Quality, Service & Commitment


  • 19 Sep 2018

    INTERRA Selected As Finalist To Receive The 2018 Illinois Sustainability Award

  • 08 May 2018

    IRTBA Announces INTERRA President To Serve On Green Council Board Of Directors

  • 28 Apr 2018


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Laboratory Certifications

  • IL & WI State DOTs
  • ASTM


Firm Certifications

  • DBE with IDOT
  • MBE with City of Chicago

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U.S. Route 34 at the Canadian National (CN) Railroad Bridge Construction: “Thanks very much for a job well done throughout this entire project. Congratulations to you and your staff!” David A. Cuthbertson, PE, Senior Project Manager, Alfred Benesch & Company

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Because of the potential for improperly constructed landfills to leak highly toxic materials into surrounding soils, surface waters, and groundwater; they are necessarily tightly regulated civil construction projects. Proper and thorough inspection, testing, and documentation is imperative to ensure soil and groundwater protection.

Professionals at INTERRA have been providing consulting and landfill construction quality assurance (CQA) and documentation services since the firm’s inception.  With its broad experience, hands-on oversight from the firm’s principals, and integrated quality systems; INTERRA is easily considered to be among the top few firms that deliver consistent and reliable CQA services and expertise.

INTERRA’s landfill CQA projects (construction oversight and certification) typically include many, if not all, of the following components:

 Clay liner installation monitoring and field compaction testing

√ Associated laboratory soil testing, including proctors, Atterberg limits, sieve analysis, flexible wall and constant head hydraulic conductivity tests; and more

 Geomembrane and Geotextile installation monitoring

 Geomembrane field non-destructive testing including air pressure testing, vacuum box testing

 Geomembrane destructive peel and shear strength testing

 Drainage layer material installation monitoring and testing

 Complete documentation and certification report preparation

As can be seen from the partial list below, INTERRA has completed numerous landfill projects throughout the Midwest, totaling millions of square feet of liner experience.