Quality, Service & Commitment


  • 08 May 2018

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

  • 28 Apr 2018


  • 08 Dec 2017

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

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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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Starved Rock Visitor Center, Ottawa, IL

Project Background

The Starved Rock Visitor Center in Ottawa, IL  has been serving the public since 1978. For more than 30 years the Visitor Center has provided an educational resource to those interested in the Corps of Engineers and its many water resources development missions.  Connected to the Starved Rock Lock and Dam on the Illinois River, the Illinois Waterway Visitor Center has experienced several floods over the years. The basement of the building has flooded periodically affecting offices and the center’s auditorium. The Corps of Engineers awarded a contract to Hammer LGC, Inc., of Caseyville, Ill., to construct an addition to the Visitor Center.

The addition moves offices and the auditorium out of the basement. The addition also extends the balcony and adds an elevator to make the balcony accessible to those with disabilities.  The $2.6 million contract included work on Starved Rock Lock’s central control station to improve the basement, making it more flood resistant, adding a removable bulkhead outside the basement door and a new flood lift station to prevent flood waters from backing up during high water events. Other work includes structural repairs to entrance steps and brick and mortar repairs to the historic building’s exterior.  Interra provided construction quality control services for earthwork, masonry and concrete placement.

The Rock Island District of the Army Corps of Engineers operates and maintains eight locks and dams on the Illinois River. The Illinois Waterway Visitor Center is the District’s primary interface with the public providing exhibits and interpretation of the building and maintaining of the Illinois Waterway System and the history of water transportation in Illinois.