About Us

Plan. Build. Integrate.


  • for the future.
  • for the unexpected.
  • for success.

We work with you to understand your current plans and your plans for the future. We work for you to make sure those future plans are possible. Whether you’re building in a floodplain or want the option for future expansion, our team plans for your future protection, success and growth.


  • lasting relationships.
  • better infrastructure.
  • a better solution.

Our mission is to be your trusted adviser. If the groundwork for your project isn’t done right, it will be harder for any future pieces to fall into place. Invest in a trusted adviser who will be your partner with your project’s best interest, current and future, in mind.


  • experience.
  • vision.
  • possibilities.

We work with developers, contractors, architects, owners, municipalities, and government clients locally and nationally and make every effort to integrate their vision into the groundwork. With over 60 years of experience, any new site plan, existing site redesign or overall infrastructure improvements come from active collaboration by all teams.

Have a project in mind?


CASCO Civil’s forward thinking team develops solutions in an ever-changing industry. We are advocates and advisers to our clients to fully address their unique needs, challenges, and success. In turn, our clients look to us as partners in their future.


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CASCO + R|5 History


CASCO Civil evolved from CASCO + R|5, a firm originally established by E. George Cassis, P.E. in Litchfield, Illinois in 1959.  Mr. Cassis was a Civil Engineer who relocated his firm to Kirkwood, MO in 1962 and it became incorporated as Cassis Associates, Inc. in June of 1963.  Around 1965, in a joint venture with William Tao and Associates, Cassis Associates built a new office building at 2357 59th Street in south St. Louis.


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Careers at CASCO Civil

We’re seeking the brightest and most talented minds to be part of our emerging culture.​ The successful candidate will emphasize client service and utilize their aptitude to create progressive design.


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