Turbidity Barriers and Silt Curtains

 

Turbidity barriers and silt curtains prevent the migration of sediment from a work site into nearby waterways.  Used for dredging, pile driving, remediation and marine construction, they are a cost-effective way to control turbidity at its source.  Their use also complies with Federal and State regulations that protect our water resources.  Turbidity barriers can prevent violations that result in work stoppages, project shutdowns, and costly fines.  Your project stays in compliance and on track while protecting the environment.

We offer a complete line of turbidity barriers for long and short term applications.  We can also design custom barriers to your project specifications.  When selecting a turbidity barrier or silt curtain, consider:

  • Size of sediments
  • Water flow velocity
  • Deflection angle relative to current
  • Debris likely to be encountered
  • USCG requirements
  • Length of deployment
  • Water depth and tides

IWT has been at the forefront in the evolution of turbidity barriers and silt curtains.  We are also a design innovator of durable barriers and curtains that withstand the harshest jobsite conditions.  From skirt reefing lines to carbon skirts or the bed load baffle system, we have a solution.  We also offer Marine Accessories to ensure a successful installation.  Please call us at 609-971-8810 so we can help you select the right barrier for your job.

Standard Turbidity Barriers and Silt Curtains

Economy

The economy floating turbidity barrier is best for temporary or short-term applications.  It is ideal for still or calm waters such as ponds, lakes, small rivers and ditches.  The skirt is manufactured from impermeable lightweight reinforced PVC coated fabric with standard depths of 5′.*  Section lengths of 50′ or 100′ are connected either by laced grommets or chain.

Type I

Type I works well in protected waterways with light wind or calm currents such as small streams, lakes and ponds.

Standard Specifications

Standard specifications include a 6” dia. flotation enclosed in impermeable reinforced PVC fabric.  It is then heat-sealed to be watertight and to keep the floats from shifting.  In addition, a 5′ standard depth skirt is installed below the float.  We can also manufacture other custom depths upon request.  Additionally, barriers are ballasted continuously along the bottom with a galvanized steel chain enclosed in a PVC pocket.  Standard section lengths are 50’ and 100’.  They can be joined together with lacing grommets and tool-free ASTM universal slide connectors or grommeted ends/tow plates.

Type I Permeable*

Permeable skirt is manufactured from either woven slit film or monofilament geotextile filter fabric.  It filters out sediments while allowing water to pass through.

Type I Impermeable*

The impermeable skirt is manufactured from 18 – 22 oz. reinforced PVC coated fabric that contains suspended solids in the work zone.

Type I DOT

Type I floating turbidity barrier complies with DOT silt control requirements.  It works especially well near bridges, canals, lakes and small streams.  DOT specifications vary by state.  Please call us at 609-971-8810 so we can determine the correct barrier for your project.

Type II

The Type II floating turbidity barrier is a good choice for inner coastal waterways with moving water, currents and tidal changes, such as estuaries and rivers.

Standard Specification

Standard specifications include a 6” dia. flotation enclosed in impermeable reinforced PVC fabric.  It is then heat-sealed to be watertight and keep the floats from shifting.  A 5′ standard depth skirt is then installed below the float.  We can also manufacture other custom depths upon request.  Barriers are then ballasted continuously along the bottom with a galvanized steel chain enclosed in a PVC pocket.  Standard section lengths of 50’ and 100’ join together with lacing grommets and tool-free ASTM universal slide connectors or grommeted ends/tow plates.
Type II also includes a 5/16” top tension cable to strengthen the barrier for more challenging project conditions.

Type II Permeable*

Woven monofilament geotextile fabric that filters out sediments while allowing water to flow through the skirt.

Type II Impermeable*

22 oz. (or heavier) reinforced PVC coated fabric that contains suspended solids in the work zone.

