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 transportation projects.  We understand NEPA and state environmental laws and assist agencies in navigating the process. We have developed hundreds of environmental documents for FHWA and state DOTs. Our 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. The I-5 Columbia River Crossing project addresses mobility, freight, safety, pedestrian, bike, and transit needs in the 5-mile corridor. The project 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. The Draft EIS was published in 2008, the Final EIS was published in September 2011, and a Record of Decision was issued in December 2011.

Our team developed a method to model and understand the impacts of pile driving on 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 - Best Available Environmental Technology for Fish Hydroacoustics Study, NAEP, 2012
  • National Environmental Excellence Award - NEPA Excellence for Green House Gas Emissions and Climate Change Adaptation, NAEP, 2009


  • Alaskan Way Viaduct | Parametrix

    Alaskan Way Viaduct Replacement Program

  • Parametrix NEPA Documentation - I-5 Columbia River Crossing, Vancouver Washington to Portland, Oregon

    I-5 Columbia River Crossing

  • Lynnwood Link Extension | Parametrix

    Lynnwood Link Extension

  • NMDOT On-Call Environmental | Parametrix

    NMDOT On-Call Environmental Services

  • Portland-Milwaukie LR | Parametrix

    Portland-Milwaukie Light Rail Project EIS

  • SR 520 Bridge Replacement and HOV Program