Farrukh Mohsen, Ph.D., P.E.

Dr. Mohsen has 34 years of experience in hydrogeology and groundwater flow and contaminant transport modeling. He has applied his technical strengths in assisting corporate clients nationwide by providing expert opinions in litigation, environmental compliance, and liability allocations. Dr. Mohsen focuses primarily on developing an understanding of the transport and fate of constituents in the subsurface in both groundwater and soil vapor. He has helped his clients by determining the source of groundwater contamination, designing and evaluating remedial options, conducting risk assessments and regulatory negotiations, achieving environmental compliance, delivering public presentations, providing expert opinions, and refuting claims by other experts. He serves as both a testifying and consulting expert.

Prior to joining Exponent, Dr. Mohsen worked as Senior Project Manager at Gannet Fleming and Environ International Corporation. He has been a Visiting Professor at Rutgers University, a Visiting Fellow at Princeton University, an Associate Professor at the University of Petroleum and Minerals, and a lecturer at Bangladesh University of Engineering and Technology.

Murphy BL, Mohsen F. Reconstructed plume method for identifying sources of chlorinated solvents. Environmental Forensics 2010; 11:60–71.

Mohsen F, Ayyaswami A, Bryant M, Lacko P. Numerical simulation of substrate-limited degradation: Comparison to field data Proceedings, 6th International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Monterey CA, May, 2008.

Ayyaswa A, Mohsen F. Transport modeling to assist design of enhanced dechlorination system. Proceedings, 5th International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Monterey CA, May 22–25, 2006.

Mohsen F, Ayyaswami A. Transport modeling to assist in designing an enhanced dechlorination system, Paper II. Proceedings, 3rd European Conference on Oxidation and Reduction Technologies for Ex-Situ Treatment of Water, Air and Soil and In-Situ Treatment of Soil and Groundwater, Gottingen, Germany, September 11–13, 2006.

Cecan L, Natitus F, Song X, Mohsen F. Groundwater Natural Resource Damage Assessment: A modeling approach. Proceedings, MODFLOW and More 2006: Managing Ground Water Systems, Denver, CO, 2006.

Cecan L, Mohsen F, Kraft B. Differences between concentrations measured in a monitoring well versus concentrations measured in a pumping well. Proceedings, MODFLOW 2004 Conference, Prague/Carlovy Vary, Czech Republic, 2004.

Mohsen MFN. Surface water-ground water interactions and modeling applications. Chapter 1. In: Contaminated Groundwater and Sediments: Modeling for Management and Remediation. Chien CC, Medina MA, Jr., Sleep B, Zheng C (eds), CRC Press, Boca Raton, FL, 2004.

Mohsen F. Tidal exchange and oscillations contaminated ground water and sediments-modeling for management and remediation. Chien CC, Medina MA Jr., Pinder GF, Reible DD, Sleep BE, Cheng C (eds), Eos,CRC Press, p. 29–37, 2004.

Mohsen MFN. Mixing zones: Surface and ground water interactions. In: Environmental Modeling, Theory, Practice, and Future Directions. Prepared by the Environmental Modeling Panel under the auspices of the DuPont Company, Today Media, 2002.

Mohsen MF, Scott M. Methodology for assessment of sites with subsurface PCB-containing soils. Proceedings, Contaminated Sites Assessment and Remediation—New Perspectives, Provincia of Milan, Environment Central Direction, Centro Congressi, November 2000.

Page RH, Watkins ML, Sieber E, Mohsen MFN. Operational definition of NAPL: From soil analysis. Proceedings, of the ASCE Water Resources in the Urban Environment Conference, Chicago, IL, 1998.

Singhal N, Mohsen F, Scott M. Development of methodologies for assessment of sites with subsurface PCB-containing soil. Proceedings, IPENZ Conference 98, Auckland, New Zealand, January 1998.

Mohsen MFN. Adsorbed concentration vs. lab-reported concentration in soil. Ground Water 1994; (32)3.

Simpson B, Mohsen MFN. Plan ahead: Using carrying capacity models. The Association of New Jersey Environmental Commissions Report, Summer 1992.

