Quality, Service & Commitment


  • 22 Jan 2018

    Civil Engineer Needed

  • 08 Dec 2017

    INTERRA Honored With 2017 IRTBA Green Industry Achievement Award For Green Initiatives

  • 26 Oct 2017

    INTERRA To Host Ribbon Cutting With Bolingbrook Mayor Celebrating Going Green

More News


Laboratory Certifications

  • IL & WI State DOTs
  • ASTM


Firm Certifications

  • DBE with IDOT
  • MBE with City of Chicago

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Chicago O’Hare Airport, Terminal 6 Project: “We would like to extend our appreciation to you and all of your employees who worked on the Terminal 6 Project.  All work was performed professionally, accurately and thoroughly. Your commitment to quality and …

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Systemwide Quality Assurance – Illinois State Toll Highway Authority

INTERRA Services

√  Serve as liaison to various construction managers for soils and aggregate related issues

  Attend materials and progress meetings

  Verity Quality Control (QC) testing and contractor procedures

  Perform regular QA split testing and independent tests, when necessary

  Trouble-shoot problems and provide recommendations

  Complete, review, and submit daily QA reports on PROLIANCE

  Verify QC reports and prepare comparisons

  Inform R.E. of any issues, failing tests, and corrective action taken/to be taken by the contractor

Project Summary

INTERRA was retained by the Illinois State Toll Highway Authority (ISTHA) under a Systemwide Contract to perform the above listed services and tasks for numerous highway rehabilitation projects throughout northeast Illinois. In general, INTERRA witnessed the producer’s quality control activities at required frequency and verified that the contractor’s quality plan was satisfactorily implemented. INTERRA’s work covered all project/field activities related to embankment construction, subgrade, MSE walls and aggregates such as PGE, and other aggregates produced on-site.