In Situ Water Quality Monitor at Naver Bridge

Managing water and runoff on construction sites is both a critical and challenging task. Protecting the eco-system and water environment is a shared responsibility, and at Wills Bros, we take this responsibility seriously. Our Ecology and Environmental Team works closely with site teams to regularly monitor water quality using handheld probes. On projects that involve in-channel works, managing silt-laden water becomes particularly difficult—especially during night shifts when visibility and response times are limited.

Recognizing these challenges, the Wills Bros team has implemented innovative solutions to support both the Ecology and environmental team, and site team. One such solution has been deployed at the Naver Bridge project: the use of real-time monitoring sondes. These sondes provide continuous water quality data at custom-set 15-minute intervals and are equipped with alarms that trigger when parameters exceed permitted levels—such as when silt or concrete enters the watercourse. This real-time feedback allows our teams to respond quickly and take corrective action, helping to minimize the impact of our construction activities on aquatic ecosystems and overall water quality.

Accessing the data

The sonde can be used as a handheld water quality monitoring device by connecting to the MantaMobile Bluetooth device via an underwater cable. A mobile device then pairs with the MantaMobile through Bluetooth, allowing real-time data viewing. Additionally, the sonde can be left in the river for continuous, long-term monitoring and data collect by using pelicase unit equipped with a solar panel that recharges the internal battery using solar energy. An integrated SIM card within the Pelicase enables real-time data transmission to the Outpost system, allowing users to remotely access water quality information. An alarm system has also been configured to send email notifications to users, alerting them to high or low readings for any monitored parameters of interest.

Reasons to invest in Water Quality Monitoring Sondes

Wills Bros has chosen to invest in in situ water quality monitoring sondes for several key reasons, including environmental and ecological protection, health and safety, and the benefits of reduced labour, cost, and time. These factors are especially critical for the A836 Naver Bridge Replacement Scheme, given the nature and location of the works.

Environmental and Ecological Considerations

The A836 Naver Bridge Replacement Scheme includes the construction of over 450 metres of new carriageway and a 65-metre, three-span bridge. The new structure is situated just south of the existing bridge over the River Naver, approximately one mile south of Bettyhill. As the majority of construction activities take place within the river channel and close to the watercourse, posing potential risk of pollution to the River Naver. The project footprint overlaps with the River Naver Special Area of Conservation (SAC), which has been designated for the Annex II species freshwater pearl mussel and Atlantic salmon. The River Naver, along with the River Borgie, represents the northern most part of the freshwater pearl mussels’ range in the UK.

To protect the river and its surrounding ecosystem and associated protected species, Wills Bros have installed in situ water quality monitoring sondeson both sides of the River Naver. These sondes record data every 15 minutes, providing continuous monitoring of water quality. This enables Wills Bros Environmental team and the project site team to assess and respond to the real-time environmental impact of our construction activities and evaluate the effectiveness of mitigation measures implemented on site, without having to access or enter deep, tidal, fast-flowing water.

The sondes are also set up with alarms configured to trigger when turbidity levels exceed 80 NTU or when pH values rise above 9 or fall below 6. These thresholds are based on the nature of the works, the location of the project, licences, and our ongoing commitment to environmental protection.