Yim CS, Mohsen MFN. Simulation of tidal effects on contaminant transport in porous media. Journal of Ground Water 1992; January/February.

Yim CS, Sternberg YM, Mohsen MFN. Practical solution for estimating the time required for aquifer restoration: An update. Proceedings, HMC ’91-South Conference, Houston, TX, April 1991.

Mitha SA, Mohsen MFN. Effect of scale on dispersion in chlorine contact chambers. Canadian Journal of Civil Engineering 1990; April.

Bhuiyan MA, Allayla RI, Hossain T, Ishaq AM, Mohsen MFN. Solution of the transport equation by collocation method in conjunction with adaptive hermite element family. Water Resources Research 1990; 26(11):2661–2677.

Page RH, Cederberg GA, Mohsen MFN. Ground water extraction system to control both vertical and horizontal migration of contaminants. Proceedings, 11th National Conference, Hazardous Material Control Research Institute, Washington, DC, November 1990.

Nielson JM, Yim CS, Mohsen MFN. Simulation of subsurface barrier wall performance near a river. Proceedings, 11th National Conference, Hazardous Material Control Research Institute, Washington, DC, November 1990.

Bhuiyan MA, Mohsen MFN, Elmasri MZ. Microtubes as an alternative to pressure-compensating emitters in drip irrigations systems. Hydrosoft 1990; 3(2).

Khondaker AN, Allayla RI, Mohsen MFN. A variational finite element solution for the Navier Stokes equation in two dimensions. Hydrosoft 1990; 3(1).

Siddiqi MS, Mohsen MFN. An analytical solution of the transient heat conduction equations under steady flux and temperature-dependent boundary conditions. Arabian Journal of Science and Engineering 1988; 13–1.

Mohsen MFN, Pinder GF. Collocation with “adaptive” finite elements in Buckley-Leverett problem. International Journal for Numerical Methods in Engineering 1986; 23:121–131.

Huque M, Mohsen MFN, Baluch MH. Method of weighted residuals as applied to higher order, non-linear, two-point boundary value problem. International Journal of Computer Mathematics 1986; 18:341–354.

Mohsen MFN. Author’s reply #2 to discussion by H.J. Welge of “Modification of Welge’s Method of Shock Front Location in Buckley-Leverett Problem for Non-Zero Initial Condition.” Journal of the Society of Petroleum Engineers—Reservoir Engineering 1986, September.

Mohsen MFN. Author’s reply #1 to discussion by Noaman El-Khatib of “Modification of Welge’s Method of Shock Front Location in Buckley-Leverett Problem for Non-Zero Initial Condition.” Journal of the Society of Petroleum Engineers—Reservoir Engineering 1986, July.

Khondaker AN, Mohsen MFN, Al-Layla RI. A variational approach to Navier-Stokes equation. Proceedings, ASCE Conference on Advancement in Aerodynamics, Fluid Mechanics, and Hydraulics, University of Minnesota, Minneapolis, MN, June 1986.

Mohsen MFN. Modification of Welge’s method of shock front location in the Buckley-Leverett problem for non-zero initial condition. Society of Petroleum Engineers Journal 1985; 521–523. Also published in the Transactions of Society of Petroleum Engineers, 1985.

Kinmark IPE, Mohsen MFN. Convergence character of a solution to the transport equation with polynomial initial conditions. International Journal for Numerical Methods in Fluids 1985; 5:293–297.

Mohsen MFN, Pinder GF. Analytical solution of the transport equation using a polynomial initial condition for verification of numerical simulators. International Journal for Numerical Methods in Fluids 1984; 4:701–707.

Mohsen MFN, Pinder GF. Orthogonal collocation with 'adaptive' elements. International Journal for Numerical Methods in Engineering 1984; 20:1901–1910.

Mohsen MFN, Baluch MH. Influence function in numerical analysis of bending of thin plates. Transactions of the Canadian Society of Mechanical Engineers 1984; 8(2):103–114.

Baluch MH, Mohsen MFN, Ali AI. Method of weighted residuals as applied to non-linear differential equations. Applied Mathematical Modeling 1983; 7.

Kouwen N, Mohsen MFN. Increased sump capacity. Canadian Journal of Civil Engineering 1983; 19(2):232–240.

