Which Type of Silt Curtain is Right For Your Job?
You may have heard of a silt curtain before, but most likely not by that name. Silt curtains, known by many as turbidity barriers, prevent the migration of silt and sediment from work sites into nearby waterways. These structures are perfect for dredging, pile driving, remediation, and shoreline restoration projects. However, did you know that there are multiple types of turbidity barriers? Let’s review each type so you can effectively choose the right silt curtain for your job.
Questions to Consider
Before diving in, there are a few questions to ask yourself when choosing a silt curtain that will best accommodate to the job at hand and the surrounding water conditions. Consider the following questions when choosing between the types of silt curtains we are about to investigate.
- Am I completing a short-term or long-term project?
- How large are the sediments?
- What is the deflection angle relative to the current?
- Is debris likely to be encountered?
- What are the USCG requirements?
- Is there stormwater intrusion?
- What is the length of deployment?
- How deep is the water?
- Is it high-tide or low-tide?
- How is the velocity of the water flow?
Type I
The first type of silt curtain, or turbidity barrier, is apt for calmer waters such as ponds, lakes, streams, and ditches. When it comes to type 1 silt curtains, there are two versions: economy and DOT.
Economy
Type 1 economy silt curtains are manufactured from impermeable lightweight reinforced PVC coated fabric. Their compact design allows for easy storage while their affordability can help you meet a tight budget. If you’re working in a small pond or protected inland area, the economy is the way to go.
DOT
Type 1 DOT silt curtains are used in areas that require DOT (Department of Transportation) regulations. These come in both impermeable and permeable varieties. If you’re working in a protected waterway with light wind and calm currents, DOT is your best bet.
Type II
The second type of silt curtain is designed for moving waters with wind, waves, currents, and tidal changes. Such locations include inland coastal waterways, estuaries, rivers, and tidal ponds. They are manufactured using high-strength fabric, complete with heavy-duty tension members, aluminum stress plates, and bottom skirt corners. Depending on the water conditions, both impermeable and permeable skirt options are available. If you’re working on rip rap installation (to keep the curtain in contact with the bottom) or sediment control in moving waters, go with type 2.
DOT
Similar to type 1, type 2 silt curtains have a DOT variety in order to comply with regulatory requirements. Whether you’re doing marine work along inland coastal waterways or dealing with tidal changes, they will help you get the job done in moderate water flow conditions.
Type III
The third type of silt curtain is perfect for robust waters rich with high winds, currents, and tides such as rivers, bays, and shorelines. They are custom-made depending on your project’s specific requirements and the proper floatation size, skirt depth, and materials. When you need a barrier that can withstand the elements and handle adverse job-site conditions, type 3 is your only option.
DOT
Just like type 1 and type 2, type 3 silt curtains can be made to meet DOT standards. They are manufactured with a permeable skirt to effectively filter our silt and sediment. If you’re working in wild rivers, harbors, and tidal zones, this is the best type of silt curtain for your job,
Options to Consider
Now that you know the three major types of silt curtains, there are additional options to consider. Turbidity barriers are designed specifically for your job site and budget. A host of float sizes, skirt fabric options, end connectors, adjusting lines, ballasts, and top tension cables are available. Additionally, silt curtains also come in a staked variety which is ideal for controlling water flow at job-sites that are adjacent to waterways. The options are seemingly endless.
Are You Ready to Choose the Silt Curtain For Your Job?
For the most effective and customized silt curtains available, there is only one name to turn to: IWT Cargo-Guard. Our expert team will provide you with the products you need to get the job done while protecting our environment. Whether you are restoring the shoreline or stabilizing the soil, we have everything you need for a successful project. Call us today to determine which type of silt curtain is right for you along with any other equipment you might need.
