Phase III Environmental Services
Nicor Gas replaced approximately 10-miles of aging high pressure, transmission pipeline line with a new twenty-four inch diameter steel pipeline in Jo Daviess County, Illinois. The Dubuque Line serves as the primary natural gas transmission line between the northwest Illinois origination point and the Nicor distribution area.
GSG performed pre-construction environmental services to identify all potential environmental concerns within the proposed project area. A desktop review of available resource information was performed prior to field investigations to identify known environmental concerns. An initial field reconnaissance was then performed to verify existing conditions and document features not identified in the desktop investigation. Formal wetland delineations were performed during the growing season to identify jurisdictional boundaries of all potential waters of the US. A geographic information system (GIS) was utilized to develop project mapping that the project design engineers incorporated into project design drawings. Consultation with the USACE was performed to ensure the project met the conditions of the Nationwide Permit program.
Threatened and endangered species surveys were performed to determine presence/absence. In cases where presence/absence could not be determined, GSG coordinated with Illinois DNR regulators to develop project approaches that would have no effect on the potential species presence.
GSG stormwater engineers prepared runoff estimates to determine BMP requirements during construction. A Stormwater Pollution Prevention Plan was developed to protect environmental features and minimize soil erosion during the planned construction.
GSG also provided construction-phase inspection and wetland and streambank restoration and stabilization.