Analysis, Review and Results

Image of crew during the test pile study at one of the acoustic monitoring sites on the Columbia River

Significant technical work has been completed to support the Columbia River Crossing (CRC) project. Results of analyses have been used to inform project planning, design and pre-construction activities.

CRC follows the National Environmental Policy Act (NEPA), a federal law requiring agencies that receive federal funding to consider the impacts to environmental, cultural and social resources from their proposed projects. The NEPA process led to the completion of the Final Environmental Impact Statement (EIS) in September 2011. This document is the culmination of years of planning and design discussions with project sponsors, stakeholders and the public. It builds on analyses included in the Draft EIS published in 2008 and public input received at more than 950 community briefings, workshops and public meetings.

Additional research has led to design refinements of the project’s highway, bridge, transit and bicycle and pedestrian elements. Technical analyses have been performed to address questions related to land use, traffic, tolling options and other topics. CRC has also asked independent experts to review aspects of the project, including topics such as greenhouse gas analysis and the project’s bridge type.

The project continues to conduct fieldwork necessary to prepare the project designs for construction. A drilled shaft and driven pile test project will be conducted in 2012 to evaluate the strength and stability of the soil and the construction techniques for the replacement I-5 bridge support structures. The results will be used to refine design assumptions and potentially reduce the construction cost. A test pile installation and noise reduction study was conducted in 2011 to evaluate construction noise at nearby residences and businesses, as well as assess techniques to reduce effects to fish and wildlife during replacement of the I-5 bridge.