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St. John - Mittelhauser & Associates (SMA) was founded in 2007 by Ron St. John and Hank Mittelhauser. Ron and Hank began working together in 1985 when Ron joined Mittelhauser Corporation (MC). Prior to Ron’s joining MC, the staff was primarily composed of chemical engineers performing permitting and remediation services for private industrial clients. MC recognized that remediation of a site required expertise of the geology and hydrogeology of the site, delineation of subsurface impacts, and developing a sound Conceptual Site Model (CSM), and Ron’s expertise in those areas was well known. Together they expanded the company to 135 people, with offices in the Midwest and on the West Coast. Essentially, all the work performed by MC was investigation and remediation of petroleum and industrial sites.

In 1995 MC was sold to Clayton Group Services, which was subsequently sold to Bureau Veritas. Ron and Hank stayed with the acquiring companies in senior management roles until 2007. At that time, they decided to return to their small-company roots, where they would have direct responsibility for the company direction and performance, to found SMA. In January 2009, several senior staff, that had worked with Ron and Hank for over 15 years, joined SMA and are now part of the SMA senior management team.

Currently SMA employs geologists, engineers, scientists, field staff, data analysts, and support staff in their Downers Grove, IL, Hartford, IL, Rockford, IL, and Indianapolis, IN offices. Almost all revenue is derived from environmental consulting, investigation, remediation, and data management and 3D visualizations.

Senior Staff



Ronald B. St. John, PHG, CPG

Principal Hydrogeologist


Gary R. Perkowitz, PG

Principal Geologist


Daniel J. Lombardi, PG

Principal Hydrogeologist


Steve Swenson, PG, CHMM

Senior Geologist


Bridget A. Lombardi

Project Operations Manager


Mark G. Detroy

Regional Office Manager


Perre E. Burns, PhD, PE

Senior Environmental Engineer


Michelle M. Wagner, PG

Senior Geologist


Eduardo Gasca, PE

Senior Environmental Engineer