Quality, Service & Commitment


  • 26 Oct 2017

    INTERRA To Host Ribbon Cutting With Bolingbrook Mayor Celebrating Going Green

  • 21 Jul 2017

    Recipient Of Service Award Thanks INTERRA for Engineering Support With Jane Byrne Circle Interchange

  • 15 Mar 2017

    INTERRA, Inc. Full-Time Field Technician Openings in Franklin, WI

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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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With this letter we provide our confidence in INTERRA in providing comprehensive field and laboratory testing for projects involving soils investigations, design and construction monitoring … Their services are consistently ontime and within budget…

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Precast Plant Inspections – IDOT, Illinois Tollway, CDOT, U.S. Navy

INTERRA Services

 Precast concrete plant inspections

Project Summary

With its certified PCI inspectors, INTERRA has provided precast plant inspection services as per the Manual of Precast Pre-stressed Concrete Products; section 1.3 Quality Assurance specifications. INTERRA has provided these services on numerous Illinois Tollway Authority, Chicago DOT, Illinois DOT, and Navy projects. Specific responsibilities have included observation of strand tensioning and fabrication details, concrete pour, tolerance measurements, observation of compressive strength tests for strand release, and final shipping strength (28 days). Final inspections for crack measurements were performed for every beam and daily inspection forms were completed and submitted to state personnel, as required.  At the time of shipping, each beam was inspected and stamped.

 INTERRA has provided inspection services at the following plants: Mid-States Concrete (South Beloit, IL); PEC (Blackstone, IL); ADL (Michigan and Wisconsin); Welch Brothers (Elgin, IL); ATMI (Aurora, IL); Utility Products (Romeoville, IL); Hoosiers (Salem, IN); Egyptian Concrete (Salem, IL); and Sanders (Indianapolis, IN). Typical structures that were inspected included: Deck Beams (Box Beams), Noise Walls, MSE Wall Panels, Drainage Structures, Retaining Walls, and Architectural Panels.