what we do

NEPA Documentation

Streamlining environmental solutions

Parametrix is recognized as a go-to firm in the West when it comes to developing and delivering high quality environmental documentation on the most complex and controversial projects. We have completed more than 200 EISs over the past 10 years. Our environmental documents ensure accountability, improve decision-making, engage the public, and protect critical elements of the natural and built environment. Our staff routinely trains environmental professionals nationally on improving the quality of NEPA documents and streamlined environmental program approaches.

I-5 Columbia River Crossing | Parametrix
I-5 Columbia River Crossing
Vancouver, Washington to Portland, Oregon
Client: ODOT & WSDOT
Partner: David Evans & Associates

I-5 near the Columbia River experiences significant congestion. This project addresses mobility, freight, safety, pedestrian/bike, and transit needs in the 5-mile corridor. It will replace the aging I-5 bridge, extend light rail from Portland to downtown Vancouver, and improve bicycle and pedestrian facilities. This highly controversial EIS was prepared for two federal lead agencies, two state DOTs, and numerous state, regional, and local agencies and stakeholder groups.

Parametrix developed a method to model and understand the impacts of pile driving to threatened and endangered fish species. In addition, we pioneered an innovative approach for estimating GHG emissions from the proposed alternatives, allowing decision-makers to understand how various alternatives and elements would affect GHG emissions.

  • National Environmental Excellence Award for Best Available Environmental Technology, NAEP
  • National Environmental Excellence Award for NEPA Excellence, Greenhouse Gas Emissions and Climate Change Evaluations, NAEP


  • Northern Mid-Columbia EA | Parametrix

    Northern Mid-Columbia EA

  • San Juan Basin | Parametrix

    San Juan Basin Energy Connect EIS

  • Columbia River Crossing | Parametrix

    I-5 Columbia River Crossing

  • Aquatic Resources Habitat | Parametrix

    Aquatic Resources Habitat Conservation Plan EIS

  • Idaho Forestry Program | Parametrix

    Idaho Forestry Program EIS

  • Portland-Milwaukie LR EIS | Parametrix

    Portland-Milwaukie Light Rail Project EIS