Mohsen MFN, Baluch MH. An analytical solution of the diffusion convection equation over a finite domain. Applied Mathematical Modeling 1983; 7(4):285–287.

Mohsen MFN. Integration of exponential expressions in natural coordinates over finite elements. International Journal for Numerical Methods in Engineering 1982; 18:1401–1419.

Mohsen MFN. Some details of the Galerkin finite element method. Applied Mathematical Modeling 1982; 6.

Mohsen MFN. Contour plotting in finite elements. Journal of the Institution of Engineers of Bangladesh 1981; 9(3).

Mohsen MFN, Farquhar GJ, Kouwen N. Gas migration and vent design at landfill sites. Water, Air and Soil Pollution 1980; 13.

Mohsen MFN, Farquhar GJ, Kouwen N. Modeling methane migration in soil. Applied Mathematical Modeling 1978; 2:294–301.

Mohsen MFN. Authors reply to discussion by Walter A. Mechler of “Removal of Air Pockets from Water Lines.” ASCE Journal of Hydraulics Division, HY3 1976; March.

Wisner PE, Mohsen MFN, Kouwen N. Removal of air from water lines by hydraulic means. ASCE Journal of Hydraulics Division, Proceedings, Paper 11142:243-257, 1995.

Presentations

Mohsen F, Ayyaswami A, Bryant M, Lacko P. Numerical simulation of substrate-limited degradation: Comparison to field data. The 6th International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Monterey CA, May, 2008.

Mohsen F, Ayyaswami A. A practical application of numerical simulation of substrate limited degradation. Proceedings, 9th International In Situ and Onsite Bioremediation Symposium, Baltimore, Maryland, May 7–10, 2007.

Mohsen F. Sensitivity of contaminant transport model in tidally influenced aquifers to storage coefficient. Presented at the Geological Society of America Annual Meeting, Philadelphia, PA, October 22–25, 2006.

Mohsen F, Ayyaswami A. Transport modeling to assist in designing an enhanced dechlorination system: Paper II. 3rd European Conference on Oxidation and Reduction Technologies for Ex-Situ Treatment of Water, Air and Soil and In-Situ Treatment of Soil and Groundwater, Gottingen, Germany, September 11–13, 2006.

Ayyaswami A, Mohsen F. Transport modeling to assist design of enhanced dechlorination system. The 5th International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Monterey CA, May 22–25, 2006.

Cecan L, Natitus F, Song X, Mohsen F. Groundwater Natural Resource Damage assessment: A modeling approach. MODFLOW and More 2006: Managing Ground Water Systems, Denver, CO, 2006.

Simpson B, Mohsen MFN. Plan ahead: Using carrying capacity models. Association of New Jersey Environmental Commissions, summer 1999.

Mohsen MFN, Page RH. Estimating leachate concentrations from extraction test results. Proceedings, Petroleum Hydrocarbons and Organic Chemicals in Ground Water: Prevention Detection, and Remediation Conference, Houston, TX, November 12–14, 1997.

Mohsen MFN, Cecan L. Practical examples of transport modeling with biodegradation in the vadose and saturated zones. Intrinsic Bioremediation Conference, Annapolis, MD, October 18–19, 1995.

McLane CF, Dielman SA, Mohsen MFN. A simple analysis of landfill drum corrosion and waste release to ground water. Presented at the National Ground Water Association Conference, Washington, DC, October 1991.

Cederberg GA, Sorauf CM, Mohsen MFN. An evaluation of strategies to contain contaminated ground water within site boundaries. Presented at the Symposium on Aquifer Rehabilitation and Case Studies, American Geophysical Union Spring Meeting, May 1989. Published in EOS Transactions, AGU, April 1989.

Khararjian HA, Mohsen MFN, Siddiqi RH, Al-Layla RI. Theoretical and experimental evaluation of single-activated sludge. Paper presented at the ASCE, Environmental Engineers Specialty Conference, Northeastern University, Boston, MA, July 1985.

Mohsen MFN. Numerical experiments using 'adaptive' finite elements with collocation. Presented at the 5th International Conference on Finite Elements in Water Resources, Burlington, VT, June 1984.

