Lesson 7 of 6
In Progress

Module 13: Turbidity Evaluation and Tools

June 3, 2021

[vc_row][vc_column][vc_single_image image=”7549″ img_size=”full”][vc_column_text]The best method to evaluate sediment in dredging would be measuring the total suspended solids (TSS). Although real-time monitoring and data collection aren’t likely to happen any time soon, TSS can, and is, measured by first taking a water sample collection, then conducting lab tests. These tests require filtering the sediment from the water, drying, and weighing it.

Because this procedure is so time consuming, for dredging projects, turbidity monitoring systems are used to test turbidity.

The most used turbidity monitoring systems will use a submersible sensor to monitor for sediment re-suspension. These turbidity sensors can use nephelometry or backscatter technology to measure the amount of light scattered by particles in the water.

Regardless of the sensor chosen, it is important to use the same sensor model throughout a project for internally consistent data. While inter-instrument relationship models can be developed, data from different instrument designs are not directly comparable.

Each sensor will read varying amounts of light scatter from suspended particles due to the differences in light source and measurement angle. In turn, the sensors will output varying results despite measuring the same water sample. In addition to cost considerations, sensor choice should be based on expected or potential turbidity readings (low, high, or a wide range), and whether or not compliant and comparable data would be useful.[/vc_column_text][/vc_column][/vc_row]