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Patrick Gagen

Patrick M. Gagen, P.G., REM

TITLE Senior Environmental Geologist
ACADEMIC BACKGROUND M.S. Geochemistry, Virginia Polytechnical Institute of Technology, 1987

B.S., Geosciences and Chemistry, University of Tennessee, 1985

EXPERTISE Hydrogeological and Geochemical Investigation/ Remediation Project Management
Advanced Environmental Management, Inc., 1992 to present:

Mr. Gagen co-founded Advanced Environmental Management, Inc. (AEM) in 1992 backed by his expertise gained through his previous experience in the Environmental Industry.  AEM has worked on landfills hazardous waste sites and UST Sites throughout Georgia and is a member of the Georgia Tank Equipment Contractors Association (GTEC), Solid Waste Association of North America (SWANA), as well as, the Georgia Association of Convenience Stores.  Mr. Gagen´s projects include:

  • UST Removals/Closure Reporting.
  • Soils Excavation remedial projects including off-site disposal as well as onsite soil volatilization and soil enhanced bioremediation.
  • Initial Site Characterizations (i.e. CAP Part-A/CAP Part-B, Site Investigation Plans) with subsurface soils and groundwater assessment.
  • Preparation of Corrective Action Plans with various remedial alternatives including Groundwater contaminant fate transport modeling.
  • Installation and operation of remedial systems including soil venting and bioremediation as well as ground water pump and treatment including bioremediation.
  • Landfill Hydrogeologic Assessments, Methane and Groundwater Monitoring Plans, Installation Reports, as well as Groundwater and Methane Monitoring.
  • Landfill Methane and Groundwater Remedial System design, installation and operation.
  • Expert Witness Testimony.
  • Landfill Methane and Groundwater Remedial System design, installation and operation.
  • Phase I and II Environmental Assessments for property transfers.
  • RCRA and Georgia HSRA Site Assessments and remediations.
  • Lead Surveys and installation of lead abatement drinking water systems.
  • Asbestos sampling and management of asbestos remediation.

Emro Marketing, Co.; 1990 to 1992:

Emro is a subsidiary of Marathon Oil, Co. and operates a chain of approximately 1600 retail petroleum stations.  At Emro, Mr. Gagen was one of three Environmental Engineers with his territory including Arkansas, Florida (Panhandle), Georgia, Kansas, Louisiana, Mississippi, Oklahoma and Tennessee including over 180 operating and closed stations.  Of these units.  Mr. Gagen managed an average of 70 to 80 active environmental projects at any given time including:

  • Real estate properties with historical releases.
  • Closed unit UST removals.
  • Newly reportable releases including line and tank tightness test failures.
  • Surface releases including discharges to nearby waterways.
  • NPDES permitting for both groundwater treatment systems and truck stop surface drainage oil/water separators.
  • All regulatory contact concerning projects.
  • Selecting and contracting with consultants and contractors to complete environmental projects.

Mr. Gagen had an annual budget of approximately $1.5 million.  This budget remained near constant over 1990 and 1991 from it´s 1989 level despite numerous newly reported releases and continued tightening of clean up standards.

OHM, Corp.; 1987 to 1990:

OHM   (formerly O.H. Materials, Corp.) is a major full service environmental consulting/contracting firm.  At OHM, Mr. Gagen served as a Hydrogeologist performing environmental and groundwater studies and remediation on a wide variety of projects including:

  • Environmental Assessments on over 20 industrial, commercial, and private properties; including the investigation of numerous manufacturing processes to determine potential environmental liabilities.
  • Served as Project Hydrogeologist responsible for QA/QC and drilling/sampling of suspected spilled-fuel sites in Florida.
  • Directed the excavation, removal, transportation, and disposal of over 600 drums containing hazardous wastes at a Tennessee site.
  • Coordinated five field crews in conducting contamination assessments at 124 underground storage-tank sites in various southeastern United States location within characterization and remediation activities for the recovery of spilled fuels at various sites in Florida.
  • Managed and aided in the design, installation and operation of several groundwater treatment and free product recovery systems.
  • Served as Project Manager over a major ground water bioremediation treatment system at an industrial site.

Additionally, Mr. Gagen has performed laboratory feasibility studies on the incorporation of nitrification inhibitors in fertilizers and on the oxidation rates of arsenopyrite and chalcopyrite in ferric chloride solution and is co-published on papers relating to both.

  • International Conference, Fluid Flow in Fractured Rocks, 1988
  • 40-hour OSHA Safety Training Course, 1987
  • Subsequent Annual 8 hr Refresher Courses to present
  • OHM Management Training Seminar
  • OHM Site-Safety and related training
  • Numerous NWWA Conferences including May 1990-Las Vegas, NV and November 1990 ? Houston, TX
  • REM Course ? March, 1992
  • SWANA Seminars ? 1996, 1997, 1998, 1999, 2000, Spring
  • 2001, Fall 2001, 2002, Spring 2003, Fall 2003, Spring
  • 2004, Fall 2004, Spring 2005                                      
  • GTEC Annual Meeting ? March 1997
  • ADEM UST Seminar ? 1996, 1997, and 1998
  • Registered Environmental Manager, REM 5104
  • National Registry of Environmental Professionals
  • Professional Geologist ? Tennessee Registration No. TN 0854
  • Professional Geologist ? Georgia Registration No. 1014
  • Professional Geologist ? North Carolina Registration No. 1279
  • Professional Geologist ? Virginia ? Registration No. 2801 001078
  • Professional Geologist ? Alabama Registration No. 167
  • Member of Solid Waste Association of North America
  • (SWANA) & Georgia Tank Equipment Contractors Association (GTEC)


  • Registered Environmental Manager (REM)
  • Georgia Registered Professional Engineer (PE)