Gadhib AH, Baluch MH, Mohsen MFN. Improved collocation point location in the influence function method as applied to the bending of thin elastic plates. Presented at the First Saudi Engineering Conference, Jeddah, Saudi Arabia, May 1983.

Mohsen F, Gadhib A, Baluch MH. Influence functions in the numerical analysis of bending of thin elastic plates. Presented at CANCAM 83, University of Saskatchewan, Canada, May 1983.

Kouwen N, Mohsen MFN. Increased sump capacity for vertical pump intakes. Presented at the Winter Annual Meeting of ASME (Fluid Engineering Division), Washington, D.C., November 1981.

Providing litigation support on remediation cost allocation of a large ground water VOC and perchlorate plume in Orange County Water District.

Developed an expert report based on transport of NAPL phase PAH from a gas station in Baltimore, MD and subsequent vapor intrusion into the living quartes of a neighboring home.

Provided senior-level oversight for the development of a groundwater flow model contaminant transport model of a large industrial facility in Henderson, Nevada, and assisted in regulatory negotiations on remediation of a massive perchlorate plume.

Provided expert opinions on the cause of escape of about 100,000 gallons gasoline out of secondary containment system at a bulk storage facility in Ohio.

Used groundwater flow modeling to support expert opinions for a litigation support case involving groundwater contamination with MtBE in Maryland. The model results identified a small subset of plaintiffs who could have been affected by contaminated groundwater emanating from the suspected source. Subsequently, developed a contaminant transport model to determine the exposure to the affected plaintiffs.

Developed a groundwater flow model to support expert opinions for a class action suit involving groundwater contamination with MtBE in Maryland. The model results indicated the likely source to be upstream of the gas station alleged by the plaintiffs.

In an insurance cost recovery case in New Jersey, conducted historical reconstruction and technical review to establish that it was highly unlikely that poor workmanship by the gas pipeline contractor caused the presence of fluids in the pipeline, as alleged by the owner gas company.

Provided litigation support by conducting a forensic investigation to determine whether numerous tar blobs that appeared in a river in Maine originated from a nearby manufactured gas plant.

Assisted managers of a coal power plant in Maryland with investigation and analyses to be presented at a meeting with neighbors, to establish the degree to which constituents leaching out of coal ash are affecting offsite residences.

Developed a groundwater flow and contaminant transport model for estimating PCE exposure to offsite residents, for a large facility in Norco, California, with complex geology.

Used free-phase transport computations to establish the time of travel of floating PAH products originating from the suspected UST to establish the time period when the release could have started in an insurance cost recovery litigation support case in Long Island, New York.

Provided expert testimony using a thorough technical review of the project groundwater modeling results, to establish that the injection system, as designed, was destined to fail by overflowing at the Savage Well superfund site in New Hampshire.

Provided expert report for an insurance cost recovery on damage caused to six homes because of dewatering in the process of constructing the West Sacramento Force Main in California.

Provided litigation support for a multinational company on a large groundwater Natural Resource Damage claim for an industrial facility in New Jersey that was contaminated with PAHs (including MtBE). Defendants based their case in part on the grounds that state statutes preclude using the allegedly contaminated aquifer for potable water supply.

Provided litigation support to refute the computations by the state’s expert on a groundwater Natural Resources Damage claim for an industrial facility in New Jersey, for a multinational company affected by PCE contamination.

Provided expert report for an insurance claim, in Sonoma County, California, for damage to a private well caused by the use of compressed air in its construction.

Provided expert report for an insurance cost recovery on damage caused to seven homes in Huntington Beach, California, because of dewatering in the process of replacing a 54-inch sewer main with a 108-inch one.

Provided senior-level technical support to a fortune 500 company in anticipation of a lawsuit involving perchlorate contamination.

Provided senior-level technical advice on the groundwater modeling aspects of a regional model for the Santa Clarita Valley, California, in cost recovery negotiations for perchlorate contamination of public water-supply wells.

Evaluated various pump-and-treat remedial options, and optimized location and pumping rates of extraction wells for a site in Sacramento, California, with an extensive offsite PCE plume.

