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Matthew Dahl, P.E.

Mr. Dahl is a professional engineer with over 16 years of experience in remediation design, landfill design, construction, O&M, post-closure monitoring, site characterization, and project management. Mr. Dahl has designed and implemented a variety of remediation systems including groundwater pump and treat, air stripping, adsorption, filtration, free phase product recovery, ozone treatment, air sparging, dual phase extraction, soil vapor extraction, and catalytic and thermal oxidation; designed and overseen groundwater extraction well maintenance and rehabilitation programs; and overseen stormwater management and sampling. He has also designed and implemented landfill gas recovery systems, designed landfill caps and liners, prepared stormwater control plans, developed infiltration HELP models, drafted landfill permit applications, developed methane migration monitoring plans, and conducted landfill post-closure care inspections.

Mr. Dahl’s primary areas of responsibility include the following:

  • Project engineer for remediation of chlorinated VOC contamination at a 9 acre chemical distribution facility in Portland, Oregon under RCRA requirements. Work includes design of the groundwater extraction system, soil vapor extraction system, and treatment systems; construction oversight; management of the O&M, groundwater extraction well maintenance; groundwater monitoring, and stormwater monitoring programs; management of site characterization activities related to stormwater and remediation system design; and preparing work plans and progress reports to USEPA;
  • Project manager for remediation of chlorinated VOC contamination at a former chemical distribution facility in Seattle, Washington. Work includes design of the soil vapor extraction and treatment system; construction oversight; management of the O&M, indoor air, and groundwater monitoring programs; management of site characterization activities; and interfacing with the current property owner and Washington Department of Ecology;
  • Project engineer for operation and maintenance of a RCRA Corrective Measures System in Kent, Washington, at a former metal finishing site contaminated with chlorinated solvents. Work includes oversight of the groundwater recovery system O&M and groundwater extraction well maintenance programs, and engineering support for the remedial alternative evaluation and design;
  • Project manager for post closure O&M monitoring and inspections at a 150 acre Superfund landfill in Marysville, Washington. Work includes overseeing the environmental monitoring program and performing quarterly engineering inspections; and
  • Project engineer for investigation of methane migration in a residential development in Mount Vernon, Washington. Work includes overseeing the site characterization activities and methane monitoring programs in two separate areas of the development.


Daniel A. Balbiani, P.E.
Robert S. Creps, P.E.
James P. Dunn, P.G.
Kyle S. Flory, P.G.
Susan E. Gahry, P.E.
William W. Mast, P.G.
Carl J. Michelsen, P.G., C.HG.
Keith O’Brien, P.G., C.HG.
Nicholas C. Pogoncheff, P.G.


Peter D. Gorman, C.HG.
William Haldeman, L.G.
Kris McCormick, CAC, REA
Brian O’Neal, P.E.
Chris J. Baldassari, P.G.
Scott Morrison, P.E.
Gary Thomas, P.G.
Mark Winters, R.G.

Senior Personnel

Matthew Dahl, P.E.
John Alexander
Justin Patterson

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