Mark Johns, Ph.D., P.G., L.H.G. Email & Phone Number

Dr. Mark W. Johns is a Principal Scientist and Office Director in Exponent’s Environmental Sciences practice. He 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 site remedial investigations/feasibility studies and has an extensive background in site remedial activities and site cleanups. Dr. Johns has over 24 years of experience specializing 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 at mine sites, petrochemical facilities, refineries, pipelines, and manufacturing sites throughout the U.S., South America, Australia, and Europe.Dr. Johns has assisted his clients with evaluations of potential remedial activity costs and their potential sensitivity to 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 that assist in the decision analysis and can be used for business planning purposes (i.e., litigation and insurance coverages).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 appropriateness of remedial cleanup and associated costs in soils, sediments, surface water, and groundwater. He has also provided expert assistance on evaluating compliance with the National Contingency Plan (NCP) and the allocation and appropriateness of remediation costs at a variety of sites. He has successfully assisted his clients with mediation of cases of up to $150 million in value.Specialties: Licensed Geologist/Hydrogeologist, Washington, LG-1262Registered Professional Geologist, Wyoming, PG-3237Licensed Professional Geoscientist, Texas, License No. 322140-Hour Level A, HAZWOPER, 1986Advanced 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)

Listed skills include Groundwater, Remediation, Environmental Science, Environmental Awareness, and 14 others.