Provided expert opinion for a client based on a risk assessment, to refute plaintiff’s claim that an asphalt/concrete cap over contaminated soil on its site required repair in a court-mandated mediation case in New Jersey.

Provided contaminant transport modeling support/supervision in pursuing monitored natural attenuation (MNA) at several sites in New Jersey and other states.

Served as a hydrogeologist expert witness for litigation involving cost recovery for the liability allocation of alleged past and anticipated remedial costs for an owner at Area 6 of North Penn Water Authority Superfund site in eastern Pennsylvania. Established that the contamination of a municipal well was clearly from another source and not from the site in question.

Served as an expert witness for a litigation case involving soil and groundwater contamination at the site of a former gas station in Rochester NY operated by a multinational oil company. Used available site assessment information, analyses, and forensic evidence to refute a claim by the opponent’s expert that contamination traveled upstream from the site of the former gas station, and established that another upstream gas station was responsible.

Served as expert witness responsible for providing litigation support in an insurance cost recovery case for a large chemical facility in Massachusetts. Used research and hydrogeological analyses to establish that injury to the environment began earlier, rather than later, originating from leakage through the bottom liners in large impoundments. This opinion provided major support for settlement negotiations.

Provided litigation support for insurance cost recovery cases amounting to several million dollars for a large corporation with facilities in several states. Directed the development of a geographic information system (GIS) for the real-time recall, visual display, and query of data in court for 42 chromium-contaminated facilities in a northern New Jersey city.

Provided litigation support using transport modeling analyses to show that the impacts from discharge of groundwater contaminated by bis(2-ethylhexyl)phthalate from stockpiled, excavated sediment would not adversely affect a neighboring stream in New Jersey.

Provided groundwater modeling and regulatory compliance support for a multinational oil company for a site in Santa Monica, California. Used a sophisticated flow model and hydrogeological analyses to determine details of a tapered pumping resumption scheme at a 3,000-gpm city well field, so as to not adversely affect methyl tertiary butyl ether (MtBE) remediation at a number of locations within the capture zone. For the same project, developed a Source Water Assessment Report pursuant to DHS Policy Memo 97-005 (Guidance for Direct Domestic Use of Extremely Impaired Sources).

Developed a sophisticated groundwater flow model to be used in the design of a containment system for a widespread petroleum hydrocarbon plume as part of a project for a multinational oil company. The resulting plume is alleged to have caused soil vapor intrusion into the living quarters of some 300 plaintiffs in Maryland. The data showed that an MTBE plume had detached and traveled offsite. The model incorporated various anthropogenic effects on the flow system.

Acted as senior project manager for a million-dollar-a-year project. Used a transport model for the complex hydrogeology of the coastal plains of New Jersey for the assessment and design of remedial alternatives. Participated in numerous regulatory negotiations, including wetland delineation consistent with FEMA policies, and made public presentations for a Superfund site. Also served as senior project manager for litigation support for insurance cost recovery.

Provided litigation support for a Fortune 500 company using extensive transport-and-fate modeling for the complex hydrogeology of the Puente Valley in California. Negotiated with a steering committee representing some 50 contributing potentially responsible parties (PRPs) concerning a valleywide volatile organic compound (VOC) plume. Showed that the portion of the plume attributable to the client was substantially smaller than claimed.

Provided litigation support for the owner of a golf course on Hampton, New York. Used research, analyses, and modeling to refute a claim by neighbors that large-scale pumping by the golf course would deprive the community of groundwater and would spread pesticide contaminants.

Provided litigation support concerning the environmental impact on the neighboring community and wetland because of the proposed expansion of a golf course in Poundridge, New York.

Developed an estimate of the cleanup time for the selected remedy at the Whitmoyer Superfund site in Pennsylvania.

Assisted in liability allocation by estimating the probable impact from dense, nonaqueous-phase liquid (DNAPL) pool in several areas of client’s facility in Freeport, Texas.

Provided litigation support in an insurance cost recovery case by establishing that DDT can migrate large distances via colloidal transport, which was contrary to conventional belief. Used transport modeling and hydrogeological analyses to bracket the time when injury to the environment began.

