Highway construction usually requires large areas of disturbance in order to be cost efficient. This creates the potential for accelerated erosion and impacts on local streams and lakes. Additional tools, or Best Management Practices, need to be tested, demonstrated, and refined to obtain reductions in sediment and, in particular, turbidity beyond current practices.
This research targets increasingly stringent turbidity limits in runoff as imposed by NCDENR. Of particular concern is the water quality of runoff from the construction of I-485 around Charlotte and the impact of runoff on nearby watersheds. Work will be coordinated with the primary Contractor.
The Objectives of the project are to:
- Compare a variety of erosion control systems for effectiveness, including combinations of standard straw, polyacrylamide, rolled erosion control products, and bonded fiber matrix hydromulchingInstall, evaluate and improve systems to increase sediment and turbidity control in standard and modified traps and basins
- Establish baseline information on stream water quality and stability in small watersheds as affected by the installation of standard and innovative erosion, sediment and turbidity control systems
- Establish stream water quality and stability in small watersheds which are impacted by NCDOT and, by comparison other commercial/residential development
- Establish the current stability of Long Creek and four tributaries and measure changes annually
- Conduct annual benthic macroinvertebrate and habitat surveys at five points along Long Creek and in two tributariesConduct workshops, demonstration, and training for staff from NCDOT, NCDENR, local programs, and private contractors
The project is significant in that it will provide an evaluation of various methods to reduce erosion and off site movement of sediment and turbidity on large, active construction sites. We will test and improve, as needed, several new sediment trap and basin designs to minimize sediment and turbidity at their outlets using PAM and modifications to the typical rock outlet. It will also be important to monitor water quality and stream stability as impacted by different levels of erosion and sediment control efforts during active disturbance.
