systems
- Drain Inlet Protection
- Perimeter Sediment Control
Terra-Tubes are most beneficial when used as systematic components of a Storm Water Pollution Prevention Plan (SWPPP). They are an ideal complement to other erosion control technologies, such as:
- Hydraulically Applied Erosion Control Products (HECPs)
- Erosion Control Blankets (ECBs)
- Turf Reinforcement Mats (TRMs)
The Keys to Terra-Tubes® Performance
Terra-Tubes leave wattles, fiber rolls and similar technologies in the dust. No other product provides Terra-Tubes’ three primary functions: flow, filtration and flocculation. For the best sediment retention and storm water treatment option, turn to the superior technology of Terra-Tubes.
Proof is in the Performance
One of the greatest problems in achieving NPDES sediment reduction goals has been the lack of quantifiable criteria for performance of Best Management Practices (BMPs). Until recently there has been little performance data available for Sediment Retention Devices (SRDs) due to no recognized standard test procedures.
Independent testing of various SRDs was conducted in 2004 at the Storm Water Lab in Ankeny, Iowa, following the recently developed protocol established in ASTM D7351—Standard Test Method for Determination of Sediment Retention Device Effectiveness in Sheet Flow Applications. This state-of-the-art facility was developed to provide quantifiable large scale performance evaluations of SRDs under conditions designed to model “real world” runoff conditions. A 10-year, 6-hour design event was selected because this return frequency is commonly used to design sediment retention structures. This equated to a 4-inch rainfall falling on a theoretical contributory slope area 100-ft long by 20-ft wide creating sheet flow conditions over a silty sand substrate.
Each SRD was installed to manufacturer specifications and subjected to the prescribed design event. The devices were monitored for flow characteristics and installation integrity. Using the prescribed collection methodology samples for turbidity, Total Suspended Solids (TSS) and sediment concentrations were taken upstream of the devices. Samples were subsequently taken below the devices every 5 minutes for the entire 45 minutes of discharge at the specified flow rate. Additional samples were collected until all water flow ceased (or 90 minutes elapsed). All samples were then evaluated by two laboratories to insure accuracy of the data.
The difference is clear! The other technologies failed to even approach the turbidity reductions, sediment retention efficiencies, water quality improvements and structural integrity of Terra-Tubes.
FFT Installation Overview
Slopes: Vertical spacing for slope installations should be determined by site conditions. Key parameters include slope gradient, length of slope, soil type, climate, design event and anticipated runoff. General guidelines follow:
When installing on highly erosive soils, decrease interval distance. On less erosive soils, increase interval distance.
- For maximum performance Terra-Tubes must be installed to maintain intimate contact with the soil surface. Terra-Tubes should be installed prior to hydraulic or dryland seeding applications. They may be installed before or after the installation of Rolled Erosion Control Products (RECPs). Smooth soil surface and remove all obstructions >1"-2" in diameter. Deploy Terra-Tubes FFT where material is to be installed.
- Anchor the upslope/upstream side of FFT using 6"- 8" U-shaped wire staples or approved devices at 1' intervals. Position anchors 1" inward from upper edge of FFT and drive flush to soil surface.
- Raise tube to fullest height and drive 12"-18" wooden stakes or approved metal rods through downslope/downstream side of FFT at 2' intervals. Drive stakes 1" inward from downslope/downstream edge of FFT, leaving 2"- 3" of the stake protruding above the FFT. Take care not to compress the FFT structure.
- The FFT should appear more rectangular than round. Backfill and compact loose soil against upslope/upstream side of FFT.
- Overlap adjacent FFT roll ends by a minimum of 1'. Reduce stake interval on downslope/downstream FFT to 1' interval making sure to place a stake at the terminus of the FFT. Continue to use wire staples on 1" centers on upslope/upstream side of FFT. Extend next FFT 1' past terminus and upslope/upstream of preceding FFT and place wire staples on 1' intervals. Then, drive stakes through outer 1" of both FFTs to complete the overlap.
- Construct anchor trench 3" deep by FFT roll diameter and place loose soil against upstream side of FFT. For channel gradients of 2%, install anchor trenches on 25' intervals. Decrease interval distance of anchor trenches with steeper channel gradients or more highly erosive soils.
- Follow above installation sequence for slope installations, but decrease interval of both upstream and downstream anchoring devices to 1'.
Fiber Filtration Tube Example Specification
Fiber Filtration Tubes shall be Terra-Tubes® as manufactured by PROFILE Products LLC and shall conform to the property values listed below
|Tube Diameter||Measured||6 in||15 cm|
|Mass/Unit Length||Measured||0.5 lb/ft||0.7 kg/m|
|Water Holding Capacity||Profile Test||1000%||1000%|
|Functional Longevity||Observed||1-2 yr||1-2 yr|
|Tube Dimensions||Average Weight||Tubes/ pallet||Truckload Quantity|
|TT 632P2,3 6” x 32.5’ (15 cm x 10 m)||16 lb (7 kg)||12||23,400 ft (7,134 m)|
|TT 913P2 9” x 13’ (23 cm x 4 m)||13 lb (6 kg)||9||12,168 ft (3,709 m)|