Senior engineering advisor responsible for pioneering a screening model used to evaluate approximately 50 sites for the transport of congener-specific PCB contamination in groundwater, which was subject to biodegradation. A similar analysis was used for a different project to show that a pile of PCB-contaminated soil on the yard of an aluminum extrusion facility on the banks of the Schuylkill River would not adversely affect the river.

Provided litigation support by estimating transport of DDT from a historic production facility in New Jersey into a neighboring a stream.

Senior project manager responsible for finding a beneficial use for a high-volume by-product from an industrial production process for a Fortune 100 company. Used a combined soil erosion model and transport model to support the use of this material as an embankment for dredged material. For the same by-product, which was stockpiled over huge areas, used a tidal model to estimate human health risks from the ingestion of fish exposed to any contaminant that leached into the Delaware River.

Senior project manager at a VOC-contaminated trucking facility in south-central New Jersey. Performed groundwater flow and contaminant transport modeling to simulate the flow of groundwater and the transport of contaminants in southern New Jersey’s complex hydrogeologic system, to develop an optimized pumping scheme to be implemented in conjunction with Hydrogen Release Compound® treatment and lowered total pumpage to 230 gpm, which was down from the 650 gpm mandated in the record of decision.

Key member of the team responsible for developing a mathematically optimized pumping scheme involving the extraction of 2.5 mgd from 44 wells, onsite treatment, and onsite recharge at a heavily contaminated Superfund site. This optimized scheme permitted system modifications that ultimately led to savings of millions of dollars.

Developed a cost estimate for the disposal of contaminated groundwater in connection with the expansion of the Waldwick Train Station. The project was facilitated by a groundwater flow model based on aquifer parameters determined from a pump test in a well installed expressly for that purpose.

Developed an airflow model and calibrated it to a pilot soil vapor extraction (SVE) test. The calibrated model was then used to design a full-scale SVE system to remove chlorinated solvents from shallow soils.

Developed the first computer code to simulate contaminant transport in a tidally influenced aquifer at an arsenic-contaminated site in southern New Jersey. Based on analyses using the code, the New Jersey Department of Environmental Protection (NJDEP) rescinded a requirement for the installation of monitoring wells along an estuary bank. This tidal model was also applied to a Fortune 100 chemical facility on the banks of the Delaware River to estimate the impacts of the discharge of chlorobenzene-contaminated groundwater on benthic organisms. Analysis indicated that no active treatment would be necessary. Presented the tidal model to members of NJDEP involved in developing guidance on the mixing zone on behalf of this Fortune 100 Company.

Managed an extensive environmental site assessment of a large parcel of land and a steel manufacturing plant contaminated with hexavalent chromium. Worked with the University’s architects in developing cost estimates for the foundations of proposed buildings, with special reference to the contaminated soil.

Managed a time-critical environmental site assessment of a Uniroyal operating facility for a possible international transaction.

Allocated costs for multiple parties that had owned a PCB-contaminated site in Massachusetts during different periods of time.

Provided technical support in a litigation case by estimating transport of PFOA from a landfill downstream by both surface water and ground water routes.

Provided technical support in a litigation case by estimating transport of pentachlorophenol at a former wood processing facility in Connecticut.

Project team leader responsible for defining, for the first time, an “operational definition of non-aqueous phase liquid (NAPL),” an ODN, using a totals analysis. The published ODN protocol was approved by EPA Region 2 and was applied to a large, highly contaminated Superfund site in central New Jersey to delineate NAPL-contaminated areas.

Senior project manager responsible for a permit renewal application for a large, hazardous solid waste management facility. Later work for the same facility involved the use of hydrogeological analyses and data from the site to demonstrate to regulators that the detection of chlorides in a number of monitoring wells did not indicate that the liner systems had failed.

Led a team that designed and implemented an innovative new protocol to estimate the concentration of contaminants in leachates based on a totals analysis and toxicity characteristic leaching procedure values. It was recommended that the published new protocol be used to determine mass loading for use in a transport model.

• American Society of Civil Engineers
• National Ground Water Association
• Institute of Engineers of Bangladesh
• American Association of Bangladesh Engineers and Architects