Turbidimeter vs. Nephelometer
How to Measure & Correct Turbidity
Water turbidity, especially when related to construction, has become a leading focus for regulatory agencies like the EPA, NPDES, as well as state regulatory agencies. Any construction project that exposes soil to the elements is fair-game for compliance inspections, potential fines, and possible job site shut-downs. As the saying goes: "The best defense is a good offense."
Triton Type 1 Turbidity Barrier Options For Calm Water Sediment Containment
The first line of defense is make sure the site has an updated Stormwater Prevention & Preparedness Plan (SWPPP). Note: Each state has varying requirements for submitting and posting SWPPPs. Make sure you're familiar with what's required for your job site, and if NPDES testing is needed. Even the best implemented plan may not prevent fines, if the rules haven't been adhered to.
What is Turbidity and Why Does it Matter?
Roughly defined, turbidity is the measure of water clarity. Sediment and other particles, when suspended in water, cloud the water. More than just discoloring the water, turbidity increases the water temperature and reduces the oxygen levels. When significant levels of turbidity are present, it can kill the aquatic plants and fish in the area. Additionally, the increased temperatures can cause algae blooms, which further contribute to the lack of oxygen in the water, and magnify the detrimental results.
How to Measure Turbidity
Turbidity, for land-based projects, is measured in the stormwater flows that exit the job site. If a SWPPP has been implemented, there will be controlled points of exit for the stormwater. At those points, measure the quality of the water with a turbidity meter to ensure compliance and that the stormwater controls are working properly.
For projects that border watersheds or that involve water-based construction, follow best management practices for containing any disturbed water resulting from the project. Test the water quality by taking a sample just outside the perimeter of the containment area. Check the sample's turbidity level with a turbidity meter.
Turbidity Meters Work for TSS Monitoring
The two most commonly used turbidity meters for monitoring TSS (total suspended solids) are: the Turbidimeter, and the Nephelometer. Both methods use the transmission of light through the water sample as the base for TSS monitoring (measuring the degree of cloudiness caused by suspended sediment particles). Each instrument uses a slightly different approach in how light is used to gauge the degree of water pollution. For both methods, as the light passes through the water, it bounces off suspended particles in its path. This changes the intensity of the light beam. The more sediment particles in the water; the more the scattered the light is, and the more the light's intensity level is affected. The size of the particulates also impacts the turbidity meter's measurement.
Turbidimeter: Measures how intense the light is after passing through the sample.
Nephelometer: Measures how intense the scattered the light is in the sample.
Choosing a turbidity meter usually comes down to a matter of satisfying any stated measurement requirements and budget. Turbidimeters are normally more affordable and produce an accurate but somewhat general reading, whereas Nephelometers offer a more precise measurement. For more information and pricing see: Turbidimeters For Sale.
Note: When using a turbidity meter, it is important that the sample is mixed well at the time that the measurement is taken. Suspended particles tend to settle, and the reading will not be accurate otherwise. For accuracy, it is best to also apply the same period of time for each measurement taken.
Solutions for Turbidity Problems
Whether the construction site is land-based, or water-based, GEI Works manufactures quality turbidity and stormwater control products at prices that will fit in your project's budget.
On-Water or By-Water Turbidity Solutions:
For water-based and waterside projects, Floating Turbidity Barrier is the most common solution for turbid water containment. It is very effective when the correct style of curtain for the site has been selected and properly installed. Triton Turbidity Barrier leads the industry with a wide-variety of affordable barrier styles available, ranging from DOT to Heavy-Duty. Permeable curtain and custom floating barrier solutions are also available.
Land-Based Turbidity & Stormwater Solutions:
Land based projects can vary in the size and breadth of solution needed for stormwater management. Requirements can include BMPs such as:
- Staked Turbidity Barrier
- Silt Fence
- Storm Drain Filters
- Dewatering Socks, Bags, & Tubes
- Other Stormwater BMPs by GEI Works
Regardless of whether you need to prevent turbidity or implement a solution for problem, we can help.