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Mark W. Johns, Ph.D., P.G., LG

Principal Scientist

Environmental Sciences

Professional Profile


Dr. Johns specializes in the evaluation of transport and fate of environmental pollutants, remediation, and cost allocation and apportionment. He has been the principal investigator on numerous remedial investigations and feasibility studies and has an extensive background in site remediation and cleanup. Dr. Johns has over 24 years of experience in the fields of geology, groundwater, and geological oceanography. He has been responsible for the technical direction of several large CERCLA-, TSCA-, and RCRA-related environmental studies pertaining to heavy metals, dioxins, PCBs, hydrocarbons, and chlorinated solvents. These studies have involved mine sites, petrochemical facilities, refineries, pipelines, and manufacturing sites throughout the U.S., South America, Australia, and Europe.

Dr. Johns has assisted clients with evaluations of remedial approaches and costs, and the influence of various site conditions. He has developed and applied innovative cost analysis tools using Monte Carlo uncertainty simulations to evaluate a range of probabilities and sensitivities involved in decision analysis, risk, and business planning purposes (i.e., litigation and insurance coverage).

Dr. Johns serves as an expert witness in environmental transport and fate and has provided expert testimony, reports, and declarations on the origin, fate, and transport of pollutants and the appropriateness of remedial cleanup and associated costs in soils, sediments, surface water, and groundwater. He has also provided expert assistance in evaluating compliance with the National Contingency Plan (NCP) and the allocation and appropriateness of remediation costs at a variety of sites.

  • Ph.D., Geological Oceanography, Texas A&M University, 1985
  • B.S., Geological Oceanography, University of Washington, 1977

    • Licensed Geologist/Hydrogeologist, Washington, #LG-1262
    • Registered Professional Geologist, Wyoming, #PG-3237
    • Licensed Professional Geoscientist, Texas, #3221
    • 40-Hour Hazardous Waste Operations and Emergency Response - Level A, HAZWOPER, 1986
    • 8-Hour HAZWOPER Managers and Supervisor Training
    • 8-Hour OSHA Annual Refresher, 2007
    • Advanced Health and Safety for Hazardous Waste Site Management, 1987
    • Registered Washington State Department of Ecology Underground Storage Tank Program, 1990
    • Division of Environmental Geosciences Charter Member, 1993
    • AAPG Division of Environmental Geosciences Charter Member, 1993