Type 1 turbidity curtains or silt curtains, as they are sometimes called, are floating barriers designed to control sediment and runoff at construction sites in calm waters. They are designed for easy deployment and meet Federal and State clean water requirements.
Type 2 turbidity curtains or silt curtains, as they are sometimes called, are durable curtains that are suitable for mild currents, waves, and wind. These barriers are designed for the control of silt and sediment during marine construction and dredging.
Type 3 turbidity curtains or silt curtains, as they are sometimes called, are suitable for use in tidal zones, rivers, and bays. This type of curtain is well suited for bridge, intake, and pipeline construction projects.
The implementation of the Clean Water Act and Phase II of the National Pollution Discharge Elimination System (NPDES) has led to major changes in operating procedures for the industrial sector. It has encouraged major product development by Elastec in order to keep up with our customers’ needs and allow them to remain in compliance with these regulations. View DOT requirements by state.
Elastec Type III Turbidity Curtain used near Golden Gate Bridge
Elastec Type III Ruffwater Screen was installed near the Golden Gate Bridge in San Francisco, CA. as part of the Crissy Field Drainage Improvement Project. Duane Bennish and Bill Andrus of the Cocoa branch were on site to help with the installation. Learn more about the project.
Turbidity Curtain Frequently Asked Questions
Are turbidity curtains in stock and ready to ship?
Account for lead times of a few weeks to produce a curtain in the factory. Most curtains will be custom and not off the shelf.
How much curtain do I need for my project?
Account for the anchor rodes. Best anchorage for turbidity curtains is a 5:1 slope. In 10′ of water you will have 50′ of anchor lines on one or both side of the curtain. Possibly into the work area.
How important are water conditions?
Water conditions (wind, wave height, flow rate) are important to ensuring proper anchorage is being used. Account for pull from intake structures, ice, debris, and wake from vessels.
How are deeper curtains affected by tidal flow?
The deeper the curtain, the calmer the conditions need to be. A curtain 30′ deep in 2 knot tidal flow will only have an effective depth of 13′ and will be difficult to keep in place even with heavy anchoring.
How deep should my curtain be?
Curtains should not touch the bottom. Flow of water is not going to be stopped by a fabric curtain. You cannot sandbag or add additional weight to the bottom of the curtain to keep it down. This will tear the curtain. Also, in calm situations, sediment can build up on the curtain making it impossible to retrieve when the work is finished. Curtains will perform better the more parallel they are to the flow.