Frequently Asked Questions About Floating Turbidity Barriers

Posted February 27, 2020

In Industry Articles, Turbidity Barriers

When it comes to turbidity barriers, there’s a lot to know. With so many applications and industries that rely on them, there are many questions to answer. We’ve put together a collection of frequently asked questions to be used as a comprehensive resource for floating turbidity barriers.

What’s the Difference Between Floating Turbidity Barriers and Curtains?

Nothing! Turbidity barriers have several nicknames – floating turbidity barriers, turbidity curtains, silt curtains, silt barriers, turbidity boom, sediment filter barriers, and floating silt fences. So, if you hear any of these references, you’ll know what they mean.

What is a Floating Baffle?

Floating baffles are similar to turbidity barriers but they are designed to drop sediment out of the water column. They create channels within different bodies of water to control the rate and direction of water flow. Baffles can float along the surface, slowing the flow of water or anchored to the bottom so they can float under the waterline allowing more time for sediment particles to settle.

What is a Moon Pool Curtain?

Moon Pool Curtains are hung from marine platforms configured into a containment cell that completely encloses a dredge site, capturing all of the contaminants/sediments within. The moon pool curtains are affixed to a platform and can be adjusted to adhere to the bottom during the dredge operation.

When Should A Barrier Be Installed?

A floating turbidity barrier should be installed before construction activities are initiated. Before beginning work, install the turbidity barrier as close to the construction area as possible. The barrier must stay in place and be maintained until construction is complete and the disturbed area is stabilized.

How Do I Know What Depth a Turbidity Barrier needs to be?

The depth of your turbidity barrier depends on the specific application you are working on. The standard depth of turbidity barriers is 5 feet but they can range from 2-100 plus feet. Engineers usually make a determination if the turbidity barrier should have contact with the bottom at all times or if it needs to stay 1-2 feet off the bottom. If no indication is made then keeping contact with the bottom is the best approach in order to keep 100% containment of sediments within the curtain.

What About Variable Water Depths?

Turbidity barriers can be designed with customizable depths, tapered bottoms, and skirt reefing lines so that they can be adjusted during operations. The reefing lines can also be helpful if the barrier needs to be moved to another location or if there are tidal fluctuations.

What Section Lengths are Available?

Turbidity barriers are typically available in either 50 or 100-foot sections. Their design allows them to interlock together to create the proper-sized barrier for your project. Different section length sizes are available upon request.

What Does Installation Involve?

Each project and industry has its own needs and installation techniques must be adjusted for different situations. These variables include tidal fluctuation, current weather, boat activity, navigational hazards and interaction from fish and wildlife. Installing turbidity barriers requires staging, connecting, deploying and anchoring them at your desired location. It is necessary to also consider the type of equipment that you will need for deployments such as excavators and skiffs.

Where Should A Barrier Be Anchored?

Floating turbidity barriers should be anchored securely and keyed into the shoreline so the area where sediment may enter the water is fully enclosed. Turbidity barriers should be installed parallel to the water flow and must not be installed across channels or current. Depending upon the depth of the curtain there can be many different options to anchor turbidity barriers. These include Danforth anchors, concrete anchor blocks, metal posts, H-piles or using an existing structure like a dock or bulkhead. The turbidity barrier can be coupled with tide risers or cable rings so that the turbidity barrier has the ability to travel up and down with the tides.

How Many Anchors are Required for a Turbidity Barrier?

Proper anchoring is imperative. The number of anchors needed depends on the depth, current, and environment of your job site. Standard anchoring is 50 to 100-foot spacing. If there is tidal influence then anchors will need to be installed on both sides of the curtain. Due to the variable nature of each project, it’s best to go over the details with your sales representative.

How Often Should Floating Turbidity Barriers Be Inspected?

If the turbidity barrier is within an area that has heavy construction activity and marine traffic, it should be inspected daily. Biweekly inspections may be sufficient for calmer environments.

When Can They Be Removed?

Turbidity barriers shouldn’t be removed until the water behind it has an equal or greater clarity than the waterway. Extra precaution is needed when removing the barrier to reduce the release of accumulated sediment back into the water.

What if the Barrier Gets Damaged?

Without a fully functioning turbidity barrier, you won’t be able to properly control sediment on your worksite. Patch kits are available that can repair barriers but there may be restrictions based on the extent and location of the damage. It is a good idea to keep a contingency barrier on hand to cut down on the downtime for repair or replacement. It’s also important to consult the manufacturer on how to properly maintain turbidity barriers to prevent future damage.

High-End Floating Turbidity Barriers

A lot of these frequently asked questions can be summed up as “it depends.” Fortunately, there are experts in the field ready to help with all your sediment control needs. IWT Cargo-Guard has been at the forefront in the evolution of turbidity barriers and silt curtains. We are a design innovator of durable turbidity barriers and silt curtains that can withstand even the harshest conditions.

Founded with the purpose of developing products to protect our environment, IWT Cargo-Guard’s mission is to provide the most cost-effective products for your project. By quickly analyzing the products and services required for the project, we become an extension of your estimating department.

We carry all types of turbidity barriers as well as containment booms, marine accessories and more. Contact us and our team will work with you to ensure you have exactly what you need to keep your project in compliance and on track.

IWT Cargo-Guard