Construction Turbidity Monitoring

Construction projects near lakes, rivers, estuaries and coastal areas can pose a threat to the surrounding water quality. To protect ecosystems, authorities often require monitoring programs to be put in place, where turbidity is used as an indicating parameter for potential releases from construction sites. Real-time turbidity monitoring systems help to meet compliance and ensure minimal environmental impact.

Typical Construction Turbidity Monitoring System

Construction sites near water bodies often have potential to release sediments or other contaminants into the water. To mitigate this, barriers called silt curtains or turbidity curtains are typically set up around the work area. To ensure the silt curtains are achieving their desired effect, data buoys equipped with turbidity sensors are placed just outside the turbidity barrier to detect increased sediment levels and send alarms to notify project personnel of high turbidity events.

Such measures are often required by authorities responsible for environmental protection, and project specifications may call for a monitoring system in accordance with given standards such as NS9433, the Norwegian Standard for turbidity measurement. A typical system consists of a reference buoy for background measurements and one or more control points located a short distance from the area impacted by construction works.

Buoy-based systems normally work best for construction turbidity monitoring because they can easily be placed and moved as needed. The NexSens CB-150 data buoy is an excellent platform for such applications. It is light enough to be deployed from a small boat but packs a sufficiently large power supply with its on-board battery and solar panels to support long-term, continuous monitoring, even during winter conditions. An M550 solar marine light can optionally be mounted on top of the buoy tower for visibility at night.

Like all CB-series buoys, the CB-150 supports the NexSens X2-CB data logger for waterproof connection of turbidity sensors. Data is transmitted wirelessly in near real-time data to the WQData LIVE web datacenter, where email or SMS alarms are configured to alert project personnel when critical thresholds are exceeded.

The X2-CB logger is compatible with nearly all industry-standard turbidity sensors from leading manufacturers such as YSI, Eureka, Campbell, In-situ and others. Multiple sensor ports on the X2-CB logger accommodate placement of sensors at various depths, or the addition of other instruments like GPS receivers, weather stations, and current profilers.

In other short-term applications, the CB-50 data buoy with X2-SDL data logger is a suitable alternative. The CB-50 system is fully submersible and easily portable.