Type III Heavy Duty

This barrier works well in tidal areas with strong winds and currents such as rivers, bays or near shorelines.  We custom build the Type III to specific project conditions.  We select flotation size according to required skirt depth and manufacture skirts to the required depth.  Skirt fabrics are either permeable, woven polypropylene geotextile fabrics or impermeable polypropylene and PVC.*

Type III heavy duty barrier also includes a 5/16” top tension cable and dual ballast chains.  This adds weight as well as strength for rough water applications.

Staked Turbidity Barrier

A temporary barrier (similar to a silt fence) but installed in a waterway.  Manufactured from woven filter fabrics or optional impermeable reinforced PVC.  Selected according to water flow and sediment size.  The material is then finished along the seams and pre-pocketed every 4-6′ depending upon job site conditions.  Barrier depths range from 2-4′.

Custom Turbidity Barriers/Silt Curtains

Deep Depth

Deep depth projects are a challenge for standard floating turbidity barriers.  It is especially important to select skirt fabrics, flotation size, tension cables, ballast chains, and skirt reefing lines according to the conditions they will encounter.  Winds, currents and tidal changes are also important.  Please call us at 609-971-8810 for more information.  We can also provide a list of reference projects.

Baffle System

Baffle systems prevent the migration of silt and turbidity from pre-defined structures.  Our standard baffle systems also offer the benefit of debris and oil containment at the water line using 22 oz. PVC oil boom fabric around the flotation compartment.*  The flotation compartment is then completely heat-sealed.  In addition, each flotation element is heat-sealed on each end.  This creates a completely watertight compartment to prevent the floats from shifting.  Below the flotation compartment we then install the skirt section to the desired depth.  Skirt materials consist either of permeable, woven polypropylene geotextile fabrics, or impermeable polypropylene and PVC fabrics.  The barriers are also ballasted continuously along the bottom with galvanized steel chain.
*Other fabrics are also available

Dredge Barge Silt Curtain

A dredge barge silt curtain system mounts directly onto the side of a barge.  It contains displaced sediment while limiting impact to nearby areas.  This is especially important for hydraulic or mechanical clamshell dredges working in environmentally sensitive areas or busy shipping lanes.  The system is also ideal for dredging projects that need the curtain to move with the barge.  Please call us at 609-971-8810 so we can help you design a system to suit your needs.

Options

We can manufacture our turbidity barriers with any of the options below.  Please call us at 609-971-8810 so we can help you design a cost-effective barrier for your jobsite.

Floats/Depths

  • 6” dia. 12 lbs./ft.
  • 8” dia. 21 lbs./ft.
  • 12” dia. 50-60 lbs./ft. (required for skirts depths of 11′ or greater)

Skirt Fabrics

  • Impermeable coated for high abrasion resistance
  • Specialty monofilament filter fabrics for higher flow and fast current environments
  • Impermeable woven coated reinforced PVC from 13 oz./sy – 28 oz./sy
  • Nonwovens for finer sediments and hydrocarbons
  • Impermeable XR-5 for high chemical resistance
  • Impermeable XR-PW for potable water/reservoirs
  • Slit film woven geotextiles

Ballast Options

  • 1/4” galvanized steel chain
  • 3/8” galvanized steel chain
  • 5/16” galvanized steel chain
  • Dual ballast chain
  • Other ballast weights and stainless steel options are also available

Top Tension Cables

  • Single 5/16” PVC coated galvanized aircraft cable
  • Dual 5/16” PVC coated galvanized aircraft cable
  • Stainless steel

End Connectors

  • Grommeted end/tow plate and lacing grommets
  • Tool-free aluminum universal slide connectors and lacing grommets
  • ASTM marine grade aluminum Quick “Z” connectors and lacing grommets
  • Stainless steel

Reefing Lines

We can install skirt reefing lines on any of our turbidity barriers.  They allow the barrier to adjust to the contours of the floor and changing water depths.

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Disclaimer: These guidelines are for informational purposes only and are intended as illustration or general information only and are not intended as a guarantee or warranty. IWT assumes no responsibilities in connection with the use of this information.