It is very difficult to pin point the exact guideline for installing turbidity curtains. The conditions vary from one place to another and the technician has to take note of all the affecting factors before suggesting a turbine curtain. However, there are certain basic rules that hold good in all the locations irrespective of the conditions of that location.
The Three Golden Rules That Must Be Followed
There are three rules that turbidity barriers must follow irrespective of the conditions in which they are employed.
RULE 1: When the turbidity curtains contain the silt and the sediment, it must be held in the area of containment for a sufficient length of time. This time duration is determined by the amount of time the silt takes to settle down to the water body's bed. The area of containment must also be wide enough such that silt will get accumulated evenly over the area.
RULE 2: The size of the silt particles must be evaluated to determine the settling time for the silt particles. Silt samples must be collected at five to six random spots along the water body and analyzed. The turbine barrier expert will then specify the perforation ratio of the barrier fabric that should be used and also the settling time.
RULE 3: The current in the containment area must be considered before deciding on the height of the barrier. Over a period of time, silt will accumulate to the top of the barrier and if the current is strong enough, water will flow over the barrier. This can be preceded in two ways.
Choosing a turbidity screen which is above the water surface by 3 to 4 feet will ensure that the water will stay within the barrier irrespective of the silt accumulation. Choosing a wide area of containment will ensure that the silt and sediment spreads evenly, avoiding mounds of silt and possibility of the water current flowing over the barrier.
Other Guidelines to Be Followed
The turbine barrier installing technician should be flexible enough to work around the conditions to ensure the optimum operation of the barrier. For example, if the water current is too string, there is no other option than to use a perforated barrier fabric. A non perforated barrier fabric will increase the pressure on the reinforcement stakes, reducing their lifespan.
Similarly, there are other obstacles which have to be faced in other locations. The important thing is to have knowledge about the different types of turbidity curtains available and use them in a way which is best suited to the location of installation.