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.

Alaskan Way Viaduct | Parametrix
Alaskan Way Viaduct Replacement Program 
​Seattle, Washington
Client: WSDOT
Partner: Parsons Brinkerhoff

At $3 billion, the Alaskan Way Viaduct Replacement program is one of the largest transportation investments underway in Washington State. The deteriorating Alaskan Way Viaduct carries more than 110,000 vehicles per day through Seattle along the City’s waterfront. Because the project was so controversial and critical to the transportation network, WSDOT knew that a typical EIS wouldn’t work; this EIS needed to clearly articulate the effects of a multi-year project in the heart of downtown Seattle. WSDOT and Parametrix pioneered new ground by creating a reader-friendly EIS document based on four concepts—tell a story, make it visual, engage the reader, and make it brief.

The Draft EIS was completed in nine months, won several local and national awards for its readability and design, and set a new standard for how environmental documents are being written in Washington State. Other EISs completed include a 2006 Supplemental Draft EIS, the South Holgate to South King Street Viaduct Replacement Project EA, a 2010 Supplemental Draft EIS, and a 2011 Final EIS and Record of Decision. Each of these environmental documents was delivered in less than one year.

  • Environmental Excellence Award for Excellence in Environmental Research, FHWA
  • National Honor Award, ACEC
  • President’s National Environmental Excellence Award, NAEP
  • Award of Merit, International Society for Technical Communication


  • 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