Turbidity Control for Water Areas

During dredging, piling, and other construction jobs, turbidity control can be essential to keeping your site in compliance and in control of the silt and turbidity produced by your activities. We’ve all seen the black silt fences around roadside construction, but many people wonder how to properly control turbidity in water-based applications.  Today, we will take a brief look at how the turbidity curtain works and what style is appropriate for use.

The turbidity curtain (also referred to as the silt curtain or floating silt barrier) is designed to form a protective barrier that contains turbidity and sediment to your site location. Barriers help to control the turbidity at the source and prevent contamination of waterways.

The floating turbidity barrier typically consists of a long curtain that extends to one foot from the floor of your water location. On the bottom of this barrier is ballast chain that helps to sink the heavy-duty material and keep the device in the upright position. The top usually contains a series of flotation devices that have been sewn into the top of the device. This balance of floating and sinking helps to provide complete coverage from top to bottom in your water location.

When looking for the right barrier to use in your construction location, there are many factors to take into consideration.  Factors include:

• Water velocity: One of the major distinguishing factors in turbidity control is the waterway in which you will be working in. When demanding forces such as waves and wind come into play, the strength of your barrier needs to be increased to handle increased sediment pressure.
• Site Conditions and Applications: As important as the speed of your water is site conditions such as the average velocity of wind, erosion control in your area, and general site functions.
• Soil Type: If the soil you will be producing is contaminated, there is a need for increased turbidity control to prevent this water from entering other systems.
• Project Duration: The length of your project is often a consideration for turbidity control. The longer your project lasts, the greater the potential for large volumes of sediment. Turbidity barriers need to be able to handle the water conditions in your location as well as the amount of sediment your area is producing.

The following is a brief overview of the three types of turbidity curtains:

• Type 1: The type 1 barrier is meant for the least demanding applications. It has often been implemented in calm water applications or short term projects. It should not be used in water areas that have waves or high flow rates.


• Type 2: The type 2 turbidity curtain is a favorite for mild water applications. It has been used during pile driving, demolition work, and silt control in fairly fast waterways. Companies typically recommend that the barrier not be used in water with a velocity higher than 1.5 knots or waves higher than 3 feet.


• Type 3: As mentioned before, the type 3 turbidity barrier is high in strength for your strongest water applications. It is used in dredging, demolition, and dam repair.

You can also check out all models on this Silt Curtains Overview Page.

Hopefully, this has helped give you a start to understanding the turbidity control barrier. Controlling turbidity is an essential part to having a safe construction, dredging, or maintenance operation. Please don’t hesitate to look into these control measures when handling sediment on your site.