Challenge
Waterfront improvements were needed at Naval Station Newport to support US Coast Guard operations related to navigational buoy installation and maintenance. The waterfront improvements included installing shore tie utilities, cleats, bollards, and fenders; waterfront paving; dredging between the piers to deepen the water for vessel maneuvering and berthing; and extending the sheet pile wall. The proposed in-water and waterfront work was expected to increase turbidity and suspended sediments, therefore the Project required real-time environmental monitoring of water quality as a condition of its permits.
Solution
TRC was engaged to provide the requisite continuous monitoring of turbidity during in-water improvement activities as part of a Haskell design-build team. Turbidity curtains were positioned around each active work area to contain suspended sediment and minimize transport outside of those areas. To verify that the turbidity curtains were working effectively, TRC developed and implemented a turbidity monitoring plan, which required prior approval from the US Navy and EPA. Prior to the start of dredging activities, TRC project scientists deployed three state-of-the-art buoy-mounted water quality systems. The scientists then continuously monitored data from the buoy locations and a reference location for the duration of in-water improvement work.
Results
TRC’s use of state-of-the-art technology was a cost-effective approach that successfully provided environmental protection while supporting the Navy and Coast Guards’ missions. Buoy data confirmed that turbidity curtains helped to contain suspended sediments, with minimal impacts to water quality. Government officials marked the completion of USCG waterfront upgrades in December 2015, and the facility received LEED silver certification in November 2016.